[Eudoxus]

So I know there are very dense gases out there. And there are very light liquids. Is it possible to have a liquid with a lower density than a gas, float on top of the gas?

The densest gas I know of is sulfur hexafluoride. Are there any liquids out there light enough they could "float" on SF₆? And that won't dissolve the SF₆?

[vmelkon]

http://www.msnbc.msn.com/id/29776085/#.TmdO6F2BpR0

Aerogels and artificial muscles.
artificial muscles is lighter than air.