[luisramalho]

Does it float on magma?

Do houses in Iceland really do that?

[david-given]

Only briefly.

[logfromblammo]

If you built a boat from SiC attached to enormous heat sinks radiating into empty space, it would float for longer.

[DrScump]

But air-conditioning expense makes it cost-prohibitive.

[adrianN]

Magma is pretty dense (it's molten rocks, after all), so many things float on magma.

[iofj]

Very interesting discussion on the subject :

http://www.wired.com/2012/01/can-you-walk-on-lava-falling-in...