This post is the next in a series that dates back several years. In fact, it's been going on for long enough that several posts ago I decided to upgrade from "50 Years of Science" to "60 Years of Science". And, if we group them together, this is the twentieth main entry in the series. You can go to https://sigma5.blogspot.com/2017/04/50-years-of-science-links.html for a post that contains links to all of the entries in the series. I will update that post to include a link to this entry as soon as I have posted it.
I take Isaac Asimov's book "The Intelligent Man's Guide to the Physical Sciences" as my baseline for the state of science when he wrote the book (1959 - 60). In this post I will review two sections. "Internal-combustion Engines" and "Radio" are both from the chapter titled "The Machine".
In "Internal-combustion Engines" Asimov starts out with an observation. Electricity displaced petroleum when it came to illumination. He doesn't mention it but the modern Oil industry started out by producing kerosene to fuel lamps. Lamps could produce much more ight than candles could. Before kerosene, however, "lamp oil" consisted of several different flammable liquids.
A common one was rendered from Whale blubber. Other sources were similarly expensive and difficult to procure in large volumes. Kerosene revolutionized all this. Once the Oil drilling, refining, and transportation infrastructure got built up, kerosene lamps quickly displaced candles. They also displaced other forms of lamp oil and made it possible for the first time for people of modest means to illuminate their homes after the sun went down. The famous Rockefeller "Standard Oil Monopoly" was a kerosene monopoly, not a gasoline monopoly.
Electricity eventually displaced the kerosene lamp. It also displaced synthetic natural gas, which was becoming available in medium to large cities at about the same time Edison invented a practical electric light bulb. Seattle, the city I live in, has a long since shut down the "gas works" facility that produced synthetic natural gas (and large amounts of very toxic pollution) for decades.
Returning to Asimov, he notes that with transportation the change went the other way. There, petroleum displaced the alternatives rather than the other way around. Internal-combustion engines are the ideal match for petroleum. The earliest internal-combustion engines, however, predate petroleum's wide availability. Designs dating back to the beginning of the nineteenth century used turpentine vapors (a plant based product) or Hydrogen for fuel.
Otto, built the first "four-cycle" engine in 1876. Then, as now, the first or "intake" cycle consists of pulling fuel and oxygen into the "cylinder", a cylindrical enclosed space, by means of a movable wall called the "piston". During the "compression" cycle the piston is used to compress the fuel-air mixture. The fuel then ignites to push the piston back down in the "stroke" cycle. The final cycle "exhausts" the burned fuel/air by pushing it out of the cylinder. The engine is now set up to do it all over again.
The up-and-down motion of the piston can be turned into rotary motion by the addition of the proper linkage and a "fly wheel" to even things out. This is the basic design of the "one cylinder" internal-combustion engine. It can be adapted to the "diesel" design (the fuel ignites on its own) or the design commonly used in gasoline engines where a "spark plug" is added to ignite the fuel at the right time.
Clerk almost immediately figured out that multiple cylinders, ganged together and organized so that each cylinder fired at a convenient time, would smooth things out. Remember that only one of the four cycles produces any power. Engines where the number of cylinders is a multiple of four are the easiest ones to optimize. 6 cylinder engines quickly became common, however, as engineers were soon able to come up with designs that worked surprisingly well. In fact, any number of cylinders can be made to work if you are clever enough.
It took a while to figure out how to force the explosion at the right time. But by 1823 electricity based designs became common. A "storage battery" (see earlier posts for the details) could provide sufficient power. The now common "lead - acid" design, still used for modern car batteries, was invented by Plate in 1859. An "Induction coil", actually a specialized type of transformer (again, see earlier posts for details), boosted the modest amount of electric power needed to get the job done to a high voltage.
It is easy to make a spark when you have even a small amount of high voltage electricity available. Spark plugs are sophisticated devices because they have to handle high voltages while simultaneously standing up in the harsh conditions produced when the fuel ignites inside the cylinder.
Once such an engine is running it will continue to run as long as fuel and air continue to be supplied to it. But it doesn't "start", make the transition from not running to running, without help. The first method employed to provide the necessary the initial impetus was to utilize the muscles of the operator.
Initially, a simple crank was provided to "turn the engine over". If turned over vigorously enough the engine would take over and keep running on its own. At the time the book came out, lawnmowers, outboard motors, and many other devices that incorporated small internal-combustion engines, relied on this "hand cranking" technique. Now, they rarely do.
