14 DAY TRIAL // One of the most interesting astronomy news for 2010 had a lot to do with the discovery of a pulsar that apparently moved faster than the speed of light. This obviously turned out to be just an illusion, but a pretty convincing one at that. Now, experts compile a list explaining why superluminal motions appear.
Producing apparent superluminal (faster-than-light) motion is oddly enough quite simple. All you need is a row of light bulbs and a computer program to control their on/off sequence.
The experiments is quite simple, and also one of the most potent illusions. So you have this row of light bulbs, which are set to that the number 1 fires first, number 2 second, and so on in a sequence.
As the bulbs begin to be turned on and off, the speed at which the sequence unfolds is increased. This will lead to a situation in which light bulb number 2 lights up after number 1 in a period of time that is a lot smaller than that which light needs to travel between the two light bulbs.
In effect, this experiment produces apparent superluminal motion, although none of the light bulbs shine faster than the speed of light. But outside observe appear to believe light speed is exceeded.
The second way of achieving this objective is to make light faster than itself, by stretching it ahead of itself. It helps to think of light as wave packets in this scenario. If the wave is stretched linearly, then the leading edge arrives at a target faster than light.
However, one wave packet equals one photon in this scenario. This means that any deformations brought to the particles might make the leading edge of the wave indistinguishable from background noise, and therefore unable to carry information.
Another possible solution to obtaining an apparent superluminal motion is by amplifying the speed of light inside a light medium, but the light pulse emerging at the other end of the medium will always have a constant speed.
In other instances, it may appear that black holes or active galaxies are spewing out jets of highly-energetic light that travels faster than the constant. This is also an illusion, brought on by the immobility of our frame of reference.
The most interesting possibility is that actual superluminal velocities may exist in the the Universe, though not in our observable one, experts say. Beyond the cosmic horizon, galaxies may indeed be pushing away from each other at speeds larger than that of light.
Astrophysicists mention however that light from those galaxies will never make its way here, which means that they will always remain hidden to us. The violation of relativistic physics cannot therefore be confirmed, Universe Today reports.