Stephen Hawking threw a party for time travellers. Is time travel really possible?
When it comes to science fiction movies, time travel has been an unavoidable part of it. However, in reality, is there a machine which can take us to the future?
Unfortunately, the answer is No. Although, we do not have the technology to make it happen, theoretically time travel is possible. Let us go through some interesting examples.
Let us consider an Athlete who is able to run 100 metres in 10 seconds on a flat terrain.
The same athlete could cover the same 100 metres in 20 seconds on a slopy terrain. The speed of the athlete was constant in both the cases. But why there is a change in time?
Let us consider a light clock. The light clock has two mirrors in the opposite direction and a light bouncing between them. The distance between the top and bottom ends is equal to d. The photon travels 2d distance in one second.
Now let us consider that this light clock is mounted on to a space ship and the space ship is travelling at some speed. Now, for one second, the light would have travelled more distance than before.
As you have seen from the video, the light now travels a greater Distance D. According to Einstein, the speed of the light is constant. But something has to change to allow the speed of light to be constant. It is none other than time. It turns out time slows down as you travel faster and faster.
As you travel faster and faster, the time slows down for you. As you approach speed of light, one day for you at the space time may be equal to 50 years on Earth. This is how we could travel to the future.
Can we also travel to the past?
It is believed that if we travel beyond the speed of light, we can go to the past. But there is still no man made technology that could travel even near light speeds. Warp drives are considered to be the future technology, which could travel faster than light.
Stephen Hawking’s Party
I know you guys are excited to know about the Stephen Hawking’s Party for time-travellers. Yes, Stephen Hawing threw a party for time-travelers on June 28, 2009. His invitations were sent out the next day, but nobody showed up to the party. This, he claims, is experimental evidence that proves time travel to the past is not possible.
In principle, the conclusion is if you could travel faster, you could go to the future.