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xchrom

(108,903 posts)
Sun Mar 18, 2012, 10:34 AM Mar 2012

Quantum Biology and the Puzzle of Coherence

http://www.technologyreview.com/blog/arxiv/27628/



One of the more exciting discoveries in biology in the last few years is the role that quantum effects seem to play in many living systems.

The two most famous examples are in bird navigation, where the quantum zeno effect seems to help determine the direction of the Earth's magnetic field, and in photosynthesis, where the way energy passes across giant protein matrices seems to depend on long-lasting quantum coherence.

Despite the growing evidence in these cases, many physicists are uneasy, however. The problem is the issue of decoherence, how quickly quantum states can survive before they are overwhelmed by the hot, wet environment inside living things.

According to conventional quantum calculations, these states should decay in the blink of an eye, so fast that they should not be able to play any role in biology.
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Quantum Biology and the Puzzle of Coherence (Original Post) xchrom Mar 2012 OP
However, it would be a big mistake... longship Mar 2012 #1
Straight to the point tama Mar 2012 #3
Is coherence selected or a structural by-product? Jim__ Mar 2012 #4
Wider context tama Mar 2012 #8
I'm not sure why you would begin by looking at a wider context. Jim__ Mar 2012 #15
To begin with tama Mar 2012 #16
A couple of thoughts. Jim__ Mar 2012 #33
A clarification tama Mar 2012 #36
Lack of any supporting data longship Mar 2012 #5
The word "decoherence" tama Mar 2012 #6
This is complete and utter rubbish longship Mar 2012 #9
But, but... someone was wrong about something before... Silent3 Mar 2012 #11
I disagree tama Mar 2012 #13
Your endless devotion to vagueness is certainly amusing, however. Silent3 Mar 2012 #17
Why don't you even try? tama Mar 2012 #19
You seem to be getting different posters confused Silent3 Mar 2012 #20
Flattering ad hominem, thanks for that tama Mar 2012 #28
I have no problem with people trying to understand "quantum" Silent3 Mar 2012 #29
You are making up tama Mar 2012 #31
New Age? longship Mar 2012 #32
Pseudoskepticism tama Mar 2012 #45
Thank you. Thank you. And THANK YOU!!! nt Joseph8th Mar 2012 #40
Nice tama Mar 2012 #12
Sorry! Your post makes no physical sense longship Mar 2012 #18
First tama Mar 2012 #24
Tama, I'm with you longship Mar 2012 #30
Well that's clearly wrong bananas Mar 2012 #34
Wonderful take down longship Mar 2012 #35
Quantum cryptography, quantum teleportation, superconductors are some other examples bananas Mar 2012 #48
Please! It's bad enough to tarnish QM... Joseph8th Mar 2012 #41
Gödel tama Mar 2012 #43
Looking for a ToE ... Joseph8th Mar 2012 #46
Abstract tama Mar 2012 #47
Not sure why I'm bothering, but... Joseph8th Mar 2012 #49
Some good points tama Mar 2012 #50
Heheh... Cantor's Paradise... Joseph8th Mar 2012 #53
LOL - "mathematical theorems ... bear no relation to physics" bananas Mar 2012 #51
Math is not physics... Joseph8th Mar 2012 #52
Physics is NOT illogical or irrational... Joseph8th Mar 2012 #54
I didn't know there were Militant Holists, now... Joseph8th Mar 2012 #38
LOL tama Mar 2012 #39
OMG... Joseph8th Mar 2012 #42
Condencending tone tama Mar 2012 #44
Anybody tama Mar 2012 #7
Hmm. DeWitt. Interesting longship Mar 2012 #10
First tama Mar 2012 #14
Okay, I'm with you on all except the "observer" longship Mar 2012 #21
Well, I think there's more to the "observer" unless you're effectively redefining the term caraher Mar 2012 #22
Touché, Zurek is above my pay grade longship Mar 2012 #23
I do think we're broadly in agreement caraher Mar 2012 #26
Thanks tama Mar 2012 #27
See post 24 for answer to also this n/t tama Mar 2012 #25
Delayed choice experiment tama Mar 2012 #37
So Stuart Kaufmann is still working.. arendt Mar 2012 #2

longship

(40,416 posts)
1. However, it would be a big mistake...
Sun Mar 18, 2012, 10:59 AM
Mar 2012

...for anybody to assign any top-down causality in quantum effects. Rather, these are emergent behaviors which are able to utilize quantum effects and of course biological evolution is able to exploit it. But that still keeps the causality arrow from bottom-up.

 

tama

(9,137 posts)
3. Straight to the point
Mon Mar 19, 2012, 07:16 AM
Mar 2012

of what is at stake: standard notions of causality and reductionism in terms of classical physics. Thanks for that!

Of course those are just certain philosophical/metaphysical premisses of theory-building (and in many cases belief systems of "scientism" with various degrees of emotional attachment), and ideals of rational inquiry and empirical method demand that also premisses need to be questioned and restated along the scientific progress.

There is no a priori reason to presuppose only linear unidirectional causality and/or arrow of time. And there are many good reasons not to, for example and especially 'self-reflection', a form that seems unexplainable by mathematical models that reductionistic determinism is based on. And, as allready Hume said, linear causality cannot be proven empirically or logically. It is just one notion of basic order among many possible. And, given the long tradition of dialectics in various cultures and philosophical schools, there is no reason to presuppose that dialectical relation between both "bottom-up" and "top-down"* couldn't be a more coherent foundation of notions of causality and theory building.

So the question is, why do you claim that it would be a "big mistake for anybody to assign any top-down causality."? That is a very strong claim and you back it up with nothing, except perhaps the classic ad hoc word salad woo-word of "emergentism".

***

Presumed reference for 'top-down':
*http://humbleapproach.templeton.org/Top_Down_Causation/


Jim__

(15,219 posts)
4. Is coherence selected or a structural by-product?
Mon Mar 19, 2012, 10:08 AM
Mar 2012

That seems to be an open question. There is a little bit of discussion of this in a short
article in Nature. An excerpt:

...

Quantum coherence in photosynthesis seems to be beneficial to the organisms using it. But did their ability to exploit quantum effects evolve through natural selection? Or is quantum coherence just an accidental side effect of the way certain molecules are structured? "There is a lot of speculation about the evolutionary question, and a lot of misunderstanding," says Scholes, who is far from sure about the answer. "We cannot tell if this effect in photosynthesis is selected for, nor if there is the option not to use coherence to move the electronic energy. There are no data available at all even to address the question."

