Time dilation and space contraction. In the theory of relativity, time dilation is an observed difference of elapsed time between two events as measured by observers either moving relative to each other or differently situated from gravitational masses. An accurate clock at rest with respect to one observer, may be measured to tick at a different rate when compared to a second observer’s own equally accurate clocks.
This effect arises neither from technical aspects of the clocks, nor from the fact that signals need time to propagate, but from the nature of space-time itself. In special relativity ( or, hypothetically far from all gravitational mass), clocks that are moving with respect to an inertial system of observation are measured to be running slower (refer Wikipedia).
Similarly, there are other concepts such as space and length contraction. For example, an observer detects a decrease in the length of objects that travel at any non- zero velocity relative to that observer. It is interesting to note that while time expands from the perspective of the stationary observer, space contracts from the perspective of the moving observer.
However, both time dilation and space contraction are not noticeable at everyday speeds. The effect of time dilation has been experimentally confirmed, thanks to very precise caesium clocks that can measure extremely small periods of time. Unfortunately, time dilation is completely outside human experience because we have not yet devised a way of travelling at speeds where relativistic effects become noticeable. Even if you spent your whole life in a jet plane that moves at supersonic speed, you would barely win a second over your contemporaries on the ground.
Not even today’s astronauts can perceive the Lorentz contraction. Imagine you are a cosmonaut on board space station Mir which is moving at 7700 metres per second relative to the earth. Looking down upon Europe from space you would see the entire 270-kilometre east to west extent of Switzerland contracted by a mere 0.08 millimetre. If, however, neutrinos really travel faster than light, time dilation and space contraction could assume a new meaning, and possibly become experienceable.
Time travel. Time travel is the concept of moving between different points in time comparable to how one would move between different points in space. So far only hypothetical, time travel would faciliate movement to any point in the past or future without the need for the traveler to experience the intervening period in its normal rate.
So far the relation between cause and effect as explained by Einstein’s theory of special relativity provides for the movement of time only in one direction. This is based on the underlying theory that nothing can move faster than light. However, if it is true that neutrinos travel faster than light, it could open the possibility of one travelling back in time.
Conversion of mass into energy and vice versa. When charged particles move in a medium with speeds faster than the speed of light in that medium, they radiate some energy. So if neutrinos travel faster than light in vacuum, there must be some energy that can be tapped from it.
Any immediate impact on electronics and communication? Prof. Karbelkar feels, “It is very difficult to predict the electronics and communication engineering implications of the claimed findings. On the domestic ground (1000km range), a head-start of a mere 60-billionths of a second might not prompt people to switch over to neutrino-based communication. Remember also that the OPERA team at the receiving end (the Gran Sasso lab) uses a really colossal detector (10x10x20 m³ with a mass of 4000 tonnes). Not very suitable for routine communication. Perhaps for inter- world galactic communications, this, if true, may help!”