[grondilu]

> Mechanical computers are computers that operate using mechanical components rather than electronic ones.

For anyone who's excited about mechanical computers, perhaps it is worth reminding that an electron is about a thousand times lighter than a nucleon. Therefore, it's probably fair to say that mechanical computers will always be more energy consuming than electronic ones, because they fundamentally need to move atoms around to operate.

[reaperman]

Taking this to its logical extreme, photonic computing should be significantly more efficient than electronic computing. Eventually.

Is that the end-game? Is there anything that would theoretically get closer to the Landauer limit than photonic computing? It’s way out of my element but I suppose this is a good venue to ask the question.

https://en.m.wikipedia.org/wiki/Landauer%27s_principle

[infogulch]

The big problem in photonic computing is actually making an optical transistor, i.e. a switch where the presence of photons coming from one source controls whether of photons coming from another source pass. This is harder than electrical transistors because photons are bosons and don't interact with each other, so even theoretically this is hard to imagine.

Papers that claim some progress pop up every once in a while but I haven't seen anything promising yet.

[gchamonlive]

Maybe not more efficient, but maybe more resilient to electromagnetic storms, not prone to overheating (maybe), etc... Maybe it's about fitting constrained scenarios.

[Terr_]

> but maybe more resilient to electromagnetic storms

If you mean solar flares, that's generally an issue with long transmission lines, as opposed to very small circuits.

[Loughla]

It seems like they may be prone to overheating in some fashion. All that electricity and motion has to cause some kind of thermal load. Or am I way off base?

[vanderZwan]

Wouldn't that all depend on how much energy is used for computing, and how much for fetching and storing the bits involved? If the requirements involve slow computation with extremely long-term storage, perhaps mechanical computing can theoretically have an advantage.

Then again, Chuck Moore's GA144 shows there's still plenty of room when it comes to optimizing electron-based computing for those kind of extreme scenarios as well.

[0] https://www.youtube.com/watch?v=0PclgBd6_Zs

[jes5199]

sure, but how many electrons do we typically move around as a single signal

[dekhn]

Few, if any; instead, it's typically the propagation of an electromagnetic wave that transmits a signal: https://en.wikipedia.org/wiki/Speed_of_electricity