He points out that it isn't obvious why selection would favour coherence. "Almost all photosynthetic organisms spend most of the day trying to moderate light-harvesting. It is rare to be light-limited. So why would there be evolutionary pressure to tweak light-harvesting efficiency?" Fleming agrees: he suspects that quantum coherence is not adaptive, but is simply "a by-product of the dense packing of chromophores required to optimize solar absorption". Scholes hopes to investigate the issue by comparing antenna proteins isolated from species of cryptophyte algae that evolved at different times.

But even if quantum coherence in biological systems is a chance effect, adds Fleming, its consequences are extraordinary, making systems insensitive to disorder in the distribution of energy. What is more, he says, it "enables 'rectifier-like' one-way energy transfer, produces the fastest [energy-transfer] rate, is temperature-insensitive and probably a few other things I haven't thought of".

These effects, in turn, suggest practical uses. Perhaps most obviously, says Scholes, a better understanding of how biological systems achieve quantum coherence in ambient conditions will "change the way we think about design of light-harvesting structures". This could allow scientists to build technology such as solar cells with improved energy-conversion efficiencies. Seth Lloyd considers this "a reasonable expectation", and is particularly hopeful that his discovery of the positive role of environmental noise will be useful for engineering photonic systems using materials such as quantum dots (nanoscale crystals) or highly branched polymers studded with light-absorbing chemical groups, which can serve as artificial antenna arrays.

...

 

tama

(9,137 posts)
8. Wider context
Mon Mar 19, 2012, 04:02 PM
Mar 2012

The question about evolution and quantum biology need to be looked from the wider context of quantum cosmology, observer participation - and nature of time and self-reference aka "consciousness". See post 7.

Jim__

(15,219 posts)
15. I'm not sure why you would begin by looking at a wider context.
Mon Mar 19, 2012, 07:07 PM
Mar 2012

Even the link that you provided on top-down causation begins by talking about systems that cannot be fully analysed in terms of component level behavior:

Top-down causation refers to the effects on components of organized systems that cannot be fully analyzed in terms of component-level behavior but instead requires reference to the higher-level system itself. A sweeping and fundamental concept, it is not only a philosophical idea but also a key ingredient in the emergence and functioning of complex systems, including life and the human brain. Together with bottom-up causation, top-down causation enables genuine complexity to emerge within specific levels of the hierarchy of complexity and causation. It also links the various levels of the hierarchy in a manner that undermines any simple-minded version of reductionism. A growing literature on complexity and emergence is providing an analysis of how this happens. Nevertheless, there are some who deny that it has any significance, or even reality.


In the link that I provided, Gregory Scholes suggests a research program that may determine whether quantum coherence has always been a part of photosynthesis, or if it came about through selection, the normal development path for complex biological systems - i.e. this system may well be explainable in terms of component level behavior:

He points out that it isn't obvious why selection would favour coherence. "Almost all photosynthetic organisms spend most of the day trying to moderate light-harvesting. It is rare to be light-limited. So why would there be evolutionary pressure to tweak light-harvesting efficiency?" Fleming agrees: he suspects that quantum coherence is not adaptive, but is simply "a by-product of the dense packing of chromophores required to optimize solar absorption". Scholes hopes to investigate the issue by comparing antenna proteins isolated from species of cryptophyte algae that evolved at different times.


This seems to be a reasonable approach toward trying to understand this phenomenon.

In your posts about top-down causality, I don't see any suggested research, but rather consideration of philosophical questions. In a paper linked to from the paper referred to in the OP, they discuss the molecular configurations that can lead to the type of coherence seen in photosynthesis; and specifically with respect to a particular protein involved:

Light harvesting components of photosynthetic organisms are complex, coupled, many-body quantum systems, in which electronic coherence has recently been shown to survive for relatively long time scales despite the decohering effects of their environments. Within this context, we analyze entanglement in multi-chromophoric light harvesting complexes, and establish methods for quantication of entanglement by presenting necessary and suffcient conditions for entanglement and by deriving a measure of global entanglement. These methods are then applied to the Fenna-Matthews-Olson (FMO) protein to extract the initial state and temperature dependencies of entanglement. We show that while FMO in natural conditions largely contains bipartite entanglement between dimerized chromophores, a small amount of long-range and multipartite entanglement exists even at physiological temperatures. This constitutes the first rigorous quantication of entanglement in a biological system. Finally, we discuss the practical utilization of entanglement in densely packed molecular aggregates such as light harvesting complexes.


There is, of course, always more to learn. But in this instance, the type of research being done and being suggested would seem to be reasonable first steps toward understanding this process. It certainly does not interfere with anything being suggested at the site studying top-down causality, and any information gained may serve as fodder for further investigation of the philosphical questions.
 

tama

(9,137 posts)
16. To begin with
Mon Mar 19, 2012, 07:47 PM
Mar 2012

Darwinian evolution has a top down causal component called "environmental adaptation". So to combine biology and physics, a biofriendly cosmological environment is required to begin with. And cosmological considerations without exceptions lead to various philosophical questions and presuppositions about time, and quantum cosmological considerations especially so, with arrows of time going both ways etc. On what kind notion of time is the basic question of the research program based on? And is it a relevant and sufficient premisse to get relevant answers concerning quantum biology?

Of course I'm all for the research program, but to begin with the basic questions of any research programs and rational inquiries need to be carefully formulated and as open and conscious as possible about their implicated presuppositions.

Jim__

(15,219 posts)
33. A couple of thoughts.
Tue Mar 20, 2012, 02:23 PM
Mar 2012

You claim: Darwinian evolution has a top down causal component called "environmental adaptation".

But the site that you cited with respect to top-down causation claims:

The core issue is volitional agency.


They don't provide any real context for that statement, so I'll take it at face value. Darwinian evolution, as it is currently understood, is not at all concerned with volitional agency.

The site further asks:

How would we or could we know that the relevant causal powers are not (even in principle) reducible to constituent properties of the “bottom” level of reality? If we cannot answer this question, does this rule out top-down causation as empirically useless?


Studying photosynthesis in all its aspects can definitely help to determine whether or not it is reducible to the constituent properties of the components.

