Saturday, May 29, 2010

Modern Physical Probability

What does 'probability' mean in quantum mechanics? I address that rather philosophical question in Modern Physical Probability, a Google doc that replaces the Geocities pages onto which I had put my MLitt dissertation (all my Geocities links need replacing, I've done this one now because a rewrite of my Two Envelopes post is in this month's issue of The Reasoner:)
The doc has 9 sections:
1. Laplace’s Urn
2. H├íjek’s Arguments
3. Von Mises’ Limits
4. Popper’s Propensities
5. Reichenbach’s Limits
6. Mellor’s Personalism
7. Humphreys’ Paradox
8. Eagle’s Arguments
9. Lewis’s Humeanism

2 comments:

Anonymous said...

Hi , Jonathan Speke Laudly here,

WOW. You have done so much work!
Such analysis! Great job.
I still am not much impressed by probability generally though.
If there are 20 balls and one is
red in the urn then you will get the red ball but it might take twenty picks. SO, 1 in 20 chance.
But this tells you nothing about
when you will draw the red ball; it could be the next draw or the last.
I think Schrodinger's equation is more like a statistical model, a distribution, than an estimation of probability.
Schrodinger, in his "what is life?" said that the only reason we exist is that the quantum fluctuations of the particles of which we consist have slightly more propensity to appear than to disappear. In other words, the something and the nothing almost balance, but the something slightly predominates.
This is sort of like the quantum version of matter slightly predominating over anti-matter.
The predominance of something or matter over anti-matter or nothing,
may be very slight indeed--but it is enough to create and perpetuate the world. In other words, small probabilities, slim chances, may have a great impact.
Which leads me to conclude that determining that something has a greater or lesser probability, according to whatever system, is not so significant, does not say much about the qualitative outcome of a context.

Neil B said...

EnigMan - in case you hadn't dropped in for awhile, the discussion at Pruss's Blog about the problems that infinities cause for probability is heating up again! Drop back in ...

And BTW I have a tough take-down of MWI at my own blog, of decoherence theory, etc. Check it out.