Mar 23, 2013

Researchers from China's Zhejiang University developed a new sponge-like solid material (which they call Graphene Aerogel) made from freeze-dried carbon and graphene oxide which they say is the lightest material ever made. It's so light it can be placed on the delicate petals of a cherry blossom:

Aerogel weighs just 01.6 milligrams per cubic centimeter, just twice the density of hyrdogen.

Graphene Oxide market report


Some news reports, like they did for Aerographite, are mistakenly saying that this material is lighter than air.

If it were lighter than air it would be floating, which it clearly does not.

Because carbon is denser than air (i.e. mix of 78% nitrogen, 21% oxygen, 1% argon + C02.), any material made from pure carbon must necessarily be denser than air.

The only way a material denser than air could make something less dense than air is if it were combined with another item whose density was less than air, thereby bringing the average density below that of air. An example of this is a rubber balloon filled with helium -- the rubber is not less dense than air but the composite object is.

A conceivable way that a carbon based material could be made lighter than air would be if was structurally sound enough to withstand atmospheric pressure and was completely airtight (which, coincidentally, graphene is) and was then evacuated. I would call this a vaccum dirigible or vacuum airship or perhaps if the poresize was small enough, a magic carpet.