Skip to comments.Natural selection acts on the quantum world
Posted on 12/23/2004 8:31:39 AM PST by PatrickHenry
click here to read article
Gibberish. On three levels.
Ok, if its gibberish, can you demonstrate a time event that is NOT a kinetic energy event?
Evolution (of all things) is evidence of God's existence. St Thomas Acquinas
The power available through kinetic energy is vastly underrated. Time, however, is a percept.
"I donno about this one. But it's a slow day for new threads."
L O L!
Here come the Quantum Creationists.
Well, this is interesting. Darwinism continues to show general utility. How would Creationism possibly be used here?
I always said it was turtles all the way down.
Sounds like a joke thread to me. All life is macroscopic in nature - even viruses and bacteria. No living thing exists on the Plank scale. An observation, in the sense of quantum mechanics occurs on the size scale were quantum mechanics dominates. To influence a quantum state, you must observe on the quantum scale. At our large scale, quantum effects blurr into the classical laws of physics. This is the decoherence mentioned in the article.
This is the part of the articel I have trouble with: Physicists agree that the macroscopic or classical world (which seems to have a single, 'objective' state) emerges from the quantum world of many possible states through a phenomenon called decoherence, according to which interactions between the quantum states of the system of interest and its environment serve to 'collapse' those states into a single outcome. But this process of decoherence still isn't fully understood.
I always thought that the quantum states were properties associated with materials invovled. For example, the green in the leaves of a tree arise from the absorption of light of a frequency whose energy matches the quantum transition from a ground state to an excited state in chlorophyll. One molecule of chlorophyll is like every other and has the same transition state. The only change would be slight variations in its chemical environent that can casue the energy for the transition to shift slightly higher or lower, hence casuing a broadening of the wavelength window responsible for the observed color. I don't see where the authors see a continuum of states and some are selected on a macroscopic scale when the quantum effects are entirely macroscopic and the possible states are determined before even reaching the classical domain.
It is physically impossible even for two macroscopic observers to see the exact same thing. For example, if two people were looking at a flower, each person sees something different. Different photons of light reach the different people. No two people detect the same photon or the same transition.
The environment as a whole is always declaring itself to itself (more or less clearly and distinctly, as Descartes might have put it), and the states of the environment which are able to successfully (and consistently) declare themselves to their surroundings are the states which come to be regarded as objective by observers (should there be any).
From one part to all of the others: makes sense to me.
Decoherence is caused by the interaction with the environment. Environment monitors certain observables of the system, destroying interference between the pointer states corresponding to their eigenvalues. This leads to environment-induced superselection or einselection, a quantum process associated with selective loss of information. Einselected pointer states are stable. They can retain correlations with the rest of the Universe in spite of the environment. Einselection enforces classicality by imposing an effective ban on the vast majority of the Hilbert space, eliminating especially the flagrantly non-local "Schrödinger cat" states. Classical structure of phase space emerges from the quantum Hilbert space in the appropriate macroscopic limit: Combination of einselection with dynamics leads to the idealizations of a point and of a classical trajectory. In measurements, einselection replaces quantum entanglement between the apparatus and the measured system with the classical correlation.
And here's a link to the PDF version of Zurek's pre-print article:
Ladder operators, perhaps. :-)
All right, I'll bite, I don't mind.
What about when the light is acting like a wave?
had not the means
Einstein didn't want 'em
It took Neils Bohr
and several more
to figure out the quantum...
(Hazy quote from memory, from (I believe) an old article in Physics Today...)
Cheers and Merry Christmas!
Merry Christmas, too!
"Actually, I'm a Quantum Presbyterian..."
Happily, this tends to happen automatically, because each individual's observation is based on only a tiny part of the environmental imprint. For example, we're never in danger of 'using up' all the photons bouncing off a tree, no matter how many people we assemble to look at it.
If you assemble enough people, those in the back won't be able to see the tree, because others are in the way. The people in front used up those photons, you see (or not, as the case may be).
