Happy Birthday, Special Relativity

[bernhard.rothenstein]

second postulate redundant

This is very interesting. Can you provide some proof of this? (references, links)

See
[1] N. David Mermin, "Relativity without light," Am.J.Phys. 52, 119-124 (1984)
[2] Achin Sen, "How Galileo could have derived the special theory of relativity," Am.J.Phys. 62 157-162 (1994) See also the references cited in this paper.
I think that the derivations are relatively complicated, involving so many intermediary steps, that I think nobody has introduced them in his teaching practice.

 

[clj4]

See
[1] N. David Mermin, "Relativity without light," Am.J.Phys. 52, 119-124 (1984)
[2] Achin Sen, "How Galileo could have derived the special theory of relativity," Am.J.Phys. 62 157-162 (1994) See also the references cited in this paper.
I think that the derivations are relatively complicated, involving so many intermediary steps, that I think nobody has introduced them in his teaching practice.

Thank you. Here is what I got for [1]:

"The relativistic addition law for parallel velocities is derived directly from the principle of relativity and a few simple assumptions of smoothness and symmetry, without making use of the principle of the constancy of the velocity of light."

This is not very interesting, there are a lot of papers like this. The application is very restrictive and it is not a fully developed theory.

Looks like [2] is the same thing as [1], not very interesting.

 

[clj4]

Never mind

Here is a better link:

http://scholar.google.com/scholar?num=100&hl=en&lr=&q=link:oxrtK336wDUJ:scholar.google.com/

From the list only :

http://arxiv.org/PS_cache/physics/pdf/0503/0503227.pdf

is a complete derivation of special relativity and I am not sure it is correct (it has not been peered reviewed). Anybody cared to review it? Should be an interesting exercise. A brief look over it and it appears that this paper has the c'=c assumption accidentally hidden which would make it irrelevant.

 

[bernhard.rothenstein]

Thank you. Here is what I got for [1]:

"The relativistic addition law for parallel velocities is derived directly from the principle of relativity and a few simple assumptions of smoothness and symmetry, without making use of the principle of the constancy of the velocity of light."

This is not very interesting, there are a lot of papers like this. The application is very restrictive and it is not a fully developed theory.

Looks like [2] is the same thing as [1], not very interesting.

please have a look at
http:arxiv.org/abs/phyics/0602054
i feel that the derivation could avoid the second postulate if the first one is better exploited. Have you some ideea in that direction? In order to ease communication ou could use
dr_relativ@yahoo.com

 

[clj4]

please have a look at
http:arxiv.org/abs/phyics/0602054
i feel that the derivation could avoid the second postulate if the first one is better exploited. Have you some ideea in that direction? In order to ease communication ou could use
dr_relativ@yahoo.com

Never mind, I found it at http://arxiv.org/ftp/physics/papers/0602/0602054.pdf, there was a typo in your link.
I think that (see my comments on the other papers of this type) it is extremely difficult, if not impossible to drop the second postulate. I have seen a lot of papers attempting to do this (there is even a book published on this subject , see :https://www.amazon.com/gp/product/9810238886/?tag=pfamazon01-20) All the attempts are either:
-plain wrong (can you detect the error in this one? http://arxiv.org/PS_cache/physics/pdf/0304/0304087.pdf)
-allow the second postulate back in thru some "back door" (see my comments in the next post)

 

[clj4]

From the list only :

http://arxiv.org/PS_cache/physics/pdf/0503/0503227.pdf

is a complete derivation of special relativity and I am not sure it is correct (it has not been peered reviewed). Anybody cared to review it? Should be an interesting exercise. A brief look over it and it appears that this paper has the c'=c assumption accidentally hidden which would make it irrelevant.

Here is one mistake in the above paper:

in deriving equation (10) in paragraph III(B) the authors are already PRESUPOSING constant c when going from the primed system (equation (9)) to the unprimed system (equation (10)). This is a classical error in such papers that attempt to do away with c'=c , the authors simply reintroduce c'=c in a sureptitious way.
Wolfgang Pauli and R.C.Tolman (among many others) tried in vain to construct a special relativity without the second postulate. Looks like a ver difficult task, unlikely that it would succeed.

 

[clj4]

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.

Hmm,

You may have to rethink your statement after the results of Gravity Probe B are published this year.

 

[clj4]

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

Well, how do you stop the kooks that keep hoping to disprove SR?
How do you stop the kooks that want to go back to Newton?
And how do you stop the kooks that claim that he plagiarized his theories?
How do you stop the kooks with "alternative" theories?
No other field has brought out so many kooks...

 

[clj4]

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}-----------}}

All very good and practical ideas, they should work on normal people.
What can we use to make the kooks go away?

 

[clj4]

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 accommodate effects of gravitation. That is why his project was abandoned.

Larmor is the correct one.

 

[robert Ihnot]

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

Not a chance! Those trains, twins, spaceship...are things Einstein used to explain his theory. Kitty Hawk was Dec 1903; the speed of the plane thought to be something like 12 miles/hr. To the young Einstein, trains were the things he saw and thought of as going fast.