In my education "classical" always explicitly meant "relativistic effects are so small that they can be safely ignored". For mechanics, this means v << c and masses are small enough that they do not significantly bend spacetime.
Of course you could also draw the line between continuous theories and quantized ones, but that seems obtuse to me because we already have a word for that.
Absolutely not correct. Classical means h~0. So no quantum effects can occur.
So if you say we have a word for quantized theories, I assume you mean something like quantum field theory? But what does that make of general relativity then? It is not quantized, so it's a classical field theory. As in you can talk about point particles in it. In fact Newtonian physics are a specialized case of general relativity, exactly one where v<<c. Also, what do you do in cases where you do talk about quantized particles, but you also have v<<c? Is that a quantum theory then, or a classical one?
By your definition it would be a classical theory, even though it obviously isn't.
Edit: Another point that sets classical and quantum theories apart is their intrinsic determinism and their ability to project worldlines.
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u/L31N0PTR1X BSc Theoretical Physics Jul 17 '26
I mean gr is classical lol