"Self starters", specialized electric motors powered by the same storage battery that was used to power the spark plugs, were soon invented but Asimov does not give a date. Automobiles that came with a self starter as standard equipment became ubiquitous by the '30s. The incorporation of a self starter has now spread to pretty much everywhere internal-combustion engines can be found. The devices I listed above now usually come with a self starter as standard equipment. The only exception I am familiar with is the chain saw.
In the case of cars, the whole "start your engine" process has now evolved to the point where it is now completely computer controlled. You can't "hand crank" a car. You can't even start one by manually operating the self starter. With any make or model of new car, the driver pushes the Start/Stop button and the computer does the rest. With hybrid cars the computer starts and stops the internal-combustion engine whenever it decides that action is appropriate. It doesn't even consult the driver, let alone cede any control over any part of the process or its timing.
Widening our focus from the engine to the whole vehicle, Asimov notes that Daimler built the first practical "horseless carriage" in 1835. But, to catch on, they had to be cheap. And that required developing the capability to do "mass production", produce a large number of essentially identical devices inexpensively.
Whitney was the first person to figure out how to do this. He is known primarily for his invention of the "cotton gin". In this case "gin" was short for engine. And at the time "engine" meant any complex mechanical device. Whitney's "gin" was capable of inexpensively removing foreign matter like non-cotton parts of the cotton plant, from freshly picked cotton so that it could then be turned into thread. The hand process the "gin" replaced was slow and, therefore, expensive.
Asimov correctly observes that, significant though this invention was, working out what was necessary to move to mass productions was far more important. The device Whitney cut his mass production teeth on was the musket.
Up to this time muskets were hand made one at a time by gunsmiths. That meant that, if a part needed to be replaced, then the replacement part had to be hand made to fit that specific musket. And muskets of the time frequently needed parts replaced.
Whitney hit on the idea of "interchangeable parts". Make all the muskets in such a way that all the parts of each musket were essentially identical. That would mean that the replacement for a part that had broken could be gotten by cannibalizing that part from another musket, one on which a different part had broken.
Alternatively, the quartermaster could stock a modest number of spare parts. As long as he had a few of each part the musket used on hand, any broken musket could be quickly repaired. Before interchangeable parts, he would have had to keep a duplicate of each musket in the unit in stock in order to guarantee that he had all the replacement parts that might be needed.
It turned out that parts needed to be manufactured to a very high precision. Whitney figured out how to do that. He also solved a myriad of other problems. The U. S. Army was the first army to be supplied with muskets made from interchangeable parts. The idea quickly caught on with other armies and later spread elsewhere.
Asimov skips over Benz, the first to mass produce cars. But a Benz car of the period was quite expensive. Ford was the first to successfully mass produce cars. This required figuring out how to make a car out of interchangeable parts. It also required figuring out how to do other things.
Ford and his crew eventually figured it all out but not the first time he tried. He built his first car in 1892. But it took him several tries to successfully produce a high quality, low cost car that could be mass produced using interchangeable parts. He finally succeeded in 1909 with the "Model T".
He kept introducing successive innovations, all designed to drive down costs and drive up production rates. He introduced the idea of specialization, a worker would perform only one small step in the overall process. He introduced the "moving assembly line" so that a worker did not have to waste time by moving around. He introduced "jigs", customized tools that made it quicker and easier for a specific task to be performed.
By the '20s he was able to sell a Model T for less than $300 and still make a profit. At that price point a car became cheaper to own and operate than a horse. Others, in the auto industry and elsewhere, quickly followed suit.
Meanwhile, in 1892 Diesel introduced changes to the internal-combustion engine that made it simpler, which made it cheaper to make, and so that it could use a less expensive fuel, what we now call Diesel fuel.
There are disadvantages to the Diesel design. But the durability and economy of using Diesel engine in heavy duty applications has made it the preferred option for commercial vehicles. That was true when Asimov wrote the book. It is still true today.
The internal-combustion engine made heavier than air aircraft practical. The first step was to understand how to fly. The "glider" an unpowered craft was the first step. The early pioneer in this area was Lilienthal. But he died in a crash in 1896. The next person to take up the mantle of the scientific investigation of flight was Langley, for a long time the head of the Smithsonian Museum.
