/sci/ - Science & Math

Going faster than the speed would violate causality.

>>4202542
uh, why?
Whenever people try to explain this they use terms that are only real given that the speed of light is infact maximum. Such that moving faster than the speed of light supposedly makes you travel 'backwards' in time according to the lorentz factor, but forgetting that the lorentz factor comes from the fact that the speed of light is constant.

If the speed of light is not constant, the lorentz factor is wrong, and can not be used to prove anything.

>>4202520
> I know this has been experimentally verified, but is there any more rigid proof than this?
There is no more rigid proof of a physical phenomenon than experimental verification, no. Experimental verification is the top, way above mathematical proofs, philosophical thought experiments, and very very far above believing whatever you just heard yourself say.

If you like you can assume the Lorentz transformation (in effect, hyperbolic spacetime metric) and the speed of light properties can be showed from that.

It goes either way - constant, unbreachable speed of light implies relativity, and vice versa. They go together. Now, we might some day show experimentally that they are both wrong in some way, but as far as rigid proofs go the best you can do is that one implies the other.

>>4202543

The math behind it is fairly complex but you have to assume that the Lorentz transformations are accurate since a normal Galilean transformation breakdowns near c. You could also check our World Diagrams it will help you understand why c is an absolute limit.

>>4202546

Oh pipe down. The experiment shows the properties appear to hold in certain situations, but could very well be extended by further experiments under different conditions.

>>4202552

The amount of energy required to 90% of the speed of light is tremendous. If I recall correctly, even in particles accelerators they only reach 0.95c. It's possible there are some conditions (most likely subatomic, with ) where c can be exceeded but as of right now we don't have the technology required to observe these conditions.

>>4202549
I thought the Galilean transforms breaking down at c was only because one, again, assumed c to be constant?

>>4202555

Lol no, they go much much faster than that.

>>4202555
That wasn't really the point. The point was that the experimental proof doesn't really say for sure that our theory holds true under all situations.

Special relativity does not postulate that the speed of light is a universal barrier or anything like that; It postulates that the speed of light is independent of the reference frame you measure it from. From this it follows that change of coordinates between inertial reference frames should be given by Lorentz transformations instead of Galilean transformations. And then from this you can deduce that going faster than light would lead to causality violations and nasty shit like that.

The fact that light propagates at the same speed with respect to any reference frame is empirical. The first evidence of this is in the famous Michealson-Morely experiments.

Light's light is light nigga.

>>4202520
>everything is proved from the assumption that the speed of light is constant and impossible to breach

Nope. In Special Relativity you start with some metric and derive all the other shit. That is it.

>>4202598
You have obviously not done these derivations. If you have, show me how you do them without assuming c has to be constant.

>>4202546
You're wrong, experimental proof is nothing, I could just now make the claim that x^x=2x by experimenting on the number 2 (2^2=2*2) or I could choose another formula that would apply on more number but that would be nonetheless wrong. What I'm trying to say is, how could you experiment that the speed of light is the maximum speed? We can experiment on particles we know but who told you there is a non-discovered particle capable of surpassing the speed light? Experiment is never a sufficient proof.

>>4202520

There is no more "rigid proof" of the invariance of the speed of light then Michelson and Morley's classic experiment (which set out to demonstrate a completely different result). If you are not familiar with it, the two aforementioned scientists tracked two light beams around the world, one travelling with the rotation of the Earth and one against...

Surprisingly, both light beams completed the journey in the same period of time!

The more interesting question is surely, why(!?) does this upper bound exist.

>>4202608
Of course. There is no concept of "proof" in science.

At best, what we have is a "belief" that we are producing a series of ever-more-accurate approximations... Mmm.

Experimental theories are never proven correct, only falsified. According to Popper, it is the property of falsification which characterises scientific theories...

>>4202608
You don't understand how science works, do you?

http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm

First of all, Einstein's theory of relativity is a theory, nothing more. Just speculation. It depends a great deal on the speed of light constant. Second of all, a team of European physicists have discovered that neutrinos can travel at speeds faster than light.

>more rigid proof than experimental evidence

I'm sorry, what?

>>4202918
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>>4202918

1/10

too obvious

ITT: people not understanding how science works.

Experimental Observation => Theory => Predictions

That's all there is. To go any further and make assertions about 'true theories' or 'proofs' is impossible.

The whole notion that time travel could occur if c were exceeded has no weight at all because it requires us to extrapolate our current theory outside of it's experimental domain, and beyond a point where the theory itself fails mathematically.

>>4202925
>>4202931
http://www.bbc.co.uk/news/science-environment-15791236

>>4202957

Hhahahahahaha

Really enlightened us

>>4202957
The posts in this thread turning increasingly into trolling probably means that we have exhausted the immediate potential of the topic.
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>>4202941
Unless it disagrees with the theories in which case it is ignored

Thread reported for blasphemy.