Question: why does gravity keep us own on earth

Hannah Farley answered on 19 Jun 2018:

Gravity keeps us on earth because masses (like people and planets) are attracted to each other. Even though I am also attracted to the chair I am now sitting on, because we are both small masses I can easily stand up and overpower the gravitational attraction – it’s basically non-existent, it’s so small. But the Earth is huge, so I can’t escape that attraction so easily. I’m not glued to the floor, but if I jump I will come back down, and it takes a lot of energy to get far enough away from the Earth to escape the attraction (e.g. in a rocket).