E-StoreTime Dilation or Time Travel
Time dilation is the phenomenon whereby an observer finds that another's clock, which is physically identical to their own, is ticking at a slower rate as measured by their own clock. This is often interpreted as time "slowing down" for the other clock, but that is only true in the context of the observer's frame of reference. Locally (i.e., from the perspective of any observer within the same frame of reference, without reference to another frame of reference), time always passes at the same rate. The time dilation phenomenon applies to any process that manifests change over time.
In Albert Einstein's theories of relativity, time dilation is manifested in two circumstances:
- In special relativity, clocks that are moving with respect to an inertial system of observation are measured to be running slower. This effect is described precisely by the Lorentz transformation.
- In general relativity, clocks at lower potentials in a gravitational field — such as in proximity to a planet — are found to be running slower. This gravitational time dilation is only briefly mentioned in this article; see that article (and also gravitational red shift) for a more detailed discussion.
In special relativity, the time dilation effect is reciprocal: as observed from the point of view of any two clocks which are in motion with respect to each other, it will be the other party's clock that is time dilated. (This presumes that the relative motion of both parties is uniform; that is, they do not accelerate with respect to one another during the course of the observations.)
In contrast, gravitational time dilation (as treated in general relativity) is not reciprocal: an observer at the top of a tower will observe that clocks at ground level tick slower, and observers on the ground will agree. Thus gravitational time dilation is agreed upon by all observers, independent of their altitude.
TIME DILATION AND THE SPACE FLIGHT Time dilation would make it possible for passengers in a fast-moving vehicle to travel further into the future while aging very little, in that their great speed retards the rate of passage of on-board time. That is, the ship's clock (and according to relativity, any human traveling with it) shows less elapsed time than the clocks of observers on Earth. For sufficiently high speeds the effect is dramatic. For example, one year of travel might correspond to ten years at home. Indeed, a constant 1 g acceleration would permit humans to travel as far as light has been able to travel since the big bang (some 13.7 billion light years) in one human lifetime. The space travelers could return to Earth billions of years in the future. A scenario based on this idea was presented in the novel Planet of the Apes by Pierre Boulle.
A more likely use of this effect would be to enable humans to travel to nearby stars without spending their entire lives aboard the ship. However, any such application of time dilation would require the use of some new, advanced method of propulsion. A further problem with relativistic travel is that at such velocities dispersed particles in the rarefied interstellar medium would turn into a stream of high-energy cosmic rays that would destroy the ship unless extraordinary radiation protection measures were taken. Strong electromagnetic fields that could ionize and deflect any interstellar matter has been suggested as one way to avoid these potentially disastrous consequences.
Current space flight technology has fundamental theoretical limits based on the practical problem that an increasing amount of energy is required for propulsion as a craft approaches the speed of light. The likelihood of collision with small space debris and other particulate material is another practical limitation. At the velocities presently attained, however, time dilation is not a factor in space travel. Travel to regions of space-time where gravitational time dilation is taking place, such as within the gravitational field of a black hole but outside the event horizon (perhaps on a hyperbolic trajectory exiting the field), could also yield results consistent with present theory.
source- Wikipedia
RATE IF YOU FIND SUITABLE
Comments (3)
Preparing for IIT-JEE ?
Arihant Revision Package for IIT JEE - Books, Practice Tests + Rank Predictor
@ INR 1,995/-
For Quick Info
|
|
|
|
|
| 35,229,755 Engineering Questions Attempted |
6,69,530 Visitors Monthly |
79 Engg. Exam Covered |
2117 Students Currently Online |
Connect with Us  |
 |
