An important quantum algorithm may be a property of nature

Post by simonh » Mon, Sep 16, 2019, 11:20 AM UTC

raverbashing wrote: post #38

knzhou wrote: post #21

Earlier quoted context omitted.

This argument proves too much. By that same argument, nuclear fission, ordinary CPUs, steam engines, rockets, helicopters, jets, X-rays, radio waves, superconductivity, superfluidity, air conditioning, liquid helium, liquid nitrogen, the Haber process, the fractional quantum Hall effect, Doppler cooling, graphene, long-distance satellite communication, gravitational waves, and GPS corrections for relativity all don't…

I think in your list of examples there are plenty of cases where nature, while not building the exact thing uses the same underlying principles. There are a lot of seeds that are aerodynamic so that they get spread more widely for example. Even seeds that have controlled falls due to "autorotation" But of course on planet earth at least it is hard for nature to use things requiring too high or low temperatures. Natur…

Post by chopin » Mon, Sep 16, 2019, 11:46 AM UTC

quotemstr wrote: post #7

Iv wrote: post #4

A reason why I allow myself some skepticism on the feasibility of quantum computing is that if it were possible, I would have expected evolution to have used it somehow. If it turns out that protein folding really use a quantum computation, I'll move quantum computers from the "too good to be true" category to the "probably revolutionary stuff that I will see in my lifetime" alongside with nuclear fusion and strong A…

Your argument doesn't stand up to cursory examination. There are all sorts of tricks of physics that evolution never found out how to use. Natural systems don't use the (macroscopic) wheel either, but that works great. Refrigeration works great, but nature doesn't use that either. Complex life has barely been around 540 million years ago. Why would you suppose evolution would have had time to explore the entire space…

Post by soulofmischief » Mon, Sep 16, 2019, 12:32 PM UTC

Iv wrote: post #35

knzhou wrote: post #21

Earlier quoted context omitted.

This argument proves too much. By that same argument, nuclear fission, ordinary CPUs, steam engines, rockets, helicopters, jets, X-rays, radio waves, superconductivity, superfluidity, air conditioning, liquid helium, liquid nitrogen, the Haber process, the fractional quantum Hall effect, Doppler cooling, graphene, long-distance satellite communication, gravitational waves, and GPS corrections for relativity all don't…

The argument I propose is not a strong one. It is still an argument: if something is possible, why did evolution not use it? There are several possible answers: 1. Life may not have a use for it 2. It may be impossible to achieve with proteins and cells 3. It may not actually be possible For quantum computer I (weakly) believe that 1 and 2 are wrong: evolution and cognition would hugely benefit from quantum accelerat…

Post by xaedes » Mon, Sep 16, 2019, 1:07 PM UTC

changoplatanero wrote: post #12

xenadu02 wrote: post #11

Earlier quoted context omitted.

Use of the vast majority of the radio spectrum is not used by any form of life that we know of. Being able to communicate non-visibly without giving away our position audibly would be a huge advantage (until your predators/competitors figured it out). Life isn't generally suitable to the use of really high energies like X-rays because it damages cells. It isn't suitable for low energies because it is difficult to cre…

lasers would be another one, right? Is there any lifeform that can make a laser?

Post by jerf » Mon, Sep 16, 2019, 1:39 PM UTC

carbocation wrote: post #2

This is a bit of a tangent (that the author takes): “But during protein assembly, each amino acid must be chosen from a soup of 20 different options. Grover’s algorithm explains these numbers: a three-step quantum search can find an object in a database containing up to 20 kinds of entry. Again, 20 is the optimal number.” 20 is the number of amino acids, but this is ignoring stop codons (and specialized amino acids u…