Dr. Phil McGraw was a guest recently on the "The Late Show with Steven Colbert". Specifically he was on the Season 4 Episode 33 show. That episode aired on October 26, 2018 on CBS but was actually recorded the day before. You can see the segment at https://www.cbs.com/shows/the-late-show-with-stephen-colbert/video/W9ZiZBuwoE7htzZq4LhfH0v8bQV2lHEQ/dr-phil-on-trans-rights-rollbacks-kiss-my-ass-/. It runs a little over ten minutes in length. So who is Dr. Phil and why does this matter?
McGraw has a Ph. D. in Clinical Psychology so he is an actual certified professional. But at some point the "show biz" bug bit him and he started appearing regularly on Oprah Winfrey's show. The appearances were popular so Winfrey decided to produce a stand-alone show called "Dr. Phil" and starring McGraw. That show has been on the air continuously since 2002. It has aired over 2,000 episodes. As part of the interview Dr. Phil announced that his show had been renewed for an additional couple of years.
"Dr. Phil" is now a household name. He is popular enough to routinely score interview segments on shows like Colbert. Shows are happy to book him because he is a popular and entertaining guest. His show falls into the general category of "advice givers". It is not a category he pioneered.
The concept probably dates back to the mists of time but I cam going to start in 1943 with a newspaper column in the Chicago Sun Times called "Ask Ann Landers" (or something similar). People would write in with their problems. Each column would reproduce a couple of letters. After each letter "Ann" would weigh in with a response.
The column was pioneered by Ruth Crowley. But in 1955 Esther Lederer took over and the column became wildly popular. It was so popular that her twin sister jumped in with a column of her own called "Dear Abby". There she wrote under the name of Abigail Van Buren. "Dear Abby" was very popular but never quite as popular as "Ask Ann Landers".
The formula, then and now, consisted of someone writing about something odd, difficult, or downright silly. The columnist would then provide a sensible answer. The formula works because readers associate themselves with the sensible columnist and feel better about themselves. "At least I am not as silly or unlucky or clueless as the writer." The successful columnists figured out this formula and picked letters to publish that fit the formula.
And the "Dr. Phil" show is just the evolution of the same idea into a daytime television format. Dr. Phil freely dishes out advice and perspective left and right. People feel that if they had a serious problem Dr. Phil would provide some help. And as a bonus they get to feel good about themselves knowing they are not as silly or stupid as other guests. McGraw did an excellent job of showcasing this particular formula in his segment on Colbert. So what's to complain about?
At about 5:20 into the segment he said "I don't follow politics because I don't think I should use my platform to influence people". If he had stopped there I would have no complaint. He gets paid a lot of money because his show gets high ratings so it pulls in big advertising fees. Alienating part of your audience risks driving a good chunk of that audience away. And that means lower ratings and, more importantly, lower advertising fees.
The problem is he continued talking. He pasted "on things I don't know enough about" onto what I have quoted above. Really? His whole format depends on people believing he is a sound thinker of above average intelligence. It also depends on him knowing things and being willing to impart that knowledge to others.
Finally, he is a certified Clinical Psychologist and a big issue in our politics is a psychological one. What he does for a living is diagnose and try to remedy psychological disorders. He should be very familiar with this particular disorder and he should have a remedy close at hand to share with us.
More than one person has observed that I have lots of opinions and I dispense them freely. Dr. Phil is the same way. He freely dispensed several opinions within the span of the interview on Colbert. If he had said "I don't publicly weigh in on political matters for business and other reasons", that would have been an honest statement. What he said instead was deeply dishonest. And credibility is part of his stock in trade. You can depend on what he has to say because "he tells it like it is".
He succeeded in his mission of entertaining Colbert's audience and creating good publicity for his show. But he did the country and his audience a disservice by being dishonest. So far I have been beating around the bush about what the problem is that he should have been willing to talk about. (Or he should have given an honest disclaimer about why he wouldn't talk about it.) That problem is the blatant dishonesty that infects the White House and the Republican Party today.
Dr. Phil has something to say about the behavior that is routinely on display in both of those institutions. I know this because he discussed the exact same behavior during the interview. He told a number of stories but I am only going to focus on two. The first one concerns some guests who appeared on a recent "Dr. Phil" show.
According to Dr. Phil there is a thing. That thing consists of women claiming to be pregnant for 3-5 years straight. This is a single pregnancy and it does not even result in a birth at the end. Instead the pregnancy goes on, apparently indefinitely. He contrasts this situation with another situation that turns out to be strange but true. In the other situation there is abundant evidence available that what those women are experiencing is an actual thing.
In the case of the "indefinitely long pregnancy" women, and apparently there are group of them. We know this because, according to Dr. Phil, there are places on the Internet that cater to them. A proper examination by competent professionals quickly determines that nothing is going on. These women are not pregnant at all.
Dr. Phil's "solution" was to tell them to their face that they were not pregnant. Needless to say he convinced none of them. But both he and his audience felt better. His point was that what these women were up to consisted of a lie that could be, and in this case was, easily disproven. He denigrated them for failing to take cognizance of the evidence, evidence he presented to them on his show, that they were wrong.
His second story arose out of the question of "when did you discover that you were 'Dr. Phil'". The short version of the answer turned out to be "in the fifth grade". This story begins about 9 minutes into the interview. He began his explanation by outlining the circumstances of a fight he got into at the time. He got involved because some kids were picking on a fellow student. Eventually this led to a trip to the principle's office.
That in turn led to was confronted with his teacher at the time, Mrs. Gates. Here the problem was that Mrs. Gates was completely uninterested in learning the facts of the situation. As a result McGraw decided she no longer deserved to be seen as an credible authority figure. And he told her so. He quotes himself as saying to her at the time "that's right lady -- that includes you".
So Dr. Phil establishes that he disapproves of people who deny the facts even when they are presented by competent authority. He also disapproves of people who are not interested in finding out what the facts are. But wait! It gets worse. At 4:15 into the interview he asks "when did it stop being okay to disagree?" So it turns out that there is an aspect of our present political climate that he disapproves of. He does have an opinion about politics. And at its most simplistic level he has a solution he recommends. "Make it okay to disagree."
We can argue about the hour or the day or the year when it stopped being okay to disagree? And Dr. Phil may not have yet spent the time and effort necessary to figure out how we got to where we now are. But he owes it to us to follow his own advice to Mrs. Gates and learn the facts of the situation. Maybe he has and he doesn't want to alienate a part of his audience by disclosing what he has found. Before continuing let me provide a longer version of "make it okay to disagree".
People need to be willing to listen, to be willing to find out what the facts are. And people need to be willing to modify their opinions when the facts unambiguously say their opinion is wrong. But we have a large group of people who behave otherwise.
Everybody does it some of the time. We sometimes choose to ignore facts or are uninterested in determining what the actual facts are. But not everybody does it to the same extent and degree. And it turns out that the Trump Administration engages in this behavior to an extreme extent. This is profoundly wrong. And they have dragged the Republican along with them. Both operate in an alternate universe where they believe that if they say something loud enough and often enough it magically becomes true.
Dr. Phil could have contributed to the solution by pointing this out but he has chosen not to. And we are all the less as a result of that decision. And this behavior by Dr. Phil and many, many, others is why we are where we now find ourselves. But Trump didn't invent any of this. He just took it to an extreme. For the remainder of this post I would like to examine what led us to this point. And that involves going back in history.
For a long period of time the Republican party was dominant. Every once in a while the Democrats had some success but overall, especially at the national level, the Republicans were by and large the dominant party. This all ended with the Great Depression.
Republicans had been generally seen as the superior stewards of the economy. Then the stock market crashed in '29 and the Great Depression set in shortly thereafter. Republicans did not stand aside idly. They immediately sprang into action. And their leader, Herbert Hoover, was well respected. And he did the obvious thing. He consulted with experts and did what they recommended. And things got worse.
By 1932 people had enough. They no longer believed Republicans knew what they were doing and they were desperate. So the turned to the Democrats and FDR. Within a year or so they saw forward progress. Things got slowly better until 1938 when FDR was convinced to adopt some Republican economic ideas because "it's over". Things immediately got worse again. This '38 experience destroyed any economic credibility Republicans had left.
Then World War II started and the US was eventually dragged into it. And the public generally approved of how FDR and the Democrats conducted the War. So by the postwar period the roles had flipped. Democrats were now the dominant party. Republicans could have some success under someone as popular as Eisenhauer but Republican were deeply concerned about how to get back on top.
In 1960 Nixon ran as the seasoned and experienced moderate who had been closely associated with the popular Eisenhauer and his popular administration. But he lost to the charismatic but inexperienced Kennedy. Things looked dire. At the time both parties were seen as centrist. And each party consisted of various factions and wings. Put in modern terms, many Republicans were more liberal than many Democrats and vice versa. Many Republicans saw a need to differentiate. In a race between two essentially similar parties the Democrats would maintain their dominant position.
While this was going on the patron saint of modern conservatism, William F. Buckley, emerged. He was a brilliant man and a fierce and effective debater. His creed was conservativism. He believed deeply in its inherent correctness. He considered himself smart enough and articulate enough to defend it against all comers. And he was right. He was smart enough and articulate enough. So over the years he took on all comers on his long running TV show, "Firing Line".
Most of the time he won, either by being brilliant enough or by pulling out various debating tricks. He took this as evidence that Republicans should differentiate themselves and that they should do so by embracing conservatism. A lot of fellow Republicans agreed with him on the "differentiation" part of the argument but they weren't convinced about the "embrace conservatism" part. So Buckley and "Firing Line" were a niche phenomenon. Die hard politics junkies and people concerned about the future of the Republican party followed him carefully but the general public didn't.
Then in 1964 Barry Goldwater, a staunch conservative, ran for President against Lynden Johnson and got shellacked. To many this meant the death of conservatism as a viable approach to gaining mainstream success. But others took away a different lesson.
Kennedy beat Nixon not by being smarter, or more knowledgeable, or ever more liberal (their positions on many issues differed in only small ways). Johnson beat Goldwater in '64 not based on his better ideas but by crass political manipulation. For instance, he appealed to the Kennedy "legacy" but Kennedy's actual record of legislative success was modest and contained no marquis successes.
So the problem, they concluded, was not the message but the messenger. Republican standard bearers needed to be more like Johnson, who they believed was deeply cynical and dishonest, and less like Goldwater, who was committed to his beliefs and completely honest.
Before moving on I am going to make one more observation about Buckley. He believed in honesty, intellectual and otherwise. Leaving aside the occasional debating trick he believed he was right so he didn't have to lie or ignore the facts. So he famously read various individuals and groups out of the conservative movement. Most famously, he read the John Birch Society out of the conservative movement. It wasn't that that their beliefs weren't conservative. They were.
It was they peddled numerous quack ideas and made up conspiracies. Fluoridation (adding Fluoride to drinking water to reduce cavities) was some kind of communist plot. That sort of thing. He found them dishonest. And he had enough power within the conservative movement at the time to make his edicts stick. While Buckley was in charge, conservatism was about ideas. They embraced facts because he thought the facts were on their side. Unfortunately, conservatism soon moved away from Buckley.
In the '70s a new kind of conservative emerged. This kind valued popularity. They soon found a suitable standard bearer in Ronald Reagan. Reagan was a believer but he was an intellectual lightweight. He believed in conservatism because "he had faith" in it. He also had a poor understanding of it. He stuck to a few slogans and left it at that. But he was a skilled politician and was extremely likable.
He ran unsuccessfully for President in '76 and successfully in '80. He came to the job with substantial executive experience. He had been Governor of California, the biggest state in terms of either population or economic power. And it was the home of Hollywood, one of the most powerful cultural institutions in the world.
So running the US was a step up from running California but it was not that big of a step. Look at the size of the step up that Kennedy, for instance, took. Before becoming President he was a US Senator, a job he had not held for all that long and which did not involve running a large bureaucracy.
Reagan was no Buckley and it showed. He appointed one of the weakest cabinets ever installed. That is until we saw the Trump cabinet. And Reagan was easily conned. To con Reagan all you had to do was to be liked by him and to construct your argument so that it sounded like what you wanted to do was in line with his principles. And, unlike modern Republicans, Reagan liked to make deals. So he and "Tip" O'Neill, the long time and very cagy Democratic Speaker of the House, made many deals.
Reagan liked Tip and Tip found ways to structure his arguments as best he could to align with the slogans Reagan believed in. And he frankly threw in some things Reagan did not want but he was careful to not do that very often. As long as Reagan believed he was getting the better end of the deal and Tip believed he was getting the best deal he was likely to get, they could and did agree to move ahead. So a lot of legislation was passed under Reagan and a lot of it attracted at least some Democratic support.
I don't know if he did it on purpose or not but Reagan introduced what I call the "both sides" ploy. He would say one thing but do exactly the opposite. For instance, he was a vigorous deficit hawk. "Deficits are evil and not to be tolerated". That's what he said. On the other hand his administration ran large deficits every year he was in office. And he took no action to reduce them.
I remember grilling a Reagan supporter about this at the time. I'd say "what about this?" He would say "well, I really like what he says on this". Then I'd ask "what about that?" The supporter said "I really like what he does on that?"
This allowed Reagan to effectively get credit for both sides of an issue. His supporters picked the "said" or "did" part, whichever they approved of, and gave Reagan credit for being on the right side of the issue. Talk about a "win", "win", situation for Reagan. There is no secret as to why he was so well liked.
As I said, I don't know if Reagan had a clue as to what was going on. I suspect he didn't. Two more examples. He also strongly believed "you don't pay off blackmailers". And, after they kidnapped about a hundred of our embassy staff and held them for ransom he saw the Iranians as blackmailers. But then along comes Oliver North. He was a mid level official in Reagan's administration.
The congress had tied the administration's hands with respect to the Nicaraguan civil war. On one side you had the government and on the other side you had the "Contra" rebels. Reagan desperately wanted to get funds to the Nicaraguan government to fight the Contras but congress had passed a law forbidding this.
North came up with a deal that involved selling arms to Iran at inflated prices. The profits would be funneled to the Nicaraguans. The Iran piece violated Reagan's deeply held belief. The Nicaraguan piece violated the congressional ban. But North pulled the wool over Reagan's eyes and put the deal together anyhow. The whole thing eventually blew up into the Iran/Contra scandal.
In the other example I am going to describe the results were actually beneficial. Reagan was fervently anti-communist. He was opposed to communism on ideological grounds but he also felt that communist leaders were untrustworthy liars. So you couldn't do a deal with them. But he ended up doing a big disarmament deal with the communist Gorbachev. Why? Because his wife Nancy convinced him that a disarmament treaty was a good thing and that he actually could deal with a communist. He ended up having a warm and friendly relationship with Gorbachev.
There is a thread that runs through all this. That thread is deception. Various people convinced Reagan of things that were not true. That followed a well established trend within the Republican party. Nixon got his start in politics by using smear and innuendo campaign tactics to defeat his Democratic opponent. He used similar tactics to climb up the political ladder to the Vice Presidency.
Then in '60 he decided he could play it straight against Kennedy as he was by far the better qualified of the two. He lost. He played it straight again in '62 when he ran for Governor of California. Again, he lost. He went back to his old ways in '68 and '72. He won both times. Being honest and ethical is for losers.
I believe Reagan thought of himself as an honest person. But he surrounded himself with people who weren't. Perhaps the most significant, even more so than North, was Lee Atwater. He was a mid level political operative. He was a firm believer in "winning is the only thing". And he became a master at lying for political advantage and getting away with it.
Various dirty tricks were played against Reagan's primary opponents, not by Reagan himself, but by Atwater and others like him. Atwater then moved on in the General Election to lying and playing dirty tricks on Democrats. Reagan might have won (maybe not the first time but definitely the second time) without these lies and dirty tricks. But he won and neither he nor Atwood paid a price for the dirty tricks played on his behalf. People liked and trusted Reagan anyhow.
With a well liked person on the top of the ticket the sky was the limit when it comes to lying as long as you take precautions. It is okay to be found out as long as it is not until later. Then it doesn't matter. All of Atwater's deceptions were eventually exposed but only when exposure no longer mattered. We just recently learned that the famous Gary Hart "Monkey Business" affair was manufactured by Atwater. But Hart stopped running for President decades ago. And the Republicans eventually won the White House after Hart was forced out.
The next key event in the story is the rise of Newt Gingrich. In the late '80s he figured out that there was a lot of money lying around that could be put to good use. He put it to good use building the "machine" that is the Republican campaign operation to this day. He is definitely of the Atwater school where only winning counts.
And he represented a move away from the Buckley belief that honesty combined with ideas were "the only thing". Gingrich started out with a bunch of ideas. They were the product of intensive polling to determine what could be sold to the public rather than from some intellectually rigorous process.
Gingrich did subscribe to "differentiation". He saw the Democratic party as not moving so he moved the Republican party away from where the Democrats were. He also introduced the "no negotiation" approach. To his way of thinking giving up on 20% of what you wanted in order to get 80% was a bad deal. It was 100% or nothing.
This was a complete repudiation of the Reagan approach. And Reagan's approach was a repudiation of the Buckley approach. As most conservatives were not as doctrinaire as Buckley they were fine with Reagan. They were tired of losing and thought that 60% or 80% of what they wanted was a win.
And if the Gingrich approach had failed badly enough then that would have been the end of that. But Gingrich won big in '94, two years into the Clinton administration. Things went backwards for a while but the Gingrich approach roared back in 2000 with the election of George W. Bush. The Bush people used a strategy that involved a lot of deception. Compare what Bush said he would do with the budget surplus he inherited with what he actually did, for instance. Or look at how the Iraq war was sold versus what the truth was.
Bush represented Reagan-light. He was likable but not as likeable as Reagan. He too saw his job as mostly to be the front man for his administration. And like Reagan, he left the details to his subordinates and was careful not to inquire too closely about what they were actually up to. This approach was successful enough that Bush got re-elected in '04. But by the end of Bush's second term the public was well and truly done with Bush and his administration.
That brings us to Mitch McConnell. As with the Republicans in the '60s there was a deep feeling that the Democrats had regained the inside track in terms of the popularity of their agenda. But the Republican election machine was so effective that Republicans won races in spite of how unpopular their agenda was.
Part of the reason for this unpopularity was that after Gingrich Republicans ran out of ideas. But by this time they had become heavily dependent on rich and powerful donors. And the "donor class" knew what they wanted. But what they wanted was very unpopular with the public.
McConnell hatched the "just say no" strategy. Oppose everything Obama and the Democrats tried to do and present nothing as an alternative. That way no one on the right had anything to complain about.
They told rich donors that Obama was blocking their initiatives. They told doctrinaire conservatives "we're with you but we are out of power". They told their base that everything Obama was trying to do was evil. And they invented outright lies like "death panels" to convince them this was so. And it worked.
It was fundamentally dishonest but it worked. And as long as Obama was in office to serve as the universal villain who was blocking all the "wonderful" things Republicans wanted to do for their donors, their increasingly out of touch conservative wing, and their base, it all worked well.
It helped that the press went along with this. Republicans had long since figured out that the press would print anything as long as it was sensational and, therefore, likely to be good for circulation/ratings. "We don't fact check. We just report what they say and let the public figure it out." But the public was spectacularly ill equipped to "figure it out" on its own.
Then Trump came along. He took dishonesty to new heights. And he applied all the skills he had developed from his years of manipulating the New York City media, both tabloid and legitimate, to his advantage. In effect he "turned the knob up to 11".
Much of the Republican establishment was appalled by Trump. But they were a victim of their own long standing behavior. Trump wasn't doing anything they hadn't already been doing for decades to a lesser extent. He just did more of it and he did it better. He got away with it because they had learned how to get away with it during his business carrier. Trump's only contribution was the idea that you could get away with far more than anyone had previously imagined possible.
