Would we exist if time travel existed

Time travel, time loops and time paradoxes The "now" is an illusion: 10 time facts to be amazed

Fact 1: Those who live in a high-rise building age faster

But not only that: This effect, which Albert Einstein already described, namely that mass, i.e. matter, has an influence on the passage of time, can already be demonstrated between two steps!
Hard to believe, but atomic clocks clearly show that even with a height difference of 33 centimeters, an atomic clock placed higher ran faster than the lower placed one.
But wait, before you terminate your rental agreement, we'll reveal: The difference is minimal. In a life of around 80 years, this difference in altitude would mean just the 90 billionth of a second in age difference. You can safely neglect this effect and continue to enjoy the view from the 10th floor! Then you'd better give up smoking than move downstairs ...

Fact 2: In theory, time can run backwards

The fact that the present always follows the past and that we glide powerlessly into the future cannot be taken for granted, even if we perceive the "flow of time" in this way.
Theoretically, a universe is conceivable in which time could also run backwards. However, there are prerequisites for this, as nuclear physicist Steffen Turkat from the TU Dresden tells us: We need a kind of mirror universe.

Nothing easier than this...

Fact 3: There are time loops in the universe

Relive a moment over and over again ?! Sounds unsettling. For some forms of matter in the universe this is actually possible ... True to the motto: The marmot greets you every day.
Prof. Hermann Nicolai from the Max Planck Institute for Gravitational Research in Potsdam told us where in the universe one would have to travel to end up in a time warp.

Unfortunately, the horizon of the black hole is not a suitable travel destination. At least not for us humans.

I'm not going there now. Or, if you get there, you won't get out. So, apart from the fact that you won't survive entering the black hole.

Prof. Hermann Nicolai

Fact 4: Time can stand still

In order to achieve a standstill, we humans would have to overcome a currently unattainable hurdle: We would have to reach the speed of light. If we were to zoom through the area at 300,000 kilometers per second (the speed of light), time would stand still for us compared to the rest of the matter.
Albert Einstein already recognized this, as Prof. Hermann Nicolai from the Max Planck Institute for Gravitational Research in Potsdam tells us:

Einstein began his deliberations with the question: What actually happens when I ride a wave of light? And then somehow it became clear to him that when I ride the wave of light, at the speed of light, time stands still.

Prof. Hermann Nicolai, quantum physicist

What is simply not possible for us (no, unfortunately we cannot ride light waves at the moment and there is currently no research in sight that even suggests that), is reality for a special form of particles. Today we imagine that light consists of so-called photons. From our perspective, time stands still for these special particles.

Fact 5: A party as proof that time travel is not possible

If time could theoretically run backwards in a mirrored universe made of antimatter and time loops exist in the horizon of black holes, then it should actually be conceivable that we could one day travel through time. Unfortunately, it doesn't look like it. Because all these crazy theories don't apply to us humans. Our bodies are simply too complex, too massive and too sluggish to even begin to reach the states described in these theories. In 2009, Steven Hawking wanted to use an unusual experiment to prove that time travel is actually not possible. He threw a big party to which he only invited time travelers from the future. The special thing about it: He did not publish the invitations until after the celebration, in the hope that people could become aware of them in several thousand years. Unfortunately nobody came. For Steven Hawking, the proof that time travel is impossible is that we have not yet met anyone from the future.

Fact 6: There is no NOW for physicists

Fact 7: The present lasts 3 seconds

Neuroscientists and psychologists have found out that we humans perceive sensory impressions in time intervals that are given by our brain. We can no longer experience events that are less than 30 to 40 milliseconds apart as separate. Our perception now seems to work in such a way that our brain processes these fixed, small time intervals by combining them into further somewhat longer time frames, time packages, if you will. And these timeframes become the "one moment" for us and it lasts two to three seconds. This is the "now" for neuroscientists and psychologists.

Fact 8: We experience events as long and short at the same time

This phenomenon is called the "subjective time paradox". When there is a lot going on, i.e. when a lot of sensory impressions shower us, we have the feeling that time goes by very quickly. When it's boring and we linger for hours in a low-irritant environment, the seconds pull apart like chewing gum. This is our subjective experience of time. But if we now remember the eventful time, it seems to us in retrospect to be much longer than the same low-stimulus moments over and over again. A paradox.

Fact 9: Nobody knows how and if time even started

If someone asks you: How did the universe and everything come about? Then you probably answer: With the Big Bang!
This answer fully agrees with the opinion of most of the research world. It is likely that everything we know, matter, space and time, came into being with the Big Bang. However, scientists cannot explain what happened during the Big Bang.

Crazy enough, with all calculation methods, you just can't get any closer than the first 10 to the power of minus 43 seconds. That is really VERY shortly afterwards, but the Big Bang itself remains in the dark, in the truest sense of the word. This is why physicists like the question: "Yes, what was it before the Big Bang? " not so happy at all. Of course we asked them anyway! Quantum physicist Prof. Hermann Nicolai answered us:

Fact 10: We only ever see the past

A look at the starry sky is a glimpse into the past, so far so good. Light that has been on the move for billions of years is shining towards us. But we can never perceive closer objects in their own presence either. For example, the rays of light from the sun that we see "now" started their journey around eight minutes ago. And even when we talk to a person, here and "now" on earth, we see the past. Because even at the shortest distance, time passes, and our brain also needs another 150 to 200 milliseconds to process this information.