Some further questions from this site are:

  • What counts as “top” in top-down causation? What counts as “bottom”? Would “whole-part causation” be a better description? If so, what difference would that make?

  • Are there any top-down realities to do the causing? If so, are they properties or substances? If properties, “of what” are they properties? If substances, of what are the substances made/composed?

  • What would be required for a supervening or emergent entity to have causal powers? And what would be required for “downward causal” power in particular?

  • Where might we get some explanatory (or metaphysical) “cash value” out of employing or hypothesizing top-down causal entities? Gaia? Agents? God? Molecules? Minds?

  • How would we or could we know that the relevant causal powers are not (even in principle) reducible to constituent properties of the “bottom” level of reality? If we cannot answer this question, does this rule out top-down causation as empirically useless?

  • How could we empirically test for the existence of the relevant causal powers?

  • ...


These questions indicate that this concept is not yet particularly well-defined and is not ready to be applied against scientific discoveries.


 

tama

(9,137 posts)
36. A clarification
Wed Mar 21, 2012, 05:22 AM
Mar 2012

"Top-down causality" is a new term for me, so I googled and made a subnote of the first hit. The term seems to be related also to holism and Bohm's notion of active information - and "bottom up" to reductionism. Philosophically the question is simply about codependent dialectic of parts and wholes and causes and consequenses.

I agree that "well defined" in terms of mathematical physics should be a mathematical formulation. This idea is very interesting:
http://matpitka.blogspot.com/2012/03/quantum-mathematics.html#comments

longship

(40,416 posts)
5. Lack of any supporting data
Mon Mar 19, 2012, 11:07 AM
Mar 2012

Also, look up "decoherence" in quantum physics.

Those who claim top-down causality in QM, Chopra, etc., are just making shit up. Anybody who has followed the research can see no causal link between human experience/thought and what occurs at the quantum level.

I suggest "Quantum Gods" by Victor Stenger, or if you're a bit more industrious, "The Comprehensible Cosmos". Both lay out in fairly good detail why top-down causality is most likely falsified.

 

tama

(9,137 posts)
6. The word "decoherence"
Mon Mar 19, 2012, 01:35 PM
Mar 2012

goes back to David Bohm and "top-down causality" seems a concept related to Bohmian notion of "active information". I've been following the discussion so long that I remember when the argument used to be about micro and macro and quantum effects limited to just micro, which has been proven wrong. Other main argument used to be that warm and moist environments don't allow decoherred quantum states and evidence has blown also that "argument" away. The materialist position wobbles mainly on the Standard Model, which is admittedly inconsistent and string/M-theories that lead to multiverse speculations.

You made strong claim which you cannot prove or defend by any rational argument except by referring to a preacher of the pseudoskeptic movement. But thanks anyway for the book recommendation, I'm currently reading Goldilocks by Paul Davies which I can recommend.

longship

(40,416 posts)
9. This is complete and utter rubbish
Mon Mar 19, 2012, 04:34 PM
Mar 2012

One of the primary consequences of Bohm's hypothesis was the entanglement of all particles in the universe (possibly from his Buddhist philosophy). But in experiments these entanglements of "non-local" effects, the EPR experiments (Einstein, Poldasky, Rosen --- after an gedanken experiment proposed by Einstein). Needless to say the non-local effects posited by Bohm and others (i.e., faster than light) were shown to be falsified.

But don't believe me. I'm only a physics BS (and you know what those initials mean ). Rather, I'd encourage you to look beyond 1950's speculation (Bohm et al) and look at what the data since these hypotheses have been put forward.

Decoherence is rather simple. Quantum states are extremely fragile. Heisenberg showed that complementary variables (velocity vs. position, energy vs. time) are simultaneously unknowable. And it's not a problem of measurement accuracy, it's that the measurement of one restricts the accuracy of the other at the physical level. It's the second, energy/time, relation which blows Bohm's putative non-locality out of the water.

Decoherence strongly implies that the universe observes itself without any requirement for intelligence. It's just the way the universe works. It's all bottom-up emergent behavior. Complexity comes from something as simple as the uncertainty of the energy times the uncertainty of the time (that the value of the energy is known) is limited by a constant, Planck's constant (divided by 2 times Pi). Likewise, the momentum/position relationship.

If you disagree with these basic quantum principles and can demonstrate it you may be on the way to a Nobel prize.

Go for it.

In the meantime all macro behavior is emergent (bottom-up) from a basis of quantum mechanics, and all quantum behavior is random (the probability of which is given by the square of the wave equation).

There's no woo-woo in quantum physics, no matter what Chopra and other loonies, like JZ Knight, think. Bohm's hypotheses have been substantially falsified.

 

Silent3

(15,909 posts)
11. But, but... someone was wrong about something before...
Mon Mar 19, 2012, 05:07 PM
Mar 2012

Last edited Mon Mar 19, 2012, 07:56 PM - Edit history (1)

...therefore whatever woo I want to believe is true until it's proved wrong, and anyone who proves it wrong is probably just closed minded and wrong themselves, and my ideas are so much more exciting and open-minded and... weeeeeeeeeeeeeeeeeeeeeee!!!! Pseudoscience is fun!!!!!!

 

Silent3

(15,909 posts)
17. Your endless devotion to vagueness is certainly amusing, however.
Mon Mar 19, 2012, 08:23 PM
Mar 2012

It keeps you entertained, obviously, but it's scientific value is practically nil.

It's not some terribly "authoritarian" standard, nor is it a "religion", that puts proven science ahead of wild speculation, and there's a big difference between realizing that current science might be wrong in some ways and falling ridiculously in love with one's own unfounded speculative notion about what might be.

 

tama

(9,137 posts)
19. Why don't you even try?
Mon Mar 19, 2012, 09:07 PM
Mar 2012

There is nothing vague about stating that 'emergentism', reduction of biology and/or mental phenomena - including math - to mere classical physics are not empirically proven science but just word salad and wishfull thinking and philosophically irrational woo woo woo. There is nothing vague about stating that those who yet so believe and make such claims in the name of science are pseudoscientific cryptoreligionists when they behave like preachers and members of inquisition defending their orthodoxy.

