What Are the Core Postulates of Einstein's Special Theory of Relativity?

Click For Summary
The core postulates of Einstein's Special Theory of Relativity include the principle of relativity, which states that the laws of physics are consistent across all inertial reference frames, and the constancy of the speed of light, asserting that light's speed remains constant regardless of the observer's or source's motion. An example illustrating the first postulate could involve measuring the mass of an object in different inertial frames, where the results would remain the same. This indicates that physical laws are independent of the frame of reference. The discussion emphasizes that as long as there is uniform translation between frames, experimental results will be consistent. Understanding these principles is essential for grasping the implications of relativity in physics.
rchenkl
Messages
12
Reaction score
0

Homework Statement


State two postulate that underlie the Special Theory of Relativity

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.
 
Physics news on Phys.org
LowlyPion said:

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?
 
rchenkl said:
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?

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.
 
LowlyPion said:
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.

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?
 
rchenkl said:
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?

I think as long as there is uniform translation between the frames.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

Replies
4
Views
2K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 57 ·
2
Replies
57
Views
7K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 78 ·
3
Replies
78
Views
7K