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tdscanuck t1_j9v2gfj wrote

Yes, trinary systems exist.

We use binary for computing because it’s really easy to map the state of electrical switches (on, off) to binary digits.

Going trinary, or higher, means you can’t use switches. The math all still works fine but the hardware becomes far more complex. And, since you can emulate any system with any other, and binary is far easier to build, we stick with binary.

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talaron t1_j9vcl66 wrote

Good explanation. One could add that in theory you can have as many levels as you want, but since electrical signals (as basically all signals) aren't exact, the on/off system makes it very easy and quick to filter out noise.

There isn't really a point in using a specific number of levels, like 3 or 4, simply because it isn't very efficient in practice, but if you use the raw signal directly with "all the levels", you end up with an analog signal. As long as you can live with some noise (e.g. for storing audio/video, where you wouldn't hear/see tiny differences), analog signals are a very efficient way to store and transmit data, but unlike digital ones they are likely to degrade over time (or distance, if we talk something like radio waves). Like, a video tape might lose its magnetism over time and become noisy, while a DVD always works perfectly until it is so damaged/scratched up that it can't be read at all anymore.

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Oclure t1_j9vn6d5 wrote

I'd also add that while we can signify binary with high and low voltages the same doesn't work as well for trinary as you would need a mid voltage.

One likley issue here is that while it may seem like electrical states change instantly they actualy take a tiny amount of time as voltage drains from a high representing a 1 to a low representing a 0. Now add a mid voltage between 1 and 0 and the voltage has to actualy pass this mid state on its way from a 1 to a 0 meaning that if you read the systems state at the wrong time you could easily mistake a voltage in transition for one that's intended to be this mid voltage. . This is actualy a common issue with overclocking as the clock rate outruns the ability for the voltage states to change, however in the case of a binary system it's possible to stabilize the system again with a bit of overvolting at the expense of producing more heat.

So unfortunately, using our traditional system of representing two states becomes a lot less stable when adding a third state, and making a stable system that can represent trinary would likely add a lot of complexity.

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