Recent content by bhobba

Indeed. That is the argument against the literal realistic interpretation of QFT as found in Art Hobson's book, Fields and Their Quanta. However, the very reality of particles becomes an issue: in QFT, they are 'knots' in the quantum field. If the field is not real - gurgle, gurgle. To the...

Indeed: Thanks Bill

I am not a fan of many worlds, but the fact that the other branches have never been seen does not disprove it. It predicts that as part of the theory. In my opinion, for what it is worth, it's unnecessarily extravagant. If you are attracted to MW, Decoherent Histories treats all possible...

Same here. I am not convinced of the betting argument either. To be fair, anyone reading this needs to see the argument and its various forms and decide for themselves. I personally stick with Gleason. Thanks Bill

Well, there is Gleason's Theorem. However, Many World proponents seem to favour a betting-type argument, possibly because they don't want to use Gleason's non-contextuality assumption. Anyway, this has been examined before on this forum...

At our current understanding of QM, that is true. Still, some think that with future research, it may be possible to experimentally distinguish between them; for example, the experimental confirmation of Bell's theorem by Alain Aspect and others rules out a whole class of interpretations, namely...

Peter's answer is exact, and IMHO leaves nothing left to be said. Thread closed. Thanks Bill

We do. It is implied by the definition. When one makes a statement, all its implications are immediately true; they are just made explicit through further analysis, but remain true regardless of whether or not that analysis is done. Thanks Bill

What the above statement means has me beat. By definition, e^x is the inverse of ln(x); ln(x) is only defined where x > 0. The only issue is that ln(x) is invertible, so the definition makes sense. The derivative of ln(x) is 1/x, which is strictly decreasing, so when you graph it, it must have...

I have been investigating Barandes's approach further, and indeed, it is quite general and can be applied to QFT. As an overview of the issues involved, Barandes gave the following interview: I must admit, as a math graduate, having studied statistical modelling and Markov Chains, although...

You may want to define it that way, but that is not its definition in mathematics. F=M*A is a definition needed for Newton's laws to have physical content, which is, as John Baez expresses it, get thee to the forces. The same goes for the definition of e^x in math. To conform to its usage in...

Interestingly, in the non-relativistic limit of QFT, they still remain operators. It is possible to formally recover the states of ordinary QM as found in QFT, The Why, What, and How by T Padmanabhan on page 39. But it is non-trivial and, as the author notes, 'is a reminder that the single...

It is defined as the inverse, not a supposition. It is like force is defined as f=m*a, not suppose f=m*a. Thanks Bill

Note that usually such derivations stick, at least implicitly, but sometimes explicitly, with the definition of an inertial frame as one where Newton's first law holds. While true, the alternate definition found in Landau Mechanics (a brilliant book) is possibly a better starting point. An...

It is its definition. You really need to see how all this stuff follows from the definition of ln(x) We define ln(x), x > 0, called the natural logarithm, as ln(x) = ∫(1 to x) (1/y) dy. Note ln(1) = 0 and ln'(x) = dln(x)/dx = 1/x. ln'(x*y) = y/x*y = 1/x (using f(g(x))’ = df/dx =...