This post is very old but I’ll try answering it as best I can.
“Nonetheless, it is mysterious how physical systems with nothing physical in common can realize the same algorithm.That suggests that the algorithm itself is not a physical thing, but something else. And those something elses have very little to do with the laws of physics.”
An algorithm is basically a step-by-step instruction of computation. First you do this calculation, then you take the result and make another calculation with it and so on until ideally you get some kind of output (be it behavior or a number on your calculator). Based on that understanding I don’t quite see the trouble with performing the same algorithm (sequence of computations) based on wildly different physical systems. The algorithm itself is of course always a physical “thing” as well in a sense, since it must be carried out on matter… you can’t do computation on “nothing”, in computers it’s electrons being herded through “gates” on microchips and in a brain it’s electrical impulses in neurons being carried along the dendrites towards the nucleus which can act as a gate and inhibit or pass on the impulse along it’s axon towards other dendrites or nuclei. Of course this is massively oversimplified, but I hope it is obvious how similar computations can be carried out by both.
Granted, a neuron is unimaginably more complex than a gate on a microchip but if you google for the “Blue Brain project” you can see how computers can be used to simulate (or should I rather say emulate?) neurons and ultimately whole neural nets. This would be an instance where (essentially) the same algorithm is implemented aka computed once by neurons and once by microchips.
That something has very little do do with the laws of physics is a statement that couldn’t possibly sound more radical and wrong to the ears of science and rationality. Computation is hardly an area where the laws of physics are insufficient to lend themselves for empiricism. To point out that it is evidently absolutely understood how algorithms can be implemented by physical stuff seems almost ridiculous, given the fact that right now we sit in front of a working computer, that was once invented and built by humans.
This post is very old but I’ll try answering it as best I can.
“Nonetheless, it is mysterious how physical systems with nothing physical in common can realize the same algorithm.That suggests that the algorithm itself is not a physical thing, but something else. And those something elses have very little to do with the laws of physics.”
An algorithm is basically a step-by-step instruction of computation. First you do this calculation, then you take the result and make another calculation with it and so on until ideally you get some kind of output (be it behavior or a number on your calculator). Based on that understanding I don’t quite see the trouble with performing the same algorithm (sequence of computations) based on wildly different physical systems. The algorithm itself is of course always a physical “thing” as well in a sense, since it must be carried out on matter… you can’t do computation on “nothing”, in computers it’s electrons being herded through “gates” on microchips and in a brain it’s electrical impulses in neurons being carried along the dendrites towards the nucleus which can act as a gate and inhibit or pass on the impulse along it’s axon towards other dendrites or nuclei. Of course this is massively oversimplified, but I hope it is obvious how similar computations can be carried out by both.
Granted, a neuron is unimaginably more complex than a gate on a microchip but if you google for the “Blue Brain project” you can see how computers can be used to simulate (or should I rather say emulate?) neurons and ultimately whole neural nets. This would be an instance where (essentially) the same algorithm is implemented aka computed once by neurons and once by microchips.
That something has very little do do with the laws of physics is a statement that couldn’t possibly sound more radical and wrong to the ears of science and rationality. Computation is hardly an area where the laws of physics are insufficient to lend themselves for empiricism. To point out that it is evidently absolutely understood how algorithms can be implemented by physical stuff seems almost ridiculous, given the fact that right now we sit in front of a working computer, that was once invented and built by humans.