Time Dilation

 *TIME DILATION: 

          Time dilation is the phenomenon where two objects moving relative to each other (Relative Velocity Time Dilation) or even just a different intensity of gravitational field from each other (Gravitational Time Dilation), experience different rates of time flow.

* UNDERSTANDING TIME: 

What is the time? While most people think of time as a constant, physicist Albert Einstein showed that time is an illusion; it is relative. It can vary for different observers depending on your speed through space. To Einstein, time is the "fourth dimension." Space is described as a three-dimensional arena, which provides a traveler with coordinates — such as length, width, and height, showing location. Time provides another coordinate – direction, although conventionally, it only moves forward.

 *RELATIVE VELOCITY TIME DILATION: 

Special relativity indicates that, for an observer in an inertial frame of reference, a clock that is moving relative to him will be measured to tick slower than a clock that is at rest in his frame of reference. This case is sometimes called special relativistic time dilation. The faster the relative velocity, the greater the time dilation between one another, with the rate of time reaching zero as one approaches the speed of light (299,792,458 m/s). This causes massless particles that travel at the speed of light to be unaffected by the passage of time. Hence, faster you move through space – slower you move through time. 

Relative velocity time dilation can help in traveling in time to the future. For traveling backward…

* TIME TRAVEL PARADOXES: 

          Time travel to the past can lead to various contradictions. These three paradoxes are well known:

•   Grandfather Paradox

•   Predestination Paradox

•   Bootstrap Paradox

 *EXAMPLES: 

           If you travel at 99.99% speed of light for one year, you will age only 5 days while a whole year would have passed on Earth. If you travel to the nearest star Proxima Centauri which is around 4.3 Light Years away, it will take you only 21 days to reach. So if you come back on Earth, 8.6 years would have passed on Earth while you will age 42 days only. You can travel around 4000 light-years and still, aged only 60 years if you somehow managed to do video calls on Earth. The video of a person from Earth would be in fast forward and your video will be in ultra slow motion.

There’s a quote witten in “Brief Answers to the big questions”:

                    “There was a lady if Wight, who traveled much faster than light, she departed one day in a relative way and arrived on the previous night”.

 *Grandfather Paradox: 

                   Assume that you go back in time and kill your grandfather before your father was born, then your father isn.t born which means you are also not born. That means you didn’t go back in time and kill your grandfather.

* Predestination Paradox:

          A Predestination Paradox refers to a phenomenon in which a person traveling back in time become part of past events, and may even have caused the initial event that caused that person to travel back in time in the first place.

 *Bootstrap Paradox: 

Once again you back in time and this time you go meet a great scientist while talking with him you tell him about great theories he will discover in the future. Inspired by this talk, scientist discover theories in the first place, then where did theory come from.

* Examples

• The time dilation shown in the movie “INTERSTELLAR” is an example of Gravitational Time Dilation. The first planet they land on is close to a supermassive black hole, dubbed Gargantuan, whose gravitational pull causes massive waves on the planet that toss their spacecraft about. Its proximity to the black hole also causes an extreme time dilation, where one hour on the distant planet equals 7 years on Earth. 

• In one experiment, James Chin-Wen Chou and his colleagues placed one clock about 13 inches higher than its counterpart. The higher clock felt less gravity because it was a tiny bit farther from Earth's gravitational field. It ticked more slowly - albeit a tiny, tiny bit more slowly. The time difference adds up to about 90 billionths of a second over a 79-year lifetime.

 *Gravitational Time Dilation: 

Time dilation due to being at different distances from a gravitational mass is described in the general theory of relativity. The closer you are to a gravitational mass, the slower your clock seems to be sticking to an observer farther from the mass. When a spaceship nears a black hole of extreme mass, observers see time slowing to a crawl for them.

 These two forms of time dilation combine for a satellite orbiting a planet. On the one hand, their relative velocity to observers on the ground slows time for the satellite. But the farther distance from the planet means time goes faster on the satellite than on the surface of the planet. These effects may cancel each other, but also can mean a lower satellite has slower-running clocks relative to the surface while higher-orbiting satellites have clocks running faster relative to the surface.

# B.R.A.I.N Foundation