
An important quantum algorithm may be a property of nature - pisky
https://www.technologyreview.com/s/614259/an-important-quantum-algorithm-may-actually-be-a-property-of-nature/
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nicwilson
Hmm, there are several things I find strange about this article.

There are 22 proteinogenic amino acids (admittedly two are rare,
selenocysteine and pyrrolysine, but with rarity comes importance when they do
occur).

The search for the correct amino acid is not class balanced, e.g. the
aromatics are much less common.

The tRNAs are also not equally distributed, neither in the codon-anticodon
pairing, the aromatics are coded for by only one or two, I suppose this is
somewhat reflected in the frequency (see above).

Even within one amino acids possible tRNA the ratio's are species dependant to
a remarkable degree (see codon optimisation in genetic engineering. You can
also tell by sequence analysis if horizontal transfer has occurred if the
frequencies are all wrong) and is used to regulate synthesis. e.g. if a
species has tRNA UUU : tRNA UUC of 3 : 1 then (classically) one would expect a
protein incorporating phenylalanine as UUC to take 3 times longer than UUU to
incorporate.

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knzhou
This is all correct, and shows why both biologists and physicists don't take
the conclusions of Patel's paper too seriously. Just aiming for "20" without
any context for what that means is a bad kind of numerology. There's probably
a grain of truth in the paper, but only enough to get to something like "20
plus or minus 10", not exactly "20".

Speaking as an MIT alumnus, some of the school's promotional material is
glitzy on the outside and hollow on the inside. The MIT Tech Review's
"Emerging Technologies" column is particularly bad. I've written numerous
rants over the years rebutting incredibly misleading viral articles from it.
It's a shame that people automatically trust it because of the MIT name.

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jessriedel
MIT Tech Review is no longer associated with MIT. The name is historical
vestige. It's just another magazine like Popular Science.

~~~
dekhn
that's not correct, they are owned by MIT.

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jessriedel
Thanks you're right. The important idea I was remembering is that they have no
editorial connection to the university; they're just an investment.

~~~
lonelappde
It's part of the trend of MIT and many other venerable institutions cashing
out their reputation instead of building on it.

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mindviews
"The Grover search as a naturally occurring phenomenon" arXiv link:
[https://arxiv.org/abs/1908.11213](https://arxiv.org/abs/1908.11213)

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carbocation
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 used for initiation).

It’s not super clear to me at what level of abstraction the search is taking
place - it can’t be the tRNA space because that’s not just 20 options.

The point that electrons seem to follow a Grover search is cool. I’m just
unclear on whether the biological part holds up.

~~~
jerf
I'd go farther; I can't even imagine in what way matching a codon to a
physical amino acid and attaching it to a protein in progress is a "database
lookup" in a Grover database lookup.

If proteins were created by the cells by selecting proteins out of quantum
superpositions of all the possible amino acids, sure. But that doesn't seem to
remotely describe how that process works.

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Iv
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 AI.

~~~
knzhou
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 exist, because nothing in life
is designed like them or takes advantage of them. You've literally taken us
back to the 1700s.

I know that it's fashionable to simply declare quantum computing is
impossible, and there are some strong arguments in this direction, but this
particular argument isn't one.

The general reason people believe quantum computing _is_ possible is that it
describes just about all the things I mentioned above absolutely perfectly,
along with literally thousands of other phenomena, with no deviations ever
measured. This gives us good reason to assume quantum mechanics actually
works, and if it does, then it's possible for quantum computing to work.
(Also, of course you need to account for quantum mechanics to account for
protein folding. You literally can't have chemical bonds at all without
quantum mechanics.)

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Iv
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 acceleration and biology operates
at a scale where quantum effects are visible. I thought 3. slightly more
likely but I'll readily admit that I am nowhere near the knowledge to be
categorical about 2.

And note that of the list of things you are giving, there are many that uses
the same _physical principles_ that are used by life: steam engine (expansion
of heated gases), rockets (ignition of gas), jets (propulsion), helicopters (a
rotating wing is a wing), radio waves/X-rays (the RF spectrum, which visible
light is part of), etc... The rest, IMO, falls either under 1. or 2. For
instance I doubt long-distance communication really offers a substantive
advantage when you know whales can already contact each other at 100s of
kilometers through shouts, and superfluidity may require conditions and
materials that are impossible to reach for organic material.

Note however that this last one is actually a kinda good (if weak) argument:
if superfluidity was achievable through organic material and conditions close
to the temperature and pressure average on earth, life would probably have
found it, as it is clearly a useful property. If tomorrow we find that you can
get room-temperature superfluids that are made out of C,H and O atoms,
wondering why it is not found in nature will be a very good question.

~~~
sriku
All that is assuming that you do know for certain the evolution did NOT
exploit it.

There is some extrapolative argument that hints at the contrary. Adrian
Thompson's evolved FPGA circuits exploited a single chip's underlying physics
in a manner no digital circuit designer would. By that thread, it would seem
possible that evolution has already exploited quantum computation ... just
that maybe we haven't had the tech eye to see it yet.

After all, all systems are quantum mechanical.

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smilliken
Rhodopsin, in our retina, exploits a quantun mechanical effect. You could
argue that our brains are quantum computers if you consider our retina
including rhodopsin to be part of the brain.

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whatshisface
Apples are red because of quantum mechanical effects, but that doesn't make
them computers.

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smilliken
Anything and everything is because of quantum mechanics, sure. But you
could've asked a classical physicist to design an apple "computer" (the
fruit)— just arrange the right atoms— but you couldn't have asked a classical
physicist to design a retina computer exploiting rhodopsin.

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jjtheblunt
Modal verb ("may") clickbait alert?

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imvetri
Everything inside living organisms are learnt from nature. organisms with
sight, learn from what it could see. Organisms with sense of sound can create
only what it had heard in past.

Now imagine primitive organisms that has distributed/scattered sensory system
like plants( don't start an argument that plant isn't an organism. instead
start the right argument with most flawed system please)

We cannot create anything new which we haven't learnt in the past.

WE CANNOT CREATE ANYTHING NEW WHICH WE HAVENT LEANRT IN THE PAST.

Great people are not great in finding relation in surroundings. They are only
good at finding what's inside their brain.

What goes inside the brain ? millions of years of nature's influence.

~~~
imvetri
We gotta turn around and rethink how we are educating ourselves and
surrounding us. We have to be very careful in not misinforming facts or the
way we think.

~~~
imvetri
Imagine boolean concept in the computer science. The first guy who theorised
did he just propose something randomly and error free, or was he able to look
/ observe how his brain thinks ? I would pick the second one.

This is an example that anything that feels flawless is from within ourselves!

