No, it isn’t actually water, but it is invisible! You may have seen videos on YouTube or TV, and it’s 100% real. The way people get the invisible water effect is by replacing air with sulfur hexafluoride. Since sulfur hexafluoride is denser and heavier than air, it sinks under air. That is why you can blow up a balloon, and sulfur hexafluoride will keep it afloat.
How to get invisible water – Mythbusters Style
For those of you who know who the Mythbusters are, know who Adam and Jamie are. They are two guys who host the TV show Mythbusters. Great show. Anyways, that’s another hub… Adam and Jamie start by filling an empty fish tank with sulfur hexafluoride. They put a cover over the top of the fish tank so the gas doesn’t escape while they are filling it. (Adam also demonstrates what sulfur hexafluoride does to your voice. When he breaths in sulfur hexafluoride like helium, his voice gets really low and deep; the opposite of what helium does.) Next, Adam and Jamie make different boat models out of foil and balloons. The first time they set the foil boats and balloons on the sulfur hexafluoride, they just fall to the bottom of the fish tank. After dozens of attempts at making invisible water, they finally get it right. A foil boat and a little balloon float in mid air! What happens next is very interesting. Jamie grabs a measuring cup, and SLOWLY scoops some of the sulfur hexafluoride into it. Then he very carefully and slowly pours the sulfur hexafluoride into the foil boat and it sinks to the bottom of the fish tank.
Sulfur hexafluoride is a colorless, odorless, non-toxic and non-flammable gas. It is about 5 or 6 times denser than air. “To give you some reference; air is 784 times less dense than water compared to the 6 times of sulfur hexafluoride, and water is about 2.5 times less dense than dirt in case you were wondering” – slipperybrick.com.