Here's an easy thing to remember: Gavitons keep us glued on the ground. Gravitons are theoretical particles which we aren't sure exists, but scientists are trying to find them with a massive 'collider' over in Europe. Its thought that 'gravitons' are what 'glue' matter together. For more info on gravitons, see: http://en.wikipedia.org/wiki/Gravity#Gravity_and_quantum_mechanics and http://en.wikipedia.org/wiki/Graviton

1) "What is gravity, and how does it keep us stuck to the ground? Well, gravity is a force between two objects. It's like an attraction where the larger object, in this case would be earth, has to force or pull on other objects, and it keeps them attached to and connected to the earth." Source and further information: http://www.videojug.com/expertanswer/fun-science-forces-of-nature/what-is-gravity-and-how-does-it-keep-us-stuck-to-the-ground (funny video on there) Further information: http://en.wikipedia.org/wiki/Gravitation 2) Anti-gravity "Anti-gravity, NASA footage of zero gravity plane, Go-Fast Jetpack, Mythbusters on the Anti-Gravity Lifter Myth, Expl of dynamical BB effect from stand point of ZPF field by T. Musha, Biefeld Brown Effect, UFOs-NASA, Gary McKinnon, Free Gary McKinnon dot org dot uk, Brian Cox, D:Ream, What on Earth is wrong with gravity?, General Relativity (intro), Newtons law of universal gravitation, Does matter with a negative mass exist somewhere in the cosmos? If it does, its bizarre properties would provide the perfect space-drive , Is anti-gravity possible?, Dr. Sten Odenwald" http://www.youtube.com/watch?v=0d5nnMjexHg