The New York (and later national) press had long since decided that Trump was "good copy". As a candidate and later as President he has continued to be good copy. As long as he continued to produce large amounts of good copy the press literally could not stop themselves from continuing to behave as they always did.
Trump would make some outrageous pronouncement. The press would cover it extensively because it was good copy. If it was the usual harmless lie or exaggeration, that was that. The story would die with no one the wiser. The real story was not good copy so it didn't run.
In other situations actual harm was being done or someone would dig down and find the story false. But this would take time. So a small story exposing the falsehood would perhaps appear somewhere days later when everybody had moved on. There would be no follow up or extensive coverage because the story had reached its "stale date". And, to the extent that the exposure of the falsehood was covered at all, it would be buried on page A-23 where only true news junkies noticed.
Trump knew this was how the news business worked and he took full advantage of his knowledge. Recently the New York Times admitted that it had published far too many "puff pieces" (their characterization) about Trump over the years. And, as you would now expect, this revelation was buried deep in the paper and there was no follow up.
As we have now seen, Republicans figured out a long time ago that you can lie if you go about it properly. They have by now so inured us to this that neither they nor the rest of us knows how to deal with Trump. He didn't start it. He just took maximal advantage of what McConnell, Gingrich, Atwater, and others, laid the groundwork for.
This is not politics in the usual sense. It is much more Psychology. And getting to the bottom of things, exposing the psychological truths that underlie this kind of behavior, that's what Dr. Phil is supposed to specialize in. And he is supposed to be on our side on this. It is sad and disappointing to find him MIA on this. On the other hand, based on his total lack of success with the "pregnant" ladies and his fifth grade teacher, maybe he doesn't have anything useful to contribute.
And in a sense Dr. Phil is now right. If caught before it got out of hand, a psychology-based solution might have been effective. But that was then. Republicans now think that this is the way they must do business if they are to be successful. After all, Trump won in 2016 and the Republican base is largely still with him. They will not change their behavior until they decide that continuing to do things the Trump (or McConnell or Gingrich or Atwater) way is a recipe for disaster.
Now the only solution left is a political one. Republicans must lose. They must lose consistently and by substantial margins. Otherwise, they will think they have encountered a dry spell not unlike other dry spells they have encountered in the past. They will only change if election results convince them they must.
Saturday, November 3, 2018
Sunday, October 28, 2018
50 Years of Science - Part 12
This post is the next in a series dating back several years. As I have previously indicated, a more correct title might be something like "59 Years of Science". But I like the original title, even though it becomes less accurate every year, so I am sticking with it. By now we are up to the twelfth post in the series. And you can go to http://sigma5.blogspot.com/2017/04/50-years-of-science-links.html to find an index with links to all of the previous posts in the series. I will update that post to include a link to this post right after this post is published.
I take Isaac Asimov's book "The Intelligent Man's Guide to the Physical Sciences" as my baseline for the state of science as it was when he wrote the book (1959 - 60). In these posts I am reviewing what he reported and what's changed since. For this post I am starting with the chapter Asimov titled "Gases". I will then move on to the chapter he titled "Metals".
The traditional "phases" of materials are solid, liquid, and gas. Since the dawn of Chemistry it has been known that a material can transition from one phase to another as the temperature is changed. In 1787 Charles discovered the law now named after him. A gas contracts as it is cooled (and expands as it is heated). He also noted that the contraction amounted to one part in 273 if the temperature was what we now call 0 degrees Celsius. (In Asimov's time the equivalent temperature scale was called Centigrade. I am going to skip over the small technical differences between the Celsius and Centigrade scales. For our purposes they are essentially the same.) Charles wondered if there was an "absolute zero" that was 273 degrees colder than 0 Celsius.
It turns out he was on to something but it would be a long time before equipment existed to lower temperatures more than a few tens of degrees below zero Celsius. When the "atomic theory of gasses" was developed temperature could be related to tiny molecules of gas moving at high speeds and banging off of each other. A decrease in speed would accompany a decrease in temperature. This would naturally lead to a decrease in the average distance between molecules. And that would make the same amount of gas occupy less space.
In the 1860's the physicist Thompson discussed with Lord Kelvin the idea that at absolute zero (-273 degrees Celsius) all molecular motion would cease. It was obviously not possible to go slower than zero speed so no lower temperature was possible. Asimov pegs Absolute zero at -273.12 degrees Centigrade. We can now add several decimal places (plus make the adjustments necessary to switch from Centigrade to Celsius) but the value has changed little in the intervening time.
Quantum Mechanics tells us, however, that it is impossible for all motion to completely stop. The Heisenberg Uncertainty principle requires that even at absolute zero there is some motion still present. And it turns out that the amount of residual motion matters. Scientists are now able to reduce the temperature of small amounts of matter to a thousandth, a millionth, or even a billionth of a degree above absolute zero. And in some cases these tiny temperature changes cause the properties of the material to change due to quantum effects. The study of temperatures very near absolute zero is now is now an area that commands the energies of a relatively large scientific community. But that's getting ahead of the story.
The coldest temperatures available to early scientists were not much lower than 0 Celsius. But that just led to "out of the box" thinking. The first step along this path was to notice that some gasses could be liquified without lowering their temperature. All that was necessary was to raise their pressure. This worked well for Chlorine, Sulfur Dioxide, Carbon Dioxide, and a number of other gasses. Pressurizing gasses tends to heat them up. But if you pressurize a gas, cool it down, then depressurize it, it becomes very cold. That's how refrigeration works. And refrigeration extended the range of cold temperatures accessible to scientists.
Another trick is evaporation. The process of evaporation draws heat out of a liquid. At the microscopic level what's going on is that all liquids contain molecules traveling at different speeds. If a high speed molecule happens to fly above the surface of a liquid it may never come back. This is how evaporation works at the molecular level and this mechanism preferentially removes the speediest molecules from the liquid. And, just as with a gas, these speedy molecules are the warmest ones. So evaporation, by removing the warmest molecules, lowers the average temperature of the remainder. In other words, it cools the liquid down. This "evaporative cooling" technique is how "Swamp coolers" work.
So scientists found clever ways to use refrigeration, evaporation, or both to reach heretofore unreachably cold temperatures. By 1885 -110 Celsius was reachable. But this is only 40% of the way to absolute zero. And, more importantly, a number of common gasses, Hydrogen, Oxygen, Nitrogen, and others, stayed in their gaseous form at this temperature. In 1869 Andrews determined that gasses had a "critical temperature". Above the critical temperature the gas would not liquify no matter how much pressure was applied. That made it all the more was important to be reduce the temperature of these gasses still further.
The "cascade" method allowed temperatures to be further lowered. An evaporation/refrigeration process using one gas was used to lower the temperature a certain amount. Then a second evaporation/refrigeration process using a different gas was used to lower the temperature further. By using a cascade consisting of several stages Pictet managed to liquify Oxygen at -140. Others liquified Carbon Monoxide (-190) and Nitrogen (-195). But it wasn't until 1900 that Dewar managed to liquify Hydrogen at -240 by using a multi-stage process that depended on these tricks plus his own invention, a "Dewar bottle", what we now call a "thermos bottle". But we are now only 88% of the way to our goal. And, as is common in these situations, the closer you get the harder it is to make additional progress.
Now we make a couple of digressions, not compliments of me, but instead compliments of Mr. Asimov. He first digresses by noting that by 1895 Hampton had been able to turn laboratory scale techniques into ones that could be performed at industrial scale. A simple modification of the same basic technique made it possible to cheaply and easily manufacture Oxygen in either liquid or gaseous form. It could then be used in Acteline torches and as a component in liquid fueled rockets, to name just two of the many applications that this breakthrough made possible.
In his second digression Asimov takes a moment to talk about what makes a good rocket fuel. As the results are informative, I am going to summarize them here. (Feel free to consult the original if you want to know more.) The magic number that tells you how efficient a rocket fuel is is something called "specific impulse". The more the better. Mixing Kerosene and Oxygen yields a specific impulse of 242. Using Hydrogen and Oxygen gives you 350.
So a pound of Hydrogen-Oxygen performs as well as about a pound and a half of Kerosene-Oxygen. But, of course, in the former case the rocket is lighter to the tune of a half a pound. Solid fuels generally have a lower specific impulse. But they are cheaper and safer and easier to work with. This makes it much easier to understand the trade-offs involved in selecting the fuel to use in your rocket.
Among the options listed, liquid Hydrogen + liquid Oxygen is the best but the hardest to work with so when you factor everything in it is likely to be the most expensive option. Solid fuels are the easiest to work and so initially they look to be the least expensive option with but are not nearly as efficient. Kerosene + liquid Oxygen is somewhere in the middle both in terms of efficiency and ease of use. Elon Musk went with this middle choice for his Space-X rockets.
And I always thought that liquid Hydrogen + liquid Oxygen was the best (as in most efficient) chemical fuel. But Asimov says I am wrong. Both Oxygen and Hydrogen are normally molecules consisting of two identical atoms bonded tightly together. And it is the combining of molecular Hydrogen with molecular Oxygen that I have been talking about. But they both elements also have an "atomic" form consisting of a single atom.
And if you start out with "atomic" Hydrogen and let it combine with itself in a rocket motor to form molecular Hydrogen you get a hell of a lot of energy. The specific impulse of this configuration is 1,300. It is almost 4 times as efficient as what I thought was the best chemical fuel. It's not used because no one has been able to figure out how to store atomic Hydrogen in the necessary quantities.
Most people know where the end of the line is when it comes to liquifying gasses. The hardest gas to liquify is Helium. But in 1908 Onnes cracked the riddle and liquified Helium under high pressure at -255 Celsius. By applying more tricks to his already extremely cold liquid Helium he was able to get small quantities down to 4.2 degrees above absolute zero (now referred to as 4.2 K for "degrees Kelvin"). At that temperature Helium is a liquid at normal pressure. The lowest temperature he was able to achieve was 1 K.
Work at these temperatures allowed Onnes to discover super-conductivity. Under the right circumstances materials lose all resistance to the movement of an electric current. Mercury becomes a super-conductor at 4.12 K. Lead becomes one at 7.22 K. In Asimov's time the highest temperature at which super-conductivity was observed was 11.2 K. Things have changed a lot since. The first "high temperature" super-conductor was discovered in 1986. Since then many others have followed.
But the holy grail, a material that super-conducts at room temperature, is still only a dream. And there is now a two track contest. Some materials become super-conductive at relatively high temperatures but only if they are compressed to very high pressures. These materials are interesting but not that practical. Unfortunately, materials that super-conduct at normal pressure do so at much lower temperatures.
And the lack of even a hint of a realistic possibility of ever finding a room temperature super-conductor has led scientists to move the bar. A material that super-conducts at normal pressure and at or above the temperature of liquid Nitrogen would be immensely useful. Liquid Nitrogen is now considered so widely and inexpensively available that a material that super-conducts in a bath of liquid Nitrogen is now considered "good enough". But even this considerably relaxed goal is still well out of reach.
Most devices that employ magnets constructed from super-conducting material like the Large Hadron Collider (LHC) at the CERN laboratory that straddles the Swiss - French border, bathe them in a cooling fluid of liquid Helium. Using materials that super-conduct at higher temperatures could instead use a less demanding and less expensive non-Helium cooling system.
But so far, no one has figured how to get such a system to work well enough to be practical. That means that everyone needing the performance a super-conducting magnet delivers has ended up being forced to go with a liquid Helium cooling system. Moving to high-temperature super-conductors for practical applications is still a dream rather than a reality.
And both the super-conducting phenomenon and super-conducting materials were quite mysterious in Asimov's time. They are now less mysterious. There is now a theory called BCS that seems to be relatively successful in providing some insight. It involves something called "Cooper pairs". I don't understand it well enough to talk about it so I'll leave it at that.
Asimov goes into a number of the starling properties of super-conducting materials in general and liquid Helium in particular. In the interests of brevity I am going to skip over them except to note that the record low temperature achieved by this time was 0.00002 K.
As I noted above, scientists can do better now. And they have discovered and explored many more remarkable ultra-low temperature phenomenon. There is something called a Bose-Einstein Condensate that displays remarkable quantum mechanical properties. Then there is the "Cesium Fountain Clock". Feel free to search out the details on your own as they are fascinating. I am going to confine myself to noting that this type of clock is so accurate that over a period of 300 million years it will be off by a second or less and that two Cesium Fountain Clocks, NIST-f1 and NIST-f2, provide the official time standard for the US.
It turns out that an interest in low temperatures naturally led to an interest in high pressures. Pressures are often measured in "atmospheres". One atmosphere is 15 pounds per square inch (PSI). The pressure at the center of the earth is about 3 million atmospheres. By the 1880s scientists could produce 3,000 atmospheres (45,000 PSI) in the laboratory. In 1905 Bridgman achieved 20,000 atmospheres. And somehow this led to a discussion by Asimov of diamonds.
It took a while for scientists to prove that diamonds were just Carbon arranged in a specific crystalline configuration. It is easy to turn a diamond into another form of Carbon. Is it possible to go the other way? Yes, but it takes a lot of pressure. The first artificial diamonds were produced in 1955 in a lab owned by General Electric. The feat required pressures of 100,000 atmospheres combined with temperatures of 2,500 degrees Celsius.
Artificial diamonds were a curiosity at the time. They are now a business, albeit a modest one. The GE process has been improved upon but not by much. The more interesting recent development is the "Diamond Anvil Cell". Diamonds are extremely hard. If you take a diamond with a point on it (the part on the bottom in the setting of an engagement ring) and chop a very small part off of it, you get a small flat spot.
Now do the same thing to a second, similarly sized, diamond. Now glue one diamond, point out, to one jaw of a vise and the other diamond, also point out, to the other jaw. If everything is lined up properly all the pressure the vice generates as it is closed is focused into the space between the two tiny flat surfaces at the tips of the diamonds. If you put something into that tiny space you can subject it to fantastic pressures.
Now add a microscope. Remember that diamonds are transparent so you can see what is going on by looking through the flat surface of one or the other diamond at whatever you put between them. You can also shine lights through the diamonds or add other components to perform a wide variety of experiments under extremely high pressure.
Diamond Anvil Cells have become a common tool in labs that want to subject materials to extremely high pressures. Lots has been learned about the inside of the earth, for instance. Before the advent of the Diamond Anvil Cell, rocks and minerals thought to be common in the interior of the earth couldn't be subject to pressures high enough to reproduce those found at depth in the earth. Now they can.
Moving on to "Metals", the first thing to understand is that the definition of what is and is not a metal evolved from experience. The ancients became familiar with Gold, Silver, Copper, Iron, and Tin. They seemed to share similarities so they were lumped together as "metals". Fast forward to the present and Chemists scan the Periodic Table of the Elements and classify many elements as metals and others as non-metals. But more than anything, what they are doing is retrofitting things to fit the ancient conception of what was and was not a metal.
The ancients observed that a metal in it's pure state was shiny. You could form it into sheets by beating it with a hammer. Later it was found to conduct electricity and heat. So over time elements that seemed to have properties similar to known metals were added to the "metals" group. This resulted in some weird decisions.
Mercury is a metal even though it is liquid at room temperature. Why? Because it is shiny and conducts both heat and electricity well. So the fact that you couldn't form it into a sheet and beat it with a hammer was ignored. And so it went to the present day when, as Asimov notes, only about 20 of the (then) 102 elements in the periodic table are classified as non-metals. The rest are metals.
Then there are the Astronomers. They have an entirely different definition of a "metal". At the time of the Big Bang the universe consisted of about 90% Hydrogen (atomic number 1), 10% Helium (atomic number 2), a trace of Lithium (atomic number 3), and pretty much nothing else. To an astronomer a "metal" is anything that is not either Hydrogen or Helium.
They ignore the trace of Lithium that was also formed during the Big Bang and use "metal" as short-hand for any element created after the Big Bang. As Asimov goes with the Chemistry definition of "metal", I will too. But knowing this Astronomical definition of a "metal" may avoid some confusion. If you come across the word "metal" in an Astronomical context and something seems wrong it's because something actually is wrong. Astronomers are just being Astronomers. Once you understand this the confusion evaporates.
Anyhow, the first metal that came into wide use in ancient times was Copper. Warfare drives a lot of technological advances and "Copper" edged weapons were found to have advantages over stone edged weapons in a lot of contexts. And Copper, as it is found in the ground, often has some Tin mixed in. As a result, a lot of ancient "Copper" was actually Bronze. Bronze has more of the hardness that stone possesses but avoids stone's brittleness. Pure Copper, on the other hand, is quite soft.
It took a while for the ancients to figure out that they wanted to avoid pure Copper when they were making weapons and go with the Copper that contained a substantial amount of Tin. By between 3,500 BC (Egypt and other palaces) and 2,000 BC (Greece and other places ) years ago people figured out what the story was and were deliberately mixing Copper and Tin together in the correct proportions to get weapons grade Bronze. And that's where the "Bronze Age" got it's name.
Iron was known to have excellent properties from antiquity but the only known source for a long time was meteorites. Smelting, the deliberate manufacture of Iron from ore, was pioneered in Asia Minor in about 1,400 BC. Iron is much harder to make than Bronze as it requires much higher temperatures and careful attention to the carbon content of the resulting metal. The early product, called "Wrought Iron", did not have the strength and other properties we now associate with Iron due to all the impurities it contained.
By the middle ages the process was better understood and "Cast Iron", an Iron with fewer impurities, became widely available, It made much better weapons. But it tended to be brittle because (as was found out later) it had too much carbon in it (4-5%). Steel (what we would now call "Mild Steel") is low-carbon (0.2-1.5%) Iron. It is both stronger than and less brittle than Iron. But it is also very hard to make.
That is, until 1876 when Bessemer came up with his process for making Steel in large volumes using the simple and inexpensive process that was named after him. He invented the process to solve a different problem. Adding rifling (groves that caused the projectile to spin and, therefore, fly much straighter) to the barrels of cannons substantially increased their accuracy. But the added stresses were too much for the Iron or Brass cannons of the day. He needed something stronger and his "blast furnace" could make Steel, and that was exactly what was needed.
It turned out that Bessemer steel was inferior if it contained Phosphorus. Bessemer got around this by using ore that was Phosphorus free. But in 1875 Thomas figured out that lining blast furnaces with limestone and magnesia enabled the use of high Phosphorous ore. The lining removed the Phosphorous. Soon, suitably lined Bessemer-style blast furnaces took over everywhere and the "Age of Steel" got under way.
By 1900 steel was showing up everywhere. It was used in the rails trains rode on and in the trains themselves. It was used in the bridges that spanned rivers. It was in the skeletons of "skyscraper" buildings that rose above the street. It was in the pipes below the streets. It was in automobiles that rode on the streets. It was in appliances in the kitchen and more appliances in the laundry room. It showed up hundreds of consumer products large and small. It was in the factories that made everything else. And it revolutionized warfare.
The "Dreadnaught" was the first modern battleship. It set the pattern that continued to the end of World War II. The "tank", a weapon invented by the British during World War I, revolutionized how land battles were fought. Rifled artillery weapons, deployed both on land (most famously as the "Big Bertha" gun the Germans used to shell Paris during World War I) and at sea (also famously as the "16", or in the case of the Japanese "18", "main battery" guns found on the battleships that fought in World War II). And many of the battles fought during World War I were, in essence, artillery duels involving thousands of guns on each side.
But Bessemer Steel pouring straight out of a blast furnace was not the end of the "Steel" story. The "Carbon" and the "Phosphorus" stories got scientists to thinking "what would happen if we added a little of this or a little of that to Steel?" The answer turned out to be very interesting. Adding Manganese, Tungsten, Chromium, and other materials, could produce Steel with very beneficial properties. Most famously, adding the right amounts of Nickel and Chromium produces "Stainless Steel".
Progress has continued in this area since Asimov published but there have been no big breakthroughs. One candidate that ultimately failed is something called "Cor-Ten" Steel. Initially it rusts. But once a thin layer of rust has built up no more rust forms. In theory that makes it a good roofing material and it was used on a number of buildings.
