Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: tanian on 13/06/2009 12:25:37

Title: Quantum Mechanical Superposition: limited or not?
Post by: tanian on 13/06/2009 12:25:37
I'm a layman, and my layman's education means my reading often poses more questions than answers. Take this article as an example:

http://www.newscientist.com/article/mg20227115.800-stretched-neutrinos-could-span-the-universe.html

New Scientist state that "relic" neutrinos have three QM Superposited mass-energy states that span the universe.

If this is so then their wave forms should be infinite, as far as our universe is concerned.

My question: Are their limits to QM Superposition, or can something become infinite by virtue of its wave function? 
Title: Quantum Mechanical Superposition: limited or not?
Post by: LeeE on 13/06/2009 18:22:16
There are a few ways which, by manipulating dimensional stuff, that a particle could span the universe but I'm not so sure about achieving it with superpositions.  I guess it might depend on what quality or property the superpositions were actually representative of.

Neutrinos, having mass, wouldn't have turned up until relatively late in the BB, but you could hypothesize a photon having a wavelength equal to the diameter of the BB in its early stages, which would thus straddle the universe.  If it did so exactly then it would continue to straddle the universe as it expanded.  Trouble with this though, is that having such a long wavelength would mean that the photon had relatively low energy, which would be incompatible with the ambient energy density around at the time; I think it might be improbable that such a low-energy photon would maintain its integrity under those conditions.
Title: Quantum Mechanical Superposition: limited or not?
Post by: lyner on 13/06/2009 20:16:26
Bearing in mind that black body radiation has a range of frequencies (starting, classically at zero) there is no conflict between the existence of a few photons with extremely long wavelength and the photons with the mean wavelength of the CMBR.