NetNews Usenet Archive 1992 #19/NN_1992_19.iso/spool/sci/physics/13963

Text File | 1992-09-02 | 3.7 KB | 82 lines

Newsgroups: sci.physics
Path: sparky!uunet!mcsun!news.funet.fi!ajk.tele.fi!funic!nokia.fi!tnclus.tele.nokia.fi!hporopudas
From: [e-mail]
Subject: Re: Redshifted light wonders
Message-ID: <[e-mail]>
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Organization: Nokia Telecommunications.
References: <[e-mail]> <[e-mail]>
Date: Wed, 2 Sep 1992 14:35:41 GMT



In article <[e-mail]>,
[e-mail] (Peter Marzlin) writes:
> In article <[e-mail]>
> [e-mail] (Kenneth Tolman) writes:
>>   If the universe is expanding merrily away, and photons fly across this,
>> there are some peculiar things that result.... how can these things be
>> resolved?
>>
>>   1) Is there some minimal energy state that a photon can be redshifted to?
>> Is there some minimal energy which a photon can have before it effectively
>> ceases to exist?  (read next question to make more sense of this)
>>
>>
>>  3) Are these photons losing energy for the whole universe? Is energy not
>> being conserved, or is it?
>
> An appropriate way to handle those questions theoreticaly is to use
> a general covariant formulation (i.e. gen. relativistic) of quantum
> mechanics (and quantum field theory) . As one can go from nonrelativistic
> QM to special relativistic QM (e.g. Dirac equation instead of
> Schroedinger eq.), that is from QM being invariant under Galilei
> transformations to QM being invariant under Lorentz tranformations, one
> can generalize QM to be invariant under arbitrary coordinate trafos.
> This works also with the classical Maxwell equations, and if one works
> out such a theory one finds that energy is conserved only
> in very special spacetimes (to be definite: those which have a timelike
> Killing vector). Robertson-Walker spacetimes do not belong to this
> class, therefore energy is not conserved.
> The momenta of the photons are continuous, as in flat spacetime, and there
> is, in principle, no minimal level.
>

 I assert that energy could be conserved in cosmic redshift of background
 radiation, if we make hypothesis about existence of one new "Universe"
 called "Anti-World" (which was described in my "Structure of Time" article),
 which consists of negative mass base particles, and which is uniformly
 contracting towards time's zero point.


>>  2) Is there a continuous energy change for a particular photon, or does
>> it get redshifted across jumps?  Does not quantum mechanics imply that
>> there are only certain meaningful energy values, and as such would not a
>> photon move from one to the other?  If not, this would imply that there
>> would be undetectable photons- high energy photons which did not correspond
>> to any absorption frequency of any detection device.  Unless of course, the
>> detection devices were somewhat forgiving.... is this the case?
>
> To answer this question one has to go one step further and has to use
> quantum field theory in curved spacetime. This theory is
> still under development (since 25 years) and it has some standing
> problems.
> One is that one cannot say where in space a photon interacts
> gravitationally. For spacetimes without the symmetry described above
> it is even harder, sometimes you even don' t know how to define your
> photons in the right way.
>
> peter.


  Some difficulties may be in quantum field theory in curved spacetime
  such that there does not exist good algebra for handling directed geodesic
  lines, and there are difficult cutting problems when one tries to combine
  two such directed geodesic lines.

              Hannu.