In this thread I've seen you root for the claim (or rather the belief system of the claimant?) that the EPR thought experiment has been empirically falsified, which is blatantly wrong as the opposite is true. Showing up with such credentials as a "defender" of science on a god damn science forum makes it rather tempting to draw opposite conclusions about your true motives. But I rather withhold my judgement, stay open minded as well as I can and listen in case you might have something to say worth listening.












 

Silent3

(15,909 posts)
20. You seem to be getting different posters confused
Mon Mar 19, 2012, 09:32 PM
Mar 2012

I haven't personally said one thing about EPR.

I'm commenting on your long posting history. There don't seem to be any Deepak Chopra-ish, woo-laden ideas with the word "quantum" shoehorned into you them you don't like, that you don't think are wonderful ideas being repressed by the Soulless Minions of Orthodoxy.

 

tama

(9,137 posts)
28. Flattering ad hominem, thanks for that
Mon Mar 19, 2012, 11:43 PM
Mar 2012

But if you have problem with people trying to understand "quantum", please share those elsewhere and not in science topic.

 

Silent3

(15,909 posts)
29. I have no problem with people trying to understand "quantum"
Tue Mar 20, 2012, 12:09 AM
Mar 2012

What I have a problem with is people treating "quantum" like it means "magical faerie dust".

You aren't trying to understand "quantum", you're trying to project new-agey hopes and dreams upon the word without a scrap of evidence, claiming only that no one has the evidence to prove you wrong rather than accepting the burden of proving yourself right.

 

tama

(9,137 posts)
31. You are making up
Tue Mar 20, 2012, 12:43 AM
Mar 2012

ad hominems from your ass without a scrap of evidence. Burden of proof is on your side.

longship

(40,416 posts)
32. New Age?
Tue Mar 20, 2012, 12:44 AM
Mar 2012

I like the way Steve Novella (of the Skeptics Guide to the Universe says it. He pronounces it "newage" (rhymes with "sewage&quot .

Perfect, eh?

 

tama

(9,137 posts)
45. Pseudoskepticism
Thu Mar 22, 2012, 03:20 AM
Mar 2012

The term pseudoskepticism has found occasional use in controversial fields where opposition from scientific skeptics is strong. For example, in 1994, Susan Blackmore, a parapsychologist who became more skeptical and eventually became a CSICOP fellow in 1991, described what she termed the "worst kind of pseudoskepticism":

"There are some members of the skeptics’ groups who clearly believe they know the right answer prior to inquiry. They appear not to be interested in weighing alternatives, investigating strange claims, or trying out psychic experiences or altered states for themselves (heaven forbid!), but only in promoting their own particular belief structure and cohesion..."[20]
http://en.wikipedia.org/wiki/Scientific_skepticism#Pseudoskepticism

 

tama

(9,137 posts)
12. Nice
Mon Mar 19, 2012, 06:22 PM
Mar 2012

a post with content.

I don't have a degree from physics and my interest in these matters originates to a close relative who was a friend and coworker of Bohm. So I know quite well that Bohm didn't intend his theory for the final answer but rather as an ice-breaker between Einstein and Bohr collapse of dialogue, and to participate in scientific progress. And so I know also that Bohm was not entirely satisfied with his quantum theory, but not for reasons you claim, but because he was unable to find the chalice of math to put it all nicely together.

And I must say that I'm astonished at your BS (in both senses) about EPR, as the thought experiment was related to Einstein's dislike of "spooky action at distance" which later "experiments appear to show that the local realism idea is false,[3] thereby supporting the position of Bohr et al., against the challenge from Einstein and his group." (http://en.wikipedia.org/wiki/EPR_paradox).

NOT Bohm's non-locality but that of Bohr et alii, and NOT putative. Your lack of basics in your academic field seems to be well matched with your blown up ego.

To really start to understand quantum theory and it's implications I feel that it ismportant to start from "top-down" notions like wave function the size of universe, that are standard notions in contemporary cosmology, regardless of reductionistic or holistic preferences.

In (at least inflationary) cosmologies actualized physical complexity comes from cooling down of the hot-hot-hot singularity/quantum superposition of possible universes.

As for Uncertainty Principle, the question of understanding it as part of a bigger whole logically and mathematically leads naturally to fundamental principle of self-referentiality of which Gödel's incompleteness theorem is a groundbraking example.

If you were more interested in learning and understanding science instead of making it into just another authoritarian religion, I could go on about my pet Theory Of Everything that has scalable hbar, new quantum math of Hilbert spaces inside each point of Hilbert space that allow mathematical modelling self-referentiality with new understanding of also transcendentals (e.g. pi) and much much else and not excluding theory of consciousness... well maybe some day...









longship

(40,416 posts)
18. Sorry! Your post makes no physical sense
Mon Mar 19, 2012, 08:53 PM
Mar 2012

I'm having difficulty following your train of thought. However, in spite of your ad hominem attack, which I shall ignore, I will attempt to persevere.

First, even in the early 20th century there were no indications that QM had anything but bottom-up causality, in spite of many people's claims. QM has advanced significantly since Planck, Einstein, Bohr, Schrodinger, Heisenberg, Dirac, Feynman, and even Wilczek.

The proof to any claim in science is not the authority of the scientist but the authority of nature herself. Anybody claiming that quantum causality can go from top (macro) to bottom (micro, ie, Planck limit) has a tall order to fill.

First, there is zero evidence that has stood up to peer review. Second, this is in spite of the fact that there are still physicists who adhere to these opinions.

I shouldn't have to repeat this but the arbitrator of truth in science is not any scientist (certainly not me) but nature herself.

I do read physics, and I firmly think that QM says that causality goes from bottom to top; the behavior of the whole universe is emergent behavior. In spite of that opinion, there is zero evidence that anything in the macro universe can have any effect on things at or below the Planck limit. If there is any substantive evidence to the contrary I would like to hear about it because that would be very interesting.

Unfortunately, that hasn't yet happened. If you have evidence to the contrary there may be a Nobel Prize in your future.

 

tama

(9,137 posts)
24. First
Mon Mar 19, 2012, 11:13 PM
Mar 2012

thank you for ignoring perceived ad hominems.

Discussing causality philosophy cannot be avoided, nor history. I hope you bear with me as deeply ingrained ideas can be hard to let go as prerequisite to be able to think well about some other ideas, as I try my best to explain my current state of understanding.

It remains unclear what you mean by "quantum causality" and especially "bottom-up-such", when in fact you seem to be still talking about notion of causality in newtonian mechanics - which goes back to ancient atomists such as Democritus.

