Pentcho Valev
2008-01-31 08:38:03 UTC
The fact that the speed of light varies with the gravitational
potential (Einstein's 1911 equation c'=c(1+V/c^2)) is rarely referred
to explicitly by criminal Einsteinians; usually they prefer to destroy
human rationality in this way:
http://groups.google.com/group/sci.physics.research/browse_frm/thread/c46ce30871328b4a?
Tom Roberts Jan 29 2008:
"There are several ways to interpret such a physical situation:
A) the photon gains energy by falling in the gravitational field.
B) the photon is blueshifted due to its travel between heights in
the gravitational field.
C) the energy scales of atom and detector are different, due to
their difference in gravitational potential; the photon does not
change energy (or frequency) during its journey, but it registers more
energy in the detector due to change of scale (time scales also
differ).
All three interpretations are valid, and correspond to using different
coordinate systems to describe the physical situation. So one cannot
say unambiguously that the photon does or does not change energy, does
or does not change frequency, or that the scale of energy does or does
not change with height.
At base, the difference is due to the non-local nature of this
physical situation in the gravitational field, and the difficulty
(inherent ambiguity) in GR of describing non-local situations. This is
traceable to the problems of doing integrals on curved manifolds, and
the result is that energy is conserved only locally in GR.
But there is an approximation that is often appropriate: if a system
is localized in spacetime and has no outside interactions, then one
can draw a closed boundary containing the system, with no energy or
momentum crossing the boundary and the manifold is asymptotically flat
there -- then inside the boundary the total energy and momentum are
conserved. This applies to the original three situations, but one
cannot draw such a boundary between the emitter and the detector in
this last situation." Tom Roberts
Pentcho Valev
***@yahoo.com
potential (Einstein's 1911 equation c'=c(1+V/c^2)) is rarely referred
to explicitly by criminal Einsteinians; usually they prefer to destroy
human rationality in this way:
http://groups.google.com/group/sci.physics.research/browse_frm/thread/c46ce30871328b4a?
Tom Roberts Jan 29 2008:
"There are several ways to interpret such a physical situation:
A) the photon gains energy by falling in the gravitational field.
B) the photon is blueshifted due to its travel between heights in
the gravitational field.
C) the energy scales of atom and detector are different, due to
their difference in gravitational potential; the photon does not
change energy (or frequency) during its journey, but it registers more
energy in the detector due to change of scale (time scales also
differ).
All three interpretations are valid, and correspond to using different
coordinate systems to describe the physical situation. So one cannot
say unambiguously that the photon does or does not change energy, does
or does not change frequency, or that the scale of energy does or does
not change with height.
At base, the difference is due to the non-local nature of this
physical situation in the gravitational field, and the difficulty
(inherent ambiguity) in GR of describing non-local situations. This is
traceable to the problems of doing integrals on curved manifolds, and
the result is that energy is conserved only locally in GR.
But there is an approximation that is often appropriate: if a system
is localized in spacetime and has no outside interactions, then one
can draw a closed boundary containing the system, with no energy or
momentum crossing the boundary and the manifold is asymptotically flat
there -- then inside the boundary the total energy and momentum are
conserved. This applies to the original three situations, but one
cannot draw such a boundary between the emitter and the detector in
this last situation." Tom Roberts
Pentcho Valev
***@yahoo.com