Langley was the first to try to extend what he learned from his glider work to the development of a powered airplane. He failed in spite of receiving substantial funding and support. We all know that the Wright brothers succeeded where Langley failed. Asimov opines that Langley might have succeeded had he gotten additional funding. But the Wrights found that some of his data was wrong.
Problems trying to use Langley's data eventually led the Wrights to redo much of his work. Along the way they invented the wind tunnel and used it in various ingenious ways to advance the state of art in the area of aeronautical engineering. One of the things this research turned up was the inadequacy of current internal-combustion engines. Their power-to-weight ratio was inadequate. So they designed and constructed their own engine which had a better power to weight ratio.
They also investigated how an airplane could be controlled. The "Wright Flyer", the airplane that flew on December 17, 1903, was very difficult to fly. Over subsequent years they developed many improvements that made later designs much easier to fly and maneuver.
All this was substantially in advance of what Langley had been able to achieve. It turned out that he had been much farther from success than most people, then and now, assumed. Frankly, the Wrights were much better scientists than Langley was. And they were able to make their many scientific advances on a shoestring budget.
Others, but not Langley, were able to build on the work of the Wright brothers. Curtis, a man with a motorcycle background, was able to build much better engines than the Wrights, for instance. The Wrights were at the forefront of the design of control systems for airplanes until about 1910 but after than others surpassed their best efforts.
Part of the reason for this was that the Wrights held what they knew closely and were unwilling to cooperate with other people. Their paranoia was justified to a considerable extent. Curtis, for instance, was one of many who built on the work of the Wright brothers but did not want to pay them for the privilege. But, in the end, this paranoia was one reason others were eventually able to surpass them.
The biggest impetus to the improvement of aircraft design, however, was World War I. Governments quickly figured out that better airplanes were critical to their War efforts and threw previously unimaginable sums of money around. As a result, the airplane of 1919 was quite different from the airplane of five years earlier, at least in Europe.
America's late entry into the War sidelined American airplane companies, including the Wright's company, during this critical period. That left them far behind their European counterparts. In spite of its wartime success, the airplane was generally seen as the stuff of daydreams, or a military tool, or a toy for the idle rich. That all changed when Lindbergh flew from New York to France in 1927.
The Atlantic has already been successfully crossed when he made his flight. But Lindberg's flight was what caused caused ordinary people to think differently about flying. This change in attitude enabled the introduction of airlines and scheduled commercial flights. But it was still seen as the plaything of the rich and famous.
The innovation that eventually changed this was another wartime innovation. During World War II the Germans were the first to develop a practical "jet" engine. (The first "jet" engine was created in 1913 by Lorin but it was not practical to use it for anything.) The jet powered ME-262 fighter could literally fly rings around anything else in the sky. But the Germans were unable to produce enough of them to effect the outcome of the War.
Experimentation leading to innovation resulted in rapid improvements. At the time of Asimov's book this had not translated into any significant penetration by jets of the market for commercial airlines. The "queen of the skies" at the time of the book was an airliner that featured four propellers driven by piston engines. Planes of this type were being manufactured by several different companies.
The first serious effort at a commercial jet powered airliner was the DE Haviland Comet. The jet engines worked fine but the plane had a design flaw that caused it to literally crack open and fall from the sky.
In a bit of bad luck for DE Haviland, the first few crashes happened over deep water and the aircraft could not be recovered and examined. So people knew the planes were crashing but not why. Eventually a crashed plane was recovered and examined, and the flaw quickly identified. But by then it was too late for DE Haviland and the Comet.
The company to first successfully crack the jet airliner puzzle was Boeing with its 707. In an early public demonstration Boeing's chief test pilot put the plane though a complete barrel roll in front of 50,000 witnesses.
The maneuver was NOT authorized by senior management but quickly became the stuff of legend. It convinced the public and airline executives that the plane was safe and sturdy. In the wake of the Comet fiasco winning over both groups was critically important to the success of the plane. And it was very successful.
Jet engines are simple. That makes them reliable and easy to maintain. Both keep costs down. The engine is also much more fuel efficient than a piston driven propeller plane. The jet allowed the airline industry to introduce the era of cheap air fares. And, like the Model T, that put flying, either for business or pleasure, within the price range of average people and cost conscious companies.
Since the introduction of the 707 much has changed and much has stayed the same. Current generation jet powered airliners fly at about the same speed the 707 flew. (The Concorde flew much faster, at supersonic speed, but was never a commercial success.)
