Friday, November 22, 2013

Sluggishly expanding wave function

Leftist-atheist-evolutionist Jerry Coyne attacks Deepak Chopra for saying things like these:
Consciousness may exist in photons, which seem to be the carrier of all information in the universe.

You know, the idea here is that if we quieten the turbulence in our collective mind and heal the rift in our collective soul, could that have an effect on nature's mind, if nature has a mind? The gaia hypothesis says nature does have a mind, that the globe is conscious. So a critical mass of people praying or a critical mass of people collectively engaging in meditation could conceivably, even from modern physics point of view, through non-local interactions, actually simmer down the turbulence in nature.

The moon exists in consciousness — no consciousness, no moon — just a sluggishly expanding wave function in a superposition of possibilities. All happens within consciousness and nowhere else.
See also Coyne's blog, here and here.

I might agree with Coyne that this is unscientific "woo", except that it is not too different from goofy interpretations of quantum mechanics espoused by big-shot physicists.

For a more sane view, Federico Laudisa writes Non-Local Realistic Theories and the Scope of the Bell Theorem:
According to a widespread view, the Bell theorem establishes the untenability of so-called 'local realism'. On the basis of this view, recent proposals by Leggett, Zeilinger and others have been developed according to which it can be proved that even some non-local realistic theories have to be ruled out. As a consequence, within this view the Bell theorem allows one to establish that no reasonable form of realism, be it local or non-local, can be made compatible with the (experimentally tested) predictions of quantum mechanics. In the present paper it is argued that the Bell theorem has demonstrably nothing to do with the 'realism' as defined by these authors and that, as a consequence, their conclusions about the foundational significance of the Bell theorem are unjustified.
That's right, there is no proof that either locality or realism is wrong. Those who say otherwise sound just like Deepak Chopra to me.

A new paper, An Introduction to QBism with an Application to the Locality of Quantum Mechanics, by Christopher A. Fuchs, N. David Mermin, Ruediger Schack, explains:
We give an introduction to the QBist interpretation of quantum mechanics. We note that it removes the paradoxes, conundra, and pseudo-problems that have plagued quantum foundations for the past nine decades. As an example, we show in detail how it eliminates quantum "nonlocality".
They act as if they have something new, but they admit that their interpretation is essentially the same as Bohr's, and so all of those problems were solved by the Copenhagen interpretation decades ago.

It is a consequence of the Schroedinger equation that the wave function of the Moon, or of an electron, is indeed a sluggishly expanding wave function in a superposition of possibilities. But electrons and moons are never observed to sluggishly expand. The obvious conclusion is that the electrons and moons are real, but the wave function is a description of our knowledge of their states. That is, my interpretation is epistemic, not ontic. You can believe in that sluggish expansion if you wish, but if you take the wave function too seriously, you can reach some faulty conclusions.

I say that the possibility of quantum computing is an open question, but my personal belief is that it will be impossible for these reasons:

1. The argument for quantum computing is not based on any proven properties of quantum mechanics, but on our inability to simulate quantum systems efficiently in a Turing machine.

2. A lot of smart people have spent a lot of money over decades to demonstrate some super-Turing computing, and no one has succeeded, in spite of recent claims.

3. The computational complexity implications would be sufficiently surprising and contrary to conventional wisdom that claims about a quantum computer should be met with the same extreme skepticism as claims of faster-than-light communication.

4. Quantum computing is an attempt to take advantage of quantum nonlocality, but there is no such thing.

5. Quantum computing requires an interpretation similar to Chopra saying that the Moon is "just a sluggishly expanding wave function in a superposition of possibilities." That sluggish superposition exists in the mind, and it is implausible that it can be used for useful computation.

Other sensible people disagree, such as Scott Aaronson betting that I am wrong. So far, no Nobel prizes have been awarded for quantum computing.

Update: Steven Salzberg piles on:
Chopra’s claim that photons have consciousness, I have to say, is the purest nonsense. Does Chopra even know what a photon is? ... So both photons and the entire planet are conscious. I can see why Coyne called this psychobabble.

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