lavalamp3773

OK, so you've decided to give away a billion dollars to aid what you consider to be deserving causes.

What five causes would you give money to, and how would you divide it up between them? Please also write a little about your rationale for why you picked those five over all the others, and originality is always welcomed and appreciated.

Hey everyone, I'm looking for a very low density solid, it needs to be relatively strong and retain it's strength and shape when heated to a couple of hundred degrees C (minimum). The higher temp it can take the better.

I looked at beryllium but it's expensive and the density is too high, even though it is only 1.85 kg / L. I also looked at polyimides, which are thermosetting plastics, but they're still too dense at about 1.4 kg / L. A plastic would really be excellent as they can be easily manufactured into the desired shape by injection moulding.

Aerogel is exceedingly light and a good insulator, but it shatters very easily and is ferociously expensive.

Basically, I'm looking for something around maybe 0.1 - 0.4 kg / L that's not too expensive and can handle a bit of heat. It'll be used to make a nearly cylindrical pressure vessel with hemisphere ends to contain low pressure hydrogen.

Does such a material even exist, and if so, what is it?