Vadim, your idea of science is very limited. This is not how science
works. The "speed of light" limit is not an experimental one but a
theoretical one.
Actually, the idea of the speed of light as a limit is in some ways
supported by one of the early experiments that led to the theory
of relativity, performed already in the 19th century: http://scienceworld.wolfram.com/physics/Michelson-MorleyExperiment.html
As you might see from the Lorentz equation, for v to be greater than c,
would imply that the "contracted length" is an imaginary number. The
equation, developed as a result of the experiment, therefore suggests that
the magnitude of a particle's velocity cannot exceed the speed of light.