[ravenstine]

> The fact that an aerogel-filled blimp might still conceivably be neutrally buoyant is actually testament to how incredibly light aerogel is.

True!

I've always had a soft spot for aerogel. I discovered it as a kid back around 2000 when Disneyland had this NASA/JPL Mars rover exhibit and they had a piece of aerogel on display. When I got home I researched it and was really impressed by all its properties. My mom got me some broken pieces of it off eBay (at the time this was way cheaper than buying an intact slab). My parents were pretty cool in nurturing my nerdiness. hah

The more I think about it, the more it seems like aerogel in a hydrogen balloon isn't the best idea for other reasons. If any moisture makes its way into the balloon, I bet it wouldn't take long for the density to suddenly drop catastrophically.