The industry had high hopes for it at one point. But, although it worked exactly as advertised, it never caught on with the general public. So the Cor-Ten craze lasted only a short while. Nor has any other "magical new" kind of Steel caught on in a big way. There have been numerous small advances but no big breakthroughs when it comes to Steel.
But Steel (or the Iron that is its principal component) is not the only metal out there. Aluminum is a striking example of this. For most of history Aluminum was considered a rare and exotic material. It's not because Aluminum itself is rare. It is actually more common than Iron. But before 1886 pure Aluminum was very hard to come by. There are a few chemical processes that will break up molecules containing Aluminum. But they were either difficult or expensive to perform. This put Aluminum in the same category of "only for the rich" as Gold and Silver.
All this finally changed in 1886 when Hall figured out that the tight chemical bonds Aluminum formed could be broken by the application of electricity. This led to the "smelting" process still in widespread use. Since it takes a lot of electric power, smelters that turn bauxite (the most common ore that contains a large amount of Aluminum) into relatively pure Aluminum ingots are all located where cheap electricity is available in large quantities.
Aluminum has two advantages when compared to steel. It is light, weighing in at only a third the weight of steel. The second advantage is corrosion resistance. Like Cor-Ten Steel, Aluminum quickly forms a tough shell on any surface exposed to the air. Once a relatively thin shell has formed it does not continue to get thicker. The difference is that the public has accepted the shell Aluminum creates while they have not accepted the shell Cor-Ten creates. So we see Aluminum items like ladders all over the place but Cor-Ten items are rare.
Pure Aluminum is too soft to be of much use. But in 1906 Wilm developed an alloy by adding Copper and Magnesium to Aluminum. The resulting "Duralumin" quickly became a hit, especially in the airplane business. Duralumin is not very corrosion resistant. But if you add a thin surface layer of pure Aluminum you get "Alclad", which is. Work has continued to find new better Aluminum alloys. There have been successes, but the story is that same as with Steel. There have been a lot of small improvements but no big breakthrough.
And there was a lot of talk for many years of moving from Steel cars to Aluminum cars. But it turns out that Aluminum is far less versatile and far harder to work with than Steel is. So modern motor vehicles have a lot more Aluminum in them these days than cars of yore. (The Ford F-150 pickup truck is an example of this.) But they also still contain lots of Steel. Efforts to use Aluminum for engine blocks, for instance, have been largely unsuccessful.
And airplanes skipped over Steel and went from wood to Aluminum. Aluminum has ruled the roost as the metal of choice when it comes to airplanes from the '20s pretty much to this day. It looks like the material that is most likely to supplant it is carbon fiber. The Boeing 787 was a big bet on carbon fiber that seems to be paying off. But carbon fiber is even harder to work with than Aluminum.
It has been a long slow learning curve for the aerospace industry to figure out how to work with it. The auto industry has moved even slower. There are a few super-expensive cars that use substantial amounts of carbon fiber. But, so far, that's it. No one had a clue as to the possible existence of something like carbon fiber in Asimov's day.
Asimov next moves on to Magnesium. Magnesium is lighter and rarer than Aluminum. There is lots of Magnesium in the ocean. All salt water contains small amounts of it. But it was not then and is still not economically practical to extract Magnesium from salt water. Besides its expense, Magnesium has the additional problem that it is easy to get it to burn. And it burns really well. A "Magnesium flare" is very bright. It's also very dangerous to be anywhere near.
After Asimov published his book it was discovered that vast beds of "Magnesium Nodules" could be found on the sea floor in various parts of the ocean Several schemes were hatched to harvest these nodules. But none of them turned out to be feasible. So Magnesium never went mainstream. There are various niche uses for it but it is too expensive and hard to work with to come into widespread use. Are there any other interesting metals?
There are seven really common metals in the earth's crust, Asimov observes. We have already covered three: Iron, Aluminum, and Magnesium. The other four are: Sodium, Potassium, Calcium, and Titanium. Quoting Asimov, "Sodium, Potassium, and Calcium are far too active chemically to be used as construction materials." This line of thinking allows him to focus on Titanium.
Titanium is roughly half the weight of Steel while being stronger, more corrosion resistant, and possessing better tolerance of high temperatures than its competitors. It sounds like the wonder metal and it is. The only thing holding it up is the difficulty of procuring it and working with it. Asimov saw it as a potential metal of the future.
Titanium has found many in the intervening years. But the cost and difficulty of working with it have limited these uses to a few high value situations. One marquis use of it is in the SR-71 spy plane. There, its ability to withstand very high temperatures while maintaining most of its strength were critical. But each SR-71 costs a bloody fortune to build and maintain.
At present, Titanium is most commonly found inside jet engines. Modern jet engines have two sets of "compressor" blades. The front set operates in a cool and relatively benign environment. The back set are literally located in the middle of the flame of the jet. That environment is very hot and very chemically harsh. And it turns out the higher operating temperature at which you can run this rear part of the engine, the more efficient you can make the engine.
So engine makers figure out exactly how much punishment blades in the back part of the engine can withstand and design the rest of the engine accordingly. As new methods and materials come along that allow the blades to stand up under still more punishment the engine design is changed accordingly.
It's a fine line that is walked as any increase in operating temperature or other means of torturing the blades that can be safely withstood translates directly into increased engine performance and/or efficiency. But if you go too far really bad things happen. The engine explodes into very hot, very sharp, shrapnel. It's a good thing Tungsten and its alloys can withstand a truly astonishing amount of torture.
Both the operating temperatures and the efficiencies of modern jet engines far surpass anything an engineer of Asimov's day could have imagined would ever be possible. And that has enabled airlines to be profitable while charging far lower fares than anyone could have imagined back then. At the time the book was written the Boeing 707 had just come into service.
Back then, most planes were still propeller driven. People forget that the piston engines in propeller planes are complex and finicky. That means they require a lot of maintenance to keep them running well. Jet engines are far simpler and turn out to require far less maintenance. And they are way more fuel efficient, lighter, etc. But at that point airlines had little experience with jets and didn't know what to expect.
The obvious expectation is that the costs and performance of jets would be similar to that of propeller planes. It turns out that jets were faster so you could get more flights in per day. And they were more fuel efficient and required far less maintenance. And modern jets can fly a lot further. The longest range jets in today's inventory can fly directly from pretty much anyplace on the earth to pretty much anyplace else. Predicting that all these changes were going to happen would have been nearly impossible. It's not any one thing. It's the combination of all of them.
Asimov ends this chapter with a trenchant observation:
In the next installment we will move on to the section titled "The Particles". This will circle back to subjects covered previously. But it will dig deeper into them and that will allow me to discuss at greater length and in more detail the new discoveries and advances that have taken place AA - After Asimov.
I take Isaac Asimov's book "The Intelligent Man's Guide to the Physical Sciences" as my baseline for the state of science as it was when he wrote the book (1959 - 60). In these posts I am reviewing what he reported and what's changed since. For this post I am starting with the chapter Asimov titled "Gases". I will then move on to the chapter he titled "Metals".
The traditional "phases" of materials are solid, liquid, and gas. Since the dawn of Chemistry it has been known that a material can transition from one phase to another as the temperature is changed. In 1787 Charles discovered the law now named after him. A gas contracts as it is cooled (and expands as it is heated). He also noted that the contraction amounted to one part in 273 if the temperature was what we now call 0 degrees Celsius. (In Asimov's time the equivalent temperature scale was called Centigrade. I am going to skip over the small technical differences between the Celsius and Centigrade scales. For our purposes they are essentially the same.) Charles wondered if there was an "absolute zero" that was 273 degrees colder than 0 Celsius.
It turns out he was on to something but it would be a long time before equipment existed to lower temperatures more than a few tens of degrees below zero Celsius. When the "atomic theory of gasses" was developed temperature could be related to tiny molecules of gas moving at high speeds and banging off of each other. A decrease in speed would accompany a decrease in temperature. This would naturally lead to a decrease in the average distance between molecules. And that would make the same amount of gas occupy less space.
In the 1860's the physicist Thompson discussed with Lord Kelvin the idea that at absolute zero (-273 degrees Celsius) all molecular motion would cease. It was obviously not possible to go slower than zero speed so no lower temperature was possible. Asimov pegs Absolute zero at -273.12 degrees Centigrade. We can now add several decimal places (plus make the adjustments necessary to switch from Centigrade to Celsius) but the value has changed little in the intervening time.
Quantum Mechanics tells us, however, that it is impossible for all motion to completely stop. The Heisenberg Uncertainty principle requires that even at absolute zero there is some motion still present. And it turns out that the amount of residual motion matters. Scientists are now able to reduce the temperature of small amounts of matter to a thousandth, a millionth, or even a billionth of a degree above absolute zero. And in some cases these tiny temperature changes cause the properties of the material to change due to quantum effects. The study of temperatures very near absolute zero is now is now an area that commands the energies of a relatively large scientific community. But that's getting ahead of the story.
The coldest temperatures available to early scientists were not much lower than 0 Celsius. But that just led to "out of the box" thinking. The first step along this path was to notice that some gasses could be liquified without lowering their temperature. All that was necessary was to raise their pressure. This worked well for Chlorine, Sulfur Dioxide, Carbon Dioxide, and a number of other gasses. Pressurizing gasses tends to heat them up. But if you pressurize a gas, cool it down, then depressurize it, it becomes very cold. That's how refrigeration works. And refrigeration extended the range of cold temperatures accessible to scientists.
Another trick is evaporation. The process of evaporation draws heat out of a liquid. At the microscopic level what's going on is that all liquids contain molecules traveling at different speeds. If a high speed molecule happens to fly above the surface of a liquid it may never come back. This is how evaporation works at the molecular level and this mechanism preferentially removes the speediest molecules from the liquid. And, just as with a gas, these speedy molecules are the warmest ones. So evaporation, by removing the warmest molecules, lowers the average temperature of the remainder. In other words, it cools the liquid down. This "evaporative cooling" technique is how "Swamp coolers" work.
So scientists found clever ways to use refrigeration, evaporation, or both to reach heretofore unreachably cold temperatures. By 1885 -110 Celsius was reachable. But this is only 40% of the way to absolute zero. And, more importantly, a number of common gasses, Hydrogen, Oxygen, Nitrogen, and others, stayed in their gaseous form at this temperature. In 1869 Andrews determined that gasses had a "critical temperature". Above the critical temperature the gas would not liquify no matter how much pressure was applied. That made it all the more was important to be reduce the temperature of these gasses still further.
The "cascade" method allowed temperatures to be further lowered. An evaporation/refrigeration process using one gas was used to lower the temperature a certain amount. Then a second evaporation/refrigeration process using a different gas was used to lower the temperature further. By using a cascade consisting of several stages Pictet managed to liquify Oxygen at -140. Others liquified Carbon Monoxide (-190) and Nitrogen (-195). But it wasn't until 1900 that Dewar managed to liquify Hydrogen at -240 by using a multi-stage process that depended on these tricks plus his own invention, a "Dewar bottle", what we now call a "thermos bottle". But we are now only 88% of the way to our goal. And, as is common in these situations, the closer you get the harder it is to make additional progress.
Now we make a couple of digressions, not compliments of me, but instead compliments of Mr. Asimov. He first digresses by noting that by 1895 Hampton had been able to turn laboratory scale techniques into ones that could be performed at industrial scale. A simple modification of the same basic technique made it possible to cheaply and easily manufacture Oxygen in either liquid or gaseous form. It could then be used in Acteline torches and as a component in liquid fueled rockets, to name just two of the many applications that this breakthrough made possible.
In his second digression Asimov takes a moment to talk about what makes a good rocket fuel. As the results are informative, I am going to summarize them here. (Feel free to consult the original if you want to know more.) The magic number that tells you how efficient a rocket fuel is is something called "specific impulse". The more the better. Mixing Kerosene and Oxygen yields a specific impulse of 242. Using Hydrogen and Oxygen gives you 350.
So a pound of Hydrogen-Oxygen performs as well as about a pound and a half of Kerosene-Oxygen. But, of course, in the former case the rocket is lighter to the tune of a half a pound. Solid fuels generally have a lower specific impulse. But they are cheaper and safer and easier to work with. This makes it much easier to understand the trade-offs involved in selecting the fuel to use in your rocket.
Among the options listed, liquid Hydrogen + liquid Oxygen is the best but the hardest to work with so when you factor everything in it is likely to be the most expensive option. Solid fuels are the easiest to work and so initially they look to be the least expensive option with but are not nearly as efficient. Kerosene + liquid Oxygen is somewhere in the middle both in terms of efficiency and ease of use. Elon Musk went with this middle choice for his Space-X rockets.
And I always thought that liquid Hydrogen + liquid Oxygen was the best (as in most efficient) chemical fuel. But Asimov says I am wrong. Both Oxygen and Hydrogen are normally molecules consisting of two identical atoms bonded tightly together. And it is the combining of molecular Hydrogen with molecular Oxygen that I have been talking about. But they both elements also have an "atomic" form consisting of a single atom.
And if you start out with "atomic" Hydrogen and let it combine with itself in a rocket motor to form molecular Hydrogen you get a hell of a lot of energy. The specific impulse of this configuration is 1,300. It is almost 4 times as efficient as what I thought was the best chemical fuel. It's not used because no one has been able to figure out how to store atomic Hydrogen in the necessary quantities.
Most people know where the end of the line is when it comes to liquifying gasses. The hardest gas to liquify is Helium. But in 1908 Onnes cracked the riddle and liquified Helium under high pressure at -255 Celsius. By applying more tricks to his already extremely cold liquid Helium he was able to get small quantities down to 4.2 degrees above absolute zero (now referred to as 4.2 K for "degrees Kelvin"). At that temperature Helium is a liquid at normal pressure. The lowest temperature he was able to achieve was 1 K.
Work at these temperatures allowed Onnes to discover super-conductivity. Under the right circumstances materials lose all resistance to the movement of an electric current. Mercury becomes a super-conductor at 4.12 K. Lead becomes one at 7.22 K. In Asimov's time the highest temperature at which super-conductivity was observed was 11.2 K. Things have changed a lot since. The first "high temperature" super-conductor was discovered in 1986. Since then many others have followed.
But the holy grail, a material that super-conducts at room temperature, is still only a dream. And there is now a two track contest. Some materials become super-conductive at relatively high temperatures but only if they are compressed to very high pressures. These materials are interesting but not that practical. Unfortunately, materials that super-conduct at normal pressure do so at much lower temperatures.
And the lack of even a hint of a realistic possibility of ever finding a room temperature super-conductor has led scientists to move the bar. A material that super-conducts at normal pressure and at or above the temperature of liquid Nitrogen would be immensely useful. Liquid Nitrogen is now considered so widely and inexpensively available that a material that super-conducts in a bath of liquid Nitrogen is now considered "good enough". But even this considerably relaxed goal is still well out of reach.
Most devices that employ magnets constructed from super-conducting material like the Large Hadron Collider (LHC) at the CERN laboratory that straddles the Swiss - French border, bathe them in a cooling fluid of liquid Helium. Using materials that super-conduct at higher temperatures could instead use a less demanding and less expensive non-Helium cooling system.
But so far, no one has figured how to get such a system to work well enough to be practical. That means that everyone needing the performance a super-conducting magnet delivers has ended up being forced to go with a liquid Helium cooling system. Moving to high-temperature super-conductors for practical applications is still a dream rather than a reality.
And both the super-conducting phenomenon and super-conducting materials were quite mysterious in Asimov's time. They are now less mysterious. There is now a theory called BCS that seems to be relatively successful in providing some insight. It involves something called "Cooper pairs". I don't understand it well enough to talk about it so I'll leave it at that.
Asimov goes into a number of the starling properties of super-conducting materials in general and liquid Helium in particular. In the interests of brevity I am going to skip over them except to note that the record low temperature achieved by this time was 0.00002 K.
As I noted above, scientists can do better now. And they have discovered and explored many more remarkable ultra-low temperature phenomenon. There is something called a Bose-Einstein Condensate that displays remarkable quantum mechanical properties. Then there is the "Cesium Fountain Clock". Feel free to search out the details on your own as they are fascinating. I am going to confine myself to noting that this type of clock is so accurate that over a period of 300 million years it will be off by a second or less and that two Cesium Fountain Clocks, NIST-f1 and NIST-f2, provide the official time standard for the US.
It turns out that an interest in low temperatures naturally led to an interest in high pressures. Pressures are often measured in "atmospheres". One atmosphere is 15 pounds per square inch (PSI). The pressure at the center of the earth is about 3 million atmospheres. By the 1880s scientists could produce 3,000 atmospheres (45,000 PSI) in the laboratory. In 1905 Bridgman achieved 20,000 atmospheres. And somehow this led to a discussion by Asimov of diamonds.
It took a while for scientists to prove that diamonds were just Carbon arranged in a specific crystalline configuration. It is easy to turn a diamond into another form of Carbon. Is it possible to go the other way? Yes, but it takes a lot of pressure. The first artificial diamonds were produced in 1955 in a lab owned by General Electric. The feat required pressures of 100,000 atmospheres combined with temperatures of 2,500 degrees Celsius.
Artificial diamonds were a curiosity at the time. They are now a business, albeit a modest one. The GE process has been improved upon but not by much. The more interesting recent development is the "Diamond Anvil Cell". Diamonds are extremely hard. If you take a diamond with a point on it (the part on the bottom in the setting of an engagement ring) and chop a very small part off of it, you get a small flat spot.
Now do the same thing to a second, similarly sized, diamond. Now glue one diamond, point out, to one jaw of a vise and the other diamond, also point out, to the other jaw. If everything is lined up properly all the pressure the vice generates as it is closed is focused into the space between the two tiny flat surfaces at the tips of the diamonds. If you put something into that tiny space you can subject it to fantastic pressures.
Now add a microscope. Remember that diamonds are transparent so you can see what is going on by looking through the flat surface of one or the other diamond at whatever you put between them. You can also shine lights through the diamonds or add other components to perform a wide variety of experiments under extremely high pressure.
Diamond Anvil Cells have become a common tool in labs that want to subject materials to extremely high pressures. Lots has been learned about the inside of the earth, for instance. Before the advent of the Diamond Anvil Cell, rocks and minerals thought to be common in the interior of the earth couldn't be subject to pressures high enough to reproduce those found at depth in the earth. Now they can.
Moving on to "Metals", the first thing to understand is that the definition of what is and is not a metal evolved from experience. The ancients became familiar with Gold, Silver, Copper, Iron, and Tin. They seemed to share similarities so they were lumped together as "metals". Fast forward to the present and Chemists scan the Periodic Table of the Elements and classify many elements as metals and others as non-metals. But more than anything, what they are doing is retrofitting things to fit the ancient conception of what was and was not a metal.
The ancients observed that a metal in it's pure state was shiny. You could form it into sheets by beating it with a hammer. Later it was found to conduct electricity and heat. So over time elements that seemed to have properties similar to known metals were added to the "metals" group. This resulted in some weird decisions.
Mercury is a metal even though it is liquid at room temperature. Why? Because it is shiny and conducts both heat and electricity well. So the fact that you couldn't form it into a sheet and beat it with a hammer was ignored. And so it went to the present day when, as Asimov notes, only about 20 of the (then) 102 elements in the periodic table are classified as non-metals. The rest are metals.
Then there are the Astronomers. They have an entirely different definition of a "metal". At the time of the Big Bang the universe consisted of about 90% Hydrogen (atomic number 1), 10% Helium (atomic number 2), a trace of Lithium (atomic number 3), and pretty much nothing else. To an astronomer a "metal" is anything that is not either Hydrogen or Helium.
