How does something physical, like a CPU or stick of RAM, move and store non-physical things, such as data?

Question

Computer components are made out of raw materials, like silicon and copper. How does something physical like that create and use things we can’t “see”, like data (0s and 1s)?

Thanks!

In: 1

Answer 1

The whole shebang works by having imbalances in electrical charge.

Everything is made of atoms. Atoms have bits which don’t move around much and which have positive charge, called protons. They have other bits which move around quite a lot and which have negative charge, called electrons. An atom which is minding its own business has an equal number of protons and electrons, so it has an equal number of positive and negative charges, so it’s neutral.

But those electrons which move around a lot can actually leave their atoms and go on adventures. The protons which don’t move around much stay put so you have a stable physical structure.

If you convince a bunch of electrons to leave their protons and if you herd the electrons together into one little area, like cattle being herded into a pen, then that little area now has a surplus of electrons, ie a surplus of negative charge. Meanwhile of course, the place the elctrons came from has a shortage of electrons, so its protons outnumber the electrons and it has a surplus of positive charge.

That imbalance of electrical charge – a surplus of electrons in one place and a deficit of electrons somewhere else – that’s what we use to represent the zeroes and ones.

And just like the cattle analogy, once we herd the electrons into one area we can close the gate and keep them there. Or we can open another gate and move them somewhere else. The paths they need are tiny, and we can move then around and open or close gates very quickly, and that’s exactly what’s going on in your computer or your phone or your games console.

A structured group of electron surpluses can represent a number. Moving structured groups of surplus electrons around is how we store, retrieve and manipulate numbers. We use numbers to represent the colours in a pixel in an image, or the loudness of a timeslice in an audio file, or the characters in the text of a Reddit question.