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Re: Same Old Quantum Thread. Date: 1997/07/06
In article <5plkf7$3hr@panix2.panix.com> erg@panix.com (Edward Green) writes:
> I suppose the pendulum and the LC circuit are a good cautionary tale > against arguing that A is really a manifestation of B because part of > the model is isomorphic.
How about we model each point in space with a pendulum and not a mass on a spring (harmonic oscillator). For small oscillations both systems have the same equations of motion but for large amplitudes the systems become fundamentally different.
Ahhhhhhh!
e+, e-, and gamma but different modes of the same "thing"? Date: 1997/07/10
Are e+, e-, and gamma but different modes of the same thing?
Consider the modes of a pendulum, a pendulums angle may:
There is a minimum energy (pseudo charged particle mass) that the pendulum needs to in order to have an orientation (clockwise or counter-clockwise rotation).
A single complex number can give the pendulums position and angular velocity.
This is not very good but i will try to go further...
when my brain does not hurt.
Next, quarks and gluons but different modes of the same thing and the connection to electrons and positrons.
A prediction, the electron field and the photon field are but different "modes" of some common "stuff".
Stronger prediction, all particle fields and gauge fields are but different "modes" of some common "stuff".
Homework, prove the above.
I can't prove it, but e+, e-, gamma, are modes of same stuff. Date: 1997/07/11
Consider a system with kinetic energy given by:
and potential energy given by:
N is some very large integer. c' and c" are positive constants chosen to make the problem interesting. a_i and b_i are the coordinates which have a range of minus infinity to plus infinity.
Some "facts" about this system.
The Lagrangian is unchanged if the same constant is added to each coordinate, big deal. The Lagrangian is unchanged if a multiple of 2Pi is added to any coordinate.
This system has "massless" modes as well as "massive" modes, again, big deal.
So what is the point? Electrons and photons are different modes of the same "stuff", i just can't prove it %^(
Can you?
Re: Elevators again (Relativity+QM) Date: 1997/07/15
In article <5q9tea$1ecq@nntp6.u.washington.edu> hillman@math.washington.edu (Christopher Hillman) writes: > > Hmm... of course any tidal forces would be negligible on the scale of a typical > elevator.
The book on general relativity by Hans C. Ohanian describes a device for such measurements. It would fit in an elevator.
> You'd be hard put to measure the red shift.
They do some interesting interference experiments with neutrons in which a neutron beam is split and latter recombined. The gravitational potential difference for the two paths (about 10cm) gives rise to measurable phase differences. The device could fit in an elevator (if one could find a small source for the neutron beam.)
Re: Electron spin and polarization. Date: 1997/07/1
In article <slrn5sbman.18h.kennel@lyapunov.ucsd.edu> kennel@nospam.lyapunov.ucsd.edu (Matt Kennel (Remove 'nospam' to reply)) writes:
> On 9 Jul 1997 07:54:49 -0400, Edward Green <erg@panix.com> wrote: > : ale2 <ale2@psu.edu> wrote: > : > :>rtomes@kcbbs.gen.nz (Ray Tomes) writes: > :> > :> > :>> Anyway, the real world is not full of strings, I am sure that we can > :>> agree. Rather, my personal preference is for the entire universe being > :>> made of a continuous elastic solid. > :> > :>How does Quantum Mechanics pop out of a spacetime made from some sort > :>of the above? How does one get "quantum weirdness" from a continuous > :>elastic solid? > : > :That is an excellent question, ale, one I have asked myself. > : > :The short answer is, you don't. There is no way to produce spacelike > :quantum entanglement, from an elastic continuum model.
Now don't start sounding like some old, worn-out, authoritative, sci.physics, fuddy-duddy, safe to say it can't be easy?
Been looking over a new (new to the schools library) book by Chris J. Isham, "Lectures on Quantum Theory", available in paperback isbn 1-86094-001-3. Well as always i jumped to the end of the book to see what he makes of all this quantum weirdness and he says:
" Of course, for many physicists, the pragmatic approach to quantum theory is quite acceptable. [...] My colleagues involved in these activities can be, and are, very effective professionally without needing to lose any sleep about the implications of the Kochen-Specher theorem or the Bell inequalities. However, in the last 20 years there has been a growing belief among physicists from many different specializations that even if modern quantum theory works well at the pragmatic level, it simply cannot be the last word on the matter. [...] The central issue in all this is really the phenomenon of quantum entanglement, and its striking contrast with the reductionist concepts of Western philosophy."
> : And this is > :the only form of 'quantum weirdness' worth a damn.
Maybe, maybe not. Maybe "quantum weirdness" of the first kind or "quantum weirdness" of the second kind is clue enough (entangled states being quantum weirdness of the third kind)? > : > :Well _almost_ . If we have a preferred rest frame, as an elastic > :continuum model might seem to indicate, then we might be able to do > :something with arbitrarily large signal velocities. > > That's silly, of course.
Well Ed can be a riot at times!
> > I think the real issue is that we are still operating on our enormously > deep seated prejudice that a physical theory must be, in effect, local > differential operators on fields evaluated on spacetime (i.e. x, t). > > With spacelike entanglements, it just ain't so. > > There is some magic enormous Hilbert space of the universe which just > "IS".
Does it exist when no one is thinking about it?
> The spacelike continuum nature with local realistic propagation is > a phenomenological consequence of the dynamics of decoherence---i.e. when > you decohere you get back to classical mechanics. But this is a > (very common) experimental exigency. If you stick with a little-interacting > truly quantum particle, you can get this spacelike entanglements. > > If you try to view QM through the lens of classical mechanics, you get > these weird issues. If you view classical mechanics through the lens of > QM, it may be more profitable.
I think we can gain insight by looking through both lens systems, why exclude one for the other, both give clues.
Book picks of the month,
"Quanta, A handbook of concepts, second edition" by P. W. Atkins and "Understanding the Properties of Matter" by Michael de Podesta.
> In other words---why does so much > physics look like 'd/dx field(x)'??
Link to thread of next article. Could a cosmic ray have brought down flight 800 ? Date: 1997/07/18
I hear that the center fuel tank on flight 800 may have had a concentration of explosive vapors and all that was needed was a ignition source. How much energy is needed to get such an explosive mixture going and could a cosmic ray have supplied it?
Link to thread of next article. Roger Penrose on QM, "it makes absolutely no sense!" Date: 1997/07/1
In the book "Quantum Concepts in Space and Time" edited by Penrose and Isham on page 129 Penrose writes:
"I should begin by expressing my general attitude to present-day quantum theory, by which I mean standard non-relativistic quantum mechanics. The theory has, indeed, two powerful bodies of fact in its favour, and only one thing against it. First, in its favour are all the marvellous agreements that the theory has had with every experimental result to date. Second, and to me almost as important, it is a theory of astonishing and profound mathematical beauty. The one thing that can be said against it is that it makes absolutely no sense!"
This material is dated around March of 1984, I hope he still feels this way?
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