Homework Help: Special Relativity Problem

1. Jun 20, 2009

rchenkl

1. The problem statement, all variables and given/known data
State two postulate that underlie the Special Theory of Relativity

3. The attempt at a solution
From the notes I have from the lecturer. It says:
The principle of relativity: The laws of physics must be the same in all inertial reference frame.
The constancy of the speed of light: the speed of light must be the same in all inertial frames, regardless of the velocity of the observer or the velocity of the source emitting the light.

My question is:
For the first statement, how do I use an example to explain this? Because I'm not too sure about "the law of physics" really means.

2. Jun 20, 2009

LowlyPion

3. Jun 20, 2009

rchenkl

Can I say the physics law in any inertial frame is independent? So when I do an experiment (say measuring the mass of a sphere) on a inertial frame, will be the same as what I do in another inertial frame. Is that correct?

4. Jun 20, 2009

LowlyPion

You have listed the two principles in your original post. If you are talking about independent of frame, then I suppose you can say your "laws" will be valid in one coordinate representation or another.

The other important postulate is the invariance of the speed of c.

5. Jun 20, 2009

rchenkl

So for example, one person is doing an experiment and obtained a result at stationary. Another person is traveling at a speed and do the same experiment. They will obtain the same results regardless the frame they are in. Is that a correct derivation from the first postulate?

6. Jun 20, 2009

LowlyPion

I think as long as there is uniform translation between the frames.