Norman Wells wrote:
John Rumm wrote:
Norman Wells wrote:

To test that, it's vital to have a definition of 'mass', isn't it?

You see, according to the definition in Chambers Dictionary of
Science and Technology, mass is defined as 'the quantity of matter
in a body'. That must mean that it's a direct measure of the number
of atoms the body contains, since all matter is composed of atoms.
From that it follows that, however hot any amount of something is,
it has exactly the same mass as it always had, because it always
contains the same number of atoms.

Relating the mass simply to the number of atoms would seem to preclude
any gain is mass with velocity (something intrinsically linked with
time dilation), and time dilation is something that has been
observed. Mass it seems is not as "fixed" as classical physics would
have us believe.

If you're going to talk about mass, as you have, you have to know what
it means, not say in Humpty Dumpty fashion "it means just what I choose
it to mean - neither more nor less".

So, what is mass? What is your definition?


This thread interests me, not because I understand a bloody word of it,
but because people with degrees in the subject end up squabbling over
what appear to be fundamentals. Is that the nature of the beast maybe?
So far we seem to have graduates from Imperial College and York, but I
may have missed some. Any chance of the others combatants declaring
their credentials? Not as a dick waving exercise, but to give people
like me an insight into the extent to which experts can disagree.