To our knowledge, a person can’t travel at double the speed of light, and it does not happen to anything that has a kind of weight that you or I have to move faster than the speed of light.
However, in some abnormal particles, the movement of twice the light speed is possible – and may return those particles in time.
General speed limit: One of our best biological theories at the moment is the relationship theory, developed by Albert Einstein. According to this theory, light speed acts as a speed limit on anything with weight.
Specifically, the relation tells us that nothing weighty can accelerate beyond the speed of light.
To accelerate an object by weight, we must add strength. If we want something to go faster, we will need more energy.
Relational statistics tell us that anything heavy – no matter how serious it is – can require unlimited energy to accelerate to light speeds.
But all the energy sources we know are limited: they are limited somehow.
Indeed, it is interesting that the Universe contains a limited amount of energy. That could mean that there is not enough energy in the Universe to accelerate a mass of light.
Since you and I are heavy, do not expect to move at twice the speed of light anytime soon. This speed limit applies to anything we might call “normal weight.”
There are, however, thought-provoking particles called tachyons that have a particular type of weight called “imaginary mass.”
There is no evidence that tachyons exist. But according to the relationship, their possible presence cannot be ruled out.
If available, tachyons should always be moving faster than light speeds. Just as an object with average weight can accelerate beyond the speed of light, tachyons cannot be reduced to light.
Some physicists believe that if tachyons were present, they would recede from time to time. That is why tachyons are associated with time in many science fiction books and movies.
There are ideas that we can use tachyons to build a time machine one day. But for now, this is still a distant dream, as we cannot see potential tachyons.
It is a shame that we cannot move faster than the speed of light. The nearest star, outside the Sun, is 4.35 light-years away. So, traveling at the speed of light could take more than four years to get there.
The farthest star we have ever seen is about 28 billion light-years away. So you can stop planning the whole Universe.
That being said, the relationship allows for the presence of “wormholes.”
The wormhole is a shortcut between any two points in space. Although a star maybe 4.5 light-years on average, it may be just a few hours away from a wormhole.
If there are authentic wormholes, they can allow us to travel long distances in a short time – allowing us to reach the farthest parts of the Universe within a single lifetime.
Unfortunately, like tachyons, wormholes always think entirely.