That kind of causality is not per se proven or empirically provable, as Hume pointed out, but a basic premisse of standard/classical physics, on which the standards of proof are built upon. Ideas about causality are dependent from notions of time.

Classic example of change in notion of time - and hence also causality - in physics is paradigm shift from absolute time in euclidean space of newtonian mechanics to relativistic time-space in non-euclidean riemannian manifolds (Einsteins theory as 4D Minkowski space). IIRC I read from Lee Smolin's popular book that the difficulties of combining general relativity with quantum mechanics arose from the latter being approached from the notion of absolute linear time inherent in newtonian mechanics, but in n-dimensional generalisation of euclidean space called Hilbert space defined as complete space with inner product. My math abilities are on the stretch here, but it is noteworthy that Minkowski space of Einsteins space-time has no inner product or indefinite inner product (http://en.wikipedia.org/wiki/Inner_product_space#The_Minkowski_inner_product).

Later partially succesfull combinations of quantum mechanics and relativity or "GUT"s such as Quantum electrodynamics have led to Feynmann diagrams where vectors called "propability amplitudes" go also backwards in time.

Hopefully this short excursion into history is sufficient to show that the basic notions of causality and time have allready changed quite a lot between the three theories mentioned - Newton, Relativity and QED, and search for empirically and logically sound TOE demands further changes. Especially if the TOE does not exclude life and consciousness, as it of course shouldn't.

Again, any notion of causality and time is not something that can be put under a microscope and directly verified, but presuppositions on which theories are build upon. And theoretical breakthroughs such as the three mentioned before require letting go of previous generally accepted notions of causality and time in order to find more general notions that allow to explain wider area of phenomena and/or combine theories allready as wide as relativity and QM.

Now, what kind of notions of time and causality are needed for a theory that can also explain itself - e.g. mathematical imaginations such as Minkowski space, Hilbert space, Feynman diagrams etc., that allow mathematical physicists to create thought experiments that pragmatic experimentalists can ask nature for empirical verifications and falsifications?

As said above in other post, Darwinian evolution presupposes complex physical environment that biological evolution adapts to - in top down manner. And only way that universe can include change and have life and evolution is that a participant observes a change - between this and that decoherred classical state. As decoherence does not presuppose collapse of wave function, and being conscious means being conscious of change between classical states, most natural and simple answer is that consciousness is quantum jump between classical states.





longship

(40,416 posts)
30. Tama, I'm with you
Tue Mar 20, 2012, 12:22 AM
Mar 2012

My argument is solely on the principle that any macro event like throwing a baseball, or thinking about throwing a baseball can have any causal effect other than what can be calculated classically.

The Coo Coo for Cocoa Puffs kooks like Deepak Chopra (all of whose top Google listings are for rubbish products marketed at his "Spa". But it's all natural! Yeah, so is arsenic.) Just because you can phrase an argument with the word quantum doesn't make it science. I'll add astrologers, ESPers, homeothepaths, dowsers, and a whole plethora of other lunacy and utter quackery who have staked their claim on a base of, as Murray Gell-Mann terms it, quantum flap doodle.

So forgive me for being skeptical of the claims of this post. As usual, the scientific method will sort it all out. Of that I'm sure. If not, I'm sure that the scientific method itself will sort itself out, as it has for centuries. It's amazing what adaptive, evolutionary processes can accomplish

On that I think we can agree.

Let the science sort itself out.

Thanks for the great discussion.


bananas

(27,509 posts)
34. Well that's clearly wrong
Tue Mar 20, 2012, 07:18 PM
Mar 2012

You wrote, "My argument is solely on the principle that any macro event like throwing a baseball, or thinking about throwing a baseball can have any causal effect other than what can be calculated classically."

If the baseball and bat are made out of uranium, then throwing a baseball certainly can have a causal effect which can't be calculated classically.

BOOM!

longship

(40,416 posts)
35. Wonderful take down
Wed Mar 21, 2012, 02:24 AM
Mar 2012

I bow to you. It's the perfect counter example. Only, I would suggest a slight modification. It would have to be U235, and then it would very rapidly blow itself apart before the chain reaction could sustain itself. Sorry, probably no mushroom cloud.

But it would still be a large bang. I can imagine Harry Caray doing the play-by-play.

 

Joseph8th

(228 posts)
41. Please! It's bad enough to tarnish QM...
Wed Mar 21, 2012, 10:27 PM
Mar 2012

... must you pick on Godel, too?!? Godel's theorems are mathematical theorems, not theories of physics. They bear no relation to physics. None. Not any. Zero (by definition). What's more, you clearly have no clue what they actually do relate to, since they are pretty damn specific, and wonderful. Godel settled an important modern issue of set theory, and made possible the set theory we now have, which enables analysis on a scale unimaginable before. Again, tama, I recommend you read and learn... as they say, "lurk moar"... about math and science, before acting like you're some sort of expert. It's truly embarrassing.

 

tama

(9,137 posts)
43. Gödel
Thu Mar 22, 2012, 03:02 AM
Mar 2012

proved that any formal logical system containing number theory has propositions that are unprovable within a finite set of axioms. That is highly relevant for all mathematical physics based on logic and especially so for approaches of physics as generalized number theory.

The philosophical problems of the relation of mathematics and physics is not an invitation to push them aside and stop thinking about them. Especially if you are looking for a TOE that does not exclude consciousness.

But if you have allready settled for a materialistic belief system, then thinking further can be dangerous and should be avoided at all costs.

 

Joseph8th

(228 posts)
46. Looking for a ToE ...
Fri Mar 23, 2012, 12:04 PM
Mar 2012

... that does not exclude consciousness is the problem. The ToE is, once again, a very specific thing. You can search for some other theory of everything that isn't THE ToE that physicists care about, if you want, but you shouldn't then expect physicists to take it seriously.

You keep talking about "mathematical physics" but physicists just USE mathematics... the physics itself is physical (hence the name), and not mathematical... only the models are mathematical. Moreover, speaking as a mathematician, physicists are mostly hand-wavers to begin with and they don't prove theorems. That's our job. Hell, there's not even a Nobel prize for mathematics, because it's not an empirical science. It's a common mistake to confuse math theories (collections of axioms, definitions, theorems, lemmas, etc.) and scientific theories, but the word "theory" has a very different meaning in pure mathematics than it does in science.

