A group of American physicists experimentally proved the existence of common sense, showing that the cause can not stay ahead of the investigation. As the NTR.Ru, conducted their experiments confirmed that a recent experiment in which the light is moving faster than its speed in a vacuum, does not contradict the idea of causality, according to which the investigation takes place later cause. The special theory of relativity, Einstein postulated that the speed of any movement can not exceed the speed of light in vacuum. If anything outrun light, it gives rise to the possibility that an event will occur before its cause arises.
Experiments were performed in which the light of a gas in a cooled metal atoms moving at a speed greater than the speed of light in a vacuum (300 thousand km / s). Then, most physicists are not worried about the problems of relativity and causality. They argued that it would not affect the marginal rate of information transfer. The fact that a light pulse represents a group of photons, moving with different velocities. . If some of the photons moving at a higher speed of light in vacuum, to boost it will have no effect — he will not be able to pass any information until then, until you arrive at the majority of photons (with the speed of light). But what exactly is the speed of information in such a pulse? Until now, physicists have tried to find an answer to this question.
Some have argued that the transmission of information will be the same as the average speed of the group and therefore can exceed the speed of light, violating causality. Others thought that the speed of information in any case be less than or equal to the speed of light. Daniel Gauthier of Duke University and his colleagues have found the answer to this question. The researchers analyzed the speed with which data can be transmitted in an environment where the speed of the photon is much higher than the speed of light. Scientists clarify that the transfer of information is not only sending a signal. The signal to be encoded and decoded when sending the other end.
The maximum baud rate, the researchers said, coincides with the earliest time when the signal change will be noticed, and its detection is a finite time, which depends on the pulse shape and the amount of background noise. Gautier group found that the information encoded in a light pulse through a gas of potassium atoms (where the light moves faster) detected for a longer time than in the same impulses that travel in a vacuum at a speed equal to the speed of light. So the speed of information never exceeds the speed of light.