Today on Neatorama and Boing Boing, we saw a great demonstration video of a light aluminum foil boat floating on a layer of exotic heavy gas– sulfur hexafluoride.

You can actually do a version of this trick at home, using stuff that you either already have or can get a the grocery store: You can blow bubbles and float them– apparently in mid air– atop a layer of carbon dioxide; a not-very-exotic heavy gas. You’ll need a big pot, pan or storage bin (made of plastic or metal), some dry ice, and bubbles.

How do you do it? Place your dry ice in the pan and wait a few minutes for a layer of carbon dioxide to form in the bottom of the pan. (We used a 20″ diameter steel wok, which turns out to have a pretty good shape for the job.) Very, very gently, blow some bubbles above the pan and let them fall in. If your carbon dioxide layer is thick enough, the bubbles will bounce off of it, or often even come to rest, sitting in place.

We made a video so that you can get the idea, but you should really just try it yourself because it’s pretty straightforward and the pictures don’t do it justice.