How many switches do you have in your house? The light switches come to mind - at least one per room, a few extra for the hallway and the outside, so maybe a dozen or two. Add your other electric devices - desk lamps, microwave, hair dryer, television, you get the idea. Add all those switches up, and - unless your are an electrical engineer or live in a huge house - I’d guess you’d be around a hundred.
However, we are still missing a lot of switches. And I am talking, of course, about the Transistors that make up the processors and other integrated circuits in your phones and computers.
On a very basic level, a transistor works as an electronic switch: By applying a current, we open or close a circuit. In reality, it is a bit more than that, since a transistor can also work as an amplifier. But still, all things considered, it kinda works like a switch. And combining all these switches within an integrated circuit such as a CPU physically enables computation.
I like to say that computers really are glorified abacuses: They basically just add and subtract numbers, but they can do it really, really fast. I am simplifying this quite a lot, but at the core of each processor is a really simple Instruction set, which is mostly used to execute mathematical calculations.
Well, where do the switches come in?
Computers uses binary numbers to represent data. This is done for technical reasons: A circuit can either be closed, or open - on, or off. So it makes sense to utilize the binary system with the numbers 1 and 0 to map to the underlying mechanism. And now we can do math with these switches. Somebody made a Marble adding machine which shows how the concept works.
This marble machine has six switches and can add numbers up to 63. A modern CPU is capable of much more than that; hence, it has a staggering amount of transistors. I am writing this on a not quite current tablet. The CPU contains 3.3 billion transistors. 3,300,000,000 tiny switches. And this is in a small handheld device.
Globally, it is thought that about thirteen billion trillion have been made so far. That’s 13,000,000,000,000,000,000,000 tiny switches. And even though Moore’s law of doubling the transistor count on a given chip area will probably reach it’s limits soon, the amount of transistors made will continue to rise - after all, we can just make the chips larger!
Modern computers are near silent, which is a blessing. But sometimes I wonder how it would sound to hear all those the tiny clickety-clack of all those happily calculating tiny switches.