Jet engine design has evolved to substantially improve their efficiency. Raising the operating temperature (see previous posts for details) increases efficiency. "High bypass" designs have also improved efficiency in ways I admit to not really understanding.
A modern jet also looks very similar to a 707, a design that is now 60 years old. The most obvious change is to add "winglets" to the tips of the wings. These change the way air flows over the wings in ways that I again don't understand. But again, they work.
The other change is in materials. The main material used to make the 707 was aluminum. "Carbon fiber" is slowly displacing aluminum as the material of choice . It has a better strength to weight ratio and that keeps the overall weight of the plane down. A lighter plane is a cheaper plane to operate.
Carbon fiber, however, is the material of the future, not the present. Eventually it will be the main material used to construct commercial airplanes. But right now most commercial airplanes currently in production use far more aluminum than carbon fiber. Only a few reverse the ratio. On to "Radio".
Asimov starts the chapter off with Hertz. In 1888 he proved the existence of radio waves by transmitting a signal from one place to another and successfully detecting it. The distance involved was modest and the equipment was extremely primitive. But it proved that the equations Maxwell had published twenty years earlier described a real phenomenon.
Hertz was able to go beyond simple detection. He was able to determine some of the characteristics of what we now call "radio waves". (For a time they were called "Hertzian waves" for obvious reasons.) He was able to determine that whatever it was had peaks and troughs like waves. He could also measure the wavelength. It turned out to be far larger than the wavelength of light.
In 1890 Branley used improved apparatus to transmit information over a distance of 150 yards. Lodge was able to make more improvements. He succeeded in transmitting Morse code using radio waves.
Marconi made further improvements and succeeded in transmitting Morse code. First, he managed 9 miles in 1896. He successfully sent a signal across the English Channel two years later. Finally, he was able to transmit a message, which I believe consisted of a single letter, across the Atlantic in 1901. All this explains why the British call it "wireless telegraphy". They also call a radio receiver a "wireless".
Marconi was the first to work out how to confine a radio signal to a narrowly constrained "frequency". (He got a Nobel in 1909 for this work.) If you know the frequency, you can calculate the wavelength, and vice versa. For historical reasons some parts of the world use "frequency" and other parts of the world use "wavelength" to denote the same thing, namely the place in the spectrum a particular signal resides. Wavelength, the term generally preferred by scientists, is very slowly winning out over frequency.
Fessenden developed the equipment necessary to generate what we now call an AM (Amplitude Modulation) signal. The signal is transmitted on a single fixed frequency and its amplitude, loudness, is modulated. He used this equipment to broadcast both words and music on Christmas Eve in 1906. This marked the first recognizably modern radio broadcast.
Asimov then goes on to describe the internal workings of "vacuum tubes". Vacuum tubes were ubiquitous at the time of the book's publication. They are now restricted to a few specialty uses. They have generally been supplanted by various "solid state" technologies. I am going to skip all this, other than to note that these developments were critical to making radio practical in those early days.
One critical capability vacuum tubes enabled was "amplification", making a weak signal louder without changing its other attributes. Amplification is obviously important if you want to create a strong signal suitable for broadcast. It is also critical for raising the extremely low level of the signal an antenna placed at a distance from the transmitter picks up. It takes a substantial amount of amplification to turn this signal into something useful.
In a similar (but harder to explain) manner, vacuum tubes could be used to perform all of the other steps necessary to take the output of a phonograph, for instance, prepare it for broadcast by an AM radio station, and then broadcast it.
On the receiving end, the signal originating from a single radio station needs to be selected while the signals from all the other radio stations are rejected. The "radio frequency" part of the signal must then be stripped off and the result amplified enough to be able to drive a speaker at sufficient intensity that we can clearly and easily hear and enjoy whatever is on the record the radio station is playing.
In the early days, pretty much all radios used AM. It make the fewest demands in terms of the complexity and sophistication of the circuitry necessary to handle it. That kept equipment simple and costs manageable. The first widespread use of radio was by the various navies of the world during World War I. For the first time in naval history it was possible to communicate with a ship at sea in real time.
At the time the equipment was expensive to make and difficult to use. Only naval vessels could afford it. But technology marches on. Easy to use and relatively inexpensive equipment became available in the late '20s. By the mid-30s costs had dropped enough that equipment was cheap enough that even depression ravaged households could afford it.
The very popularity of radio soon exposed a weakness of AM radio. It was not that good at providing a solid, noise free signal in many circumstances. This led to the development of FM (Frequency Modulation). With FM, signal strength stays constant. The frequency the signal is broadcast on is varied instead.