Number theory in particular has very few applications in physics, though some M-theorists have been flirting with Number theory's elliptic curve theory. It's 1st application, though, was to cryptology, not physics, at all.

In short, it's a mistake to consider mathematical objects "real" and math theories "scientific". Godel's is math.

 

tama

(9,137 posts)
47. Abstract
Fri Mar 23, 2012, 02:37 PM
Mar 2012

physics is abstract noun as is category of physicists as whole, and so their "seriousnes" does not really concern me or the ideas I like to discuss, it is concern of those who like arguments from authority and expect those to be taken seriously. There are people with title "physicist" who have interesting and deep ideas about "Life, Universe and Everything" and many that don't have much to say.

That said, there are some physicists who have had close relation with Gödel and his ideas (Einstein) and think that his proof is relevant to the search for Final Theory version of TOE:


Freeman Dyson has stated that
“ Gödel’s theorem implies that pure mathematics is inexhaustible. No matter how many problems we solve, there will always be other problems that cannot be solved within the existing rules. [...] Because of Gödel's theorem, physics is inexhaustible too. The laws of physics are a finite set of rules, and include the rules for doing mathematics, so that Gödel's theorem applies to them. ”

—NYRB, May 13, 2004

Stephen Hawking was originally a believer in the Theory of Everything but, after considering Gödel's Theorem, concluded that one was not obtainable.
“ Some people will be very disappointed if there is not an ultimate theory, that can be formulated as a finite number of principles. I used to belong to that camp, but I have changed my mind. ”

—Gödel and the end of physics, July 20, 2002

Jürgen Schmidhuber (1997) has argued against this view; he points out that Gödel's theorems are irrelevant for computable physics.[18] In 2000, Schmidhuber explicitly constructed limit-computable, deterministic universes whose pseudo-randomness based on undecidable, Gödel-like halting problems is extremely hard to detect but does not at all prevent formal TOEs describable by very few bits of information.[19]

http://en.wikipedia.org/wiki/Theory_of_everything#G.C3.B6del.27s_incompleteness_theorem

Also you are probably familiar with Wigner's classic article called "The Unreasonable Effectiveness of Mathematics in the Natural Sciences.
http://en.wikipedia.org/wiki/The_Unreasonable_Effectiveness_of_Mathematics_in_the_Natural_Sciences

I would rather say that the Big Ego of some physicists think it is just using math, just as the Big Ego of English speakers makes them say and think that they are using English, forgetting that category of subject is internal to language and very small part of it.

Many sources say that most theoretical physicists support some form of platonism, as you can't do theoretical physics without math and number theory (I don't have any actual survey available so that hearsay can be wrong). And as for particulars, most famously there is close connection between Riemann hypothesis and quantum theory known as Hilbert-Pólya conjecture; there are p-adic descriptions of quantum theory, etc. See more:
http://empslocal.ex.ac.uk/people/staff/mrwatkin/zeta/surprising.htm

Scientific realism "states that the universe contains just those properties that feature in a scientific description of it; not properties like colour per se but merely objects that reflect certain wavelengths owing to their microscopic surface texture." Scientific descriptions being mathematical descriptions, but mathematics itself not being scientifically described and in that sense "transcendental" or "supernatural" (instead real part of nature just as phenomena described by math) is very paradoxical and irrational position.

This is one of the main reasons why I consider "Scientific realism" a lá materialism and positivism and objectivism irrational belief systems and especially so when emotionally attached to.

 

Joseph8th

(228 posts)
49. Not sure why I'm bothering, but...
Mon Mar 26, 2012, 09:52 PM
Mar 2012

... interesting synopsis that doesn't advance any position that I can discern, as it is full of contradictory positions. I'm aware of these debates, but again assert that they are completely secondary and only interesting from a philosophy of science POV. Naturally, they're quite interesting to mathematicians, who regularly deal with both the unimaginable and the physically impossible. (Just try visualizing an N-dimensional sphere.) But physicists are constrained by additional considerations that are uninteresting to most mathematicians. Things like the boring ole laws of physics. I mean, really. I have no desire to whip out some maths so astronauts can poo in space. Often, we don't even understand each other's notation on the same exact subject (just look in Lie groups by math ppl vs. physicists). And, of course, there is a famous historical animosity between pure and applied math, even within the single department.

For math, Godel's thm is great because it's job security. We'll always have interesting problems to work on.

But only a tiny percentage of those will be found to be useful in the sense that they somehow model behavior of observables. For instance, string-theory asserts that nature has a minimum size -- that means that if we want to apply that model, we can no longer assume (as we normally do in the analysis underlying almost all physics) the Archimedean Principle holds in nature. That's pretty big, and that's why string theory math is hairy. If you start shrinking down to Planck scale, you will just start getting bigger, again. That's completely unintuitive when we're used to assuming that we can always find another point between any two points. So here's an example of a really really fundamental mathematical principle that physicists assume all the time, but which physicists cavalierly tossed aside to even begin to reconcile QM and relativity at the Planck scale.

So insofar as Godel's says there's an infinite pools of math problems (of a certain sort), then yeah, there's plenty of maths for physicists to exploit. Doesn't mean any of it accurately models nature.

 

tama

(9,137 posts)
50. Some good points
Mon Mar 26, 2012, 10:26 PM
Mar 2012

First, all math that physicists exploit presupposes number theory. But it also seems that standard set theory is not enough to model nature and the "Cantor's Paradise" has to be abandoned as the premisse of mathematical physics.

One of the problems that you seem to refer to is reals with infinite measurement resolution and physical universe of finite measurement resolution. P-adics and adeles show much promise for fixing this problem and describing the fractal and non-continuous nature of quantum world.

 

Joseph8th

(228 posts)
53. Heheh... Cantor's Paradise...
Wed Mar 28, 2012, 07:19 AM
Mar 2012

Welll... that's not what I'm suggesting. String theory solution is topological, but still over a field (i.e., real or complex, not a ring or lattice, and not a physical field), in that way maintaining uniformity of spacetime so that relativity can hold at near Planck scales. In that all fields depend on ZFC set theory, it's just really silly to toss Cantor out the window for no reason at all. Not sure where you got that. There has been some research into the possible usefulness of some number theory to string theory, but we don't just abandon set theory willy-nilly.

