You might have seen in some movies and stories about people travelling to the past or future. This is known as time travel. Have you ever thought of travelling to the past or future as well? You may think that time travel is completely impossible. But actually, scientists have found a way to carry out time travel. In other words, they have found a way to travel to the past or future! So, time travel is not impossible. However, the steps to carry out time travel are extremely difficult and complicating.
Before I explain about time travel, I will first explain about something known as wormhole. A wormhole is similar to a blackhole. A blackhole is actually the remains of a very large star after the star dies. A blackhole has very strong gravity and very great density. It will attract everything including light into it. Then, the blackhole will focus everything to a point. Therefore, a blackhole has no exit.
On the other hand, a wormhole can be explained as a blackhole that has exit. A wormhole has two ends. It connects two time space. A time space is a location in the universe at a particular time. If you enter a wormhole from one end, you can exit from its other end. Since a wormhole connects two time space, you will end up in another time space after going through a wormhole. Therefore, wormhole can be used for time travel.
However, until now, scientists have not yet discovered any wormhole, nor they are sure if wormholes really exist. Although many blackholes have been discovered, a blackhole cannot be used for time travel because it has only one end and no exit. Even if wormholes exist, when you enter a wormhole, your body will be stretched when you go through the centre of the wormhole. But, scientists have came out with a way to create a wormhole which can be used for time travel. To create a wormhole, you will need a device known as time machine. A time machine is made up of three parts.
The first part of the time machine is used to create a wormhole. In this part of the machine, electrons are accelerated at very high speed in a tube. Actually, a similar electron tube smaller in size is also present behind a standard television set. When the electrons are accelerated at high speeds, a wormhole is produced. The longest electron tube in the world is 2 kilometres long, and is used to produce wormholes for scientific research. However, time travel requires a wormhole that is very large in mass. In order to produce a wormhole with a mass large enough for time travel, the size of the electron tube must be at least as big as the whole solar system. Based on our current technology, it is not possible to create an electron tube that large.
The second part of the time machine is used to expand the wormhole. Even if you succeed in creating the first part of the time machine, the electron tube can only produce a wormhole with a very small volume. A wormhole with very small volume cannot be used for time travel. Therefore, the wormhole must be expanded to increase its volume. In a blackhole, its very strong gravitational force causes anything attracted into it to shrink. So, if you do the opposite, by applying anti-gravitational force, this will cause the wormhole to expand. To do so, you need a 'special' substance that can produce anti-gravitational force. However, currently scientists have not yet discovered any substance that can produce anti-gravitational force.
The third part of the time machine is used to transport the wormhole. It is actually a spacecraft that can transport a wormhole. After the wormhole has been created and expanded by the first and second part of the time machine, this part of the time machine transports the wormhole to the correct location in space and makes the necessary calculations. After that, the time travel can be carried out. However, scientists are not yet able to create a spacecraft that can transport a wormhole.
Although the scientists have found a way to build a time machine to carry out time travel, our current technology doesn't allow us to do so. There are many great problems and difficulties that we have to face and overcome in order to create a time machine. So, currently it is surely impossible for us to carry out time travel. Maybe in the future, scientists are able to overcome these problems and successfully create a time machine.