# Experimental Proofs

1. Jul 28, 2006

### philipp2020

Hi

Im new in this Forum. Im from Switzerland, in the first year of Physics at University. Please forgive some mistakes I might will make in english

I read a little bit in advance for the next years about the SRT and its relation to other fields of study.

Basically I wanted to know about past experiments which proofed about the highest speed possible. I read about the experiment by W. Bertozzi in the 60th, who accelerated electrons by an electric field generated by a Van de Graaf Generator.

Then there is this experiment with Myons un- and accelerated: If they decay to gamma rays, both gamma rays, from the accelerated and not accelerated myons have the same speed.

Which other significant experiments exists beside those? Could anyone give me some information about that?

And just for my understanding: If I have, for example a space ship, travelling half the velocity of light trough space. Then inside the spaceship I send a light ray in vacuum from the back to the front of the the ship, this light doesnt travel 1.5 times the speed of light, according to the special theorie of relativity?? Is this because, also according to SRT, the spaceship travelling 0.5 c, already constructs a big time deletation, when looking at the spaceship from outside?

So basically, the fundament of the SRT is, that the highest speed possible is detirmined by the speed of light? If this fundament wouldnt be true, SRT also couldnt be stand out?

Greetings

Philipp

2. Jul 28, 2006

### Staff: Mentor

3. Jul 28, 2006

### philipp2020

ok, thanks very much for the link. maybe just what I was looking for. I will read it next day.

further, may I ask again about the thing I asked about the spaceship traveling half the speed of light etc? Is this right what I was writing in my opening thread?

4. Jul 28, 2006

### Staff: Mentor

yes, two relative velocities combine not simply by adding:

$$u = u' + v$$

but rather, in such a way that the result can never exceed c:

$$u = \frac {u' + v}{1 + (u'v/c^2)}$$

Look up "relativistic velocity addition" or "relativistic composition of velocities" in your textbooks or on a search engine.