Zurek speaks of 'environmental monitoring', seeming to reserve 'observing' for the sort of monitoring that we do. What might monitoring mean if there are no observers like us around? Something along these lines, I'd surmise: exchanges of energy/momentum. A source of photons, for example, is announcing itself to its surroundings, and any absorption event of any of the emitted photons constitutes a 'monitoring' of the emitter by the absorber. If the source is constant and prolific, there will be many opportunities for many different absorbers to 'monitor' that source. It's precisely such sources that observers (whenever and wherever they come to be) come to recognize as 'objective'.
If I can find some time, I'm going to read selected portions of Zurek's pre-print (skipping over the parts that would require too much work to understand). If I find reason to modify the previous paragraph, I'll post a correction on this thread. However, if I don't post a correction, don't take that as evidence that the previous paragraph is correct. Maybe I just didn't get around to reading the pre-print, or, if I did, I didn't properly understand it!
If you assemble enough people, those in the back won't be able to see the tree ...
And if everyone goes home, the decoherence goes with them, the forest reverts to quantum mush, and the elves come out to play.
| [sighs] These kind of threads
always make me wonder why
if the researchers
have a deep insight
into randomness, they don't
live in Las Vegas . . .
The 'pointer states' are the 'robust' states, which are able to survive and continue to announce themselves to their surroundings. The analogy with Darwinism is a bit strained, I'll agree. Zurek wouldn't be the first physicist to co-opt some aspect of evolution into physics. Lee Smolin comes to mind.
I read it. It hurt. I'm going to go lie down for a while.
Those with a deep understanding of randomness either avoid Las Vegas (and other gambling estblishments) or the own one (or at least they own a floating crap game, on a riverboat.)
I dunno. When I was a teenager, and just learning about quantum, I misread the term "hadron" as "hardon."
I was giggling for days until I realized my mistake.
Ah, the wonders of selective dyslexia...
Color me poor, but
I bet some day, someone with
("Parrondo games") makes
roulette a "game" of the past.
Now, lottery games . . .
Decoherence is caused by the interaction with the environment. Environment monitors certain observables of the system, destroying interference between the pointer states corresponding to their eigenvalues. This leads to environment-induced superselection or einselection, a quantum process associated with selective loss of information. Einselected pointer states are stable. They can retain correlations with the rest of the Universe in spite of the environment. Einselection enforces classicality by imposing an effective ban on the vast majority of the Hilbert space, eliminating especially the flagrantly non-local "Schrödinger cat" states...Thank you, modern science, for providing yet more evidence of the truth of creationism! All you scientist scaled the mountaintops only to find the priests already there. Here's how it works...
This loss of information happened at The Fall. When G-D kicked Adam & Eve out of the garden, He removed H~s protection of all the majickal, non-localized quantum states, eventually leaving only cold, cruel, Darwinian objectivity to survive.
In short: Objectivity is all Satan's fault.
But now, if we let G*D into our hearts, He'll extend H-s protection back to all those fragile quantum states while you pray to H^m. This is why prayer produces miracles.
(This argument, or something like it, coming soon to an AiG or Creation/Evolution Headlines website near you. :-)
What's the superiority of Zurek's approach over Bohmian mechanics?
Ideas based on the immersion of the system in the environment have recently gained enough support to be described (by sceptics!) as the new orthodoxy (Bub, 1997). This is a dangerous characterization, as it suggests that the interpretation based on the recognition of the role of the environment is both complete and widely accepted. Neither is certainly the case.In other words, Zurek's approach is not known to work, whereas Bohmian mechanics is known to be equivalent to the Copenhagen interpretation where the latter is unambiguous.
I donno. I just post the stuff. Maybe one of the smart guys around here can help.
This is quantum natural selection, not quantum evolution. As someone who questions macro-evolution, I have no problem with the ideas put forth in this article.
Metaphysical paraconformities ping. (aka quantum fun-house mirror)
My understanding is different. Decoherence is interaction with the environment destroying entanglement - in effect, the environment "factors" an entangled quantum state into independent parts. It does not explain how a mixed state "collapses" to a single outcome.
Whoever wrote this apparently has been spending too much time with my sister or has fallen into a Mixmaster at some point in his life.
This whole mess is B.S.; rather like comparing a telescope to a fishing net.
... or in the back of the Biltmore Garage, especially if his name is Nathan.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.