Can you time-travel and change the past?

In 1905, Einstein proposed the relativity theory. Since this time, among scientists (especially physicists later), time travel has been seriously discussed and researched. Some believe it is possible to time travel into the past. Most physicists believe that time travel to the past is “theoretically possible”.

So here comes a question. If we could time travel to the past, the question is, would it be possible to change the past?

This is a difficult question to answer. Because if we could go back to the past and make changes, we would encounter problems that could not be solved. In other words, no one can solve the problem of what happens if the original timeline and the modified timeline are different.

But according to the calculations of physicists at the University of Queensland in Australia, even if time travelers could go, they would not be able to change past history.

They have published their findings in the journal Classical and Quantum Gravity Research.

According to this paper, if we tried to go back to the past and try to fix it, the principles of physics would automatically avoid any event that would be paradoxical in the future.

If you were to go back in time and try to change an event, the events that followed would correct history back to where it started.

To put it simply, even if we could go back in time, we would not be able to change history.

Grandfather paradox

One of the most famous and unsolved riddles (inconsistencies) related to time travel

Maung Phyu invented a time-travel machine. Then he went back in time with the time machine. It was before his grandfather met his grandmother when he was young. And then his grandfather in the past made a shield again. Grandfather died. When my grandfather died, I didn’t see my grandmother. Mon Phyu’s father was no longer born here. Maung Phyu’s father was not born, so Maung Phyu was not born.

Because Maung Phyu was not born, he could not invent a time travel machine. And there is no Maung Phyu who will travel through time. Maung Phyu is no longer there, and Maung Phyu will return to the past and defend his grandfather. Grandfather died. So I’ll see Grandma. Maung Phyu’s father will be born. Mon Phyu’s father continued to give birth to Maung Phyu. When Maung Phyu grew up, he invented a time travel machine. Back to the past Do it again with a shield against the grandfather. So go back for a week.

Now they see the problem of the viyodhi, don’t they? (If it’s not clear, please read it again.)

Time travel

Einstein’s time travel is not the same as going back on the time line that many people talk about now. According to Einstein’s calculations, time travel means that the time line will bend and return to the original place. In other words, this is the concept of seeing time as a closed, time-like curve.

To solve the paradox caused by time travel, like the grandchild-grandfather paradox, physicists at the University of Queensland created a model that resembles time travel and conducted research experiments.

These researchers chose to represent the collision of billiard balls on a billiard table as “events”. The circular billiard table was represented as a closed, time-like curve.

Let us consider this experiment. Billiard balls are placed on this circular billiard table. If you hit one of these, the ball will move and collide with other balls. Or it will hit the side panel and kick out. Then, until his speed runs out, he will hit other balls and move sequentially.

At this stage, the researchers simulated the trajectory of the ball with a computer. I remember this route, and when I simulate it again, I change the route in some way.

But the amazing thing is that even with this change of course, the displacement of the other balls that this ball collided with caused the original ball to return to its original path.

In other words, even after the billiard balls have moved on the billiard table circle, even if there are disturbances in between, the events that take place will make this billiard ball return to its original path.

What is the point of this research?

What this research shows is that “You may be able to go back in time. But we cannot change history.”

Let’s use this finding to try to solve the grandchild-grandfather paradox.

According to this finding, if Maung Phyu were to go back to the past and try to shield the person who made him his grandfather, new events would arise in the meantime, and they would intervene and stop Maung Phyu from making him a shield.

Or, it could be that the grandmother was pregnant with Maung Phyu’s father when her grandfather died after being stabbed by a shield.

The researchers who presented the paper admit that this research simply compares the cause-and-effect processes of the time travel theory with respect to the universe as a whole, so it is by no means exhaustive.

“But this is just the beginning (for further research),” said Nomura, one of the researchers who presented the paper.