[AFreeBird]

It may have not been a constant during the early stages of development of the universe, but in the fairly steady state we are in I think it is fairly constant, maybe changing a bit every billion years or so.

Sorry, then its not a constant.

Constant is constant.

[microgood]

Sorry, then its not a constant. Constant is constant.

Well, since we have only been measuring things the last hundred years or so, then we really do not know. That means nothing is a constant. There are no constants.

Being an engineer and not a scientist, however, I am cool with something being essentially constant from 100 years ago until the next 300 years for the purpose of applying our current scientific knowledge.