I did actually read all of those sections. And if you read carefully, you’ll notice he uses “mass”, etc., in these other ways in this very section (“Use and Abuse of the Concept of Mass”), even while writing about clarifying these exact issues. (You might not have noticed this because (if I may WAG) you would naturally read right through these usages, as they are the cleanest, clearest way of presenting the ideas.)
Yes, he is talking about local effects when he uses “mass”, etc., in these ways, but that’s exactly my point – there are times, contexts, constructions, …, when it is helpful to do this. Even Wheeler does this, and I do not fault him for it anymore than I would fault Exapno Mapcase.
Hear, hear. “Momenergy” is just plain silly. But, it does go to show that language and terminology is malleable, so long as context is clear. Wheeler (and Taylor) got their required pedagogical mileage out of it.
Fine with me. Anything to end this God forsaken thread. BTW if you decide to go with Pasta’s, “anything can mean anything philosophy,” at least put a modifier in front of the word, i.e local mass defect or deficit.
Are you trying to say that two photons, each of which weighs absolutely nothing, weigh more than nothing when they are in some sort of system? If so, what sort of system? And if the mass isn’t in the photons, where the hell is it?
When their velocities are not parallel there will always be a frame which minimizes the total energy of the system this will be the rest frame of the system and this energy is the rest energy of the system.
As someone lurking in the thread up to this point, I just want to say how fascinating this “god-forsaken” thread has been in showing how the role of communication and intent play in conveying meaning. Certain disciplines require fixed, tight definitions - per Ring. Communication - especially to non-expert audiences - allows for broader, looser definitions - as long as the intended meaning appears to be exchanged. That is was **Exapno **was looking for and **Pasta **provided (thanks Pasta!). It is when folks try to cross streams - e.g., trying to communicate to non-experts while requiring expert-strict definitions - that things start to go wonky…
Mass. mass masses massively - or something like that…
Well, one thing I learned on this board is that the equals sign is never used loosely in mathematics. So, isn’t it correct to say that according to Einstein, the OP is right? Mass is energy?
at least put a modifier in front of the word, i.e local mass defect or deficit.
