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Isn't that just analog computing? Or is it something more fancy?
by trenchgun 6y ago
Isn't that just analog computing? Or is it something more fancy?
- enriquto 6y agoThis is analog computing, and it is really cool. Yet, I guess if it corresponds to a circuit it should be more an ODE than a PDE (unless your "circuit" involves large pieces of surface of non-uniform resistivity).
- 3pt14159 6y agoIt was a true PDE, not an ODE. The circuit was non-trivial, but though I knew PDEs at the time he told the story, I'd never used them on electronics (only heat / pressure flow, and other physical engineering stuff) so I couldn't really understand what he was saying.
- jonah-archive 6y agoYou can definitely do this! Check out Karplus's "Analog Simulation" for examples with conductive fluids and resistance networks: https://archive.org/details/analogsimulation0000karp https://archive.org/details/analogsimulation0000karp
- marcosdumay 6y agoYes. And a numerical calculus software would probably get there faster and with less work.
- jhayward 6y agoand higher precision.
- enriquto 6y agoNumerical solution of PDE is not really a solved problem. If your PDE involves shockwaves or turbulence (which happen for really simple PDEs) then the methods to compute solutions get incredibly fancy. There's no "black box" solution for numerical PDE, as there is for ordinary equations.
- marcosdumay 6y agoIf you can solve with an analog computer, without problems with metastability, oscillations or excessive noise, then you can solve it with numeric calculus too. Those computers have much more strict limitations than digital math.
- 3pt14159 6y agoI should call the guy up sometime and get the details about what they were working. It wasn't a run of the mill analog computer, but who knows how novel it really was.
- klyrs 6y agoYour description covers pretty much every quantum computer ever conceived. How certain are you?
- sudosysgen 6y agoNot sure you can call any of the actual quantum computers we've made "analog", but if you're talking about the quantum annealment machines, they are generally more limited and take longer than an equivalent supercomputing cluster.
- marcosdumay 6y agoHum... Quantum computers tend to be digital, not analog. The word "q-bit" is there for a reason, just because the bits are entangled it doesn't make them analog. Besides, the set of problems you can solve is different from the set of problems you can solve quickly. When discussing analog and digital computers, the speed difference isn't all that relevant, but you seem to be confusing them here. Quantum computers do not solve any problem you can't solve on a classical computer, they just solve some faster.
- sudosysgen 6y agoWell yeah, that's exactly my point. Quantum computers are digital, which is not what the above comment claimed, except for quantum annealers which are closer to analog computers. What I'm saying is that even quantum annealers aren't really faster at any practical problem than a comparable supercalculator as of yet.
- creato 6y agoIt depends on what "back in the day" means. Modern computers are absurdly capable compared to what might have been available to these engineers "back in the day".
- adamnemecek 6y agoIt is. I hope it comes back in the photonic form.