Can we deal with relativistic mass once and for all?

[stevendaryl]

It could but it doesn't.

I thought you said that it doesn't change the physics whether you use 4-vectors or 3-vectors. So Newton may not have used 4-vectors, but it's the same theory, whether you do or not.

 

[PeterDonis]

I would trace that difference to the fact that the relationship between clock time (or proper time) and coordinate time is more complicated in SR.

Sure, but it's still a difference, and other people might have different preferences for how to express it. Nobody appears to be disagreeing anywhere in this thread on the actual physics--the actual predictions for experimental results. It's all just about how to describe things in ordinary language, and such arguments will never end.

 

[PeterDonis]

You can't simply replace Newton's p=m·v by P=m·V and expect that it is still the same definition.

No, but that's not what "4-vector formalism" means. It just means you can derive all of the same experimental predictions: the two formulations of the same theory are mathematically equivalent. It doesn't mean every symbol has to have the same definition. As I've already noted, that's impossible, since the two theories (Newtonian mechanics and SR) are different theories and make different experimental predictions; it's just a matter of personal preference how you want to express the differences in words or symbols.

 

[PeterDonis]

Nobody appears to be disagreeing anywhere in this thread on the actual physics--the actual predictions for experimental results. It's all just about how to describe things in ordinary language, and such arguments will never end.

it's just a matter of personal preference how you want to express the differences in words or symbols

And with that, this discussion has run its course and this thread is closed.