P-adics are interesting and useful in some contexts, but are just another way of expressing numbers. Particularly useful as a way of dealing with incomprehensibly tiny rationals without resort to decimal expansion or scientific notation.

Again, it's a mistake to look to mathematics for answers to empirical problems. Look to math for useful tools to model empirical data within the scientific method... sure. But not the meaning of life or true nature of reality. Math isn't 'real'. It's all in our heads. Abstract.

bananas

(27,509 posts)
51. LOL - "mathematical theorems ... bear no relation to physics"
Tue Mar 27, 2012, 01:40 PM
Mar 2012

You guys crack me up!

Math is all about logic and reasoning, apparently you think physics is illogical and irrational.
Physics is about using logic and reasoning to understand the physical universe,
and mathematical theorems absolutely do apply.

http://en.wikipedia.org/wiki/Mathematical_physics

The effort to put physical theories on a mathematically rigorous footing has inspired many mathematical developments. For example, the development of quantum mechanics and some aspects of functional analysis parallel each other in many ways. The mathematical study of quantum statistical mechanics has motivated results in operator algebras. The attempt to construct a rigorous quantum field theory has brought about progress in fields such as representation theory. Use of geometry and topology plays an important role in string theory.


Joseph8th, I recommend you read and learn... as they say, "lurk moar"... about math and science, before acting like you're some sort of expert. It's truly embarrassing.

 

Joseph8th

(228 posts)
52. Math is not physics...
Wed Mar 28, 2012, 06:52 AM
Mar 2012

... "has inspired many mathematical developments"

... "the development of quantum mechanics and some aspects of functional analysis parallel each other in many ways"

... "Use of geometry and topology plays an important role in string theory."

Yeah. That's what I said. I'm sorry if you're embarrassed, but I'm not wrong. Physical theories are comprised of models, which use math that is proven in theorems. But pure mathematics is NOT an empirical science. What physicists do with math is up to them, and I've already said that some cool physics has inspired some groovy math (calculus springs to mind), but we write proofs. When we want to prove Pythagoras' Theorem (triangle inequality), we don't measure the sides of the triangle and compare the numbers. That doesn't prove squat. We resort to abstract logic, completely divorced from 'reality' or empirical data.

If physicists then use the triangle inequality in their effort to explain, i.e., elliptical orbits, and need some sort of method to sum infinitesimal areas, inventing calculus in the process, it doesn't obviate the need to prove the Fundamental Theorem of Calculus mathematically -- that is, without recourse to empirical data or specific examples.

Even the definition of "mathematical physics" hints at the long-simmering animosity between pure and applied mathematics, and modern efforts to bridge that gap. My pure math profs still complain about all the "hand-waving" that applied math & physics profs use to make short cuts. My applied & physics profs don't disagree. I think most physicists would like to "put physical theories on a mathematically rigorous footing", but when you're trying to keep a rocket in space, it's less important to understand FTC than it is to be an equation monkey.

It still doesn't change the fact that it's a mistake to suggest that math is 'real' in nature, or that mathematics is a science. All my pure math profs call it the art of writing elegant logical proofs. Or as my number theory prof exclaimed, "I HATE numerals!"

 

Joseph8th

(228 posts)
54. Physics is NOT illogical or irrational...
Wed Mar 28, 2012, 07:30 AM
Mar 2012

... MY point is that proving a purely mathematical theorem proves nothing about the physical universe. Physics depends on mathematics, but the converse is not true.

I'm not acting like some sort of expert...

 

Joseph8th

(228 posts)
38. I didn't know there were Militant Holists, now...
Wed Mar 21, 2012, 05:56 PM
Mar 2012

... verrrry interesting. Have you tr0lled randi.org yet?

 

tama

(9,137 posts)
39. LOL
Wed Mar 21, 2012, 07:31 PM
Mar 2012

the occational militant tone comes from getting too much entangled with Militant Reductionists... ;D

 

tama

(9,137 posts)
44. Condencending tone
Thu Mar 22, 2012, 03:09 AM
Mar 2012

is not an argument, it's just a psychological trick when playing power games. Boring waste of bandwidth.

 

tama

(9,137 posts)
7. Anybody
Mon Mar 19, 2012, 03:38 PM
Mar 2012

who follows the research can understand that causal link, and that the causal link is not just linear but also codependent:


The resolution of this paradox suggested by Bryce DeWitt is rather instructive (DeWitt, 1967). The notion of evolution is not applicable to the universe as a whole since there is no external observer with respect to the universe, and there is no external clock that does not belong to the universe. However, we do not actually ask why the universe as a whole is evolving. We are just trying to understand our own experimental data. Thus, a more precisely formulated question is why do we see the universe evolving in time in a given way. In order to answer this question one should first divide the universe into two main pieces: i) an observer with his clock and other measuring devices and ii) the rest of the universe. Then it can be shown that the wave function of the rest of the universe does depend on the state of the clock of the observer, i.e. on his ‘time’. This time dependence in some sense is ‘objective’: the results obtained by different (macroscopic) observers living in the same quantum state of the universe and using sufficiently good (macroscopic) measuring apparatus agree with each other.

Thus we see that without introducing an observer, we have a dead universe, which does not evolve in time. This example demonstrates an unusually important role played by the concept of an observer in quantum cosmology. John Wheeler underscored the complexity of the situation, replacing the word observer by the word participant, and introducing such terms as a ‘self-observing universe’.

Most of the time, when discussing quantum cosmology, one can remain entirely within the bounds set by purely physical categories, regarding an observer simply as an automaton, and not dealing with questions of whether he/she/it has consciousness or feels anything during the process of observation. This limitation is harmless for many practical purposes. But we cannot rule out the possibility that carefully avoiding the concept of consciousness in quantum cosmology may lead to an artificial narrowing of our outlook.


Inflation, Quantum Cosmology
and the Anthropic Principle
Andrei Linde
http://arxiv.org/abs/hep-th/0211048v2

longship

(40,416 posts)
10. Hmm. DeWitt. Interesting
Mon Mar 19, 2012, 04:59 PM
Mar 2012

You're talking about MWI, multiple worlds interpretation, of quantum mechanics.

