Thanks for your comments and explanation Dr. Chinese (interesting moniker ;-{) ) I probably should have included the rest of the paragraph after the excerpt that I quoted, vis:It seems to us that this criterion, while far from exhausting all possible ways of recognizing a physical reality, at...
I'm slowly working my way through what I need to really understand the Bell papers. Everyone says that a good start is the EPR paper. I understand that Einstein may not have read the final version before publication and may not even have wanted his name appended (sort of convoluted logic and...
Terminology; "distinguished"
I've always thought that understanding at a profound level requires real precision in the use of language. I was recently reading Julian Barbour's book, The End of Time where he regularly uses the word distinguished as an adjective, as in "distinguished frames of...
Stepping back a bit (sorry to use this to think on-line) the actual measurement that must be dealt with, vis a vis HUP, is a photograph (actually three for reconstruction purposes), since the whole event is 3 dimensional, not planar. The photograph(s) capture, in 3 dimensions, the entire...
Interesting! I really need to get my mind around how time t enters into the px HUP and how E does as well. p and x are the three space vector parts of covariant 4 vectors, while E,t are the rest (the timelike parts) so the two HUP aspects are sort of fundamentally different. I'm wondering, since...
In thinking about QM, I was wondering if anyone could comment on this? Back in prehistoric times, I did research using bubble chambers. In a bubble chamber, you see a number of curved (because of the magnetic field the chamber is imbedded in) tracks corresponding to different particles...
Thanks, DrChinese for your reference and explanation. Good stuff. Have you seen Louisa Gilder's book,with a good history, but pretty accessible. Right at the beginning she gives a pretty good picture and explication of Mermin's apparatuslike explanation. Worth recommending to your non-physiker...
Thanks Fredrik,for your comments. I think we are still talking somewhat at cross purposes. You said:
You have only determined what the state is after the measurement. There's no measurement that can tell you what the state was before the measurement, if you didn't know it already as a result of...
All of this has already been answered. It isn't possible to determine which state the system is in. The observables of a theory that says that this is possible satisfy Bell inequalities, and Bell inequalities do not hold in the real world, so the possibility you're describing has been ruled out...
Well, folks, this has wandered interestingly (sometimes) far from the original question! I was not particularly shilling for any interpretation, just wondering if there was a situation where I could not conclusively tell what the wave function was (had to have (might have) been?) from the...
Sorry for a (maybe) dumb question, but... I understand that according to QM, the description of the situation for a particle or system is described by a linear superposition of the wave functions of all the possible states (eigenstates) of the system. When a measurement is made, the wave...
In all I've read, in GR gravity is not a force, per se. Particles, in the absence of anything except mass, simply move along geodesics which are determined by the curvature of the space. Read Wheeler's famous quote , paraphrased; "The curvature of space tells mass how to move, mass determines...
Minor point, probably already mentioned. Minkowski and GR spaces are semi-Riemannian manifolds, R4, S4 etc are Riemannian. Speaking of directions, I think you can have transformations that invert the time axis and you can always look at what happened in the past, it is just that changing it is...
For a fairly far-out take on this, take a look at Wolfram's book "A New Kind of Science", both the chapter on Physics and the accompanying notes. Can all be had on-line, but I don't have the website immediately at hand, Google Wolfram.