Of all the laws of science, this is probably among the most fun: If there exists a law, there exists a violation to the law. (And yes, even this has violations.) Researchers at NIST have recently found a new method to create superluminal pulses.
A consequence of Einstein’s Special Theory of Relativity is that no information can travel faster than the speed of light. While this would seem to indicate that nothing can travel at superluminal speeds, there is a loophole to it. An uninformed signal can exceed light speed without issue, and the NIST researchers have developed a better way to make these signals.
Light pulses can be visualized as a bell curve. The leading tail of the curve cannot exceed the speed of light, but it is possible to shift the peak of the curve forward or back. As the peak is already travelling at the speed of light, shifting it forward breaks the speed limit. This is done by using a second beam of light that interferes with the original beam. The interference causes the leading tail to amplify while the back of the curve is damped out. This has been accomplished by other research groups already, but the NIST work creates less noise in the superluminal light pulses.
The next step for the researchers will be to measure the quantum discord between the original light beam and the superluminal beam it becomes. Quantum discord is the difference in quantum information between two related systems. Depending on what the results of that are, these superluminal light pulses may be useful for the transmission and processing of quantum information.