Could physical constants like the speed of light be different?

If they could be different they are contingent, I.e. Their value depends on unknown factors. But what are these factors?

If they could not be different they are necessary. But what makes them necessary?

In either case we are faced with an unsolved problem. So it would seem that the foundations of science are enigmatic. What is your view?

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?

This gets at the great debate over the anthropic principle. As Perito says, there are a whole bunch of constants that seem to be fundamenal to the universe, but we have no idea "why" they are what they are. But it can be shown that with some of these constants if their vaue was just a little bit different than they are, the universe would not exist as we know it, and we would not exist. So some say that the constants are what they are because if they were different there would be no one here to ask this question. See:

Anthropic principle - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Anthropic_principle)

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?

Thanks for your speedy reply :) Some scientists believe there is evidence that physical constants change:

"Modern theories of fundamental interactions (SUSY GUT, Superstring/M-theory and others) not only predict the dependence of fundamental physical constants on energy ("running" constants), but also have cosmological solutions in which low-energy values of these constants vary with the cosmological time."

http://www.ioffe.rssi.ru/astro/QC/const_00.htm

Multiverse theories also entail different values for constants. There is no obvious reason why they are false nor why the constants in our universe must have their present values.

Existence is a fact but the nature of existence is probably beyond our comprehension. How can finite beings understand the infinite? We can manipulate infinity in mathematical equations but that is about all!

Existence is a fact but the nature of existence is probably beyond our comprehension. How can finite beings understand the infinite? We can manipulate infinity in mathematical equations but that is about all!

How do you know it's infinite? Just because I think it is, doesn't make it so.

This gets at the great debate over the anthropic principle. As Perito says, there are a whole bunch of constants that seem to be fundamenal to the universe, but we have no idea "why" they are what they are. But it can be shown that with some of these constants if their vaue was just a little bit different than they are, the universe would not exist as we know it, and we would not exist. So some say that the constants are what they are because if they were different there would be no one here to ask this question. See:

Anthropic principle - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Anthropic_principle)

I agree with you that we have no idea why the constants are as they are. The fact there would be no one here to ask this question if they were different does not imply that the constants must always have their present values! The universe existed before we arrived and will continue to exist after we depart so our existence has no bearing on what the universe could be like. For all we know, the constants may change so that life becomes extinct. As David Hume pointed out, there is no guarantee that the future will be the same as the past.
It is highly probable but not certain...

How do you know it's infinite? Just because I think it is, doesn't make it so.

Obviously I don't know that existence is infinite because I believe its nature is beyond our comprehension. But our recognition of infinity as a mathematical concept may well correspond to the physical reality of infinity. The fact that scientists and philosophers disagree on whether the universe is infinite makes one wonder whether there is any way of establishing the truth of the matter!