Answering another question sent in by a reader:
In a science fiction movie, the characters live on space stations where gravity is artificially created, allowing them to swim in a pool, etc. Is it possible to create such conditions in reality?
At the moment, there are several concepts for creating artificial gravity on spaceships, and only some of them can facilitate the functioning of a pool.
Warping space-time
Let’s start with the most utopian concept. In the general theory of relativity, gravity is a manifestation of the warping of space-time. Usually, in space, space-time is warped by massive objects like stars and planets.
The idea is to artificially create a localized area of warped space-time inside the ship, producing gravity. Currently, this is not possible. Physics doesn’t even possess a comprehensive theory of gravity: Newton’s theory of gravitation describes gravity well at a basic level, and the general theory of relativity does at a higher level. However, both these theories are inapplicable at the quantum level, and a new quantum theory of gravity is needed. Many scientists are currently working on it, but the work is far from complete.