This provided a much more robust method but it also required substantially more complex equipment. That made the equipment more expensive and put it out of range for the average consumer. It was not very popular at the time Asimov wrote the book.
That changed in the following decade. FM equipment got better and the price dropped. FM was able to provide a much clearer and realistic sound. It was also quickly adapted so that shows could be broadcast in stereo.
At first it was only used by symphonies and other "high brow" entertainment where the better signal quality was important. But aficionados soon found that rock and roll and other "low brow" music also sounded much better on FM that it did on AM.
Soon, all forms of popular entertainment migrated to FM and AM became a wasteland. This resulted in "talk radio", where good sound quality was not very important but low operating costs were, to take over the AM band.
The advent of the Internet drove still another revolution. Now many people never listen to the radio. Everything that was available there is now available on the Internet and/or your smartphone. Radio, both AM and FM, is still out there but nobody pays much attention to it.
After briefly mentioning FM Asimov moves on to television. He notes that the first step was the "wire photo". This was a technology that was used to transmit a picture from London to Paris in 1907.
A still picture was scanned line by line. The variation in light and darkness underneath each line was transmitted over a telephone line or via radio. On the other end a matching device would draw a line of varying intensity on a piece of photographic film. When the result wad developed and printed it yielded something resembling the original picture.
The process was slow and expensive. It might take a minute or two to transmit a single picture. Initially it was used only by newspapers and law enforcement. It was too inconvenient for anybody else to bother with. But the process contained all the ideas necessary to do television. It just needed to be speeded up by orders of magnitude. And, of course, the cost needed to drop by orders of magnitude too.
The sound part of the process was essentially radio so it presented no new challenges. It was the picture part that represented the challenge. The the toughest "picture" component that needed to be developed was the television camera. Zworykin patented an "iconoscope" that got the job done in 1938.
Since it is a fancy vacuum tube I am going to skip over the details of how it worked. But it was able to duplicate the "scan a picture a line at a time" process discussed above. And it could scan a complete picture in a small fraction of a second. It worked fast enough to be "moving pictures" compatible.
The television equivalent of the radio receiver already existed. It was, you guessed it, another kind of vacuum tube. As with the TV camera, it was capable of building up a compete picture from a series of lines in a small fraction of a second.
The "picture tube" had a relatively flat front face with a phosphorescent coating on the back of it. Hit with the appropriate stuff, lines would glow at varying intensities resulting in the picture being reproduced.
Lots of other equipment was necessary to connect all of it together. But RCA, then a giant electronics company, now an infrequently used brand name, was able to demonstrate a complete end to end system at the 1939 Worlds Fair in New York City. World War II diverted all high quality radio equipment to the War effort. TV equipment definitely fell into that category.
But commercial TV broadcasting started up shortly after the War. At the time TV was only capable of broadcasting in black and white. Asimov make reference to the advent of color TV in the mid '50s. But what was then available was more of a proof of concept than actual reality. Color TV actually took off in a noticeable way in the mid-'60s. And all of this was in what we would now call low-fi - low fidelity.
The TV pictures of the time, initially in black and white, later in color, were good enough to be usable. You could see what was being shown. But the picture was not very sharp and the colors were not very well defined. That was the limit of the equipment of the time.
We now talk of pixels and lines of resolution. A first generation "IBM PC" home computer used a custom "display" that supported a screen resolution of 640x480. This meant that the picture it displayed consisted of 480 lines, each of which had 640 pixels (separate dots of picture information) in it. Theoretically, TV did better. It featured 525 lines. But this was a cheat. The scan lines were "interleaved".
In one scan only the even lines were processed. In the next scan only the odd lines were processed. So each individual TV picture only had about 260 lines in it. The "aspect ratio" was 4:3. The picture was 4 units wide and three units high. If we apply this same 4:3 ratio we get a line with about 350 pixels per line. So think of a TV picture from this era as having a resolution of 350x260 and you get a more accurate idea of the true situation.
As a cross check, if we take 480 and multiply it by four then divide it by three we get 640. So a 640x480 picture has the same 4:3 aspect ratio. And this was by design. PC makers wanted to reproduce what consumers were seeing when they looked at their TV.
Some early home computers did not require a custom made "display". They could be hooked up to a standard, cheap, black and white TV set. But the screens on these computers were not able to reproduce the 640x480 resolution the first generation IBM PC was capable of.
