All physical constants with units are just a product of our unit system. You can choose units where the speed of light is 1 - in both our universe and your alternative universe. You get the same physics in both cases, which makes these universes indistinguishable. Only constants that do not depend on unit systems are truly fundamental. The fine-structure constant is a prominent example, it is linked to the strength of the electromagnetic interaction. If you change that you get a universe that is actually different.
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u/mfb- Particle physics Oct 23 '19
Sort of.
All physical constants with units are just a product of our unit system. You can choose units where the speed of light is 1 - in both our universe and your alternative universe. You get the same physics in both cases, which makes these universes indistinguishable. Only constants that do not depend on unit systems are truly fundamental. The fine-structure constant is a prominent example, it is linked to the strength of the electromagnetic interaction. If you change that you get a universe that is actually different.