Explaining Stephen Hawking's final prediction: Can time travel come true?

Hawking said that time travel would be a reality, but he was also aware of something extremely important.

* The article is based on the views of Peter Millington - Department of Astrophysics, University of Nottingham (United Kingdom)

"If someone made a research proposal on time travel, it would be immediately rejected." - Stephen Hawking wrote so in the "Brief Answer to the Big Questions" (roughly translated: short explanation) Compact for macro questions).

And he is absolutely right. With the ability of the present man, time travel is unimaginable, so no one invests in such a innocuous research.

However, according to Hawking, time travel is still a really necessary issue for science to get involved. Because of the fact that current theories have not rejected the possibility of time travel.

Hawking thinks that time travel will become a reality.

So the question here is whether people will be able to create a real time machine in the future?

In fact, time is a very abstract concept. Try it: right now, the video call calls a friend half way around the world, and knows what he / she is doing. But really, you will never know, because their voices, signals and images need some time to reach us (though that time is extremely fast). The moment you receive the signal, people have already taken another action.

Speed ​​and time

The fact that you can't really know what a person is really doing is the same idea Einstein gave in his theories. Einstein argues that time and space are separate variables of a concept that is " spacetime " , that is, we need to think of time as a quantity like space spacing.

For example, when asked: "What is the distance between Birmingham and London?" , an English will answer "2.5 hours". The idea of ​​this sentence is that going from London to Birmingham will take about 2.5 hours, at a speed of 50 miles per hour.

The faster the speed, the slower the time.The question is if the speed of light is exceeded, the time will be reversed

But time may vary depending on speed. Less velocity, time will last longer and vice versa.

Talking about speed, the current speed of light is still the fastest, the maximum speed that signals can reach. According to Einstein, there is a causal relationship between speed and time, both of which are inseparable. A moving clock will be slower than a standing one.

The faster you move, the slower your time will be. And when you touch the speed of light, you will enter freezing time. In other words, the time of a normal person will come forward, and you will stop.

So what if we move faster than the speed of time? Is time going back, like what science fiction novels still mentioned?

In fact, the ability to reach the speed of light was unimaginable - at least with current theory. According to Einstein, you will need an infinite amount of energy to bring an object to the speed of light, let alone overcome it.

But even when it is done, time will not simply run backwards. More precisely, at that time, time did not matter or back. Because, the law of cause and effect now has no meaning.

Worms - where time stops

According to Einstein, gravity is something that can bend space and time. The greater the gravitational force, the greater the compressive force, the more spacetime the space is twisted, and the slower the clock runs.

When we compress a gravitational force large enough, spacetime will be twisted to the maximum, so that even light cannot escape. That was the time of birth. And if we somehow touch the edge of the black hole, the time around you will be so slow that it almost stops.

Worm holes exist.

So the question is, can spacetime be bent so much that time runs backwards?

The answer is possible, and where the time is twisted is the wormhole . This is an assumed space-time structure with the ability to create shortcuts in spacetime. They connect from one region of time to another, and sometimes matter moves from one region to another by going through this hole.

However, science proves that we will have to create a sound source that is dense enough to help the worm worm become stable . Which, according to classical physics from the 19th century, is unimaginable.

We will have to create a sound source that is dense enough to help the worm worm become stable.

But with modern quantum physics, it is different. The universe in the quantum world is not empty, but the set of pairs of energy molecules in the state exists or not. If it is possible to create an area of ​​less molecular mass to the extreme, there will be enough sound energy.

It is not easy to combine Einstein's theory and quantum theory. More precisely, it is one of the biggest challenges in the history of theoretical physics.

Time travel, maybe or not?

In short, is time travel a reality someday? According to Peter Millington - a molecular molecular researcher at the University of Nottingham - although humanity's current knowledge cannot be dismissed or proven, it is most likely that it cannot be realized.

According to Peter Millington, time travel is likely to be impossible.

According to Millington, Einstein's theory could not explain the spacetime structure when applied at extremely small scales. And although natural laws may become quite contradictory, they remain consistent, leaving no room for the existence of causal paradoxes of spacetime.

For Hawking, though optimistic about his ability to travel in time, he also realized that there is a theory that will disprove Einstein's theory that currently humans cannot find. It is this theory that will reject our ability to travel time in the future.

In other words, history will not be changed through time travel machines (because it will not become reality), and Hawking understands that.