They ignore the trace of Lithium that was also formed during the Big Bang and use "metal" as short-hand for any element created after the Big Bang. As Asimov goes with the Chemistry definition of "metal", I will too. But knowing this Astronomical definition of a "metal" may avoid some confusion. If you come across the word "metal" in an Astronomical context and something seems wrong it's because something actually is wrong. Astronomers are just being Astronomers. Once you understand this the confusion evaporates.
Anyhow, the first metal that came into wide use in ancient times was Copper. Warfare drives a lot of technological advances and "Copper" edged weapons were found to have advantages over stone edged weapons in a lot of contexts. And Copper, as it is found in the ground, often has some Tin mixed in. As a result, a lot of ancient "Copper" was actually Bronze. Bronze has more of the hardness that stone possesses but avoids stone's brittleness. Pure Copper, on the other hand, is quite soft.
It took a while for the ancients to figure out that they wanted to avoid pure Copper when they were making weapons and go with the Copper that contained a substantial amount of Tin. By between 3,500 BC (Egypt and other palaces) and 2,000 BC (Greece and other places ) years ago people figured out what the story was and were deliberately mixing Copper and Tin together in the correct proportions to get weapons grade Bronze. And that's where the "Bronze Age" got it's name.
Iron was known to have excellent properties from antiquity but the only known source for a long time was meteorites. Smelting, the deliberate manufacture of Iron from ore, was pioneered in Asia Minor in about 1,400 BC. Iron is much harder to make than Bronze as it requires much higher temperatures and careful attention to the carbon content of the resulting metal. The early product, called "Wrought Iron", did not have the strength and other properties we now associate with Iron due to all the impurities it contained.
By the middle ages the process was better understood and "Cast Iron", an Iron with fewer impurities, became widely available, It made much better weapons. But it tended to be brittle because (as was found out later) it had too much carbon in it (4-5%). Steel (what we would now call "Mild Steel") is low-carbon (0.2-1.5%) Iron. It is both stronger than and less brittle than Iron. But it is also very hard to make.
That is, until 1876 when Bessemer came up with his process for making Steel in large volumes using the simple and inexpensive process that was named after him. He invented the process to solve a different problem. Adding rifling (groves that caused the projectile to spin and, therefore, fly much straighter) to the barrels of cannons substantially increased their accuracy. But the added stresses were too much for the Iron or Brass cannons of the day. He needed something stronger and his "blast furnace" could make Steel, and that was exactly what was needed.
It turned out that Bessemer steel was inferior if it contained Phosphorus. Bessemer got around this by using ore that was Phosphorus free. But in 1875 Thomas figured out that lining blast furnaces with limestone and magnesia enabled the use of high Phosphorous ore. The lining removed the Phosphorous. Soon, suitably lined Bessemer-style blast furnaces took over everywhere and the "Age of Steel" got under way.
By 1900 steel was showing up everywhere. It was used in the rails trains rode on and in the trains themselves. It was used in the bridges that spanned rivers. It was in the skeletons of "skyscraper" buildings that rose above the street. It was in the pipes below the streets. It was in automobiles that rode on the streets. It was in appliances in the kitchen and more appliances in the laundry room. It showed up hundreds of consumer products large and small. It was in the factories that made everything else. And it revolutionized warfare.
The "Dreadnaught" was the first modern battleship. It set the pattern that continued to the end of World War II. The "tank", a weapon invented by the British during World War I, revolutionized how land battles were fought. Rifled artillery weapons, deployed both on land (most famously as the "Big Bertha" gun the Germans used to shell Paris during World War I) and at sea (also famously as the "16", or in the case of the Japanese "18", "main battery" guns found on the battleships that fought in World War II). And many of the battles fought during World War I were, in essence, artillery duels involving thousands of guns on each side.
But Bessemer Steel pouring straight out of a blast furnace was not the end of the "Steel" story. The "Carbon" and the "Phosphorus" stories got scientists to thinking "what would happen if we added a little of this or a little of that to Steel?" The answer turned out to be very interesting. Adding Manganese, Tungsten, Chromium, and other materials, could produce Steel with very beneficial properties. Most famously, adding the right amounts of Nickel and Chromium produces "Stainless Steel".
Progress has continued in this area since Asimov published but there have been no big breakthroughs. One candidate that ultimately failed is something called "Cor-Ten" Steel. Initially it rusts. But once a thin layer of rust has built up no more rust forms. In theory that makes it a good roofing material and it was used on a number of buildings.
The industry had high hopes for it at one point. But, although it worked exactly as advertised, it never caught on with the general public. So the Cor-Ten craze lasted only a short while. Nor has any other "magical new" kind of Steel caught on in a big way. There have been numerous small advances but no big breakthroughs when it comes to Steel.
But Steel (or the Iron that is its principal component) is not the only metal out there. Aluminum is a striking example of this. For most of history Aluminum was considered a rare and exotic material. It's not because Aluminum itself is rare. It is actually more common than Iron. But before 1886 pure Aluminum was very hard to come by. There are a few chemical processes that will break up molecules containing Aluminum. But they were either difficult or expensive to perform. This put Aluminum in the same category of "only for the rich" as Gold and Silver.
All this finally changed in 1886 when Hall figured out that the tight chemical bonds Aluminum formed could be broken by the application of electricity. This led to the "smelting" process still in widespread use. Since it takes a lot of electric power, smelters that turn bauxite (the most common ore that contains a large amount of Aluminum) into relatively pure Aluminum ingots are all located where cheap electricity is available in large quantities.
Aluminum has two advantages when compared to steel. It is light, weighing in at only a third the weight of steel. The second advantage is corrosion resistance. Like Cor-Ten Steel, Aluminum quickly forms a tough shell on any surface exposed to the air. Once a relatively thin shell has formed it does not continue to get thicker. The difference is that the public has accepted the shell Aluminum creates while they have not accepted the shell Cor-Ten creates. So we see Aluminum items like ladders all over the place but Cor-Ten items are rare.
Pure Aluminum is too soft to be of much use. But in 1906 Wilm developed an alloy by adding Copper and Magnesium to Aluminum. The resulting "Duralumin" quickly became a hit, especially in the airplane business. Duralumin is not very corrosion resistant. But if you add a thin surface layer of pure Aluminum you get "Alclad", which is. Work has continued to find new better Aluminum alloys. There have been successes, but the story is that same as with Steel. There have been a lot of small improvements but no big breakthrough.
And there was a lot of talk for many years of moving from Steel cars to Aluminum cars. But it turns out that Aluminum is far less versatile and far harder to work with than Steel is. So modern motor vehicles have a lot more Aluminum in them these days than cars of yore. (The Ford F-150 pickup truck is an example of this.) But they also still contain lots of Steel. Efforts to use Aluminum for engine blocks, for instance, have been largely unsuccessful.
And airplanes skipped over Steel and went from wood to Aluminum. Aluminum has ruled the roost as the metal of choice when it comes to airplanes from the '20s pretty much to this day. It looks like the material that is most likely to supplant it is carbon fiber. The Boeing 787 was a big bet on carbon fiber that seems to be paying off. But carbon fiber is even harder to work with than Aluminum.
It has been a long slow learning curve for the aerospace industry to figure out how to work with it. The auto industry has moved even slower. There are a few super-expensive cars that use substantial amounts of carbon fiber. But, so far, that's it. No one had a clue as to the possible existence of something like carbon fiber in Asimov's day.
Asimov next moves on to Magnesium. Magnesium is lighter and rarer than Aluminum. There is lots of Magnesium in the ocean. All salt water contains small amounts of it. But it was not then and is still not economically practical to extract Magnesium from salt water. Besides its expense, Magnesium has the additional problem that it is easy to get it to burn. And it burns really well. A "Magnesium flare" is very bright. It's also very dangerous to be anywhere near.
After Asimov published his book it was discovered that vast beds of "Magnesium Nodules" could be found on the sea floor in various parts of the ocean Several schemes were hatched to harvest these nodules. But none of them turned out to be feasible. So Magnesium never went mainstream. There are various niche uses for it but it is too expensive and hard to work with to come into widespread use. Are there any other interesting metals?
There are seven really common metals in the earth's crust, Asimov observes. We have already covered three: Iron, Aluminum, and Magnesium. The other four are: Sodium, Potassium, Calcium, and Titanium. Quoting Asimov, "Sodium, Potassium, and Calcium are far too active chemically to be used as construction materials." This line of thinking allows him to focus on Titanium.
Titanium is roughly half the weight of Steel while being stronger, more corrosion resistant, and possessing better tolerance of high temperatures than its competitors. It sounds like the wonder metal and it is. The only thing holding it up is the difficulty of procuring it and working with it. Asimov saw it as a potential metal of the future.
Titanium has found many in the intervening years. But the cost and difficulty of working with it have limited these uses to a few high value situations. One marquis use of it is in the SR-71 spy plane. There, its ability to withstand very high temperatures while maintaining most of its strength were critical. But each SR-71 costs a bloody fortune to build and maintain.
At present, Titanium is most commonly found inside jet engines. Modern jet engines have two sets of "compressor" blades. The front set operates in a cool and relatively benign environment. The back set are literally located in the middle of the flame of the jet. That environment is very hot and very chemically harsh. And it turns out the higher operating temperature at which you can run this rear part of the engine, the more efficient you can make the engine.
So engine makers figure out exactly how much punishment blades in the back part of the engine can withstand and design the rest of the engine accordingly. As new methods and materials come along that allow the blades to stand up under still more punishment the engine design is changed accordingly.
It's a fine line that is walked as any increase in operating temperature or other means of torturing the blades that can be safely withstood translates directly into increased engine performance and/or efficiency. But if you go too far really bad things happen. The engine explodes into very hot, very sharp, shrapnel. It's a good thing Tungsten and its alloys can withstand a truly astonishing amount of torture.
Both the operating temperatures and the efficiencies of modern jet engines far surpass anything an engineer of Asimov's day could have imagined would ever be possible. And that has enabled airlines to be profitable while charging far lower fares than anyone could have imagined back then. At the time the book was written the Boeing 707 had just come into service.
Back then, most planes were still propeller driven. People forget that the piston engines in propeller planes are complex and finicky. That means they require a lot of maintenance to keep them running well. Jet engines are far simpler and turn out to require far less maintenance. And they are way more fuel efficient, lighter, etc. But at that point airlines had little experience with jets and didn't know what to expect.
The obvious expectation is that the costs and performance of jets would be similar to that of propeller planes. It turns out that jets were faster so you could get more flights in per day. And they were more fuel efficient and required far less maintenance. And modern jets can fly a lot further. The longest range jets in today's inventory can fly directly from pretty much anyplace on the earth to pretty much anyplace else. Predicting that all these changes were going to happen would have been nearly impossible. It's not any one thing. It's the combination of all of them.
Asimov ends this chapter with a trenchant observation:
There is reason to think, however, that the older metals (and some non-metals, too) can be made far more "wonderful" than they are now.This observation has proven to be spot on. Progress consists of a combination of new discoveries and ways of making old things work better than anyone thought possible.
In the next installment we will move on to the section titled "The Particles". This will circle back to subjects covered previously. But it will dig deeper into them and that will allow me to discuss at greater length and in more detail the new discoveries and advances that have taken place AA - After Asimov.
Sunday, October 14, 2018
50 Years of Science - Part 11
This post is the next in a series dating back several years. As I have previously indicated, a more correct title would be something along the lines of "59 Years of Science". But I like the original title so, even though it becomes less accurate every year, I am sticking with it. By now we are up to the eleventh post in the series. And you can go to sigma5.blogspot.com/2017/04/50-years-of-science-links.html to find an index with links to all the previous posts in the series. I will update that post to include a link to this post right after this post is published.
I take Isaac Asimov's book "The Intelligent Man's Guide to the Physical Sciences" as my baseline for the state of science as it was when he wrote the book (1959 - 60). In these posts I am reviewing what he reported and what's changed since. For this post I am starting with the chapter Asimov titled "Radioactive Elements". I will then move on to the chapter he titled "Electrons".
It turns out that X-Rays were critical to understanding the structure of atoms. And the structure of atoms is critical to the understanding of radioactivity. One of the many reasons scientists do experiments is because they sometimes turn out quite differently than expected. In 1896 Becquerel did an experiment that involved a Uranium containing compound and X-Rays. The idea was that sunlight would react somehow with the Uranium containing compound and make X-Rays. And that seemed to be what was happening. But it turned out that sunlight was not necessary. The compound would fog photographic film that had been covered in black paper even if no sunlight was involved at all. Uranium produced X-Rays all by itself.
The person most responsible for moving the story along from there was Marie Sklodowska. She is better known under her married name of Curie. Mrs. Curie decided that Uranium threw off "radiation" through a process she named "radioactivity". (She and her husband Pierre were also responsible for naming and studying the "piezo-electric effect".) She also identified Thorium as being radioactive. Further experimentation determined that Uranium and Thorium emitted not X-Rays but an even more powerful kind of radiation called "Gamma Rays". Gamma Rays can also fog photographic plates. Hence the initial confusion.
The Curies laid the foundation of what is now called nuclear chemistry. Just as chemical reactions change the properties of compounds, nuclear reactions change the properties of atoms. In particular, radioactivity and "transmutation", the changing of an atom from one element into an entirely different element, go hand in hand. Asimov gets into this in more detail later in his book so I am going to leave it at that for now.
Uranium was not as valuable then as it is now but it was valuable. And the way you got Uranium was by extracting if from something called Pitchblende. Pitchblende turned out to be more radioactive than it would have been had it been pure Uranium. That caused Marie and her husband to go searching for more radioactive elements in the Pitchblende. This led to the discovery of a hitherto unknown element, which they named Polonium after the country of Marie's birth. Further detective work led to the discovery of a second new element, which they named Radium.
A key to what they were able to do is the simple fact that not all radioactive elements are equally radioactive. We tend to think of Uranium as being very radioactive. It isn't. Polonium is much more radioactive than Uranium. And Radium is much more radioactive than Polonium. What's going on can be simply explained.
Radioactive atoms are "unstable". Left to themselves their nucleuses will literally explode into pieces. This process is called "nuclear fission". And that's why nuclear chemistry comes into play. What kind of an element an atom is is determined by how many Protons it has in its nucleus. Uranium famously has 92. When a Uranium atom explodes multiple nucleuses are created, one for each piece that the Uranium atom explodes into. The explosion may throw off what is called an "Alpha particle". An Alpha particle has two Protons. That means it literally is a Helium atom. If the rest of the Uranium atom stays in one piece it will have 90 Protons and will be an atom of Thorium.
More commonly, one of the pieces will have 82 Protons and will, therefore, be an atom of Lead. There are many different ways a Uranium atom can explode. But nuclear physicists have been studying this for a long time. So they can assign probabilities for each combination. But that level of understanding came well after the work of the Curies.
As a result of work by the Curies and others the list of radioactive elements increased quickly. And further careful study of pitchblende yielded three other hitherto unknown elements: Actinium, Radon, and Protactinium. If you have read the earlier installments you will remember the periodic table and the search to fill holes found in it. The exploration of radioactivity was responsible for filling many of these holes in. The Curie work still left holes to be filled but that became harder and harder. Why?
Well, remember the business about some elements being more radioactive than others. Early on it seemed likely that transmutation was going on. Uranium would disappear over time and other elements would appear. And it wasn't just Uranium. Radioactive elements had a habit of disappearing. But when they did other elements would appear. And these new elements might be radioactive and they might not. It took a long time to figure out what was going on, that atoms were fissioning into other atoms. But this "Y" appears when radioactive element "X" disappears was noted early on.
For instance, as Uranium disappears, Thorium and Radium appear. But then if you wait a while longer some of the Thorium would disappear and other elements would appear. These patterns acquired the name "decay chain". "X" decays into "Y" which, in turn, decays into "Z".
Eventually a concept called "half life" emerged. After a fixed amount of time, which was specific to the element, exactly half would disappear to replaced by elements in its decay chain. And the more radioactive an element was, the shorter the half life. So the half life of Uranium was a long time. The Half life of Radium was a short time. And the half life of Polonium was somewhere in the middle.
The reason holes in the periodic table became harder and harder to fill turned out to be related to half life. Let's say the half life of element "X" is a million years. That sounds like a long time. But it is very much shorter than the amount of time the Earth has been around. So say at the time of Earth's formation 1% of it is element "X". If we wait a million years element "X" will only constitute 1/2% of the composition of the Earth. That's still a lot.
After ten million years we would have to multiply 1/2 by itself ten times. It turns out the result is about a thousandth. And after another ten million years we will have a thousandth of a thousandth or only a millionth of the original amount of element "X" remaining. But at this point we are still more than 4.5 billion years away from the appearance of humans on Earth.
Unless a radioactive element has an extremely long half life, one measured in billions of years, little or none of what was originally there will remain. And that was the secret. All of the holes in the periodic table that lasted to the start of the twentieth century belonged to elements that had relatively short half lives. So whatever amount of the element that was around when the Earth formed would be long gone by now.
And let me confess to a wee bit of a simplification. Elements don't have half lives. Isotopes do. Elements come in multiple types called isotopes. All isotopes of a particular element have the same chemical properties. What makes two isotopes of the same element different is the number of Neutrons in its nucleus. Neutrons don't affect chemical properties but they do affect radioactivity properties. Some isotopes are stable. Other isotopes are radioactive. Each isotope of each element has it's own distinct half life. If the isotope is stable we can think of its half life as being infinitely long.
Carbon-12 has 6 Protons and 6 Neutrons. It is stable. Carbon 14 has the same 6 Protons but it has 8 Neutrons. It is extremely radioactive. We know this because it's half life is less than 6,000 years. Uranium-235 is not very radioactive. It's half life is 700 million years. Uranium-238 is even less radioactive with a half life of 4.5 billion years. The difference in half life between Uranium-235 and Uranium-238 is one of the reasons that almost all the Uranium now on earth is Uranium-238.
Now, it sounds like all this means that by now there should be no Thorium left. There is no Thorium left from the time when the Earth was created. But there is a way to make more. You just let Uranium-238 decay. That's why we have Carbon-14 around today in spite of its extremely short half life. All the original Carbon-14 is long gone by now but new Carbon-14 is continuously being created by various processes. So it is found pretty much everywhere but only in trace amounts.
To cut to the chase, all of the holes from one (Hydrogen) to 92 (Uranium) were filled in before the start of World War II. This constitutes the list of "naturally occurring elements", elements we expect to find in nature. But as far back as 1934 people were searching for evidence of the existence of "trans-uranic elements", elements with a number higher than 92.
If it is possible to break an atom apart (fission it) is it also possible to build it up instead, to "fusion it", by fusing two atoms together to create a new element with an atomic number (number of Protons) equal to the sum of the atomic numbers of the constituent parts? It took a while to confirm that the answer was "yes". And at the same time things got more complicated.
Atomic number is literally the number of Protons in the nucleus of an atom. In the early part of the twentieth century a strange particle called a Neutron was discovered. Besides contributing to an element's atomic number a Proton has an electrical charge And it is this electrical charge that turns out to confer the specific chemical properties of each element. So Hydrogen is Hydrogen specifically because it has a nucleus with one Proton in it and that Proton confers exactly one unit of positive electrical charge on the nucleus of the Hydrogen atom.
Uranium is Uranium because its nucleus has 92 Protons in it resulting in a total positive electrical charge of 92 units. If you know the number of Protons in the nucleus you know the chemical properties of the atom you are talking about. But the Neutron has zero electrical charge (and the zero electrical charge is why it has no effect on chemical properties). It is electrically neutral, hence the name. But other than that, the Neutron seems very similar to the Proton. Both particles weigh roughly the same, for instance.
An obvious question is "can you turn a Neutron into a Proton or vice versa"? In 1934 Fermi was trying to answer questions like that. And it turned out that is some cases you could. If you slammed a Neutron into an atom you could sometimes get the Neutron to stick. Beyond that, you could sometimes get it to magically change into a Proton. And that meant the atomic number went up by one and an atom of "X" turned into an atom of "X+1". Very interesting.
