Why do we still refer to "Einstein's theory" instead of "Einstein's law"?

Question

Einstein's "theory" of general relativity is one of the most rigorously tested tenents of science and all modern physicists accept it as valid. It is highly unlikely that it will ever be disproven. In fact, the very fact that television sets (at least the old cathode ray tube sets) and global positioning satellites function the way they do depends on the predictions made by Relativity. Why do we still refer to it as a "theory?" Isn't it high time we started refering to "Einstein's Law?"

Answer 1

That is both a yes, and a no.

You do make great points for the yes part, however we are talking about calling it a >LAW<. There is a possiblilty that it will either be partially wrong, or completely wrong. Remember, we only know about so much, and yet there is much more to learn.

Answer 2

I think you are equivocating with the meaning of theory.  In common speech, theory means guess; however in science theory is a testable model that accounts for the evidence available.  We refer to the theory of gravity and the atomic theory, but these are both well attested as well.

Answer 3

Not a physicist so this is jut going on what I have read and thus may not be totally correct.

From what I understand not all of the theory of relativity has been tested. There are parts of it that deal with the speed of light and since we are unable to travel that fast it will be difficult to test.

Just what I have heard anyway.

Answer 4

I think it is because it is too complex to be just a law.

Laws say simple things like "objects move in a straight line unless acted on by a force". (Newton's 1st Law of Motion). They're straightforward and easily stated. Theories are much more complex, allowing you to make predictions. A theory would contain a number of laws. The above law is part of Newton's Theory of Motion.

Both laws and theories are things which have been proven beyond reasonable doubt. Calling Relativity a "theory" means that it has been proved by experiment and fits all the fact.

Answer 5

Well, I guess it just depends on how it sounds when you say it.

The Theory of Relativity.

Einstein's Theory of Relativity.

vs.

Einstein's Law of Relativity.

The Law of Relativity.

Answer 6

His General Theory does not deal with the examples you give. The problem with his Special Theory is that it is impossible to prove 'The twin Paradox,' of time dilation.

Answer 7

Well, if you kinda take a look at history, it seems that as you take the wheel further back in time more and more things are titled physical law than they are nowadays.  These naming conventions don't really mean that the Laws back then were super tested or that the theories of today are poorly supported.  A couple of good examples are Hooke's Laws for springs and the Law of gravitation, both of whcih are known to not always work.  On the flipside, relativity has been tested again and again and again, never failing, yet its still called a theory.

Don't get caught up so much in the naming of these things.  In everyday language "theory" is used as a hunch or a good hypothesis, but in physics, something with the name theory attached almost always means its something substantial.