Question: Is it possible to change the gravity in the room so that you would be pulled to the ceiling?

Duncan McNicholl answered on 17 Nov 2017:

Not really, sadly. Gravity is caused by things that have mass, and it happens between all things that have mass, so you’re being gravitationally attracted to your computer (or phone or tablet or whatever you’re reading this on) right now, and it’s being gravitationally attracted to you too. That means that all we have to do to change the gravity in the room is put something with mass at the top of the room, and then we’ll all be gravitationally attracted to that and be pulled to the ceiling. The catch is that the thing pulling us up by gravity would have to have as much mass as the thing pulling us down (more, actually, if we wanted to go to the ceiling and not just sort of float around in between them), and the thing that’s pulling us down is the whole of the earth. That means to get pulled to the ceiling you’d need something with the mass of the earth just on the other side of the ceiling, and if you did that then the earth would be pulled towards it too, and the room and everything inside it would be squashed. Sorry.