this question comes a bit late since it addresses the concept of mass which was already discussed in the detail some weeks ago. John Denker summarized very nicely
various meanings of mass in his web site
(<http://www.av8n.com/physics/mass.htm>).
There he writes:
"According to modern ideas and modern notation, m is frame-independent, while E is just one component of a four-vector, and cannot be frame-independent."
My question is: is m (invariant mass) frame-independent also if non-inertial reference frames are considered?
I would tend to think so but I can't justify it; special relativity starts with the postulates explicitly dealing with inertial frames. Would then all the linked notions (like energy-momentum four-vector) share this crucial restriction?
OTOH special relativity can deal with accelerating
systems, at least in some situations: e.g. the twin paradox
can be understood completely in terms of special relativity
as shown by former Phys-L postings (also by John D. in
<http://www.av8n.com/physics/twins.htm>)
Regards,
Antti
Antti Savinainen, Ph.D.
Senior Lecturer in Physics and Mathematics
Kuopio Lyseo High School
Finland
E-mail: <antti.savinainen@kuopio.fi>
Website: <http://kotisivu.mtv3.fi/physics/>