We might know about “Time Travel” from films, TV series or science fiction books, like Back to the Future, Avengers: Endgame… But, what is “Time Travel”? Can we really travel in time? In this article, I will look at this question.

According to its name, “Time Travel” means travel to the past or future. It was introduced by British author Herbert George Wells in his science fiction book The Time Machine in 1895. After knowing its meaning, is time travel feasible? In my opinion, it is impossible to come true in the twenty-first century. There are three reasons to support my opinion.

First, there is a famous paradox called “Grandfather Paradox”. “Grandfather Paradox” is a paradox that was proposed by French science fiction author René Barjavel in his 1943 novel Le Voyageur Imprudent. “Grandfather Paradox” goes something like this, if you successfully go back to the past, and kill your grandfather, this means that your father will not be born. If your father was not born, you will not be born too, if you did not have a birth, then nobody will kill your grandfather.

Second, “Wormhole” is an object that can possibly make time travel come true. The theory of a “Wormhole” was proposed by Albert Einstein and Nathan Rosen in 1930, and is called “Einstein-Rosen Bridge” So, what is wormhole? Wormholes are tubes connecting distant regions of the universe. Dark matter keeps the wormhole exit open. Wormholes could link parallel universes to baby universes and offer the possibility of time travel. A wormhole could also be the tunnel connecting a black hole to a white hole. Wormholes have been proposed for about 92 years, yet scientists have not found any evidence of them yet. Some scientists say that wormholes might be in the microscopic world, like quantum entanglement. The relationship between wormholes and quantum entanglement is “ER=EPR”, ER refers to Einstein-Rosen Bridge (Wormhole), EPR refers to Einstein-Podolsky-Rosen Paradox (EPR Paradox). “What is microscopic world?” someone might ask. Nowadays, physicists divide the world into a macrocosm world and a microscopic world, macrocosm world means the world that we live in now, microscopic world means the world where molecules, atoms, electrons are. In order not to make this paragraph too long and too hard to understand, if you are interested in wormholes, please check my next article.

Third, according to relativity, the faster the speed, the slower the time. So does it mean that if you are fast enough, you can “travel further”? And let me apply another famous paradox called “Twin Paradox”. “Twin Paradox” goes something like this, there were two brothers. The older brother boarded a spaceship for a long journey into space, the speed of the spaceship is near the speed of light, while the younger brother stayed on Earth. As a result, when the older brother returned to the Earth, he found that the age of his younger brother was older than him. This result is inferred by Special Relativity (Time Dilation) that is what we started with “the faster the speed, the slower the time”. So logically, does not the older brother achieve time travel? At this point, someone will say, “I thought you said time travel would never happen in the twenty-first century. Why are you now saying that time travel can come true with Time Dilation?” Yes! That is true, but do you think we can develop spaceships in the twenty-first century that can travel near the speed of light?

Time Travel, is very attractive and lets people think they can go back and change something that failed them, make up for the mistakes they made before… But the thing that I want to say is, the chances of time travel being possible in our generation are almost zero, so why don’t we cherish every moment, every second that you spend your time with your family and friends, so that you will not have any regrets in the future. Let me end this article with a Latin sentence that my English teacher told me before: Carpe Diem (Seize the day.).