Of course, IBM made you buy a special display device that could handle a resolution of 640x480. And I can tell you from personal experience that they cost significantly more than a black and white TV of similar size. On the other hand, the display device connected to my IBM PC could easily show me 25 lines of text, each consisting of 80 characters. On the other hand, the TV connected to the home computer could only display 40 characters on a line. And the line count was significantly lower too.
A resolution of 640x480 represented the state of the art back then. Things have gotten a lot better since. Current PCs usually sport a screen resolution of 1080x1920. If we do the appropriate math we find that the aspect ratio is 16:9. That's the aspect ratio used by the HD (high definition) TV specification. A side by side comparison of an actual TV from the '50s or early '60s with a modern screen would bear out the fact that we are comparing aa resolution of 350x260 to a resolution of 1920x1080. We've come a long way, baby!
Asimov then goes on to discuss videotape. This is an extension of the audio tape that was discussed in earlier posts. The idea is the same. We just need to improve things enough so that video tape can handle the information load TV puts on it. At the time the book came out professional video tape machines were available for use by networks and TV stations. Over time this changed. The video tape cassette and VCR (Video Cassette Recorder) were introduced.
In their time they represented a massive change. When Asimov wrote his book you could go to a movie theater, buy a ticket, and watch what was showing on the schedule the theater operator chose. Or you could turn your home TV on and watch what one of the three or four TV stations then operating in your area was showing. And you had to watch it on the schedule the station manager chose..
The idea of saying "I want to watch move X and I want to watch it now" was literally an impossibility. The video cassette and the VCR changed all that. Once you owned a VCR you could buy cassettes preloaded with a specific movie. You could take it home and watch it any time you wanted to. And you could watch it as many times as you wanted to without having to pay any additional money. And, unlike TV, it was commercial free.
But wait! There's more. You could also record a show off of TV then watch it at a later time. This is what we now call "time shifting". And you could re-watch it as many times as you wanted. But wait! There's still more. Stores opened up that would rent you a video for a couple of bucks. Let's face it. Most shows and movies are only worth a single viewing. The rental was usually only good for a day or two. But you could rent and watch any video the store had in stock. And a typical store stocked many thousands of titles.
This put the consumer in charge for the first time. They had much more freedom to watch what they wanted when they wanted. Consumers were no longer chained to the schedule dictated by nearby movie theaters or TV stations, be they local or cable. This change truly represented a revolution.
But wait! There's porn. Up to this period of time it was hard to make real money in the porn business. All the access channels were successfully blocked by various religious and other organizations. Most people's idea of "the worst of the worst" at the time was Playboy magazine. Then things opened up a little and seedy theaters in medium to large cities started showing porno movies. The money wasn't that good but it was much better than what had come before. Video tape and the VCR changed all that.
The porn companies quickly shifted to releasing their product on video cassettes. And the public snapped it up. All of a sudden there was big money in porn. Video tape rental stores quickly figured this out and added "porn" sections. It was not long before they were making half their revenue from porn. It turned out that there had been a giant untapped market for porn.
The big problem with VCRs and video cassettes was that their picture quality was terrible. In many cases it was poorer than broadcast TV. That didn't matter in the early days. The fact that people could now watch what they wanted when they wanted was such a powerful force that people forgave the poor picture quality.
Then DVDs came along. I am not going to dive into how the technology works. For our purposes I am just going to note that DVDs delivered much better picture and sound quality. The era of the high end TV system was born. At first people thought that the fact that you couldn't record your own DVD (you can now but you couldn't then) would be a deal breaker. But it turned out that most people found the process of recording things more trouble than it was worth.
It turned out that people were mostly interested in buying and renting and not much into recording stuff themselves. So the "direct to consumer" movie (and porn and everything else - by now you could buy or rent boxed sets of old TV shows) business continued to grow.
Everybody quickly switched from cassettes to DVDs. The rental stores started with small DVD sections tucked into a corner. Over the course of a few years they shifted to having large DVD sections. It was the video cassette section that ended up tucked into a corner. But that did not change the business in a significant way.
What did drive a big change was the Internet. At first it did not affect video. It was too slow to handle it. But that changed. The speed of my first computer connection to the outside world was measured in hundreds of bits per second. It quickly changed to thousands of bits per second then tens of thousands of bits per second.
