Can we time travel The theoretical physicist offers possible answers
Certain theories of time travel suggest that you can look back at the past in the same way as watching a film. However one can’t interfere with the activities of the people who are within it. (Rodrigo Gonzales/Unsplash)
Physics laws
Albert Einstein’s theory of relativity, which describes the nature of space, and time, as gravity — is the most profound theory about time; we’d like to believe the possibility of time travel was not allowed by the relativity theory. Unfortunately, one of his fellows at the Institute for Advanced Study, Kurt Godel, invented the concept of a universe that was one in which time travel was not only feasible but that the past and future were connected.
We could actually create time machines, but the majority of the times, these (in principle) viable ideas rely on positive energy or mass, which doesn’t appear it exists in this universe. If you throw a tennis ball with a negative mass, the ball will bounce upwards. This argument is not very satisfying as it explains the reason it is impossible to time travel in real life only by using another concept — the concept of mass or energy -that we don’t know how to comprehend.
The mathematically minded scientist Frank Tipler conceptualized a time machine that doesn’t require negative mass, but it needs more energy than what is currently available in the universe.
Time travel also breaks also the 2nd law of thermodynamics, which says that randomness or entropy will always increase. The speed of time can only be moved in a single direction — or, in other words, you can’t break an egg. Particularly, by traveling through the past, we travel from the present (a high level of entropy) to the past, which is likely to have a lower entropy.
The idea of this argument came from the English Cosmologist Arthur Eddington and is essentially unfinished. It may stop you from traveling back in time. However, it does nothing about the possibility of time travel into the future. In real life, it’s the same as difficult it is for me next Thursday as it is to the last Thursday.
Resolving paradoxes
It’s not a secret that if we could time travel indefinitely, we would encounter the paradoxes. The most well-known one is known as “the grandfather paradox. “The grandfather paradox” suggests one could utilize a time machine to travel back in time and kill their grandfather prior to the father’s conception, negating the possibility of having their birth. It is logically impossible to exist and not be.
Read more: Time travel could be possible, but only with parallel timelines.
Kurt Vonnegut’s anti-war novel Slaughterhouse-Five, published in 1969, describes how to evade the grandfather paradox. If free will simply does not exist, it is not possible to kill one’s grandfather in the past since he was not killed in the past. The novel’s protagonist, Billy Pilgrim, can only travel to other points on his world line (the timeline he exists in), but not to any other point in space-time, so he could not even contemplate killing his grandfather.
The universe described in Slaughterhouse-Five is in line with all the knowledge we have. Second law thermodynamics functions flawlessly within it and is in no way at odds with relativity. However, it’s incompatible with the beliefs we hold, such as free will. It is possible to observe the past, as in movies, but you can’t alter the decisions of the people who participate in the film.
Can we permit real-time modifications to the past in order to be able to go back and kill our father — as well as Hitler? Many multiverse theories claim that there are multiple timelines in different universes. It is also a popular concept, which is illustrated In Charles Dickens’ A Christmas Carol; Ebeneezer Scrooge has two alternate timelines to choose from, One of which leads to a horrible death, and the other leads to happiness.