How do you make AntiGravity vehicles?

Answer 1

You can't. At least, with what we know about gravity right now, its impossible.

Here's why: As far as we can tell, gravity is not actually a force, properlly speaking. In physics, all forces require an exchange of particles that exert some sort of push or pull. The electromagnetic force, weak nuclear force and strong nuclear force all exhibit this property, generally through the exchange of photons.

And while particle physics speculates that there could be a "graviton" (the particle which causes gravitational attraction), we haven't seen it yet. If there was such a particle, it would be theoretically possible to build a device which is not affected by gravitons and so would be a true anti-gravity device.

However, the view we get of gravity from Einstein and other's is that gravity is just a bend in space caused by massive objects. Imagine a trampoline with a Bowling ball in the center. Normally, space-time is flat (or mostly flat) like the trampoline, but like the bowling ball, when you introduce heavy objects, you make dents in the surface that extend past the ball itself, creating what is (in astrophysics) called a "gravity well".

In this model, the only way to fight against gravity is to create a force that goes in the opposite direction (like a rocket) that provides sufficient excelleration to escape the well.

Read-up about the Nazi Bell Experiment