Standing on the Shoulders of Predecessors

It's often said that, in science, one advance is built on another. In technology or inventions, it's also true that one advance depends on one or more prior inventions.

Movies, for example, were built on the previous invention of photography, but with the new addition of the idea that, if you took a series of photographs and showed them in rapid sequence, you could produce the illusion of motion. So the camera (and film) had to exist, and then what was new was the idea of a camera that could take rapid, sequential photos—and a machine (projector) to show the movies. And that of course also needed a light source, and it was not Edison's incandescent light bulb that was used but an arc lamp, which was brighter. (A similar arc lamp was used to light the movie sets.)

Television, of course, drew upon several prior inventions. First there was the concept of creating a "moving picture" by breaking a scene down into a succession of still frames projected and viewed in rapid sequence—as in the movies.

Also there was the idea of wireless transmission, from radio; and the idea of the camera. Plus, the cathode ray tube, which had been invented several decades earlier, and the notion of creating an image on the screen of that tube by building it up with a sequence of lines which in turn were made up of dots.

Plus, again, the camera. But this time the camera had to create an image that was broken down into lines and dots—the reverse of how the TV image was created on the TV receiver's screen.

And now the television set using a cathode ray tube is pretty much obsolete because the TV sets using LCD and plasma displays (which evidently have come to be called "flat-screen" TV sets) are actually cheaper to make.

Copyright © 2012 by Richard Stein