Huh
The fish tank is filled with a gas called sulfur hexaflouride, which is more dense than air. This gas is so dense you can actually fill a fish tank with it and then put an aluminum foil boat on top of it to give the impression that the boat is floating. He then scoops some of the heavier gas out of the fish tank and pours it into the boat. The boat fills up with the heavier air, and sinks to the bottom
The hell
Science is just witchcraft that can be explained… No one can tell me any different.
Gases act like liquids but the molecules are spread out further than liquids so we generally can’t see them or feel them. But they move like liquids.