Question: WHAT is gravity? how does it keep us on the ground?

Mark Collins answered on 8 Nov 2015:

Excellent Question and honestly, no one really knows! We have ideas and we have suggests but the actual mechanism of gravity we do not know. We can think of Newton’s first law that each force applied has an equal yet opposite force applied to it but this will not fit for gravity! We know it is created by a large mass and it is proportional to that mass, think of the gravity associated with the sun…it is enormous! And the gravity associated with the earth is so much smaller. We are just not sure what is causing this and may think this will the next truly great discovery in science/physics and I know there are a lot of labs who are looking into this with the hope of becoming the next Einstein! maybe it will be you who discovers this! If you are interested in gravity, ask your physics teacher about black holes, a truly fascinating subject!