On 8/12/2017 11:46 am, Bruce Kellett wrote:
On 8/12/2017 11:43 am, smitra wrote:
On 08-12-2017 00:22, Bruce Kellett wrote:
On 8/12/2017 3:31 am, Bruno Marchal wrote:
On 06 Dec 2017, at 12:19, Bruce Kellett wrote:
But as I pointed out, thermal motion gives momenta of magnitudes
such that the quantum uncertainties are negligible compared to the
thermal randomness. And thermal motions are not coherent.
You seem to work in Bohr QM, with some dualism between the quantum
reality and the classical reality.
Not at all. The (semi-)classical world emerges from the quantum
substrate; if you cannot give an account of this, then you have failed
to explain our everyday experience. And explaining that experience is
the purpose of physics.
You are right that this does not change anything FAPP, but our
discussion is not about practical applications, but metaphysics.
No, we were talking about tossing a coin, we were not talking about
metaphysics. Your metaphysics has served merely to confuse you to the
extent that you do not understand even the simplest physics.
Andreas Albrecht is not confused about anything,
How do you know?
and yet he agrees with Bruno on the point of coin tosses.
Argument from authority?
I presume you are referring to this paper: Albrecht and Phillips,
arXiv:1212.0953
I find the arguments present in this paper far from convincing. It
appears to be based on his analysis of an idealized gas of billiard
balls in Section III. He takes and initial uncertainty in transverse
position of a typical particle as given by the width of the associated
wave packet. The uncertainty in transverse momentum is given by the UP.
He then calculates the number of collisions such that the uncertainty in
the impact parameter equals the diameter of the particles involved. He
concludes that if this number is small (<~ 1) then quantum uncertainties
dominate the random fluctuations.
But this does not follow. He has used a classical calculation and has
taken no account of thermal fluctuations.He suggests that thermal
fluctuations should be calculable in this way, but that flies in the
face of a long history of classical statistical mechanics and
thermodynamics. The motions in the ideal gas are dominated by thermal
chaos. The uncertainties in positions and momenta are thermal, and
follow the classical Boltmann distribution. Because they fail to compare
their pseudo-quantum calculation with the known thermal effects, their
calculation is essentially meaningless.
They then seek to claim that the randomness in a coin toss is due to
uncertainties in neural transit times, and further claims that the prior
analysis shows that these are fundamentally quantum in origin. This does
not follow from the arguments presented. Furthermore, even if these
uncertainties are largely quantum in origin, it does not follow that a
single coin toss is the amplification of a single quantum event, so they
have not demonstrated that for every "heads" result, there is a parallel
universe in which the result was "tails" -- because they have not
demonstrated the existence of the required binary quantum state.
The rest of the paper just magnifies the silliness arising from the
deeply flawed analysis.
Bruce
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