Originally Posted by
Perito
According to Einstein's special and general theories of relativity, the speed of light is a constant. Other constants, insofar as we understand them (Boltzman's constant, Heisenberg's constant, etc) are also constant.
Could they be different? Scientists will say "no". If you say "yes", I would expect that you would have to justify your reasoning, and in this context, you would have a difficult problem, indeed.
Are they necessary? Scientists will say that there is no reason to say they are necessary, they simply are. Is existence necessary or is it just a fact?