Quantum weirdness is everywhere in life • Hacker News Board

Re: Quantum weirdness is everywhere in life

#31

Post by deepnet » Mon, Aug 10, 2015, 1:19 PM UTC

ild wrote: post #3

That claim about DNA, mutations and quantum effects - well it makes the paper less credible. DNA and its replication and mutations are largely non-quantum and it is also not true at all that in DNA every matters; minor alterations of the do not produce invalid code.

The pull quote from the article is indeed misleading.

McFadden's work is an attempt to provide a foundation for adaptive mutation.

Adaptive mutation is where only well adapted mutations occur at odds with a random explantion.

From (the OP's author) McFadden's and Khalili's 1999 paper: A quantum mechanical model of adaptive mutation

"The principle that mutations occur randomly with respect to the direction of evolutionary change has been challenged by the phenomenon of adaptive mutations. There is currently no entirely satisfactory theory to account for how a cell can selectively mutate certain genes in response to environmental signals. However, spontaneous mutations are initiated by quantum events such as the shift of a single proton (hydrogen atom) from one site to an adjacent one. We consider here the wave function describing the quantum state of the genome as being in a coherent linear superposition of states describing both the shifted and unshifted protons. Quantum coherence will be destroyed by the process of decoherence in which the quantum state of the genome becomes correlated (entangled) with its surroundings."

http://www.researchgate.net/profile/Johnjoe_Mcfadden/publica...

Re: Quantum weirdness is everywhere in life

#32

Post by n4r9 » Mon, Aug 10, 2015, 1:19 PM UTC

gfodor wrote: post #29

n4r9 wrote: post #25

Earlier quoted context omitted.

If you mean "what has led you to think they're further away from consensus": mostly just gut feeling, as a (younger) member of that community. I've not seen any rigorous and comprehensive studies of which interpretations garner the most support, but it does seem like popularity is currently divided between the orthodox and several other interpretations that have evolved from "niche" to "significant minority" in recen…

http://www.preposterousuniverse.com/blog/2013/01/17/the-most... In short Copenhagen still (sadly) rules the day, followed by many worlds and QIT.

I meant "rigorous and comprehensive" to include "representative of the entire quantum community". That poll was conducted at a single conference and had 33 participants. The bias inherent in this approach can be seen when the same poll was conducted at two other conferences:

http://arxiv.org/abs/1303.2719

http://arxiv.org/abs/1306.4646

In both cases, de-Broglie Bohm interpretations ruled the day. As the abstract of the latter paper states:

> ...the results do strongly suggest several interesting cultural facts -- for example, that there exist, within the broad field of "quantum foundations", sub-communities with quite different views, and that (relatedly) there is probably even significantly more controversy about several fundamental issues than the already-significant amount revealed in the earlier poll.

Re: Quantum weirdness is everywhere in life

#33

Post by sklogic » Mon, Aug 10, 2015, 1:30 PM UTC

ild wrote: post #24

sklogic wrote: post #14

Earlier quoted context omitted.

Protein folding is a quantum thing indeed. And folding matters no less than the amino acids sequence.

Folding has nothing to do with DNA.

DNA encodes the amino acid sequence. Quantum mechanics defines the folding. These two things combined determine the colour of your eyes, etc., etc. Encoding per se is meaningless without the folding.

Also, the way how RNA polymerase work (i.e., transcription) is of quite a quantum nature too.

Re: Quantum weirdness is everywhere in life

#34

Post by williamjennings » Mon, Aug 10, 2015, 1:31 PM UTC

sklogic wrote: post #13

TeMPOraL wrote: post #11

Earlier quoted context omitted.

Exactly. It's not quantum physics that is weird, it's our intuitions that are wrong (since we never had to explicitly deal with nanoscale before XX century).

Our intuition is so poor that it even gets many classical mechanics problems wrong. Most hilariously the various resonance-related things (my favourite practical example is a pendulum swinging upwards, which looks like pure magic). Intuition is also very poor in dealing with nonlinear things (think soliton waves and all that stuff). So, trusting an intuition is always wrong and intuition got no place in science anywa…

Even when intuition fails, intuitionist logic may still prove quite useful.

Re: Quantum weirdness is everywhere in life

#35

Post by sklogic » Mon, Aug 10, 2015, 1:31 PM UTC

4Data wrote: post #16

sklogic wrote: post #13

Earlier quoted context omitted.

Our intuition is so poor that it even gets many classical mechanics problems wrong. Most hilariously the various resonance-related things (my favourite practical example is a pendulum swinging upwards, which looks like pure magic). Intuition is also very poor in dealing with nonlinear things (think soliton waves and all that stuff). So, trusting an intuition is always wrong and intuition got no place in science anywa…

Can you give an example of a pendulum swinging upwards? Is that an inverted pendulum? [1] [1] https://www.youtube.com/watch?v=5oGYCxkgnHQ

Yes, that's a good example. The recipe I used for such demos was based on an old Soviet electric shaver and a standard bicycle wheel spoke, it's a known combination to get an inverted pendulum (even at funny angles, not necessarily entirely upward).

Re: Quantum weirdness is everywhere in life

#36

Post by gfodor » Mon, Aug 10, 2015, 1:37 PM UTC

n4r9 wrote: post #32

gfodor wrote: post #29

Earlier quoted context omitted.

http://www.preposterousuniverse.com/blog/2013/01/17/the-most... In short Copenhagen still (sadly) rules the day, followed by many worlds and QIT.

