Question: How does time work in space fabric, I'm pretty sure it changes depending on the gravitational mass of an object?

Euan Allen answered on 14 Jun 2016:

Hi Ensign,

That is a great question, and you’re absolutely right! The gravitational mass of an object does change how space and time work. This was discovered by Albert Einstein in around 1915 and is what we call general relativity.

Their are two main effects that occur. The first is that space gets bent by very high mass objects such as black holes. This is actually one of the only ways we know black holes exist, because we have seen them bend the light that is passing near them. We call this gravitational lensing (because the gravity is acting a bit like a camera lens).

The second effect, which is my favourite, is that time actually runs slower when you are next to extremely high mass objects. If you’ve ever seen the film “Interstellar”, then they show this in the film. What happens is that some astronauts go down onto a really large planet for a couple of hours. When they return to the spaceship, the astronaut they left on there has aged by around 30 years! This is because the planet slowed down the time for the astronauts so they aged more slowly!