3 ms·
That's pretty cool. But I'm a bit confused... FTA, the aerographite density is 0.2 mg/cm3. From Wikipedia on Aerogel (another very lightweight solid) [1], The
by beambot 14y ago
That's pretty cool. But I'm a bit confused... FTA, the aerographite density is 0.2 mg/cm3.
From Wikipedia on Aerogel (another very lightweight solid) [1], The lowest-density aerogel is a silica nanofoam at 1 mg/cm3, which is the evacuated version of the record-aerogel of 1.9 mg/cm3. The density of air is 1.2 mg/cm3 (at 20 °C and 1 atm). Only the recently manufactured metallic microlattices have a lower density at 0.9 mg/cm3.
How are they computing the density of the aerographite such that it doesn't float away (having 1/6 the density of air)? Are they only considering the mass of the carbon and not the internal air?!
[1] http://en.wikipedia.org/wiki/Aerogel http://en.wikipedia.org/wiki/Aerogel
- ehsanu1 14y agoIt's probably "evacuated" as well, ie there's no internal air. You can get the weight inside a vacuum so it doesn't float away.
- Ralith 14y agoIf you RTFA, you see there's a video of them sitting on a table in regular atmosphere. You'll also see that it's just basically a very fine carbon hairball. They're obviously measuring the density of the thing itself, and not the air that happens to be drifting through the gaps.
- SilasX 14y agoWhich is to say, they're counting the air passing through the gaps for purposes of volume but not mass in the density calculation. So, could I claim to have the lightest material if I made a hollow, porous, giant hairball?
- ThePherocity 14y agoObviously, yes. You just need to find a way to get the density of the evacuated hairball to 0.1 mg/cm3. Duh! ;)
- sigkill 14y agoAs someone who has worked with metal foams, you are technically correct.