Byjus Logo

Is Time Travel Possible?

Team StoryWeavers|January 05, 2022, 12:32 IST|

 

Image with purple and pink background, showing outer space and an orange spaceship in the foreground, with the text "Did you know time travel was actually possible?"

Did you ever wish you could go back in time and see how the Egyptians built the pyramids? Or maybe go ahead in time and see where you would be 10 years from now?

We’d all love to travel through time, stopping at periods that we want to watch or even see if we could change something (without having serious consequences, of course!). But before we go meddling with the time-space continuum, let’s see whether time travel is actually possible.

Time travel is real

To answer the burning question: Yes, time travel is possible. However, not in the way you think. In fact, you’re time travelling right now. As you’re reading this, you’re hurtling through time at the speed of one second per second. You’re constantly travelling through time, even when you’re sitting in that extra-long and dry class and it feels like the clock has stopped.

Unfortunately, time travel isn’t what sci-fi movies and books have told us it is. Who wouldn’t love to sit in a machine and shuttle through time? But many scientists have tried to prove time travel exists and have failed. Noted physicist Stephen Hawking once said, “The best evidence we have that time travel is not possible, and never will be, is that we have not been invaded by hordes of tourists from the future.”

Experiencing time relatively

So what’s the big deal about travelling through time one second per second? Well, because we all experience it differently.

Famous scientist Albert Einstein came up with a theory about time and space called relativity. It is, even today, considered to be one of the most basic principles of physics. In the theory, Einstein put forth one very important point: nothing can travel faster than the speed of light. The theory also stated that the faster you travel, the slower you experience time.

This has been proven by many scientists over the years. One experiment had two clocks, one on the ground and one on an aeroplane flying in the same direction that the Earth rotates. After the plane completed a trip around the world, scientists saw that the clock on the ground was slightly faster than the clock on the plane, by a fraction of a second. So, this proved that the clock on the plane was travelling through time slower than one second per second.

Time and travel

You may be wondering what the big deal is if a clock is a fraction of a second slower in an aeroplane. It doesn’t make a difference when you’re travelling, but it does make a difference to a vital part of our daily life: GPS tracking.

GPS satellites, or that tiny app on your phone that maps your location, help us all figure out where we are and where we’re headed. GPS (which stands for Global Positioning System) satellites orbit the Earth at approximately 14,000 kilometres per hour. And just like Einstein’s theory of relativity states, these satellites’ clocks are slower than the ones on Earth by a fraction of a second.

But there’s a twist: Another part of Einstein’s theory states that gravity curves time and space. What this means to time, is that when the GPS satellites are in space, they are orbiting at more than 20,000 kilometres per hour. This translates to the satellites experiencing time slightly faster than one second per second. This would make your navigation map go faster than you would be on Earth.

Thankfully, scientists in NASA and other space agencies, use maths to correct this gap and match our time with that of the satellites.

But we shouldn’t be disappointed. There is another, more technical, way to time travel — by crossing the international date line or IDL. The IDL is an imaginary line that runs from the North Pole to the South Pole, used to mark the end of a day and the start of another. When you cross it, you either lose or gain a day, depending on which direction you are travelling. If you are travelling westward, you gain a day and if you travel eastward, you lose a day. This is why, if you travel from the US to Australia, you tend to go back in time when you land!

Now that you know how we travel through time, which time period would you go to if sci-fi time travel was possible? Let us know in the comments below.

Learn more about space and time with these fascinating articles from Science Feed:

Can Your Cat or Dog Tell What Time It Is? The Answer Will Amaze You!

The time-travelling sneeze: How healers of the old world dealt with a cold

There’s a Traffic Jam in Space and It Could Turn Dangerous

 

About the Author


When she's not scrolling through endless cat and food videos, Madhavi Pothukuchi loves to read, paint, and binge on K-dramas and chips. A former journalist and an education enthusiast, she believes that asking more questions only makes life more interesting.

Leave a Comment