# Happy Birthday, Special Relativity

1. Jun 30, 2005

### robphy

2. Jun 30, 2005

### George Jones

Staff Emeritus
100 years young, still compellingly beautiful, and a long life ahead of her!

3. Jun 30, 2005

### joecoss

Special Relativity is amazing and although it is its' 100th Birthday today, I predict that General Relativity will not live to its centennial, and will be revised sometime before 2016.

4. Jun 30, 2005

### Pengwuino

Lets all give SR a present, whos with me

5. Jun 30, 2005

Staff Emeritus
How about a moratorium on amateur attempts to falsify it? No more trains, twins, spaceships,...

6. Jun 30, 2005

Staff Emeritus
How about a moratorium on amateur attempts to falsify it? No more trains, twins, spaceships,...

STO LAT!

7. Jun 30, 2005

### robphy

Trains, spaceships, etc... help us understand the consequences.

Here are some ideas for a "birthday present for SR":

1) draw more spacetime diagrams and appeal to geometry,
2) adopt consistent and unambiguous terminology [definitions!], and
3) eliminate poor phrases and poor analogies.

I think (1) helps make the algebraic calculations more concrete.
I think (2) gives us a common language.
I think (3) removes "myths" and other "folklore".
Otherwise, folks are arguing over semantics, often misusing or misinterpreting mathematical symbols.

(When we analyze forces on an object, we draw [or should be drawing] Free Body Diagrams before plopping down equations. We should do the same for analyzing situations in relativity.)

4) drop the word "Theory" when discussing Special Relativity.
$$\mbox{Theory of\hspace{-9ex}{\color{red}-------------} Special Relativity}$$
$$\mbox{Special Theory of\hspace{-9ex}{\color{red}-------------} Relativity}$$
$$\mbox{Special Relativity Theory\hspace{-7ex}{\color{red}-----------}}$$

8. Jun 30, 2005

### Aer

All of you seem to have some background in relativity, hopefully one or more of you will be able to clarify something for me. My question is posted here - post #26. Although it would be helpful if you read the details of the problem as posted in the thread starter.

9. Jun 30, 2005

### Pengwuino

Never! Ether ether ether!!!

On a more serious note, people should be allowed to try to falsify things. If they figure something out that we all missed, more power to them! Didn't Einstein say one of the reasons he was able to come up with SR was that he thought like a child and went against conventional wisdom?

And by the way, when i ask this question to myself, i feel like im asking a stupid question but i wanted to ask other people anyways incase its not actually stupid. Can you derive SR from classical physics?

Last edited: Jun 30, 2005
10. Jun 30, 2005

### Smurf

geeze, we're such geeks.

11. Jun 30, 2005

### TOKAMAK

Yeah, why not? It's essentially a consequence of Maxwell's equations, which are purely classical. (Assuming of course that Maxwell's equations are written the same in all reference frames.) So yes.

12. Jun 30, 2005

### Integral

Staff Emeritus

All you NEED to derive SR is Einstein's 2 postulates. Of course all he had to base it on was Classical Physics. So I would guess if you wanted a derivation based on Classical Physics you need only read Einstein.

13. Jun 30, 2005

### Aer

So what exactly is your reason for dropping the word "theory"

Theory: a well-substantiated explanation of some aspect of the natural world; an organized system of accepted knowledge that applies in a variety of circumstances to explain a specific set of phenomena; "theories can incorporate facts and laws and tested hypotheses"; "true in fact and theory"

Are you implying Special Relativity is not any of the above?

14. Jun 30, 2005

### εllipse

I'm not wearing socks tomorrow!

15. Jun 30, 2005

### εllipse

Maybe we should make it the Special Law of Relativity! Of course, that can cause problems when it needs revision, but Einstein deserves it. When did Newton's theories start getting called laws?

16. Jul 1, 2005

### wisp

The answer to your question is yes. Using basic classical physics and an ether frame you can derive equations that match the predictions of special relativity to almost 100%.

17. Jul 1, 2005

### arildno

Sir Joseph Larmorr (Lormar?) developed an ether theory superficially consistent with classical physics, and thus, in the first decade of the 20th century, Cambridge theoretical physicists dismissed Einsein's approach as both unnecessary and overly philosophical.

However, when GR came along, Larmor's theory was shown to fail miserably when trying to accomodate effects of gravitation. That is why his project was abandoned.

18. Jul 1, 2005

### pervect

Staff Emeritus
Using basic classical physics and an ether frame, one can predict that the Michelson-Morley expeirment should not have a null result. Unfortunately, experimentally, it does have a null result. This should be enough to show that the "ether" idea is not compatible with basic classical physics. Only a wild "ether enthusiast" could make the claims that wisp is making above.

At this point in time, one has to add in additional forces and/or "scalar fields" to have any sort of preferred frame or "ether". There is currently no direct experimental evidence that such forces or scalar fields exist. The assumption that such forces or scalar fields may exist is not "basic" classical physics, but a highly speculative extension to classical physics.

19. Jul 1, 2005