Question: and i know that gravity is the reason we are standing on earth but what is gravity and can you give a bigger explanation for why gravity helps us stand up on earth?

Christie Waddington answered on 17 Jun 2016:

Simply put, gravity is a force that attracts other things with mass. If the mass is bigger, it has more gravity. Even we produce gravity, but because we don’t have a lot of mass it’s not a very strong force!

The earth though does have big mass, and that’s why we are pulled towards it, but just the right amount so that we aren’t all squashed on the floor!

In terms of standing up, that’s partly an evolutionary thing. We have evolved to develop strong spines, back muscles and so the ability to walk upright whilst living with the earth’s gravity.

It’s not just what keeps us on earth, it is also why our planet revolves around the sun, and the moon revolve around the earth. The earth has a gravitational force that attracts the moon, and the sun has a gravitational force that attracts all the planets in the solar system. It does get a little more complicated than that, but that involves space-time!