Timeline for Is amount of substance fundamentally a scalar quantity? (in the mathematical sense of scalar)
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 7, 2023 at 2:29 | comment | added | RC_23 | I second John Doty's point. Moles and scalars and measurements are things human beings create, and as such will always be open to interpretation and differing conventions. Debating fine points to extreme pedantry is not so much revealing anything new about reality as it is like debating the Oxford comma, or whether "Dr/Dr." should have a period. | |
| Feb 7, 2023 at 1:59 | answer | added | Myridium | timeline score: 3 | |
| Feb 7, 2023 at 0:56 | answer | added | Andrew | timeline score: 2 | |
| Feb 7, 2023 at 0:15 | comment | added | John Doty | Particles don't care: they just go about their business without calculating anything. Mathematical objects like scalars exist only in the mind. So, the question becomes, what aspect of reality are you attempting to model? | |
| Feb 7, 2023 at 0:10 | comment | added | Ghoster | @Greendrake Yes, that’s my point of view. Except I wouldn’t have said scalar. | |
| Feb 7, 2023 at 0:08 | comment | added | Greendrake | @Ghoster A mole of matter and a mole of antimatter is two scalar moles of substance. Until it becomes zero. | |
| Feb 6, 2023 at 23:57 | history | edited | Vincent | CC BY-SA 4.0 |
added 629 characters in body
|
| Feb 6, 2023 at 23:41 | comment | added | Sebastian Riese | But that's the only reasonable definition of a conserved quantity "particle number" (or baryon and lepton number or whatever). Of course the "amount of substance" stops being useful in situations where we have pair production as the energy scales break chemical bonds, ionizes atoms, etc. | |
| Feb 6, 2023 at 23:35 | comment | added | Ghoster | @SebastianRiese So if I have a particle-antiparticle pair, I have no “substance”? I doubt that that is how the OP thinks about “substance”. A mole of matter and a mole of antimatter is not zero moles to me. | |
| Feb 6, 2023 at 23:34 | comment | added | Sebastian Riese | (However particle number is a scalar under any reasonable coordinate transformation – even if we are in a strongly accelerated frame where the Unruh bath becomes relevant the particle number does not change as particles and antiparticles are created symmetrically. And the "amount of substance" is just a convenient rescaling of the particle number.) | |
| Feb 6, 2023 at 23:31 | comment | added | Ghoster | pedantic standpoint: There is no such thing as “a scalar quantity”. There are “scalars under 3D rotations”, “scalars under Lorentz transformations”, etc. You have to specify the transformations being considered. For example, relativistic energy $\gamma mc^2$ is a scalar under 3D rotations but not under Galilean boosts, and it’s the temporal component of the energy-momentum four-vector under Lorentz transformations. | |
| Feb 6, 2023 at 23:17 | history | asked | Vincent | CC BY-SA 4.0 |