But DeWitt's hypothesis is based on the apparent paradox of wave-particle duality, most specifically in the dual slit experiment. The premise is that light (or because of deBroglie, any particle of matter) acts differently when the measurement tries to detect a wave vs. when the measurement tries to detect a particle. But, this is wrong. Light (electrons, or any other quantumly entangled system) is neither a wave nor a particle. It is something for which we have no common experience. But that doesn't mean that some kook like Chopra or a lunatic look like J Z Knight can turn physics upside-down by mere pronouncement.

To do that it takes evidence, not opinion. If you can demonstrate to the satisfaction of the very picky physics community that there is any top-down causality in QM, fame and fortune would deservably be yours. And I would be on your side.

It's the evidence, not the idea. As of now, too many of the proponents of this are demonstrable nut cases.

 

tama

(9,137 posts)
14. First
Mon Mar 19, 2012, 06:54 PM
Mar 2012

I'm not a big fan of the "million flies can't be wrong" argument (though as a gardener I agree that shit is good ). String theorists and with them much of the "very picky physics community" are also IMO "not even wrong", as the famous and often used quote from Pauli says.

Also, I'm not a proponent of Chopra and J Z Knight I don't know and don't bother to google up.

And no, the point was not the many-world-interpretation by Everett, DeWitt and Deutch et alii, which IMO is just a poor attempt to hold on to deterministic linear causality in its most crude form.

The point was the content of the quote - relations between change and time and observer participation. Very basic and simple. And that the million flies that claim that we live in lifeless universe devoid of consciousness keep (actively?) forgetting a very simple fact. Which is...?

longship

(40,416 posts)
21. Okay, I'm with you on all except the "observer"
Mon Mar 19, 2012, 09:57 PM
Mar 2012

That's where many QM conversations go horribly wrong. The observer is just that, one who sees but has no effect. Looking only has an effect when the technology of your looking bridges the gap (make no mistake here, the gap is very real) between the quantum world and the macro world.

Putting it crudely, there is a qualitative difference between baseballs and electrons. Don't expect either to act like the other. No metaphor about quantum mechanics prepares a physics student for the study of quantum mechanics.

Richard Feynman was correct when he said that anybody professing to understand quantum mechanics doesn't understand quantum mechanics. But that doesn't mean that we know nothing about quantum mechanics. After all, Feynman himself said that the accuracy of the the theory was such as measuring the distance from LA to NYC to the diameter of a single hair.

Yes, to a non-physicist QM is mysterious, and there are aspects of it that still puzzle all physicists. But that doesn't give just any wackaloon permission to make up shit like there's top-down causality. Just ain't there, so far as anybody knows.

caraher

(6,359 posts)
22. Well, I think there's more to the "observer" unless you're effectively redefining the term
Mon Mar 19, 2012, 10:07 PM
Mar 2012

Usually I'd put it the other way around: the observer *always* has an effect, but the observer need not be conscious. I do agree there's a bit of a muddle brought on by the use of that word, but it's been with us since the time of Bohr and friends and it's probably too late to come up with a new convention.

Pretty much by definition there's a qualitative difference between the classical and quantum worlds, but really nailing down exactly how the classical world emerges from the laws of quantum theory is surprisingly challenging. I'm most intrigued by the work of Zurek, who does exactly the kinds of calculations mentioned in the OP that imply very fast decoherence times that seem to preclude the roles claimed for quantum coherence in most biological systems.

longship

(40,416 posts)
23. Touché, Zurek is above my pay grade
Mon Mar 19, 2012, 10:35 PM
Mar 2012

However, he's still talking about quantum effects at quantum scales. One of the huge problems in quantum computing is to have the principles of QM scale to a high enough level to make the Qbit a practical reality.

The most advanced research in this field, as far as I know, is that of Bose-Einstein condensates. It's where multiple atoms, or molecules, can act as a single quantum entity. This is cutting edge shit. And anybody could guess where it's going. But one thing's for sure, there ain't yet any top-down causality.

(just re-emphasizin')

caraher

(6,359 posts)
26. I do think we're broadly in agreement
Mon Mar 19, 2012, 11:20 PM
Mar 2012

What's nifty about the paper in the OP is that it suggests that in systems with the right dynamics, you can get very long coherence times in circumstances where we'd expect them to be very short. So in terms of quantum computing you might get very long-lived qubits, or at least long-lived storage of quantum states (even if you can't operate on them).

 

tama

(9,137 posts)
27. Thanks
Mon Mar 19, 2012, 11:35 PM
Mar 2012

The no-cloning theorem sounds highly relevant also in this discussion. If I understood correctly it also implies that the state of this chair my ass is now located on can be "cloned" (at least close enough to prevent my ass observing a drop on the floor) only by these "clones" being included inside a larger inclusive "Russian doll" quantum state.

 

tama

(9,137 posts)
37. Delayed choice experiment
Wed Mar 21, 2012, 11:08 AM
Mar 2012

is Wheeler's modification of the original Young's double slit experiment:
http://en.wikipedia.org/wiki/Wheeler%27s_delayed_choice_experiment

If you are looking for empirical evidence of observer effect and "backwards causation", there you go:



John Archibald Wheeler is one of those thinkers who takes the ideas of quantum mechanics seriously. After studying the Copenhagen explanation of the double slit experiment – with its emphasis on what the observer knows and when it is known – Wheeler realized that the observer's choice might control those variables in a test.

"If what you say is true," he said (in effect), "then I may choose to know a property after the event should already have taken place." [1] Wheeler realized that in such a situation, the observer's choice would determine the outcome of the experiment – regardless of whether the outcome should logically have been determined long ago.

"Nonsense," said the reductionists. "Rubbish," said the materialists. "Completely absurd," said the naïve realists. "Yup," said the mathematicians.

And so Wheeler's thought experiment and the predictions of quantum mechanics were brought to the laboratory for testing. [2] This is what happens.

(...)

So it seems that time has nothing to do with effects of quantum mechanics. And, indeed, the original thought experiment was not based on any analysis of how particles evolve and behave over time – it was based on the mathematics. This is what the mathematics predicted for a result, and this is exactly the result obtained in the laboratory.

http://www.bottomlayer.com/bottom/basic_delayed_choice.htm

arendt

(5,078 posts)
2. So Stuart Kaufmann is still working..
Sun Mar 18, 2012, 10:57 PM
Mar 2012
Stuart_Kauffman has always been a difficult read.

He was most well-known in the early 1990s for "The Origins of Order".

Thanks for posting.
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