On Sun, Nov 26, 2017 at 10:04 PM, Jason Resch <jasonre...@gmail.com> wrote:
> > Richard Feynman in "The Character of Physical Law" Chapter 2 wrote: > > "It always bothers me that according to the laws as we understand them > today, it takes a computing machine an infinite number of logical > operations to figure out what goes on in no matter how tiny a region of > space, and no matter how tiny a region of time. How can all that be going > on in that tiny space? Why should it take an infinite amount of logic to > figure out what one tiny piece of space/time is going to do?" > Obviously infinite logic is not required unless infinite precision is also required, but sometimes (and protein folding would be a good example of this) an astronomically huge number of calculations are required for even a very modest approximation of what is happening in a tiny piece of spacetime, and yet nature can do it with great precision in a fraction of a second. How come? Feynman himself took the first first tentative steps toward answering that question just before he died, as far as I know he was the first person to introduce the idea of a quantum computer. > > > Does computationalism provide the answer to this question, No natural phenomenon has ever been found where nature has solved a NP-hard problem in polynomial time. Quantum Computer expert Scott Aaronson actually tested this and this is what he found : *" taking two glass plates with pegs between them, and dipping the resulting contraption into a tub of soapy water. The idea is that the soap bubbles that form between the pegs should trace out the minimum Steiner tree — that is, the minimum total length of line segments connecting the pegs, where the segments can meet at points other than the pegs themselves. Now, this is known to be an NP-hard optimization problem. So, it looks like Nature is solving NP-hard problems in polynomial time!Long story short, I went to the hardware store, bought some glass plates, liquid soap, etc., and found that, while Nature does often find a minimum Steiner tree with 4 or 5 pegs, it tends to get stuck at local optima with larger numbers of pegs. Indeed, often the soap bubbles settle down to a configuration which is not even a tree (i.e. contains “cycles of soap”), and thus provably can’t be optimal.* *The situation is similar for protein folding. Again, people have said that Nature seems to be solving an NP-hard optimization problem in every cell of your body, by letting the proteins fold into their minimum-energy configurations. But there are two problems with this claim. The first problem is that proteins, just like soap bubbles, sometimes get stuck in suboptimal configurations — indeed, it’s believed that’s exactly what happens with Mad Cow Disease. The second problem is that, to the extent that proteins do usually fold into their optimal configurations, there’s an obvious reason why they would: natural selection! If there were a protein that could only be folded by proving the Riemann Hypothesis, the gene that coded for it would quickly get weeded out of the gene pool." * For more I highly recommend Aaronson's book *"Quantum Computing since Democritus".* John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
