May 2022

The Physics of Time Travel: Is It Fact or Fiction?

May 20, 2022

The Physics of Time Travel: Is It Fact or Fiction?

When you think of time travel, you tend to picture Big Budget Hollywood movies where people are shot forward or backward decades in time. While the truth of time travel might not be so extreme, it’s still just as amazing to think about.

You might have heard your physics tutor explain the theory of special relativity, which describes the relationship between speed and space, mass, and time. In summation, the object that moves slower relative to another object experiences time faster than said object. But how does that relate to the concept of time travel?

Can we actually do it?

Einstein once theorised that time and space are intrinsically linked, dubbing this idea the theory of relativity. According to him, there’s a hard limit on how fast objects can travel – the speed of light (300 000 km/second). The idea is that the faster an object is able to travel, the slower they feel the effects of time.

You can see this in practice by just looking up at the sky at night. The stars we observe in the sky are millions of years old, but it actually just takes that long for their light to travel to Earth for us to be able to see them.

In a more concrete example, scientists once conducted an experiment involving two airplanes. One was sent flying with the Earth’s rotation, and one remained on the ground. Both contained clocks that were set to the exact same second. However, the clock aboard the plane flew slower than the other one. The difference was infinitesimal but still present, giving us an idea of how this concept might work on a much larger scale.

But, perhaps, the most well-known but ridiculous example of this phenomenon was when an astronaut who spent a year in space orbiting the planet aged just a little slower than his twin brother.

While it’s fun to ponder what it would be like to go back in time to alter certain events or take a peek into the future, the physics of time travel serves us in a much more practical but important way.

Everyday Time travel

Did you know that navigating the roads while driving also requires a little bit of time travel? That’s right! The Global Positioning System (GPS) is a system that tells us where we are by communicating with multiple satellites that orbit the planet in space. If all that we’ve posited so far is true, these satellites can shed seven-millionths of a second off per day. But factoring in general relativity, the Earth’s gravitational pull in relation to the distance between the satellites and the planet causes the clock to speed up just a bit. This results in an addition of 38 millionths of a second added per day.


Watching physics at work can be endlessly fascinating. Here at Best Physics Tuition, we cover a variety of intriguing topics, such as the gravitational pull of black holes and the electromagnetic spectrum. Alternatively, you could sign on with us to learn more first-hand from one of our highly-trained tutors. Contact us to start your foray into the world of advanced physics.

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