Time Travel’s Unpleasant Side Effect: Memory Loss

Imagine that you had the ability to travel back in time. But when you returned to the present, you found that you could not remember anything about it. Physicists believe that this is a real consequence that time travelers may face.

The study was published in the journal Classical and Quantum Gravity, as reported by Interesting Engineering.

While most research has focused on the mechanics of time travel, little attention has been given to its effects on the traveler. The new study suggests that journeying through time could come with unusual side effects—most notably, the loss of all memories from the trip.

Researchers believe this phenomenon is tied to the concept of a “closed timelike curve” (CTC), a feature of Einstein’s general theory of relativity.

A closed timelike curve is a concept in Einstein’s general theory of relativity where, under certain conditions, spacetime forms loops. These loops result in paths in spacetime that return to their starting point, allowing time travel to an earlier point.

According to scientists, when a person travels back in time and returns to the present, the second law of thermodynamics states that entropy, or the degree of disorder in a system, always increases with time.

This process cannot be easily reversed, because it would mean a decrease in entropy, which does not naturally occur in the universe.

Physicists believe that when a person travels along a closed timelike curve, going from the present to the past and then back to the present, his entropy should first increase, reach a peak, and then return to the same level.

According to the study, after entropy reaches its peak and the time traveler returns to the present, disorder begins to decrease, and as a result, all thermodynamic processes, including biological processes such as memory formation, are reversed.

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Therefore, a person is unlikely to remember anything from their trip to the past, as their memories will be erased by the time they return to the present.

You might think that if you can’t remember your trip back in time, you can take a photo of the events and then look at the photos and remember everything. But physicists say that the second law of thermodynamics applies not only to people, but also to machines and other inanimate objects.

So if a person saves data, for example, on their smartphone during a time trip, it will also most likely be erased as soon as the person returns to the present.

The study’s authors also concluded that a person’s wristwatch may show the wrong time during time travel because it is designed to move only linearly. Although time travel is theoretically possible, humans have no way to travel into the past, meaning the physicists’ findings cannot be tested.