Fermi didn't actually do what he was trying to do, which was turning Uranium into a new element with an atomic number of 93. But he did succeed in doing a lot of other important things, things that have justifiably made him famous. Element 93 (Neptunium) and element 94 (Plutonium) were both discovered in 1940. They constituted the first of many trans-uranics. The atomic number list now goes all the way to 118. (It ended at 105 when Asimov wrote the book.) And traces of several of the "not found in nature" trans-uranics were eventually found in tiny quantities in nature, once scientists knew exactly what to look for.
Asimov delves no deeper into the subject of radioactivity at this point so I won't either. On to Electrons.
Protons are heavy subatomic particles that have one unit of positive electric charge. Electrons are light subatomic particles that have one unit of negative electric charge. Like Protons, Electrons are critical to understanding why Chemistry works the way it does. But that doesn't mean they were easy to detect and study. The first to take a shot at it was Faraday. He got nowhere. It turns out he didn't have access to a good enough vacuum pump to make his experiments work. But in 1854 Geissler perfected a pump that was good enough.
With a "Geissler tube" you could make part of its wall glow green under the right conditions. In 1876 Goldstein hypothesized that the effect was caused by some kind of radiation being emitted from a negative electrode placed in the vacuum inside the tube. This radiation was then hitting the glass wall of the Geissler tube. Since the negative electrode was then called a "cathode" the radiation was called "cathode rays". (Older readers should recognize this as the origin story of the formerly ubiquitous but now rare CRT or Cathode Ray Tube.)
Crookes improved on Geissler by improving the quality of the vacuum and by adding small magnets inside the tube. The magnets could deflect the path of the rays. And Crookes decided they were particles, not rays, anyhow. Thompson in 1897 went a step farther and showed that cathode rays could also be deflected by electric fields. Further experimentation showed that these particles (the consensus position by now) were unbelievably light. Two thousand of them weighed about as much as a single Hydrogen atom, the then lightest thing known. That meant they pretty much had to be their own thing. In 1891 Stoney suggested they be called "electrons" and the name stuck.
Given how light they were it seemed possible that they were a part of an atom. But the whole idea behind atoms was that they were the smallest thing possible and indivisible. They were supposed to have no internal structure. But a number of experiments seemed to indicate that if you kicked an atom in one of several ways an electron would come flying out. If you started with a neutral atom (one with no electrical charge) then what got kicked out had exactly one unit of negative charge and what was left behind had exactly one unit of positive charge. The books stayed balanced. That was interesting.
And it turned out that there were lots of ways to get an atom to kick out an electron. That suggested that the electron was located at or near the outside edge of the atom. Still more interesting was what happened in the reverse situation. Suppose an atom absorbed an electron. Then it would emit some light. And there was a complicated relationship between the color of the light and the conditions under which the electron was absorbed. This electron emission/absorption business changed the electrical charge of the atom but did not change which element it was. All this took a lot of sorting out.
And by this time it was well understood that "visible light" was just one kind of electromagnetic radiation. Various members of the family might seem like they were different but in reality the differences were superficial. The electromagnetic spectrum stretched from radio waves to gamma rays, with visible light roughly in the middle. But the same rules applied to all of them.
Radio was ultra-low frequency and ultra-low energy. Gamma rays were super-ultra-high frequency and super-ultra-high energy. And frequency is just wavelength turned inside out. So low frequency is just long wavelength and high frequency is just short wavelength. If you know the energy or the frequency or the wavelength you can directly calculate the other two.
Why is this discussion relevant to the issue at hand? Because it was determined that if you did a certain specific thing to an electron often light (well, technically electromagnetic radiation) of a specific frequency was emitted. Now, this "light" might actually be X-Rays (more energy than regular light) or microwaves (less energy than regular light). But if you calculated the energy of whatever kind of electromagnetic radiation it was, patterns quickly emerged.
Mosely found that you could associate a "characteristic" X-Ray wavelength with a specific metal. In other words, you could identify the type of metal from the X-Rays it emitted. And there was a specific mathematical progression in the characteristic wavelengths as you walked up and down the periodic table a step at a time. He made the leap to suggesting that there was a certain amount o energy associated with each electron in an atom so you could use X-Ray wavelengths to calculate electron counts.
For a neutral atom Proton counts give you electron counts and vice versa. That led to a simple idea of how an atom is put together. You have a "nucleus" with a bunch of Protons (and later Neutrons too) in it and an outer "shell" with a bunch of electrons in it. And it is possible to give an atom an negative charge by somehow stuffing some extra electrons into the shell. You could also give an atom a positive charge by somehow stealing some electrons so the shell was a couple of electrons short.
Chemists were already familiar with "Ions". These were versions of molecules that had either extra positive charge or extra negative charge. This simple model of the atom brought it all together. Negative ions featured one or more atoms with extra electrons in their shells. Positive ions featured one or more atoms that been short changed one or more electrons from their standard compliment. Of course, this model turned out to be vastly too simple but it was a good starting point.
And one of the problems with the above model was there there was a dominant wavelength that could be associated with a specific atom, particularly when it came to the metals. But atoms could emit or absorb lots of different wave lengths, not just the dominant one. That meant there was more going on.
But again, patterns emerged. If you kicked a Hydrogen atom just right it would emit or absorb one of several wavelengths. But if you were doing a certain thing you always saw the same set of wavelengths. Some of these sets showed up so frequently that they were assigned names like "K series", "L series", etc. And there was a simple mathematical relationship between the various permitted wavelengths. The pattern was obvious but scientists initially did not know what to make of it.
An early idea was that of "shells". Instead of a single shell electrons could occupy one of a number of shells. The wavelength of the light gave you the amount of energy. And that was presumably exactly the amount of energy it took to kick an electron from a certain specific shell to a certain other specific shell. The idea worked fine but soon there were lots of shells. And the shells ended up having very odd attributes. For instance, they were definitely not simple rings or spheres.
Generations of what started out as simple models of the atom were by necessity replaced by more and more complicated models. And each model seemed to fail in ways that suggested that the failed model had just not been weird enough. Cutting to the chase, eventually Quantum Mechanics emerged, very roughly in 1930, and finally produced models that fully worked. Quantum Mechanics has since been replaced by the "standard model". But the standard model pulls many of its key concepts directly from Quantum Mechanics.
Both Quantum Mechanics and the standard model are based on mathematics that are beyond me. But frankly we got to them because all the simpler and more "natural" models failed. It turns out that the atom is quite complex. Atoms have structure. They are composed of particles like the Proton and the Neutron. But it turns out both of these particles are actually composed of smaller, more fundamental, sub-sub-particles like Quarks.
And it is important to remember that at a certain point (the arrival of Quantum Mechanics) things stopped getting more complicated. We have had pretty much the same complicated model involving shells for a long time now. Nothing new has shown up for a long time now that would necessitate a major change to the model.
Electrons can and do jump up from one shell to another, higher energy shell. To do this the electron must absorb a photon of light containing a sufficient amount of energy. Or an electron can jump down to another, lower energy shell. It does this by emitting a photon of light. The wavelength of that photon is precisely determined by the energy difference involved. Remember that a specific amount of energy translates into a specific wavelength.
I have left out a lot of details like hyperfine splits but all of it is just that, detail. And nothing behaves anywhere near what sounds sensible. But if say electrons behaved at all sensibly, none of it would work. For instance, we are all used to every system containing at least some friction. With that in mind, consider an electron orbiting a nucleus. Throw some friction in. It doesn't matter if you throw a little in or a lot. What happens is that the electron spirals into the nucleus and atoms don't work.
How much friction you throw in just determines how long it takes the electron to crash into the nucleus. Any friction at all will cause the crash to happen sooner or later. The "Quantum" rules are batshit crazy but absolutely necessary. Since the orbit of an electron can't decay a little bit at a time (Quantum rules forbit it) a small amount of friction becomes impossible and the electron can merrily keep orbiting in the same grove forever (or until something gives it a Quantum sized kick).
Asimov does a nice job of explaining how this business of shells explains chemistry. Most of the chemical attributes of a specific element are determined by how many elements are in its outer shell. This is the shell that is easiest for other atoms to see. And the Quantum rules determine how many electrons it takes to fill that shell. There is an urge to get to full shells. This results in chemical bonds.
Let's say two atoms have an outer shell that holds 8 electrons. And let's say that in their natural states one atom has 6 electrons in its outer shell and the other atom has two. If they can somehow share electrons then each atom can behave sort of like it has an outer shell filled with 8 electrons. And in this case, 8 is the magic number. What I have just described is called an "ionic bond". There are other kinds of sharing arrangements resulting in other kinds of bonds.
The specifics of the sharing arrangements depend on Quantum Mechanics so I am going to skip them. But they have been worked out and they tell Chemists what combinations of atoms want to form into molecules and how "stable" (resistant to disruption) the resulting molecule will be. Let me end with a quick observation about why "Noble Gasses" are the way they are.
Noble gasses don't like to combine with anything to make molecules. Why? Well, Helium has 2 electrons in its outer shell and the magic number for that shell is 2. Neon has 8 electrons in its outer shell and the magic number for that shell is 8. The same is true for Argon and the other Noble gasses. All of them feature the exact number of electrons in their outer shell to fill it completely. This means that their outer electrons don't want to go anywhere. And that means that these elements really don't like to be part of a molecule.
Asimov goes into all this and much more in considerable detail. (This chapter is the longest in the whole book.) He is a great explainer so if you want to know more about shells and chemical bonds and the like, find his book and read this chapter. But my summary gives you the general idea so I am going operate on the "enough is plenty" principle and spare you any more of it.
And just so you know, we are at the half way point in the book. I don't know whether that sounds like good news to you or not.
I take Isaac Asimov's book "The Intelligent Man's Guide to the Physical Sciences" as my baseline for the state of science as it was when he wrote the book (1959 - 60). In these posts I am reviewing what he reported and what's changed since. For this post I am starting with the chapter Asimov titled "Radioactive Elements". I will then move on to the chapter he titled "Electrons".
It turns out that X-Rays were critical to understanding the structure of atoms. And the structure of atoms is critical to the understanding of radioactivity. One of the many reasons scientists do experiments is because they sometimes turn out quite differently than expected. In 1896 Becquerel did an experiment that involved a Uranium containing compound and X-Rays. The idea was that sunlight would react somehow with the Uranium containing compound and make X-Rays. And that seemed to be what was happening. But it turned out that sunlight was not necessary. The compound would fog photographic film that had been covered in black paper even if no sunlight was involved at all. Uranium produced X-Rays all by itself.
The person most responsible for moving the story along from there was Marie Sklodowska. She is better known under her married name of Curie. Mrs. Curie decided that Uranium threw off "radiation" through a process she named "radioactivity". (She and her husband Pierre were also responsible for naming and studying the "piezo-electric effect".) She also identified Thorium as being radioactive. Further experimentation determined that Uranium and Thorium emitted not X-Rays but an even more powerful kind of radiation called "Gamma Rays". Gamma Rays can also fog photographic plates. Hence the initial confusion.
The Curies laid the foundation of what is now called nuclear chemistry. Just as chemical reactions change the properties of compounds, nuclear reactions change the properties of atoms. In particular, radioactivity and "transmutation", the changing of an atom from one element into an entirely different element, go hand in hand. Asimov gets into this in more detail later in his book so I am going to leave it at that for now.
Uranium was not as valuable then as it is now but it was valuable. And the way you got Uranium was by extracting if from something called Pitchblende. Pitchblende turned out to be more radioactive than it would have been had it been pure Uranium. That caused Marie and her husband to go searching for more radioactive elements in the Pitchblende. This led to the discovery of a hitherto unknown element, which they named Polonium after the country of Marie's birth. Further detective work led to the discovery of a second new element, which they named Radium.
A key to what they were able to do is the simple fact that not all radioactive elements are equally radioactive. We tend to think of Uranium as being very radioactive. It isn't. Polonium is much more radioactive than Uranium. And Radium is much more radioactive than Polonium. What's going on can be simply explained.
Radioactive atoms are "unstable". Left to themselves their nucleuses will literally explode into pieces. This process is called "nuclear fission". And that's why nuclear chemistry comes into play. What kind of an element an atom is is determined by how many Protons it has in its nucleus. Uranium famously has 92. When a Uranium atom explodes multiple nucleuses are created, one for each piece that the Uranium atom explodes into. The explosion may throw off what is called an "Alpha particle". An Alpha particle has two Protons. That means it literally is a Helium atom. If the rest of the Uranium atom stays in one piece it will have 90 Protons and will be an atom of Thorium.
More commonly, one of the pieces will have 82 Protons and will, therefore, be an atom of Lead. There are many different ways a Uranium atom can explode. But nuclear physicists have been studying this for a long time. So they can assign probabilities for each combination. But that level of understanding came well after the work of the Curies.
As a result of work by the Curies and others the list of radioactive elements increased quickly. And further careful study of pitchblende yielded three other hitherto unknown elements: Actinium, Radon, and Protactinium. If you have read the earlier installments you will remember the periodic table and the search to fill holes found in it. The exploration of radioactivity was responsible for filling many of these holes in. The Curie work still left holes to be filled but that became harder and harder. Why?
Well, remember the business about some elements being more radioactive than others. Early on it seemed likely that transmutation was going on. Uranium would disappear over time and other elements would appear. And it wasn't just Uranium. Radioactive elements had a habit of disappearing. But when they did other elements would appear. And these new elements might be radioactive and they might not. It took a long time to figure out what was going on, that atoms were fissioning into other atoms. But this "Y" appears when radioactive element "X" disappears was noted early on.
For instance, as Uranium disappears, Thorium and Radium appear. But then if you wait a while longer some of the Thorium would disappear and other elements would appear. These patterns acquired the name "decay chain". "X" decays into "Y" which, in turn, decays into "Z".
Eventually a concept called "half life" emerged. After a fixed amount of time, which was specific to the element, exactly half would disappear to replaced by elements in its decay chain. And the more radioactive an element was, the shorter the half life. So the half life of Uranium was a long time. The Half life of Radium was a short time. And the half life of Polonium was somewhere in the middle.
The reason holes in the periodic table became harder and harder to fill turned out to be related to half life. Let's say the half life of element "X" is a million years. That sounds like a long time. But it is very much shorter than the amount of time the Earth has been around. So say at the time of Earth's formation 1% of it is element "X". If we wait a million years element "X" will only constitute 1/2% of the composition of the Earth. That's still a lot.
After ten million years we would have to multiply 1/2 by itself ten times. It turns out the result is about a thousandth. And after another ten million years we will have a thousandth of a thousandth or only a millionth of the original amount of element "X" remaining. But at this point we are still more than 4.5 billion years away from the appearance of humans on Earth.
Unless a radioactive element has an extremely long half life, one measured in billions of years, little or none of what was originally there will remain. And that was the secret. All of the holes in the periodic table that lasted to the start of the twentieth century belonged to elements that had relatively short half lives. So whatever amount of the element that was around when the Earth formed would be long gone by now.
And let me confess to a wee bit of a simplification. Elements don't have half lives. Isotopes do. Elements come in multiple types called isotopes. All isotopes of a particular element have the same chemical properties. What makes two isotopes of the same element different is the number of Neutrons in its nucleus. Neutrons don't affect chemical properties but they do affect radioactivity properties. Some isotopes are stable. Other isotopes are radioactive. Each isotope of each element has it's own distinct half life. If the isotope is stable we can think of its half life as being infinitely long.
Carbon-12 has 6 Protons and 6 Neutrons. It is stable. Carbon 14 has the same 6 Protons but it has 8 Neutrons. It is extremely radioactive. We know this because it's half life is less than 6,000 years. Uranium-235 is not very radioactive. It's half life is 700 million years. Uranium-238 is even less radioactive with a half life of 4.5 billion years. The difference in half life between Uranium-235 and Uranium-238 is one of the reasons that almost all the Uranium now on earth is Uranium-238.
Now, it sounds like all this means that by now there should be no Thorium left. There is no Thorium left from the time when the Earth was created. But there is a way to make more. You just let Uranium-238 decay. That's why we have Carbon-14 around today in spite of its extremely short half life. All the original Carbon-14 is long gone by now but new Carbon-14 is continuously being created by various processes. So it is found pretty much everywhere but only in trace amounts.
To cut to the chase, all of the holes from one (Hydrogen) to 92 (Uranium) were filled in before the start of World War II. This constitutes the list of "naturally occurring elements", elements we expect to find in nature. But as far back as 1934 people were searching for evidence of the existence of "trans-uranic elements", elements with a number higher than 92.
If it is possible to break an atom apart (fission it) is it also possible to build it up instead, to "fusion it", by fusing two atoms together to create a new element with an atomic number (number of Protons) equal to the sum of the atomic numbers of the constituent parts? It took a while to confirm that the answer was "yes". And at the same time things got more complicated.
Atomic number is literally the number of Protons in the nucleus of an atom. In the early part of the twentieth century a strange particle called a Neutron was discovered. Besides contributing to an element's atomic number a Proton has an electrical charge And it is this electrical charge that turns out to confer the specific chemical properties of each element. So Hydrogen is Hydrogen specifically because it has a nucleus with one Proton in it and that Proton confers exactly one unit of positive electrical charge on the nucleus of the Hydrogen atom.
Uranium is Uranium because its nucleus has 92 Protons in it resulting in a total positive electrical charge of 92 units. If you know the number of Protons in the nucleus you know the chemical properties of the atom you are talking about. But the Neutron has zero electrical charge (and the zero electrical charge is why it has no effect on chemical properties). It is electrically neutral, hence the name. But other than that, the Neutron seems very similar to the Proton. Both particles weigh roughly the same, for instance.
An obvious question is "can you turn a Neutron into a Proton or vice versa"? In 1934 Fermi was trying to answer questions like that. And it turned out that is some cases you could. If you slammed a Neutron into an atom you could sometimes get the Neutron to stick. Beyond that, you could sometimes get it to magically change into a Proton. And that meant the atomic number went up by one and an atom of "X" turned into an atom of "X+1". Very interesting.
Fermi didn't actually do what he was trying to do, which was turning Uranium into a new element with an atomic number of 93. But he did succeed in doing a lot of other important things, things that have justifiably made him famous. Element 93 (Neptunium) and element 94 (Plutonium) were both discovered in 1940. They constituted the first of many trans-uranics. The atomic number list now goes all the way to 118. (It ended at 105 when Asimov wrote the book.) And traces of several of the "not found in nature" trans-uranics were eventually found in tiny quantities in nature, once scientists knew exactly what to look for.
Asimov delves no deeper into the subject of radioactivity at this point so I won't either. On to Electrons.
Protons are heavy subatomic particles that have one unit of positive electric charge. Electrons are light subatomic particles that have one unit of negative electric charge. Like Protons, Electrons are critical to understanding why Chemistry works the way it does. But that doesn't mean they were easy to detect and study. The first to take a shot at it was Faraday. He got nowhere. It turns out he didn't have access to a good enough vacuum pump to make his experiments work. But in 1854 Geissler perfected a pump that was good enough.
With a "Geissler tube" you could make part of its wall glow green under the right conditions. In 1876 Goldstein hypothesized that the effect was caused by some kind of radiation being emitted from a negative electrode placed in the vacuum inside the tube. This radiation was then hitting the glass wall of the Geissler tube. Since the negative electrode was then called a "cathode" the radiation was called "cathode rays". (Older readers should recognize this as the origin story of the formerly ubiquitous but now rare CRT or Cathode Ray Tube.)
Crookes improved on Geissler by improving the quality of the vacuum and by adding small magnets inside the tube. The magnets could deflect the path of the rays. And Crookes decided they were particles, not rays, anyhow. Thompson in 1897 went a step farther and showed that cathode rays could also be deflected by electric fields. Further experimentation showed that these particles (the consensus position by now) were unbelievably light. Two thousand of them weighed about as much as a single Hydrogen atom, the then lightest thing known. That meant they pretty much had to be their own thing. In 1891 Stoney suggested they be called "electrons" and the name stuck.
