Can humans travel forward or backward in time?

In science fiction movies, characters use special machines, even hop into a futuristic car to travel back or forth in time.

Is time travel just a fun idea for movies, or is it actually possible?

According to The Conversation, the question of whether time can be reversed remains one of the biggest unanswered questions in science.

If the universe obeyed the laws of thermodynamics, this would probably not happen. Second law of thermodynamics: everything in the universe can either stay the same or become more chaotic over time.

According to this law, the universe can never return to exactly the way it was before. Time can only move forward, like a one-way street.

Whether time can be reversed is still the biggest unanswered question in science - (Photo: THE CONVERSATION).

Relative time

However, physicist Albert Einstein's theory of special relativity shows that time passes at different rates for different people.

Someone on a spaceship traveling at nearly the speed of light, more than 1 billion km/h, would experience time more slowly than a person on Earth.

Spaceships that can travel at nearly the speed of light have yet to be built, but astronauts visiting the International Space Station orbit Earth at more than 28,000km/h.

Astronaut Scott Kelly spent 520 days on the International Space Station and as a result, he aged a little slower than his twin brother, Mark Kelly, who is also an astronaut.

Paradoxes and failed parties

There are also paradoxes associated with time travel. The 'Grandfather Paradox' (*) The famous 'Grandfather Paradox' suggests that if someone were to travel back in time and accidentally prevent their grandparents from meeting, it would create a paradox: "if the grandparents had not met, the person would not have had parents and therefore the person would not have been born". 

The question is: How could someone travel back in time in the first place? It's a puzzling puzzle that adds to the mystery of time travel.

Renowned physicist Stephen Hawking tested the possibility of time travel by hosting a champagne party for time travelers with premium Krug wine and appetizers in 2009.

The card contained the exact time and location of the party, along with the message: " You are cordially invited to a party for time travelers ." And he only sent the invitation after the party had ended.

His hope was that the invitation would be read by someone living in the future who had the ability to travel back in time. But no one showed up.

' Time travel is impossible and will never happen, ' Hawking pointed out . 'That's because we haven't been invaded by tourists from the future yet . '

Telescope is a time machine

Interestingly, astrophysicists equipped with powerful telescopes possess a unique form of time travel.

When they look into the vastness of the universe, they are looking into the past.

Light from all galaxies and stars takes time to travel, and these beams of light carry information from the distant past.

When astrophysicists look at a star or a galaxy through a telescope, they don't see it as it is now, but as it existed millions to billions of years ago when its light began its journey to Earth.

NASA's James Webb Space Telescope is observing galaxies that formed at the beginning of the Big Bang, about 13.7 billion years ago.

While we're unlikely to have time machines like the ones in the movies anytime soon, scientists are actively researching and exploring new ideas.