Five things that don’t make sense about gravity
It is really weak Although it can never reduce to zero, gravity is around 1040 times weaker than the electromagnetic force that holds atoms together, and no one really knows why.
We have no theory for quantum gravity Currently, when trying to describe gravity on the tiniest scales, if we try to tie gravity into quantum mechanics, the equations just don’t add up.
Gravity can only attract objects Unlike the other forces, such as electromagnetism, gravity only works in one direction. Objects can only be attracted through gravity, not repelled.
We can’t counter gravity Because gravity is only an attractive force, we have no way of overcoming it. This is a problem for people who want to travel large distances in space.
Not everyone agrees what it really is Some call gravity a force, but others, like Einstein, say it is not a force. Instead, it is simply a consequence of the shape of space-time.