Hmm...very insightful.But in short,mass increases as velocity increases? Assuming the object doesnt lose any mass due to loss of fuel etc
This was posted from The Student Room's iPhone/iPad A
Last edited by Vadevalor; 24-07-2012 at 15:34.
He's actually right, and relativistic mass is a misleading,
wrong, concept. The better, more advanced formulations of special relativity by such physicists as John Wheeler have scrapped the idea entirely. The gamma in the expression for momentum should be tied to the velocity, and not the mass; the mass does not increase, the velocity transforms due to the existence of an upper limit (note that if c = infinity (and hence we'd live in a Galilean universe), then gamma becomes 1, and Einstein's relativity obsolete).
(Original post by 3nTr0pY)
In a Newtonian limit that is correct but in Einsteinian physics it is very, very wrong.
In relativity, a massive object travelling very close to the speed of light will be measured to be much heavier than one which is stationary. It comes from the proof of time dilation coupled with the conservation of momentum.
Last edited by FireGarden; 26-07-2012 at 00:11.
Aha, I am familiar with this:
(Original post by suneilr)
Taylor and Wheeler both rejected the concept of relativistic mass and I think Einstein did as well later. The concept of relativistic mass is equivalent to that of energy as can easily be seen when working in natural units. Mass is the the length of a four vector and so is an invariant. The energy-momentum four-vector is what undergoes the Lorentz transforms.
m^2 = E^2 - p^2, setting c=1 for convenience.
I now see what you and FireGarden are alluding to. That does make sense. (Although from an experimental/practical point of view I suppose it could still be argued that mass does increase at relativistic speeds)
When I was first taught SR, relativistic mass was taught as being correct, to my memory. When I later learnt the above equation I never really considered how it conflicted with my previous understanding of the subject. Thanks.
Last edited by 3nTr0pY; 26-07-2012 at 01:09.