A person cannot, as far as we know, travel at two times the speed of light. In reality, no object with the mass that you or I possess can move faster than the speed of light in any direction. Einstein’s theory of relativity seems to say that it can’t happen, but what if it could? Some unusual particles may be able to move at twice the speed of light — and this may allow them to travel back in time.
A Universal Speed Limit
Albert Einstein’s theory of relativity is one of the most useful physical theories we have at the moment. The speed of light, according to this theory, serves as a universal speed limit for anything with mass. Relativity states that nothing with mass can travel faster than the speed of light.
A mass object must be given additional energy to accelerate. Hence, the speed of the object is directly proportional to the energy provided to it. Einstein’s equations of relativity say that it takes an infinite amount of energy to speed up anything with mass to the speed of light, no matter how much mass it has.
However, all of the energy sources that we are aware of are limited in some way. Indeed, it’s conceivable that the universe has a finite amount of energy to begin with. That would imply that the universe lacks the energy necessary to accelerate anything of mass to the speed of light. As long as we have mass, we won’t be able to travel at twice the speed of light.
Tachyons
Anything with “ordinary mass” is subject to this universal speed limit. There are, however, “imaginary mass” tachyons, which have a unique type of mass. The existence of tachyons has never been proven. Relativity, on the other hand, says that it’s impossible to rule out the possibility of such things.
If tachyons exist, they must always be traveling at a speed greater than the speed of light. Tachyons can’t be slowed down below the speed of light, just like regular mass can’t be accelerated above the speed of light. It is hypothesized by some physicists that if tachyons existed, they would constantly be travelling backwards in time. As a result, tachyons are often used to depict time travel in science fiction.
There is speculation that one day we may be able to construct a time machine by utilizing tachyons. However, as we do not yet have the capability to identify probable tachyons, this remains a distant dream for the time being.
Shortcuts?
Our inability to travel faster than the speed of light is a disappointment. 4.35 light years is the distance between us and the closest star other than the Sun. It would take more than four years to get there if you traveled at the speed of light. The most distant star we’ve ever found is located 28 billion light years away from Earth. So it’s time to give up on trying to map the entire cosmos.
Relativity does, however, allow for the existence of “wormholes.” A wormhole is a shortcut between any two places in space. In normal terms, a star may be 4.5 light years away, yet through a wormhole it may be only a few hours away.
For all we know, the farthest reaches of the universe could be reached in one lifetime if there were real wormholes somewhere in our universe. Wormholes, like tachyons, are only a theory at this point.
We can try to envision what it would be like to travel faster than light, despite the fact that we can’t actually do so. If we think this way, we are involved in “counterfactual thinking.” We’re imagining what life would be like if things had been different. We have to think about a lot of different possible outcomes, each of which is based on a different set of physical laws.
It’s impossible to predict what would happen if we could travel faster than light, so we don’t know what would happen. We can only speculate about what might happen. Do some scientists believe that tachyons could allow us to go back in time?
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