Invisible water

How does that happen?

You have probably heard of the gas Helium which is lighter than air, well that glass container is filled with a gas called Sulfur hexafluoride. Sulfur hexafluoride is a colorless, odorless gas which is heavier than air. Because it is so dense you can float a light aluminium boat on top of it.

What’s even more interesting is that it has the opposite effect on your voice to the effect helium has. When you breathe in helium it makes your voice higher pitched, but when you breathe in Sulfur hexafluoride your voice become deeper, as this video illustrates. Don’t try that at home by the way! r