4 ms·

That's all fine, but from the moment Maxwell's eq's are invoked, we enter an empirical framing, not a first principles one. (as Maxwell's results follow from ob

That's all fine, but from the moment Maxwell's eq's are invoked, we enter an empirical framing, not a first principles one. (as Maxwell's results follow from observations of the behavior of charged phenomena, current, magnets, & electromagnets). The paper & video seek to postulate the existence of a universal speed limit from first principles. They do so, and without changing the framing from a first principles one to an empirical one, associate their notational 'c' with the observed (i.e. empirical) speed of light. I find this element of their rhetorical strategy at odds with their intentions.

lisper 3y ago
> That's all fine, but from the moment Maxwell's eq's are invoked, we enter an empirical framing, not a first principles one. Yes, of course. First principles only leads you to the conclusion that there is a reference speed. It tells you nothing about its actual value. In fact, first principles cannot rule out the possibility that the reference speed is infinite. They can only lead you to suspect that it might not be.
- ricksunny 3y ago
  Yes, this one also strikes me as an accurate framing of the situation's epistemology, Ty for clarifying :)
akalin 3y ago
I think what's left unsaid in the paper is that if a Lorentz-invariant speed exists, then it is unique. (This is easy enough to show.) Therefore, once you show that the speed of light in a vacuum is Lorentz-invariant, then it has to be the unique Lorentz-invariant speed (i.e., the universal speed limit).
- ricksunny 3y ago
  Yes, this strikes me as an accurate framing of the situation's epistemology.:)
ajross 3y ago
> Maxwell's results follow from observations of the behavior of charged phenomena, current, magnets, & electromagnets I mean, historically yes. But you can define the fields as purely postulates if you like. The theory actually requires very little input to derive.

lisper 3y ago

> That's all fine, but from the moment Maxwell's eq's are invoked, we enter an empirical framing, not a first principles one. Yes, of course. First principles only leads you to the conclusion that there is a reference speed. It tells you nothing about its actual value. In fact, first principles cannot rule out the possibility that the reference speed is infinite. They can only lead you to suspect that it might not be.

ricksunny 3y ago
Yes, this one also strikes me as an accurate framing of the situation's epistemology, Ty for clarifying :)

akalin 3y ago

I think what's left unsaid in the paper is that if a Lorentz-invariant speed exists, then it is unique. (This is easy enough to show.) Therefore, once you show that the speed of light in a vacuum is Lorentz-invariant, then it has to be the unique Lorentz-invariant speed (i.e., the universal speed limit).

ricksunny 3y ago
Yes, this strikes me as an accurate framing of the situation's epistemology.:)

ajross 3y ago

> Maxwell's results follow from observations of the behavior of charged phenomena, current, magnets, & electromagnets I mean, historically yes. But you can define the fields as purely postulates if you like. The theory actually requires very little input to derive.