Given how light they were it seemed possible that they were a part of an atom. But the whole idea behind atoms was that they were the smallest thing possible and indivisible. They were supposed to have no internal structure. But a number of experiments seemed to indicate that if you kicked an atom in one of several ways an electron would come flying out. If you started with a neutral atom (one with no electrical charge) then what got kicked out had exactly one unit of negative charge and what was left behind had exactly one unit of positive charge. The books stayed balanced. That was interesting.
And it turned out that there were lots of ways to get an atom to kick out an electron. That suggested that the electron was located at or near the outside edge of the atom. Still more interesting was what happened in the reverse situation. Suppose an atom absorbed an electron. Then it would emit some light. And there was a complicated relationship between the color of the light and the conditions under which the electron was absorbed. This electron emission/absorption business changed the electrical charge of the atom but did not change which element it was. All this took a lot of sorting out.
And by this time it was well understood that "visible light" was just one kind of electromagnetic radiation. Various members of the family might seem like they were different but in reality the differences were superficial. The electromagnetic spectrum stretched from radio waves to gamma rays, with visible light roughly in the middle. But the same rules applied to all of them.
Radio was ultra-low frequency and ultra-low energy. Gamma rays were super-ultra-high frequency and super-ultra-high energy. And frequency is just wavelength turned inside out. So low frequency is just long wavelength and high frequency is just short wavelength. If you know the energy or the frequency or the wavelength you can directly calculate the other two.
Why is this discussion relevant to the issue at hand? Because it was determined that if you did a certain specific thing to an electron often light (well, technically electromagnetic radiation) of a specific frequency was emitted. Now, this "light" might actually be X-Rays (more energy than regular light) or microwaves (less energy than regular light). But if you calculated the energy of whatever kind of electromagnetic radiation it was, patterns quickly emerged.
Mosely found that you could associate a "characteristic" X-Ray wavelength with a specific metal. In other words, you could identify the type of metal from the X-Rays it emitted. And there was a specific mathematical progression in the characteristic wavelengths as you walked up and down the periodic table a step at a time. He made the leap to suggesting that there was a certain amount o energy associated with each electron in an atom so you could use X-Ray wavelengths to calculate electron counts.
For a neutral atom Proton counts give you electron counts and vice versa. That led to a simple idea of how an atom is put together. You have a "nucleus" with a bunch of Protons (and later Neutrons too) in it and an outer "shell" with a bunch of electrons in it. And it is possible to give an atom an negative charge by somehow stuffing some extra electrons into the shell. You could also give an atom a positive charge by somehow stealing some electrons so the shell was a couple of electrons short.
Chemists were already familiar with "Ions". These were versions of molecules that had either extra positive charge or extra negative charge. This simple model of the atom brought it all together. Negative ions featured one or more atoms with extra electrons in their shells. Positive ions featured one or more atoms that been short changed one or more electrons from their standard compliment. Of course, this model turned out to be vastly too simple but it was a good starting point.
And one of the problems with the above model was there there was a dominant wavelength that could be associated with a specific atom, particularly when it came to the metals. But atoms could emit or absorb lots of different wave lengths, not just the dominant one. That meant there was more going on.
But again, patterns emerged. If you kicked a Hydrogen atom just right it would emit or absorb one of several wavelengths. But if you were doing a certain thing you always saw the same set of wavelengths. Some of these sets showed up so frequently that they were assigned names like "K series", "L series", etc. And there was a simple mathematical relationship between the various permitted wavelengths. The pattern was obvious but scientists initially did not know what to make of it.
An early idea was that of "shells". Instead of a single shell electrons could occupy one of a number of shells. The wavelength of the light gave you the amount of energy. And that was presumably exactly the amount of energy it took to kick an electron from a certain specific shell to a certain other specific shell. The idea worked fine but soon there were lots of shells. And the shells ended up having very odd attributes. For instance, they were definitely not simple rings or spheres.
Generations of what started out as simple models of the atom were by necessity replaced by more and more complicated models. And each model seemed to fail in ways that suggested that the failed model had just not been weird enough. Cutting to the chase, eventually Quantum Mechanics emerged, very roughly in 1930, and finally produced models that fully worked. Quantum Mechanics has since been replaced by the "standard model". But the standard model pulls many of its key concepts directly from Quantum Mechanics.
Both Quantum Mechanics and the standard model are based on mathematics that are beyond me. But frankly we got to them because all the simpler and more "natural" models failed. It turns out that the atom is quite complex. Atoms have structure. They are composed of particles like the Proton and the Neutron. But it turns out both of these particles are actually composed of smaller, more fundamental, sub-sub-particles like Quarks.
And it is important to remember that at a certain point (the arrival of Quantum Mechanics) things stopped getting more complicated. We have had pretty much the same complicated model involving shells for a long time now. Nothing new has shown up for a long time now that would necessitate a major change to the model.
Electrons can and do jump up from one shell to another, higher energy shell. To do this the electron must absorb a photon of light containing a sufficient amount of energy. Or an electron can jump down to another, lower energy shell. It does this by emitting a photon of light. The wavelength of that photon is precisely determined by the energy difference involved. Remember that a specific amount of energy translates into a specific wavelength.
I have left out a lot of details like hyperfine splits but all of it is just that, detail. And nothing behaves anywhere near what sounds sensible. But if say electrons behaved at all sensibly, none of it would work. For instance, we are all used to every system containing at least some friction. With that in mind, consider an electron orbiting a nucleus. Throw some friction in. It doesn't matter if you throw a little in or a lot. What happens is that the electron spirals into the nucleus and atoms don't work.
How much friction you throw in just determines how long it takes the electron to crash into the nucleus. Any friction at all will cause the crash to happen sooner or later. The "Quantum" rules are batshit crazy but absolutely necessary. Since the orbit of an electron can't decay a little bit at a time (Quantum rules forbit it) a small amount of friction becomes impossible and the electron can merrily keep orbiting in the same grove forever (or until something gives it a Quantum sized kick).
Asimov does a nice job of explaining how this business of shells explains chemistry. Most of the chemical attributes of a specific element are determined by how many elements are in its outer shell. This is the shell that is easiest for other atoms to see. And the Quantum rules determine how many electrons it takes to fill that shell. There is an urge to get to full shells. This results in chemical bonds.
Let's say two atoms have an outer shell that holds 8 electrons. And let's say that in their natural states one atom has 6 electrons in its outer shell and the other atom has two. If they can somehow share electrons then each atom can behave sort of like it has an outer shell filled with 8 electrons. And in this case, 8 is the magic number. What I have just described is called an "ionic bond". There are other kinds of sharing arrangements resulting in other kinds of bonds.
The specifics of the sharing arrangements depend on Quantum Mechanics so I am going to skip them. But they have been worked out and they tell Chemists what combinations of atoms want to form into molecules and how "stable" (resistant to disruption) the resulting molecule will be. Let me end with a quick observation about why "Noble Gasses" are the way they are.
Noble gasses don't like to combine with anything to make molecules. Why? Well, Helium has 2 electrons in its outer shell and the magic number for that shell is 2. Neon has 8 electrons in its outer shell and the magic number for that shell is 8. The same is true for Argon and the other Noble gasses. All of them feature the exact number of electrons in their outer shell to fill it completely. This means that their outer electrons don't want to go anywhere. And that means that these elements really don't like to be part of a molecule.
Asimov goes into all this and much more in considerable detail. (This chapter is the longest in the whole book.) He is a great explainer so if you want to know more about shells and chemical bonds and the like, find his book and read this chapter. But my summary gives you the general idea so I am going operate on the "enough is plenty" principle and spare you any more of it.
And just so you know, we are at the half way point in the book. I don't know whether that sounds like good news to you or not.
Friday, September 7, 2018
Guns for Dummies
A couple of years ago I did a post simply called "Guns" (see: http://sigma5.blogspot.com/2016/07/guns.html). In that post I covered ground that had been well trod by others, something I try to avoid in these posts, but I just couldn't stop myself. I had become so disgusted by the arguments put forward by the gun lobby that I just couldn't restrain myself. Their arguments are easy to eviscerate because, frankly, they are baloney.
For this post I am going to talk about the actual thing, the gun. So let me review my credentials. I owned cap guns and squirt guns as a little kid. I have fired but not owned BB guns and pellet guns, also as a kid. But I have never owned or even fired what we now think of as a gun, a device that uses an explosive to expell a small piece of metal at high speed.
Nevertheless, I know something about guns. I have read vast amounts of fiction of the detective, thriller, or action kind. Guns feature heavily in this type of literature and you can learn a lot of you pay attention. Also, we swim in a vast ocean of guns and gun culture. Guns frequently feature prominently in the news. Again, if you pay attention you can learn a lot. Then there are also lots of opportunities to see and hear what actual experts have to say. And I avail myself of that. But in terms of actual formal education and training on the subject, there I can make no claims whatsoever.
But I am going to proceed anyhow. And, unfortunately, you will learn a lot more accurate and reliable information about guns here than you will by listening to the bloviating on TV of many so called experts. That's because many of these "experts" are more interested in pushing an agenda than giving you clear, concise, and dependable information. So here goes.
Guns come in a lot of different shapes and sizes. They can be small enough to conceal in the palm of your hand or so big that they don't fit in a standard railroad car. These larger guns are often called artillery or "field pieces". I am going to ignore them (and all kinds of other specialty types of guns) and stick with guns that are designed for single individuals to hold in their hands and use.
They come in two general types. The smaller ones are generally referred to as handguns and can be operated by an adult using one hand. The larger ones are often referred to erroneously as "rifles" but are more accurately called "long guns" because they feature a barrel (a long tube with a hole down the center) that is more than about 16" (the actual number varies slightly depending on who is making the distinction) long.
Long guns feature one of three types of barrels. A "shotgun" has a barrel with thin walls and is typically used to fire a group of pellets out of the hole in the center of the barrel rather than a single "bullet". A "musket" has a thicker, stronger barrel and fires a single bullet. When people say "musket" they are generally referring to the "smooth bore" type of musket. A "rifle" is a musket that has a set of carefully designed groves on the inside that spin the bullet as it travels down the barrel. (The lack of "rifling" is what gives the smooth bore its name.) The spin causes the bullet to follow a straighter path resulting in better "accuracy".
The next most important thing that distinguishes between types of long guns is the "action". The action is the mechanism for handling ammunition. Revolutionary War era muskets featured a "flint lock" action. Earlier designs were called "wheel lock" actions. (For our purposes, these are indistinguishable.) The "trigger" (a small lever operated by a single finger) caused a mechanism to make a "flint" (a type of rock that sparks when hit) strike a "steel" (literally a small piece of steel).
If all went well a spark got thrown into the "pan", a small depression filled with gunpowder, lighting the gunpowder on fire. The fire in the pan then burned along a small channel into the rear of the barrel. This would ignite a larger quantity of gunpowder that would "explode". This explosion would propel the bullet out of the end of the barrel of the gun at high speed.
Can something go wrong with this process? Yes! So guns of this period were cranky and required a great deal of skill and care to operate successfully. And we haven't even talked about the whole business of getting the bullet to hit what we want it to. And these guns were heavy. It typically took a strong man to hold them steady and fire them. And if you tilted them the wrong way the powder would spill out of the pan and it wouldn't fire. It was also a complicated and time consuming process to load one and prepare it for firing. But if everything went well they were quite deadly. And that was the point.
The design of muskets had evolved considerably from when they were first introduced hundreds of years before the Revolutionary War to the Revolutionary era. That evolution continued and continues up to the present day. And one target of this evolution was the action. Something quicker and more reliable was needed. In several stages the "cartridge" was developed.
The bullet is one component of the cartridge. But also includes is a housing, usually called the "shell". Inside the shell is the explosive and some other stuff. On the back of the shell is a special spot called the "primer" that can be set on fire just by hitting it smartly. The shell holds everything including the bullet together and keeps all the pieces properly aligned. This means you just have to put the cartridge into the gun and you are ready to go. The process of getting the gun to go off is also much simplified. You how cause a "firing pin" to strike the primer smartly and everything goes boom. Note that "bullet" and "shell" are often wrongly used as if they are synonyms for cartridge.
From here the evolution of the action focused on the specifics of how the cartridge got loaded into place to be ready to be fired. An early design was called a "bolt" action. An easily manipulated lever called the bolt sticks out to the side of the gun. Moving the bolt appropriately ("operating" it) causes an area at the back of the barrel (the "chamber") to open up.
An "ejector" mechanism causes any spent cartridge/shell present to be "ejected" (thrown to the side) from the gun. The operator then places a fresh cartridge into the chamber and moves the bolt appropriately. This causes everything to close up, the cartridge to be moved into place, and the firing pin to be "cocked" so that a small pressure on the trigger will now cause it to strike the primer smartly.
All this was a big improvement. But more improvement was possible. A "magazine" containing several cartridges was added to the action. As the bolt was operated it would feed a new cartridge from the magazine into the chamber as soon as the old one had been ejected. That sped things up considerably. Early magazines held on the order of a half dozen cartridges. But this meant the operator only had to occasionally mess with reloading.
But things could be improved even more. The action could be and was improved so that it used part of the power of the main explosion to, in effect, operate the bolt. This meant that the gun required no operator action to be ready to fire again almost immediately. This kind of action is called a "semi-automatic" action. It means that the gun will fire once each time the trigger is pulled as long as there are cartridges left in the magazine. But wait! There's more.
Why require a trigger pull each time you want the gun to fire. A slightly more complicated action would permit the gun to keep firing rapidly as long as the trigger is held down and there remains "ammunition" (cartridges) in the magazine. This kind of action is called a "fully-automatic" action and the gun is now called a "machine gun".
The first gun that was capable of firing continuously was the "Gatling Gun". It saw use in the later stages of the Civil War. It was big enough and heavy enough that it had to be mounted on its own little cart. The original design had between six and ten barrels and was operated by means of a fairly large crank instead of a trigger. A couple of years later a British fellow named Maxim invented a single barrel design that used a fully-automatic action similar to the one described above. There are advantages and disadvantages to both the Gatling and The Maxim design. And we see this trade off playing out right down to the present.
And now let me move on to short guns designed for one-handed use, often called "pistols" or "handguns" (the terms are synonymous). The same kind of evolution characterized their history. All the very earliest guns were long guns. But it didn't take long for people to figure out how to jam all the mechanisms of a flint-lock musket into a design that could be used one handed. So flint-lock pistols existed at the time of the Revolutionary War. But they were not very practical. The same "tilt" problem affected them and it was much easier to tilt them because they were smaller. So, other than "dueling pistols", pistols literally designed in pairs to be used in a duel, they were rare.
But once the cartridge was introduced pistols became a much more practical alternative. And the original pistols were single-shot weapons roughly similar in design and use to a bolt-action musket. And, due to their small size, a "double barrel" design was eminently practical and was quickly developed. These guns featured two triggers, one for each barrel.
A very popular double barreled "derringer" (the term actually refers to any small gun) was introduced by Remington in 1866 and by others soon thereafter. The double barrel derringer design remained in general use all the way to the 1930's. Many western movies and TV shows feature double barrel derringers being waved around (and occasionally used) so they are a good place to check out what I am talking about.
But two shots were not enough so the "revolver" design was developed. Colt came out with an early example in 1836. A portion of the barrel was replaced with a larger revolving cylinder that had holes drilled in it to hold five or six (in the most popular designs) cartridges. After each shot a mechanism would automatically rotate the cylinder to align the next cartridge with the barrel and firing pin. Early revolvers actually predated the general use of the cartridge. But revolver designs almost identical to modern ones were in general use by the end of the Civil War.
The process of reloading a revolver was fairly elaborate and no way to simplify things and speed the process up was ever developed. Nevertheless, the revolver was the most common pistol design in use until the 1980's when an entirely different design largely took over.
In 1911 Colt sold a radical new design for a pistol to the U. S. Army for use as a "sidearm" (a pistol in a holster attached to a man's belt at the side) by its officers. (All the other services ended up eventually adopting it.) This design used a semi-automatic (but often incorrectly shortened to "automatic" or even "auto") action. The magazine, (often referred to as a "clip") was housed in the grip of the gun.
A simple lever released the magazine to drop out of the bottom of the gun where it could easily be filled ("loaded") with cartridges. If an additional magazine that had been pre-loaded was available then the gun could be put back into action within a couple of seconds. Each standard magazine held seven cartridges but a fully loaded magazine would fit into a gun that already had a cartridge in the chamber so it was possible to fire as many as eight shots before needing to reload.
The "Luger" pistol uses one of several other semi-automatic action designs that have been developed for use in pistols. But the patents on the Colt 1911 design eventually expired and most "automatic" pistols now use a minor variant of the Colt 1911 design for their action. And the evolution of the pistol eventually followed that of the long gun and fully automatic actions were developed. Some designs date back to World War I. But designs that achieved substantial popularity did not arrive until the US MAC 10 in the 1970s and the Israeli Uzi of the '80s. Other successful designs have since entered the market.
But, as I mentioned above, there are trade-offs. The most basic and most long standing is short barrel versus long barrel. The longer barrel permits more accuracy. But a long gun is, well, long. It can't be carried around in a holster as a sidearm. Foot soldiers most value the long-range accuracy so they carry a long gun. Officers value convenience more so they go with a pistol.
The other long standing trade off is power. In the US the "caliber" of the gun is the number most commonly used to providing a rough estimation of its power. In much the way, engine displacement is used to provide a rough estimation of how powerful a particular car is. Both are misleading but represent a popular starting point. (You will have to look elsewhere for more on this with respect to cars. I provide lots of specifics with respect to guns below.) Popular guns vary in caliber from "22" (actually .22) to "45" (actually .45). What is being measured is the diameter of the bullet. The diameter of a "22" is twenty-two hundredths of an inch. The diameter of a "45" is forty-five hundredths of an inch.
The rest of the world also uses bullet diameter to provide a rough estimate of the power of a gun. But instead of using a measure based on English units (inches or fractions thereof) they use metric. Specifically, they use millimeters abbreviated as "mm". But it's just a different way of saying the same thing. "9mm" is pretty much the same as "38 caliber". 7.62mm is the same as "30 caliber". And the caliber of bullets in an M-16/AR-15/M-4 is .223. This turns out to be "5.56mm" and references to 5.56mm ammunition are common.
The old "NATO standard" M-14 military rifle used "NATO standard 7.62mm" ammunition. The original AK-47 was specifically designed to be able to use NATO standard 7.62mm ammunition. (In a clever move it could also use a slightly larger "Soviet standard" cartridge that did not work in an M-14.) You can now get an AK-47 that is "chambered for" (uses) other common sizes of ammunition if you want. But there are lots of AK-47s chambered for 7.62mm ammunition around so 7.62mm ammunition is still manufactured in large quantities.
It would seem like a "45" should be about twice as big as a "22" and, therefore, perhaps twice as powerful. But a bullet is a three dimensional object and all the dimensions scale in proportion. So a "45" is actually about 8 (2x2x2) times as powerful as a "22". Other common sizes like "25", "32", and "38", (along with other less common sizes) also all scale accordingly. So the size and weight of a specific type of bullet is important. But the amount and type of explosive in the cartridge is also important.
"22"s come in "short" and "long". In both cases the diameter of the bullet is the same but the "22 long" cartridge contains more explosive so it is more powerful. In general, we have standard loads and "magnum" loads of explosive. A "magnum" cartridge generally contains a bullet of the same diameter as the same size standard cartridge but the "shell" is bigger so it can contain more explosive. How much more? There is a standard for the amount of explosive in a "357" cartridge and a different standard amount of explosive in a "357 magnum" cartridge. The same thing goes for a "44" and a "44 magnum" or for other standard/magnum pairs. But I don't know if the amount of explosive in each type of cartridge of the same caliber follows a standard ratio or not.