I meant "rigorous and comprehensive" to include "representative of the entire quantum community". That poll was conducted at a single conference and had 33 participants. The bias inherent in this approach can be seen when the same poll was conducted at two other conferences: http://arxiv.org/abs/1303.2719 http://arxiv.org/abs/1306.4646 In both cases, de-Broglie Bohm interpretations ruled the day. As the abstract of t…

My bad, on a phone and recalled the link from a while back to share it.

Re: Quantum weirdness is everywhere in life

#37

Post by VLM » Mon, Aug 10, 2015, 1:40 PM UTC

sklogic wrote: post #13

TeMPOraL wrote: post #11

Earlier quoted context omitted.

Exactly. It's not quantum physics that is weird, it's our intuitions that are wrong (since we never had to explicitly deal with nanoscale before XX century).

Our intuition is so poor that it even gets many classical mechanics problems wrong. Most hilariously the various resonance-related things (my favourite practical example is a pendulum swinging upwards, which looks like pure magic). Intuition is also very poor in dealing with nonlinear things (think soliton waves and all that stuff). So, trusting an intuition is always wrong and intuition got no place in science anywa…

> Our intuition is so poor

Even better example, "Heavy things fall faster". Or "The sun revolves around the earth".

As a greater cultural trend there is often a bit of quantum-whitewashing that everything in physics is obvious and straightforward except quantum mechanics because I suffered thru the annoying math and need to show off superiority at being one of the few humans (on a percentage of entire population) who understand a good chunk of QM. Relativity gets the same treatment.

However its important to note that none of physics is very intuitive. Heavy things don't fall faster. The sun doesn't orbit the earth. The general public has some peculiar ideas about the laws of thermodynamics. Orbits in space are not perfect circles. Atomic structure is not a fractally small solar system. QM is typical and normal for physics in having non-intuitive dark corners, that's the norm for all of physics not a peculiarity of QM.

There is shibboleth value in that you define a physicist or a dude who knows physics as a guy who walks around saying QM is the only non-intuitive component of physics. Not because its true, but because that's one of the official physicist mating calls or whatever you want to call it, shibboleth I guess.

There is also the deus ex machina aspect that in all forms of non-technical drama (aka all of it) people who like to write magical fantasy have decided to fool us into thinking its new by copy-and-replace word processing "quantum" in for "Tolkienish magic", see also the multiverse people.

Re: Quantum weirdness is everywhere in life

#38

Post by deepnet » Mon, Aug 10, 2015, 1:40 PM UTC

ewzimm wrote: post #30

Drakim wrote: post #6

Earlier quoted context omitted.

That quote instantly makes me lose any credibility in the author. Is he/she really that ignorant of basic biology, or am I misunderstanding something?

The author is a molecular biologist with several published books and over 100 peer-reviewed articles, so he definitely has a grasp on basic biology. I think that what you are missing is the assertion that each atom plays an individual role in the process. That is, there are low-level processes that take place on a small enough scale to depend on quantum effects that make direct contributions to DNA. The point is that…

The author's 1999 paper proposes a quantum mechanic to explain adaptive mutation.

They assert that E. Coli mutates to develop lactase in a lactose enviroment, it does this quickly and seemingly without adverse mutations - randomness fails to explain this.

McFadden and Khalili propose that adaptive DNA mutation is a quantum computation.

The many possible mutations are explored simultaneously and the quantum state collapses to one highly correlated to the enviroment.

Their 1999 paper A quantum mechanical explanation for adaptive mutation goes in depth.

http://www.researchgate.net/profile/Johnjoe_Mcfadden/publica...

This has led to a new scientific discipline Quantum Biology http://www.ias.surrey.ac.uk/workshops/quantumbiology/

Re: Quantum weirdness is everywhere in life

#39

Post by williamjennings » Mon, Aug 10, 2015, 1:50 PM UTC

n4r9 wrote: post #32

gfodor wrote: post #29

Earlier quoted context omitted.

http://www.preposterousuniverse.com/blog/2013/01/17/the-most... In short Copenhagen still (sadly) rules the day, followed by many worlds and QIT.

I meant "rigorous and comprehensive" to include "representative of the entire quantum community". That poll was conducted at a single conference and had 33 participants. The bias inherent in this approach can be seen when the same poll was conducted at two other conferences: http://arxiv.org/abs/1303.2719 http://arxiv.org/abs/1306.4646 In both cases, de-Broglie Bohm interpretations ruled the day. As the abstract of t…

My opinion is that the Copenhagen interpretation does not contradict DeBroglie in terms of nuclear chemistry, but solely thermodynamics.

The Copenhagen interpretation makes a leap of faith with the Born Rule as it is based on Maxwell-Boltzmann statistics. The work of t'Hooft is a more modern alternative for ensembles where the outcome is stochastic, rather than probabilistic. Photosynthesis has that property, as do many other enzymatic systems.

Re: Quantum weirdness is everywhere in life

#40

Post by duaneb » Mon, Aug 10, 2015, 1:53 PM UTC

feelix wrote: post #28

titzer wrote: post #4

"The colour of your eyes, the shape of your nose, your intelligence or propensity for disease are encoded at the quantum level." Uh, nope.

It is Schroedinger who said that, who, considering his time in history, had a very broad view of what quantum mechanics and DNA are. Given his high level viewpoint he was correct, considering that he was making a reference to interactions at the level of the universe. Although it is actually your DNA which codes the colour of your eyes, it is also true that quantum mechanics plays a part in the DNA encoding itself, w…

So, everything on the nanometer level is quantum mechanics? Seems like a cop-out answer. Quantum mechanics as opposed to what? This is hardly new.