The speed of my first "high speed" internet connection was measured in millions of bits per second. At that point decent quality streaming video becomes possible. I have had a one gigabit (billion bit) per second connection for a little more than a year now. I may be foolish but I believe that will be as fast as I will ever need.
The widespread availability of high speed Internet has again revolutionized things. If it's instantly available online why bother to own it or even rent it from a store? Netflix and its competitors have turned us from people who buy or rent DVDs to people who stream from Netflix.
Again, in a certain sense, we have gone backwards. If I own a DVD I can watch it forever whenever I want. But many of the movies and TV shows on Netflix come and go. They may be available for a couple of years but after that, they are gone. Netflix may license them again at a later dare. And then again, they may not.
But it turns out that if Netflix has something I want to watch now it doesn't matter to me (speaking as a typical customer) that they don't have exactly what I want. Movie studios, and keep in mind they make most TV shows too, used to make good money from selling DVDs. They even made good money providing rental stores with product.
But not any more. There used to be tens of thousands of rental stores. Now, only a few remain. Some people still buy the odd movie or boxed set of a TV show. But that market has also dropped away to almost nothing.
Streaming is booming. In fact, it has gotten completely out of hand. It used to be that you could count streaming services on the fingers of one hand. Now there are so many of them you can hardly keep track. And this has resulted in a fragmentation of content. This service has a few shows you might be interested in but most shows are on another streaming service.
If you want to have access to it all you have to subscribe to perhaps twenty services. And that will still leave gaps in what you have access to. And even if you sign up to lots of streaming services, something that costs lots of money, it is a complete PITA to keep track of which show is in what streaming service.
My best guess is that a lot of these services will go under. They are all counting on other services going under leaving the field open for them to survive and thrive. In reality, nobody knows how it is going to all shake out.
Back to Asimov. He then tackles solid state electronics. He goes into some detail about how transistors work. His explanation is based on Germanium. At the time Germanium seemed like the best material to make transistors out of. But Silicon eventually won out as the material of choice. (There are technical differences between Silicon and Germanium transistors. But they aren't worth getting into.)
The book was written during the "discrete transistor" era, an era that ended up not lasting very long. Asimov discusses how this type of vacuum tube can be replaced by that type of transistor. For a while that's basically what happened.
But at the about the time the book was coming out the "integrated circuit" was being invented. It's just a method for simultaneously creating multiple transistors on a single small piece of silicon. Connections between the various transistors can be created as part of the same overall process. And that means that you can skip the later "solder everything together" step.
A few years later, a single LSI (Large Scale Integration) chip might have contained the equivalent a thousand discrete transistors, all hooked together. Now, the equivalent of tens of billions of transistors, complete with connections, are manufactured at once. This is possible because the manufacture of an IC (Integrated Circuit) is essentially a photographic process.
Various "process steps" are needed. But the important steps involved projecting a "mask", essentially the negative of a picture, onto the surface of the IC. The light hitting the surface causes a chemical change to take place wherever the light is bright. Using as many as 40 masks, carefully coating the surface with various chemicals at the right time and in the right sequence, and by taking other steps, a complex pattern consisting of various sub-patterns of materials with various properties is "etched" into the surface or near-surface area of the IC.
There is a pattern for where the "wire" material needs to be. There is a pattern for where the insulator material needs to be. There is a pattern for where each of the various components that go together to make a transistor "gate" need to be. In the end there are many transistors connected by wires and insulated from other transistors and wires laid out on the surface of the IC.
What's important to know is that the cost of manufacturing a specific IC is not dependent on how many "features" there are on the surface of the IC. The cost is in the number and type of "process steps" necessary. If the manufacturing process for two different ICs follows the same recipe then an IC containing a million gates costs the same to make as an IC containing a billion gates.
As the component count goes up and as the "feature size" goes down the cost of building that "fab", the manufacturing facility capable of fabricating a particular family of ICs, might go up. But hopefully you will be able to produce so many ICs using that fab that the cost of the fab itself ends up being a small part of the cost of producing any individual IC.
This "it costs the same to make an IC with a lot of components as it costs to make an IC with many fewer components" characteristic of IC manufacturing is the IC "secret sauce". It explains why the price of IC based electronics doesn't go through the roof. This is in spite of the fact that typically the new gadget contains much more complex ICs. They enable the new model to do things the old model of a few years ago only dreamed of being able to do.
And that's where this particular installment comes to an end.
