Party at Azim's this weekend was excellent. I enjoy interesting people.
Met an organizer of the Spirit Bear Youth Coalition, who is doing some interesting things working towards an economically feasible model for conservation. Also caught up with lots of Vancouver folk, all of whom are doing great. I like my friends.
I have decided to communicate for 30 minutes per day. It will be hard but should ultimately be worth it.
Godfrey (rmutt.diaryland.com), azim (he doesn't yet know) and I will be using these blogs to teach each other things about our respective fields. If you want to join in just comment and you will be read by our little collective.
I am going to start with something I read in The Elegant Universe by Brian Greene.
Determinism is a philosphy which is not easily adopted since it removes one's free will. Initially found to be a problem (at least in the west) come the onset of Newtonian mechanics, it was thought that perhaps atoms moved in a manner akin to billiard balls. While difficult to calculate exact trajectories and interactions, such calculations should not be impossible, even if humans are never able to do it. The fact that such calculation are, in theory, possible removes free will.
The discovery of quantum mechanics seemed to make determinism impossible, since an important aspect of QM was the inherent uncertainties in that QM described probabilities. This was found to be a thought based on falsehoods. It is actually the description of QM in terms of classical (Newtonian) mechanics that seems to indicate uncertainty. Schroedinger's equation (time dependent) fully describes a wave function as it evolves in time and so, if you accept the wave function as being real in itself and not as a descriptor of probability in classical mechanics, then you find that QM can be deterministic as well.
This has been discussed for a while. The interesting discovery outlined in The Elegant Universe (and admittedly somewhat refuted in the same book) revolves around black holes. It was initially though that black holes did not radiate. It turns out that they do, but I want to save that for the next update. Black holes do, though, remove wavefunctions when they attract matter into their belly. This is a loss of information from the Universe. In analogy, if you strike a ball on a billiards table with a certain velocity in a certain direction, you could theoretically calculate the final positions of all the balls. But if a ball was removed suddenly and unexpectedly from the table your calculations would not hold. If black holes did not radiate, then one may have been able to assume that the information contained in the wavefunction passed to a locked area of the universe (the black hole) and this would not affect determinism because the information still existed although it was not easily accessible. The problem, then, is that black holes do radiate and this radiation results in evaporation of the black hole. Hawkins argues that when the black hole fully evaporates the information is not recovered.
With disappearing information, determinism is impossible.
The refutation is, of course, that black holes do return the information they stole.
Still, it is interesting to see how physicists are looking at this issue.
Subscribe to:
Post Comments (Atom)
1 comment:
matthew, what we have here is a failure to communicate. insofar as all communication is false communication, that people can never truly understand one another but, rather, merely come to compromises in and through language, it would help me understand what you're saying if you spelled things out more. for example, it is not evident to me what the trajectory of atoms has to do with free will. at all. the information and black holes business also made no sense to me, though it does sound interesting. in any event, i'll see you soon.
Post a Comment