Another long standing difference is between "smooth bore" and rifled barrels. Rifled barrels are much harder and, therefore, much more expensive to produce. And rifling a shotgun barrel makes no sense so it is never done. But there is something very roughly equivalent with shotguns called "choke". This has to do with how broadly the pellets are dispersed.
If the pellets are tightly grouped then more of them will hit the target but your aim must also be more accurate for any of them to hit the target at all. So if "winging it" is good enough the choke can be set for a broad disbursal pattern. If only a multi-pellet hit will do the job then the choke should be set for a tight disbursal pattern.
A key attribute of a gun is its "stopping power", its ability to kill and maim effectively. Generally speaking a bigger bullet going faster has more stopping poser. So a "45" has a lot more stopping power than a "22". At one end a "22 short" is unlikely to kill you. It's possible but the stars would have to align just right. It can maim you but it isn't particularly that good that either. It has little stopping power. That's what all those other bigger bullets are for. And, as you might expect, a Colt 1911 "45" has a lot of stopping power. A big factor in this is the fact that it uses a big, heavy bullet. But there is more to the story.
Its "muzzle velocity", the speed the bullet leaves the "muzzle" (opposite end of the barrel from the chamber), is relatively low. And this affects what the bullet does when it hits you. It tends to break and tear a lot of things. If any one of those things is critical, you die. Even if nothing critical is hit you are still likely to be grievously wounded and, therefore "out of the fight". To a first approximation, the human body is a bag of water and a "45" bullet happens to throw up a big bow wave. And this bow wave spreads damage far and wide.
The problem with a Colt 1911 "45" is that it is a big, heavy, not very accurate gun. My father carried one as a Naval Officer during World War II. It is almost impossible to hit anything at any kind of distance, he told me. And everything I have learned since bears this out.
And, among other problems, it has a vicious "kick". The barrel is a long way from the gun's center of gravity. When you fire it this "eccentricity" causes the barrel to kick (jerk) up a lot. And that's if you are strong and have a good grip on the gun. If you aren't or don't, the gun can fly completely out of your hands. This makes it hard for the gun to stay "aimed" (pointed in such a way that the bullet will hit what you want it to) as the bullet travels down the barrel.
After you have fired the gun you must get the gun's kick under control, reposition it to the general direction you need it pointing in, and re-aim it, all before you are ready to fire again. And, of course, all this being jerked around is hard on your hand. Hand fatigue can make it hard to fire the gun rapidly and repeatedly.
A "22" doesn't have much kick so it doesn't suffer from this problem. But remember that it also doesn't have much stopping power. There is a happy medium. The "38" and "9mm" both have lots of stopping power but also much less kick than a "45". As a result law enforcement used "38" revolvers almost exclusively for many decades. The "9mm" is a smaller, lighter gun than the "38" that has the same stopping power. This combination is why it has become so popular in the last few decades. And that brings me to another point.
An explosion is, in actuality, just something burning very rapidly. It is common in old time movies to see someone carefully pour out a line of gunpowder (also often referred to as "black powder") on the floor. The line leads up to a keg of powder. He will then light the other end of the line and run away. The line burns slowly (and telegenically) until it reaches then keg. Then you get a "boom".
The fact that we can observe the line of black powder burning tells us that at that point it is burning too slowly to qualify as an explosion. But once confined by the keg, the very same black powder does explode. (The reasons black powder explodes in the keg but not in the line are too complicated to get into so I am just going to skip over them.)
For the purposes of this discussion my point is that when it can be gotten to explode, black powder is a "low" explosive. The rate at which the burning propagates might be faster in the keg than in the line on the floor but it's still not all that fast compared to other explosives.
AMFO is another low explosive. The name comes from the fact that its primarily components are Ammonia fertilizer (the "AM") and fuel oil (the "FO"). Commercially prepared AMFO is commonly used in open pit mining. Timothy McVeigh used a "mix it yourself" recipe he found on the Internet to make the AMFO he used in the Oklahoma City bombing.
C-4 (also known as "plastique") is an example of a "high" explosive. The burning propagates much faster in a high explosive. There are technical reasons to prefer a low explosive over a high explosive for use in a cartridge but both can be made to work.
The "low explosive" attribute of black powder is an advantage when it comes to using it in a cartridge. But other attributes of black powder confer distinct disadvantages when it is used this way. When it explodes it creates a lot of smoke. If lots of guns are going off lots of times then after a while no one can see anything. This led to a change to "smokeless" powder roughly at the time of the Civil War.
And that's not the only problem with black powder. Relative to modern alternatives, it takes a lot of it to make a given amount of explosion. So pistols tended to be quite big and heavy before the Civil War. They needed to be to allow for enough black powder. Better explosives led to smaller and lighter pistols after the Civil War.
But the improvements did not stop there. The specifications for a standard "38" cartridge were set a relatively long time ago. It was more compact than the old black powder cartridges because better powders were available but a "38" cartridge still had to accommodate a fairly large amount of explosive. As the chemistry of explosives continued to evolve still better options became available.
When the specifications for "9mm" cartridges were set these "still better" powders could be and were specified. So the "9mm" cartridge could be and was much smaller than the "38" cartridge and still delivered the same amount of power. And a smaller and lighter cartridge meant the 9mm gun could be made smaller and lighter than its "38" sibling. And that's why "9mm" guns are so popular now.
Now remember a "38" and a "9mm" are pretty similar in terms of stopping power. But the ammunition for each is not interchangeable. The sensible thing would be for Americans to just go with the millimeter thing that everybody else uses. Instead a pretty idiotic and barely workable alternative was adopted.
There is now such a thing as a "380". The bullets are the same .38 caliber but the cartridge uses the more modern "9mm" explosive. So a "38" and a "380" use quite different cartridges. American gun buyers are told in effect "it's a 38" in terms of stopping power but are told at the same time that they must use the more compact but equally effective "380" cartridge instead of a standard "38" cartridge. Like I said, idiotic.
There is one more aspect of all this that needs to be explored. That is the design and construction of the bullet. Originally, bullets were spheres. This was the easiest shape to make. Then over time they became more "bullet-shaped". They had a little bit of a nose on the front and a round cylindrical shape in the back. This was more aerodynamic so bullet-shaped bullets flew straighter.
Later some bullets were given a sharp point. Muzzle velocities had by this time gotten a lot faster and some bullets were now going faster than the speed of sound. The sharp point was found to help with the "bow shock" of the "sonic boom" a bullet flying at supersonic speed created.
Another innovation was "jacketing". Early bullets were made of pure lead. When they hit something they often shattered or splattered. This tended to give them a lot of stopping power when it came to shooting people. But it also meant that even modest efforts at bullet-proofing were effective. A core made of something heavy like lead allowed bullets to remain heavy. A steel jacket, on the other hand, meant a bullet could also punch though at least a modest amount of bullet-proofing on its way to its intended target.
But a steel jacketed bullet tends to make a nice neat hole through a body. This is ideal for hunting as the objective is supposed to be to put meat on the table. A nice "through and through" wound means only a small amount of the meat is rendered unsuitable for dining on. And, in fact, hunters are heavily regulated in terms of the guns and ammunition they are allowed to use. They must use a single shot (bolt action or similar) long gun of middling caliber (roughly .30 caliber) firing a steel jacketed bullet and having a magazine that holds only a few (roughly 5) rounds.
But a hunting rifle is not a very good gun to use for a military weapon. The neat hole it makes substantially reduces its stopping power. It is a step in the wrong direction when compared to a big spherical unjacketed hunk of pure lead from an older weapon. So the military spent a lot of money looking for a third way. And they found it. A steel jacketed round can do a tremendous amount of damage if it tumbles once it has hit its target. And it is easy to make a long slim bullet tumble. So the M-16 (introduced during the Vietnam War in the '60s) pulls together a lot of threads.
It uses a small .223 caliber bullet. That sounds bad because it is so small. But the cartridge is a super-magnum design that produces an extremely high muzzle velocity. The barrel is rifled so the gun is extremely accurate. And the bullet is much longer than it is around. So it flies straight while it is in the air but starts tumbling immediately when it hits something. The high speed is a substitute for the weight. And the tumbling is a substitute for the shattering/splattering behavior of a pure lead bullet. The result is a whole lot of stopping power jammed into a small, light package. This combination is the columniation of hundreds of years of well financed research into the best way to kill people.
And the M-16 can be set to "single shot", "fully automatic", or "three round burst". So the rate of fire can be adjusted to whatever is most appropriate for the circumstances that are encountered. The military has since tweaked the M-16 design in various modest ways since to produce the M-4. It is essentially the same gun and uses exactly the same ammunition. And Colt, the original manufacturer of the M-16, produced a civilian version of the M-16 called the AR-15. It is exactly the same gun except that it lacks the "selector" lever. It is always in "single shot" mode. Unless, of course, you buy an aftermarket "mod" kit that adds the selector back and turns an AR-15 back into an M-16.
And various manufacturers now make knock-offs of the AR-15. Regardless of make and model they are all called, for good reason, "assault weapons". But the tip-off for figuring out if a particular make and model of gun is an AR-15 knock off is the ammunition. Anything that uses .223 caliber (or 5.56mm) ammunition is an AR-15 or a knock off and, therefore, an assault weapon. (Guns that are civilian knockoffs of AK-47s are also lumped into the assault weapon category. As are actual M-16s, M-4s, AK-47s and any other kind of machine gun.)
A gun can be but rarely is used solely for target practice. And there are guns that are designed and built specifically for competitive target shooting competitions. It turns out they are bad at killing and maiming and that's why almost no one buys one. As a result we never see them outside of when there are showing target shooting events in the Olympics. And we see damn little of them even then.
Other than that, the only thing a gun is good for is killing and maiming. The market for hunting rifles (see above for their specifications) represents a small and diminishing part of the gun market. Most guns sold today are military weapons or their close cousins. That means these guns are designed to solely kill and maim people and are not much good for anything else.
How good are they? Guns work better than the blasters (or phasers, or whatever they are called at the moment) in science fiction movies and TV shows. They work better than light sabers. We see blasters and light sabers and the like in these movies and on TV not because the work better than a plain old military-style gun (they don't) but because they look cooler. That's how good today's guns are at doing what they have been designed to do.
I grew up in the old "six-shooter" or "six-gun" days, so called because everybody packed a five shot or six shot revolver. All the cowboys and cops in entertainments carried revolvers of one model or another. And frankly, in almost all situations, if five or six shots doesn't get the job done then it's not going to get done. (Sometimes through the magic of editing everybody would blast away seemingly forever without reloading in some kind of melee but often nobody the results were pretty ineffective.)
The exception, of course, is mass slaughter. If you want to kill a whole lot of school kids or people attending a music concert, or the like, then a gun that is able to fire many rounds at a high rate is the right tool for the job. Soldiers are now trained to avoid "full auto" and use either the "single shot" or "three round burst" modes.
"Full auto" just doesn't work in most military situations. And remember that a soldier's job, when he is in combat, often boils down to killing and maiming as many of the enemy as he can as quickly as he can. But at the same time it is also important to not injure innocent bystanders and modern warfare often puts soldiers in close proximity to innocent bystanders. In a mass slaughter situation, however, killing innocent bystanders is the whole point so "full auto" works just fine.
There is just no situation in which an assault weapon is the appropriate tool for civilian use. It is a poor hunting weapon. It is also almost always illegal to hunt with an assault weapon. It is a poor "home security" weapon. It's too big and clumsy. A handgun just works better. It is a poor "self defense" weapon. You can't holster it while you can holster a handgun. It is a decent weapon to use for target practice. But better guns for this purpose are available and they are cheaper. It is, in short, irresponsible for regular people to own these weapons.
And this brings me to the phrase "responsible gun owner". We are supposed to take it as gospel that 99+% of gun owners are responsible gun owners. But the evidence is overwhelming that this is wrong. There are lots of irresponsible gun owners out there.
You are an irresponsible gun owner if you own an assault weapon.
You are an irresponsible gun owner if you own large capacity magazines. They are only good for shooting lots of civilians quickly.
You are an irresponsible gun owner if you one a "bump stock" (a device that turns a semi-automatic rifle into an full-automatic rifle).
You are an irresponsible gun owner if you "open carry" a long gun in a populated area.
You are an irresponsible gun owner if you own a gun that doesn't have a "safety" on it. You are also an irresponsible gun owner if you don't religiously set safeties ON for all guns they are not in use.
You are an irresponsible gun owner if you don't always keep all your guns secure. That means stored under lock and key when not in use. It means when you have a pistol on your person and it is not in use then it is in a holster that has a security strap and the strap is engaged.
There are a few tiny exceptions. If you are a collector and you keep your collection unloaded and under lock and key then it's okay for you to own assault weapons or guns that don't have safeties.
Thousands of people are killed by guns every year. A lot of them are suicides. And a lot of people commit suicide with a gun they don't own. If a potential suicide does not have easy access to a gun then the chances of that person committing suicide is greatly reduced. And if you have suicidal tendencies get rid of your guns immediately.
A lot of other people are killed by gun accidents. In many cases a small child (under 6) gets hold of an unsecured gun and kills himself or another small child. Lots of other people (teenagers, adults who should know better, "responsible" gun owners) get to fooling around with a gun and it goes off "by accident" and someone is killed or severely wounded.
Responsible gun owners should know this and act accordingly.
Finally, here is some good safety advice from various experts I have seen -
*** Always assume a gun is loaded even if you "know" it is not.
*** Never point a gun at a person unless you really intend to shoot them.
*** Keep your finger well away from the trigger (outside the trigger guard and extended along the side of the gun works well) unless you are about to shoot your gun.
*** Always make sure a gun is accessible only to those who should have access to it. That means lock guns up when there are children, strangers, people with mental problems, and especially if there are people who are drunk, angry, or both, around. If it is physically possible for any of these kinds of people to be around then behave at all times as if they actually are around.
And, of course, the best way to make sure this advice is followed is to have no guns around and stay away from people who do (or even might) have guns around.
For this post I am going to talk about the actual thing, the gun. So let me review my credentials. I owned cap guns and squirt guns as a little kid. I have fired but not owned BB guns and pellet guns, also as a kid. But I have never owned or even fired what we now think of as a gun, a device that uses an explosive to expell a small piece of metal at high speed.
Nevertheless, I know something about guns. I have read vast amounts of fiction of the detective, thriller, or action kind. Guns feature heavily in this type of literature and you can learn a lot of you pay attention. Also, we swim in a vast ocean of guns and gun culture. Guns frequently feature prominently in the news. Again, if you pay attention you can learn a lot. Then there are also lots of opportunities to see and hear what actual experts have to say. And I avail myself of that. But in terms of actual formal education and training on the subject, there I can make no claims whatsoever.
But I am going to proceed anyhow. And, unfortunately, you will learn a lot more accurate and reliable information about guns here than you will by listening to the bloviating on TV of many so called experts. That's because many of these "experts" are more interested in pushing an agenda than giving you clear, concise, and dependable information. So here goes.
Guns come in a lot of different shapes and sizes. They can be small enough to conceal in the palm of your hand or so big that they don't fit in a standard railroad car. These larger guns are often called artillery or "field pieces". I am going to ignore them (and all kinds of other specialty types of guns) and stick with guns that are designed for single individuals to hold in their hands and use.
They come in two general types. The smaller ones are generally referred to as handguns and can be operated by an adult using one hand. The larger ones are often referred to erroneously as "rifles" but are more accurately called "long guns" because they feature a barrel (a long tube with a hole down the center) that is more than about 16" (the actual number varies slightly depending on who is making the distinction) long.
Long guns feature one of three types of barrels. A "shotgun" has a barrel with thin walls and is typically used to fire a group of pellets out of the hole in the center of the barrel rather than a single "bullet". A "musket" has a thicker, stronger barrel and fires a single bullet. When people say "musket" they are generally referring to the "smooth bore" type of musket. A "rifle" is a musket that has a set of carefully designed groves on the inside that spin the bullet as it travels down the barrel. (The lack of "rifling" is what gives the smooth bore its name.) The spin causes the bullet to follow a straighter path resulting in better "accuracy".
The next most important thing that distinguishes between types of long guns is the "action". The action is the mechanism for handling ammunition. Revolutionary War era muskets featured a "flint lock" action. Earlier designs were called "wheel lock" actions. (For our purposes, these are indistinguishable.) The "trigger" (a small lever operated by a single finger) caused a mechanism to make a "flint" (a type of rock that sparks when hit) strike a "steel" (literally a small piece of steel).
If all went well a spark got thrown into the "pan", a small depression filled with gunpowder, lighting the gunpowder on fire. The fire in the pan then burned along a small channel into the rear of the barrel. This would ignite a larger quantity of gunpowder that would "explode". This explosion would propel the bullet out of the end of the barrel of the gun at high speed.
Can something go wrong with this process? Yes! So guns of this period were cranky and required a great deal of skill and care to operate successfully. And we haven't even talked about the whole business of getting the bullet to hit what we want it to. And these guns were heavy. It typically took a strong man to hold them steady and fire them. And if you tilted them the wrong way the powder would spill out of the pan and it wouldn't fire. It was also a complicated and time consuming process to load one and prepare it for firing. But if everything went well they were quite deadly. And that was the point.
The design of muskets had evolved considerably from when they were first introduced hundreds of years before the Revolutionary War to the Revolutionary era. That evolution continued and continues up to the present day. And one target of this evolution was the action. Something quicker and more reliable was needed. In several stages the "cartridge" was developed.
The bullet is one component of the cartridge. But also includes is a housing, usually called the "shell". Inside the shell is the explosive and some other stuff. On the back of the shell is a special spot called the "primer" that can be set on fire just by hitting it smartly. The shell holds everything including the bullet together and keeps all the pieces properly aligned. This means you just have to put the cartridge into the gun and you are ready to go. The process of getting the gun to go off is also much simplified. You how cause a "firing pin" to strike the primer smartly and everything goes boom. Note that "bullet" and "shell" are often wrongly used as if they are synonyms for cartridge.
From here the evolution of the action focused on the specifics of how the cartridge got loaded into place to be ready to be fired. An early design was called a "bolt" action. An easily manipulated lever called the bolt sticks out to the side of the gun. Moving the bolt appropriately ("operating" it) causes an area at the back of the barrel (the "chamber") to open up.
An "ejector" mechanism causes any spent cartridge/shell present to be "ejected" (thrown to the side) from the gun. The operator then places a fresh cartridge into the chamber and moves the bolt appropriately. This causes everything to close up, the cartridge to be moved into place, and the firing pin to be "cocked" so that a small pressure on the trigger will now cause it to strike the primer smartly.
All this was a big improvement. But more improvement was possible. A "magazine" containing several cartridges was added to the action. As the bolt was operated it would feed a new cartridge from the magazine into the chamber as soon as the old one had been ejected. That sped things up considerably. Early magazines held on the order of a half dozen cartridges. But this meant the operator only had to occasionally mess with reloading.
But things could be improved even more. The action could be and was improved so that it used part of the power of the main explosion to, in effect, operate the bolt. This meant that the gun required no operator action to be ready to fire again almost immediately. This kind of action is called a "semi-automatic" action. It means that the gun will fire once each time the trigger is pulled as long as there are cartridges left in the magazine. But wait! There's more.
Why require a trigger pull each time you want the gun to fire. A slightly more complicated action would permit the gun to keep firing rapidly as long as the trigger is held down and there remains "ammunition" (cartridges) in the magazine. This kind of action is called a "fully-automatic" action and the gun is now called a "machine gun".
The first gun that was capable of firing continuously was the "Gatling Gun". It saw use in the later stages of the Civil War. It was big enough and heavy enough that it had to be mounted on its own little cart. The original design had between six and ten barrels and was operated by means of a fairly large crank instead of a trigger. A couple of years later a British fellow named Maxim invented a single barrel design that used a fully-automatic action similar to the one described above. There are advantages and disadvantages to both the Gatling and The Maxim design. And we see this trade off playing out right down to the present.
