A friend of mine told me that there has been found examples showing that it is possible to find speed higher than the speed of light. As long as I can remember I have believed that the speed of light, c, is a nature constant and that the speed of light in vacuum is the highest possible.

I will be happy to know if this is correct. Is it possible to find observation that can only be explained if it is supposed that what is observed is an object , particle, wave .. having a speed higher than the speed of light.

As I understand relatively it depends by assuming that c, the speed of ligt, is the highest possible and is found in the famous equation : E=mc²

c=299.792.458 m/s.

Please write me if you know that the speed of light is not the highest to be found by particles or waves: pallej88@gmail.com Thank you. Palle jensen

### From Wikipedia, the free encyclopedia:

“Upper limit on speeds

…According to special relativity, the energy of an object with rest mass *m* and speed *v* is given by *γmc*^{2}, where *γ* is the Lorentz factor defined above. When *v* is zero, *γ* is equal to one, giving rise to the famous *E* = *mc*^{2} formula for mass–energy equivalence. The *γ* factor approaches infinity as *v* approaches *c*, and it would take an infinite amount of energy to accelerate an object with mass to the speed of light. The speed of light is the upper limit for the speeds of objects with positive rest mass. This is experimentally established in many tests of relativistic energy and momentum.^{[32]}

More generally, it is normally impossible for information or energy to travel faster than *c*. One argument for this follows from the counter-intuitive implication of special relativity known as the relativity of simultaneity. If the spatial distance between two events A and B is greater than the time interval between them multiplied by *c* then there are frames of reference in which A precedes B, others in which B precedes A, and others in which they are simultaneous. As a result, if something were travelling faster than *c* relative to an inertial frame of reference, it would be travelling backwards in time relative to another frame, and causality would be violated.^{[Note 5]}^{[34]} In such a frame of reference, an “effect” could be observed before its “cause”. Such a violation of causality has never been recorded,^{[16]} and would lead to paradoxes such as the tachyonic antitelephone.^{[35]…..” from Wikipedia 30. oct 2014}