Gravity is caused by the earth spinning (17,500 MPH I think) so on and on.
If you were able to get magnetism to work for you, you might be able to beat gravity.
Over simplistic but it still stands:
Put two positive magnets together and they’re push. Off set them slightly but join the together (with a tooth-pick or something) put it on a ball and round it goes.
Tweak is slightly then put some cleaver people behind it and off you go.