Science knows there is a collective touching of reality. But we can not know what is behind that. So gravity may MAY just be an illusion.
If we do a demonstration we always have to wear safety chords as most humans just leap off any building. As such is their arrogance and the beauty of the concept, absintheanly intoxicating. Harmless yet...
It is a hypothesis say, if we program a robot (no human has the heart) to puncture a bit of skin of one of my vampires, that it would malfunction before it could do that. We not going to take THAT experiment very far down the line by the way.