What if Lightspeed were not constant.

[[Tycho?]]

Yes, but Einstein[/i'] still had to postulate it. It already had to hold in E&M applications in order for Maxwell's equations to work, so it wasn't too much of a stretch. But it has some bizarre implications for the uninitiated.

 

Yeah it was a postulate of special relativity wasn't it. Well the point stands, its not a "theoretical" thing, its something that was measured, not deduced by the theory itself. I really is wierd when you think about it.

[5614]

its a set law represented by a mathematical equation. the one thing with the 'theory' of special relatively and many other 'theories' is that they are not theoretical at all, they are true tested facts.

[ed84c]

would that not make them a theorem then ?

[5614]

well yes... i would assume, a theorem is:

a general proposition or statement, not self-evident but demonstrable by argument or a chain of reasoning on the basis of given assumptions

 

where as a theory is:

a hypothesis that has been confirmed or established by observation or experiment and is accepted as accounting for known facts.

 

therefore the theory of relativety is a theory, where as pythagoras's theorem is a theorem!

 

the definition of 'a theory' is often placed parallel to theoretical, which it isnt.

 

definitions supplied by shorter oxford english dictionary (5th edition) on CD-ROM v2.0

[JaKiri]

To explain a bit more quickly: theories are based on evidence, theorems are based entirely on logical progression.