And now let me move on to short guns designed for one-handed use, often called "pistols" or "handguns" (the terms are synonymous). The same kind of evolution characterized their history. All the very earliest guns were long guns. But it didn't take long for people to figure out how to jam all the mechanisms of a flint-lock musket into a design that could be used one handed. So flint-lock pistols existed at the time of the Revolutionary War. But they were not very practical. The same "tilt" problem affected them and it was much easier to tilt them because they were smaller. So, other than "dueling pistols", pistols literally designed in pairs to be used in a duel, they were rare.
But once the cartridge was introduced pistols became a much more practical alternative. And the original pistols were single-shot weapons roughly similar in design and use to a bolt-action musket. And, due to their small size, a "double barrel" design was eminently practical and was quickly developed. These guns featured two triggers, one for each barrel.
A very popular double barreled "derringer" (the term actually refers to any small gun) was introduced by Remington in 1866 and by others soon thereafter. The double barrel derringer design remained in general use all the way to the 1930's. Many western movies and TV shows feature double barrel derringers being waved around (and occasionally used) so they are a good place to check out what I am talking about.
But two shots were not enough so the "revolver" design was developed. Colt came out with an early example in 1836. A portion of the barrel was replaced with a larger revolving cylinder that had holes drilled in it to hold five or six (in the most popular designs) cartridges. After each shot a mechanism would automatically rotate the cylinder to align the next cartridge with the barrel and firing pin. Early revolvers actually predated the general use of the cartridge. But revolver designs almost identical to modern ones were in general use by the end of the Civil War.
The process of reloading a revolver was fairly elaborate and no way to simplify things and speed the process up was ever developed. Nevertheless, the revolver was the most common pistol design in use until the 1980's when an entirely different design largely took over.
In 1911 Colt sold a radical new design for a pistol to the U. S. Army for use as a "sidearm" (a pistol in a holster attached to a man's belt at the side) by its officers. (All the other services ended up eventually adopting it.) This design used a semi-automatic (but often incorrectly shortened to "automatic" or even "auto") action. The magazine, (often referred to as a "clip") was housed in the grip of the gun.
A simple lever released the magazine to drop out of the bottom of the gun where it could easily be filled ("loaded") with cartridges. If an additional magazine that had been pre-loaded was available then the gun could be put back into action within a couple of seconds. Each standard magazine held seven cartridges but a fully loaded magazine would fit into a gun that already had a cartridge in the chamber so it was possible to fire as many as eight shots before needing to reload.
The "Luger" pistol uses one of several other semi-automatic action designs that have been developed for use in pistols. But the patents on the Colt 1911 design eventually expired and most "automatic" pistols now use a minor variant of the Colt 1911 design for their action. And the evolution of the pistol eventually followed that of the long gun and fully automatic actions were developed. Some designs date back to World War I. But designs that achieved substantial popularity did not arrive until the US MAC 10 in the 1970s and the Israeli Uzi of the '80s. Other successful designs have since entered the market.
But, as I mentioned above, there are trade-offs. The most basic and most long standing is short barrel versus long barrel. The longer barrel permits more accuracy. But a long gun is, well, long. It can't be carried around in a holster as a sidearm. Foot soldiers most value the long-range accuracy so they carry a long gun. Officers value convenience more so they go with a pistol.
The other long standing trade off is power. In the US the "caliber" of the gun is the number most commonly used to providing a rough estimation of its power. In much the way, engine displacement is used to provide a rough estimation of how powerful a particular car is. Both are misleading but represent a popular starting point. (You will have to look elsewhere for more on this with respect to cars. I provide lots of specifics with respect to guns below.) Popular guns vary in caliber from "22" (actually .22) to "45" (actually .45). What is being measured is the diameter of the bullet. The diameter of a "22" is twenty-two hundredths of an inch. The diameter of a "45" is forty-five hundredths of an inch.
The rest of the world also uses bullet diameter to provide a rough estimate of the power of a gun. But instead of using a measure based on English units (inches or fractions thereof) they use metric. Specifically, they use millimeters abbreviated as "mm". But it's just a different way of saying the same thing. "9mm" is pretty much the same as "38 caliber". 7.62mm is the same as "30 caliber". And the caliber of bullets in an M-16/AR-15/M-4 is .223. This turns out to be "5.56mm" and references to 5.56mm ammunition are common.
The old "NATO standard" M-14 military rifle used "NATO standard 7.62mm" ammunition. The original AK-47 was specifically designed to be able to use NATO standard 7.62mm ammunition. (In a clever move it could also use a slightly larger "Soviet standard" cartridge that did not work in an M-14.) You can now get an AK-47 that is "chambered for" (uses) other common sizes of ammunition if you want. But there are lots of AK-47s chambered for 7.62mm ammunition around so 7.62mm ammunition is still manufactured in large quantities.
It would seem like a "45" should be about twice as big as a "22" and, therefore, perhaps twice as powerful. But a bullet is a three dimensional object and all the dimensions scale in proportion. So a "45" is actually about 8 (2x2x2) times as powerful as a "22". Other common sizes like "25", "32", and "38", (along with other less common sizes) also all scale accordingly. So the size and weight of a specific type of bullet is important. But the amount and type of explosive in the cartridge is also important.
"22"s come in "short" and "long". In both cases the diameter of the bullet is the same but the "22 long" cartridge contains more explosive so it is more powerful. In general, we have standard loads and "magnum" loads of explosive. A "magnum" cartridge generally contains a bullet of the same diameter as the same size standard cartridge but the "shell" is bigger so it can contain more explosive. How much more? There is a standard for the amount of explosive in a "357" cartridge and a different standard amount of explosive in a "357 magnum" cartridge. The same thing goes for a "44" and a "44 magnum" or for other standard/magnum pairs. But I don't know if the amount of explosive in each type of cartridge of the same caliber follows a standard ratio or not.
Another long standing difference is between "smooth bore" and rifled barrels. Rifled barrels are much harder and, therefore, much more expensive to produce. And rifling a shotgun barrel makes no sense so it is never done. But there is something very roughly equivalent with shotguns called "choke". This has to do with how broadly the pellets are dispersed.
If the pellets are tightly grouped then more of them will hit the target but your aim must also be more accurate for any of them to hit the target at all. So if "winging it" is good enough the choke can be set for a broad disbursal pattern. If only a multi-pellet hit will do the job then the choke should be set for a tight disbursal pattern.
A key attribute of a gun is its "stopping power", its ability to kill and maim effectively. Generally speaking a bigger bullet going faster has more stopping poser. So a "45" has a lot more stopping power than a "22". At one end a "22 short" is unlikely to kill you. It's possible but the stars would have to align just right. It can maim you but it isn't particularly that good that either. It has little stopping power. That's what all those other bigger bullets are for. And, as you might expect, a Colt 1911 "45" has a lot of stopping power. A big factor in this is the fact that it uses a big, heavy bullet. But there is more to the story.
Its "muzzle velocity", the speed the bullet leaves the "muzzle" (opposite end of the barrel from the chamber), is relatively low. And this affects what the bullet does when it hits you. It tends to break and tear a lot of things. If any one of those things is critical, you die. Even if nothing critical is hit you are still likely to be grievously wounded and, therefore "out of the fight". To a first approximation, the human body is a bag of water and a "45" bullet happens to throw up a big bow wave. And this bow wave spreads damage far and wide.
The problem with a Colt 1911 "45" is that it is a big, heavy, not very accurate gun. My father carried one as a Naval Officer during World War II. It is almost impossible to hit anything at any kind of distance, he told me. And everything I have learned since bears this out.
And, among other problems, it has a vicious "kick". The barrel is a long way from the gun's center of gravity. When you fire it this "eccentricity" causes the barrel to kick (jerk) up a lot. And that's if you are strong and have a good grip on the gun. If you aren't or don't, the gun can fly completely out of your hands. This makes it hard for the gun to stay "aimed" (pointed in such a way that the bullet will hit what you want it to) as the bullet travels down the barrel.
After you have fired the gun you must get the gun's kick under control, reposition it to the general direction you need it pointing in, and re-aim it, all before you are ready to fire again. And, of course, all this being jerked around is hard on your hand. Hand fatigue can make it hard to fire the gun rapidly and repeatedly.
A "22" doesn't have much kick so it doesn't suffer from this problem. But remember that it also doesn't have much stopping power. There is a happy medium. The "38" and "9mm" both have lots of stopping power but also much less kick than a "45". As a result law enforcement used "38" revolvers almost exclusively for many decades. The "9mm" is a smaller, lighter gun than the "38" that has the same stopping power. This combination is why it has become so popular in the last few decades. And that brings me to another point.
An explosion is, in actuality, just something burning very rapidly. It is common in old time movies to see someone carefully pour out a line of gunpowder (also often referred to as "black powder") on the floor. The line leads up to a keg of powder. He will then light the other end of the line and run away. The line burns slowly (and telegenically) until it reaches then keg. Then you get a "boom".
The fact that we can observe the line of black powder burning tells us that at that point it is burning too slowly to qualify as an explosion. But once confined by the keg, the very same black powder does explode. (The reasons black powder explodes in the keg but not in the line are too complicated to get into so I am just going to skip over them.)
For the purposes of this discussion my point is that when it can be gotten to explode, black powder is a "low" explosive. The rate at which the burning propagates might be faster in the keg than in the line on the floor but it's still not all that fast compared to other explosives.
AMFO is another low explosive. The name comes from the fact that its primarily components are Ammonia fertilizer (the "AM") and fuel oil (the "FO"). Commercially prepared AMFO is commonly used in open pit mining. Timothy McVeigh used a "mix it yourself" recipe he found on the Internet to make the AMFO he used in the Oklahoma City bombing.
C-4 (also known as "plastique") is an example of a "high" explosive. The burning propagates much faster in a high explosive. There are technical reasons to prefer a low explosive over a high explosive for use in a cartridge but both can be made to work.
The "low explosive" attribute of black powder is an advantage when it comes to using it in a cartridge. But other attributes of black powder confer distinct disadvantages when it is used this way. When it explodes it creates a lot of smoke. If lots of guns are going off lots of times then after a while no one can see anything. This led to a change to "smokeless" powder roughly at the time of the Civil War.
And that's not the only problem with black powder. Relative to modern alternatives, it takes a lot of it to make a given amount of explosion. So pistols tended to be quite big and heavy before the Civil War. They needed to be to allow for enough black powder. Better explosives led to smaller and lighter pistols after the Civil War.
But the improvements did not stop there. The specifications for a standard "38" cartridge were set a relatively long time ago. It was more compact than the old black powder cartridges because better powders were available but a "38" cartridge still had to accommodate a fairly large amount of explosive. As the chemistry of explosives continued to evolve still better options became available.
When the specifications for "9mm" cartridges were set these "still better" powders could be and were specified. So the "9mm" cartridge could be and was much smaller than the "38" cartridge and still delivered the same amount of power. And a smaller and lighter cartridge meant the 9mm gun could be made smaller and lighter than its "38" sibling. And that's why "9mm" guns are so popular now.
Now remember a "38" and a "9mm" are pretty similar in terms of stopping power. But the ammunition for each is not interchangeable. The sensible thing would be for Americans to just go with the millimeter thing that everybody else uses. Instead a pretty idiotic and barely workable alternative was adopted.
There is now such a thing as a "380". The bullets are the same .38 caliber but the cartridge uses the more modern "9mm" explosive. So a "38" and a "380" use quite different cartridges. American gun buyers are told in effect "it's a 38" in terms of stopping power but are told at the same time that they must use the more compact but equally effective "380" cartridge instead of a standard "38" cartridge. Like I said, idiotic.
There is one more aspect of all this that needs to be explored. That is the design and construction of the bullet. Originally, bullets were spheres. This was the easiest shape to make. Then over time they became more "bullet-shaped". They had a little bit of a nose on the front and a round cylindrical shape in the back. This was more aerodynamic so bullet-shaped bullets flew straighter.
Later some bullets were given a sharp point. Muzzle velocities had by this time gotten a lot faster and some bullets were now going faster than the speed of sound. The sharp point was found to help with the "bow shock" of the "sonic boom" a bullet flying at supersonic speed created.
Another innovation was "jacketing". Early bullets were made of pure lead. When they hit something they often shattered or splattered. This tended to give them a lot of stopping power when it came to shooting people. But it also meant that even modest efforts at bullet-proofing were effective. A core made of something heavy like lead allowed bullets to remain heavy. A steel jacket, on the other hand, meant a bullet could also punch though at least a modest amount of bullet-proofing on its way to its intended target.
But a steel jacketed bullet tends to make a nice neat hole through a body. This is ideal for hunting as the objective is supposed to be to put meat on the table. A nice "through and through" wound means only a small amount of the meat is rendered unsuitable for dining on. And, in fact, hunters are heavily regulated in terms of the guns and ammunition they are allowed to use. They must use a single shot (bolt action or similar) long gun of middling caliber (roughly .30 caliber) firing a steel jacketed bullet and having a magazine that holds only a few (roughly 5) rounds.
But a hunting rifle is not a very good gun to use for a military weapon. The neat hole it makes substantially reduces its stopping power. It is a step in the wrong direction when compared to a big spherical unjacketed hunk of pure lead from an older weapon. So the military spent a lot of money looking for a third way. And they found it. A steel jacketed round can do a tremendous amount of damage if it tumbles once it has hit its target. And it is easy to make a long slim bullet tumble. So the M-16 (introduced during the Vietnam War in the '60s) pulls together a lot of threads.
It uses a small .223 caliber bullet. That sounds bad because it is so small. But the cartridge is a super-magnum design that produces an extremely high muzzle velocity. The barrel is rifled so the gun is extremely accurate. And the bullet is much longer than it is around. So it flies straight while it is in the air but starts tumbling immediately when it hits something. The high speed is a substitute for the weight. And the tumbling is a substitute for the shattering/splattering behavior of a pure lead bullet. The result is a whole lot of stopping power jammed into a small, light package. This combination is the columniation of hundreds of years of well financed research into the best way to kill people.
And the M-16 can be set to "single shot", "fully automatic", or "three round burst". So the rate of fire can be adjusted to whatever is most appropriate for the circumstances that are encountered. The military has since tweaked the M-16 design in various modest ways since to produce the M-4. It is essentially the same gun and uses exactly the same ammunition. And Colt, the original manufacturer of the M-16, produced a civilian version of the M-16 called the AR-15. It is exactly the same gun except that it lacks the "selector" lever. It is always in "single shot" mode. Unless, of course, you buy an aftermarket "mod" kit that adds the selector back and turns an AR-15 back into an M-16.
And various manufacturers now make knock-offs of the AR-15. Regardless of make and model they are all called, for good reason, "assault weapons". But the tip-off for figuring out if a particular make and model of gun is an AR-15 knock off is the ammunition. Anything that uses .223 caliber (or 5.56mm) ammunition is an AR-15 or a knock off and, therefore, an assault weapon. (Guns that are civilian knockoffs of AK-47s are also lumped into the assault weapon category. As are actual M-16s, M-4s, AK-47s and any other kind of machine gun.)
A gun can be but rarely is used solely for target practice. And there are guns that are designed and built specifically for competitive target shooting competitions. It turns out they are bad at killing and maiming and that's why almost no one buys one. As a result we never see them outside of when there are showing target shooting events in the Olympics. And we see damn little of them even then.
Other than that, the only thing a gun is good for is killing and maiming. The market for hunting rifles (see above for their specifications) represents a small and diminishing part of the gun market. Most guns sold today are military weapons or their close cousins. That means these guns are designed to solely kill and maim people and are not much good for anything else.
How good are they? Guns work better than the blasters (or phasers, or whatever they are called at the moment) in science fiction movies and TV shows. They work better than light sabers. We see blasters and light sabers and the like in these movies and on TV not because the work better than a plain old military-style gun (they don't) but because they look cooler. That's how good today's guns are at doing what they have been designed to do.
I grew up in the old "six-shooter" or "six-gun" days, so called because everybody packed a five shot or six shot revolver. All the cowboys and cops in entertainments carried revolvers of one model or another. And frankly, in almost all situations, if five or six shots doesn't get the job done then it's not going to get done. (Sometimes through the magic of editing everybody would blast away seemingly forever without reloading in some kind of melee but often nobody the results were pretty ineffective.)
The exception, of course, is mass slaughter. If you want to kill a whole lot of school kids or people attending a music concert, or the like, then a gun that is able to fire many rounds at a high rate is the right tool for the job. Soldiers are now trained to avoid "full auto" and use either the "single shot" or "three round burst" modes.
"Full auto" just doesn't work in most military situations. And remember that a soldier's job, when he is in combat, often boils down to killing and maiming as many of the enemy as he can as quickly as he can. But at the same time it is also important to not injure innocent bystanders and modern warfare often puts soldiers in close proximity to innocent bystanders. In a mass slaughter situation, however, killing innocent bystanders is the whole point so "full auto" works just fine.
There is just no situation in which an assault weapon is the appropriate tool for civilian use. It is a poor hunting weapon. It is also almost always illegal to hunt with an assault weapon. It is a poor "home security" weapon. It's too big and clumsy. A handgun just works better. It is a poor "self defense" weapon. You can't holster it while you can holster a handgun. It is a decent weapon to use for target practice. But better guns for this purpose are available and they are cheaper. It is, in short, irresponsible for regular people to own these weapons.
And this brings me to the phrase "responsible gun owner". We are supposed to take it as gospel that 99+% of gun owners are responsible gun owners. But the evidence is overwhelming that this is wrong. There are lots of irresponsible gun owners out there.
You are an irresponsible gun owner if you own an assault weapon.
You are an irresponsible gun owner if you own large capacity magazines. They are only good for shooting lots of civilians quickly.
You are an irresponsible gun owner if you one a "bump stock" (a device that turns a semi-automatic rifle into an full-automatic rifle).
You are an irresponsible gun owner if you "open carry" a long gun in a populated area.
You are an irresponsible gun owner if you own a gun that doesn't have a "safety" on it. You are also an irresponsible gun owner if you don't religiously set safeties ON for all guns they are not in use.
You are an irresponsible gun owner if you don't always keep all your guns secure. That means stored under lock and key when not in use. It means when you have a pistol on your person and it is not in use then it is in a holster that has a security strap and the strap is engaged.
There are a few tiny exceptions. If you are a collector and you keep your collection unloaded and under lock and key then it's okay for you to own assault weapons or guns that don't have safeties.
Thousands of people are killed by guns every year. A lot of them are suicides. And a lot of people commit suicide with a gun they don't own. If a potential suicide does not have easy access to a gun then the chances of that person committing suicide is greatly reduced. And if you have suicidal tendencies get rid of your guns immediately.
A lot of other people are killed by gun accidents. In many cases a small child (under 6) gets hold of an unsecured gun and kills himself or another small child. Lots of other people (teenagers, adults who should know better, "responsible" gun owners) get to fooling around with a gun and it goes off "by accident" and someone is killed or severely wounded.
Responsible gun owners should know this and act accordingly.
Finally, here is some good safety advice from various experts I have seen -
*** Always assume a gun is loaded even if you "know" it is not.
*** Never point a gun at a person unless you really intend to shoot them.
*** Keep your finger well away from the trigger (outside the trigger guard and extended along the side of the gun works well) unless you are about to shoot your gun.
*** Always make sure a gun is accessible only to those who should have access to it. That means lock guns up when there are children, strangers, people with mental problems, and especially if there are people who are drunk, angry, or both, around. If it is physically possible for any of these kinds of people to be around then behave at all times as if they actually are around.
And, of course, the best way to make sure this advice is followed is to have no guns around and stay away from people who do (or even might) have guns around.
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