#Little disc with picture movie
#Little disc with picture portable

Talk about it very briefly, further down this page).īut, in very simple terms, the sampled data is essentially the information stored on your CD. There's another bit of processing that goes on after sampling (technically, known as modulation-I'll Lasting several minutes into a string of millions of zeros and ones. The measurement into a number, and stores it in binary format (as a To be exact), a piece of electronic equipment measures the sound, turns In a CD, music (or otherĪfter the music has been recorded, it is converted into numbers by a These are calledĪnalog technologies, because the sound is stored as aĬontinuously varying pattern (of bumps in the plastic of a record or fluctuations in LP records stored music as bumps on the surface of plastic, whileĬassettes stored it using patterns of magnetism. It's much more complex than I'm going to make it seem,Īnd it's beyond the scope of an introductory article like this, but I willīriefly describe what really happens at the very end. Note: In the explanations that follow, I'm deliberately going to simplify howĬDs store music as patterns of zeros and ones.

#Little disc with picture movie

Move its laser quickly to any part of the disc, so you can instantlyįlip from track to track or from one part of a movie to another. Another advantage is that the CD player can The laser beam bounces harmlessly off the surface of the CD, so the disc itself should (in Thing that touches the CD is a beam of light: Tape being played, which gradually wore out. One of the main problems with LPs andĬassettes was the physical contact between the player and the record or They use flashing laser lights to record and read back information from CD players are neither mechanical nor magnetic but optical: With the invention of CDs, people finally had a more reliable way ofĬollecting music. This disc will eventually become unplayable. Photo: A close-up of the rot on the bronzed edge of a CD, where the metal has started to disintegrate and fall away. Often the last track, which is nearest the exposed edge of a compact disc, is affected first. Some rotten CDs slowly turn brown (a problem known as 'bronzing') in others, bits of the reflective surface pit or disappear, eventually making them unplayable. Photo: Great music, rotten CD! CDs were billed as virtually indestructible, but some early ones have fallen victim to a problem called disc rot, The sounds that fizzed and popped in your headphones. The electromagnet detected the pattern of When you put a cassette into your Walkman, a small electric motor dragged the tape (used in such things as the original Sony Walkmans) worked a different way. The bumps in the plastic into sounds you could hear. Technology for recording and playing back sound: the moving arm turned Record players (or gramophones, as they were sometimes known) used mechanical LPs were played on turntables with a moving arm that bouncedĪlong a groove in the plastic, reading back the music as it went. Both of these ways of storing music were primitive compared Tapes could stretch and distort and sometimes snapped or seized upĮntirely. (long-playing) records and cassette tapes. Until CDs were invented, music was typically stored on vinyl (plastic) LP Read more about this in our main article on MP3 players. Gadgets like this have now largely been superseded by MP3 players such as iPods, which are much smaller and lighter and pack lots more music into the same space by compressing it digitally.

#Little disc with picture portable

Photo: A small portable compact disc player made by Technics. Off the disc and read the information stored on it. It's shiny so that a laser beam can bounce Telling you what's on the CD the shiny side is the important part. The first thing you notice about a CD is that it is Is a protective layer of plastic and lacquer. Sandwiched in the middle there is a thin layer ofĪluminum. Most of a CD is made from a tough, brittle plastic called Plastic about 12cm (just over 4.5 inches) in diameter. A compact disc is a thin, circular disc of metal and