Will we ever be able to travel in time?

Will we ever be able to travel in time?

Forwards or backwards in time - is it possible?

We've all seen time machines in films and TV. But will scientists ever be able to build one? And if they do build one, will it be as cool as the TARDIS?

Flying faster than light

Scientists haven't worked out how to make a time machine yet. But they have worked out how to slow down time.

Einstein's theory of relativity says that if you're travelling very fast compared a friend who is stationary, time will pass slower for you.

Scientists tested this by putting a very accurate clock on an aeroplane. This clock was synchronised with an identical clock on the ground. After several long distance flights, the clock on the plane was running slower than the clock on the ground. But it was slower by less than a billionth of a second.

Aeroplane_144343014

Travelling fast can slow down time for you, compared to someone standing still

The same thing happens with GPS satellite clocks. GPS satellites zoom around the Earth at 14,000 kph and lose 7 microseconds off their clocks daily, relative to clocks on Earth. The GPS clocks have to be reset daily.

If you could fly at the speed of light, you would be moving through time much more slowly than someone on the ground. But we can't travel that fast yet!

Theoretically, if you could fly faster than the speed of light, you might be able to travel backwards in time. So far, nothing has been able to travel faster than light, not even those pesky neutrinos.

Speed of light_104118986

If we could travel faster than the speed of light, we might be able to travel back in time

What about wormholes?

Some scientists think that wormholes could allow us to travel in time. Wormholes are a "shortcut" through spacetime. Think of spacetime as a piece of paper. Fold that piece of paper in half. What's the quickest way to get from one side to the other?

The quickest way is to travel in a straight line through the paper, instead of going all the way round. If spacetime in our universe is folded, then wormholes could be used to take shortcuts through space.

Neutrinos take a short cut

Wormholes are a shortcut through space

If wormholes do exist, humans would probably disintegrate if we went through them. Some scientists think that the bit of you that went in first would accelerate so fast compared to the bit of you that went in last that your atoms would stream off into space!

Most scientists think that wormholes don't exist. We haven't seen any yet. However, some physicists are convinced that wormholes are out there, we just haven't found them. Perhaps one day wormholes will let us take shortcuts through spacetime, just like Thor.

Will we ever travel in time?

You can never say never in science. Einstein's theory of relativity does allow for the possibility of time travel in our universe. But at the moment, most scientists think that time travel is unlikely. The practical problems of time travel are probably too difficult to solve.

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