[marcosdumay]

If I get the GP correctly (IANAP and everything), he is pointing that General Relativity works equally well with many different descriptions of space-time.

The one where everything always move at c, and only the direction of movement changes is one among many possible (and indistinguishable) descriptions, and not a very useful one.

[gnaritas]

If he understood how to communicate with people at all, he'd have simply said what you just did. He's also mistaken, it is an extremely useful one because it makes a complex topic clear in a way that explains why C can't be exceeded. All models are wrong, that model is useful because it can be expressed very simply, it doesn't matter that it's not the only valid way to see things.

[smallnamespace]

> it doesn't matter that it's not the only valid way to see things.

It certainly does though -- the existence of many valid models and simple mappings between them implies a 'deeper model' at play, and putting one particular model above all others as the 'correct' is actually discouraging the reader from getting towards the deeper truth.

If you say 'the sun is stationary and the planets revolve around it' is the only valid description of the solar system, you would be wrong, and you're also making it harder for a person to understand relativity down the line.

[gnaritas]

> and putting one particular model above all others as the 'correct' is actually discouraging the reader from getting towards the deeper truth.

No one is putting a particular model above all others, one model is simply being used to explain the relationship between C and time, it's not incorrect just because other models are also valid as long as they all explain the same relationship between C and time.

[cyphar]

> the existence of many valid models and simple mappings between them implies a 'deeper model' at play

Not necessarily. You can have completely different formulations of the same physics. Lagrangian, Hamiltonian, and Newtonian dynamics are different models of classical motion. Does that imply there's a "deeper model" of classical motion? I wouldn't say so.

[Koshkin]

But the way he communicates eliminates ambiguity and allows the conversation to stay on topic. As soon as you try to express things "very simply", the conversation quickly degrades into an almost meaningless argument about things the participants do not (and, worse yet, do not wish to make a serious effort to) understand - which is exactly what we see here.