no no no no jesus fucking christ I can't take this shit anymore
Ask any physicist and I am 99% sure he will tell you that Einstein's theories of relativity (both general and special) and quantum mechanics (both have been modified since their original incarnations, also) are equally well tested and accepted. What you clearly don't understand is that they simply have not been reconciled with each other yet. The mathematics of relativity and quantum mechanics are separate, and the big problem in theoretical physics now is blending the two into a unified theory.
Both relativity and quantum mechanics have been subjected to rigorous experimental verification and so far neither has failed.
I have some things to tell everyone:
A) I hate to toot my own horn, but I have been studying physics in college for 3 years and I probably know more about it than you. That's why you should listen to me.
B) The speed of light is not like the speed of sound. It's not some speed that just presents technical problems to vehicles trying to go faster. It's a fundamental law of the universe that no matter can be accelerated to a speed faster than light, which travels at 3.0 x 10^8 m/s. This was NEVER thought to be the case with the speed of sound, at least in the past few centuries.
C) The question "what would happen if you went 3 times the speed of light" is fundamentally flawed because the theory of relativity does not allow for such a thing to happen, and yet relativity is what all you guys are trying to use to explain this. Does that make sense? I don't think so. If you want to accurately answer this question, you are going to need to invent a new branch of physics that stands up to every test relativity has withstood over the past hundred years, and use that theory to answer the question. You CANNOT use relativity because it FUNDAMENTALLY DISALLOWS THIS SITUATION.
Relativity, like quantum mechanics, has a mathematical core. It is not intuitive. It cannot be easily grasped by the human mind except in a mathematical context. And I don't think many of you guys fully understand even the basic ideas of relativity, let alone the math that actually describes what's happening.
Lots of experimental trickery with tiny particles and other things has been done to make stuff travel "faster than light". These are allowed by theory, and if they were not then we would have heard about it, and scientists would not still be trying to verify relativity (and quantum mechanics) with ever-increasing degrees of accuracy. Not even a single atom has been made to exceed the speed of light, however. And I somehow doubt one ever will. Search the internet if you don't believe me.
As a final note, special relativity does not disallow the existence of particles (called "tachyons") that always travel faster than light. These have not been proven or disproven to exist, and you can find out about them with google.