How Your Tiny Little IPod Can Hold so Many Songs

It seems preposterous when you think about it, how all those songs of yours can somehow exist in that tiny little iPod of yours, or on any other player for that matter, but somehow they do. How do they do it?

Your iPod and any other player is made up of several parts, all of which are very tiny; so tiny in fact, that you'd have to use a magnifying glass to get a good look at them. What you'd see is a circuit board with computer chips soldered on; and some tiny wires to hook up the buttons and display screen; and that would be pretty much it.

What you might find surprising is that the parts that hold the songs actually take up very little of the inside of your iPod, the rest is used to run the run the video display, the sound output and the brains to run the make the whole thing work. The songs themselves are held in little memory chips, which are little more than wired silicon. The chips look sort of like robotic centipedes, because they have legs that sprout from a black body that are used to allow the chip to plug into the circuit board. And what you might find even more surprising is, memory chips don't do anything except hold electronic representations of 1s and 0s, which means that everything you hear when you listen to your music is somehow represented in your iPod as nothing but 1s and 0s, or more aptly, as an On, or an Off. The magic is in how engineers have been able to figure out a way to not only make this happen, but to do it in a way that fits on a computer chip.

In nature, sound is actually nothing more than the vibration of air in our ears. Something out there in the world causes the air around us to vibrate at certain frequencies and our brains interpret it as the sound we hear. To make this happen electronically, engineers convert those vibrations to a series of 1s and 0s to represent volume and frequency. And then to first record them as such, and then to play them back to us by sending those signals to a speaker where a membrane is jolted into vibrating at the same frequency as it was originally recorded, making the air vibrate in our ears.

In your iPod, these 1s and 0s are represented as tiny gates, which are either open or closed, which correlate to sending an electronic pulse, or remaining quiet. The key is in having so many of these 1s and 0s so as to represent every sound that can be recreated and then having the brains of your iPod read through them at a very high rate of speed so that you can't hear the small silent spaces between each gate. Sort of like how you can create the effect of animation by drawing on flash cards or running film cells through a camera fast enough to create the illusion of movement.

The key then to making a lot of songs fit on a tiny iPod is to make those memory chips very, very tiny. And they do that by using robots and tiny moulds and etchings to make the little gates so small that you would need a microscope to see them; its advances in these techniques that allow both the processors and the memory chips to hold and run all of those songs in your iPod.