Still enjoying this discussion, and appreciate responses to my question.
I'm afraid my main question might not have been very clear. I really wanted
to address this statement made in various forms in this thread:
I really don't believe that energy resides in any single object, but in
its relationship to something else.
Is this statement compatible with rest mass energy of an object? For my
object, I choose an electron, which as far as I know, is fundamental, with
no constituent particles. When I say that the rest energy of an electron is
0.511 MeV, should I be aware that I am stating this energy in reference to
something else?
When I state the kinetic energy of an electron, I am aware that this is
frame dependent. When I state the potential energy of an electron, I expect
most people look for some information about system, other objects, fields,
etc (though it's quite clear from this thread that different people look for
different things!). Is there a similar expectation about stating the rest
mass energy of an electron?
(To be specific, when I say rest mass energy of an electron, I mean the
inner product (dot product?) of the energy-momentum four vector (of the
electron) with itself, divide by c^2, take the square root. That should be
invariant, and all (constant-velocity?) observers should agree on its
value.)
Hope my specific question is clearer now. Thanks for your thoughts.
--
regards
-Krishna
Krishna Chowdary
Department of Physics & Astronomy
Bucknell University