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Comment by dmak | Hacker News Reader

I thought the air density might have been a mistake, but I checked and your numbers are correct. Theoretically, it should float, right?

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If you put a vacuum in it and shrink wrapped it it would float.

But I don't know if the material is strong enough to result air pressure if it was shrink wrapped (i.e. would the air pressure squish it?)

So, basically, it would be ideal for building a zeppelin. Put a bunch of it into a container, and evacuate it to go up. Fill the container with air again to go down. Nothing flammable to explode.

Awesome.

It's still heavy compared to helium gas. Air is 1.2 kg/m^3 helium is 0.164 kg/m^3 and this stuff is .9kg/m^3

Of course, if this could be used for large portions of the structure, that really changes the equations a lot. You don't need nearly as much lift for a given weight of cargo.

The Hindenburg used 200,000m^3 of hydrogen (generating a lifting force of approx. 215,000kg. Net useful load was only 10,000kg.

When selecting materials for building aircraft weight is only one of many concerns. Durability, flexibility, strength, cost, etc are all major issues. Considering the design goals for this material seem to primarily just be weight I would be surprised if it's strength to weight ratio was impressive enough to overcome cost issues.

Also compared to a modern blimp the Hindenburg an ancient design that's been far surpassed. A modern Zeppelin is much closer to 20% lift to weight ratio than 5 for the Hindenburg despite using less efficient helium gas. Their maximum permitted takeoff weight is 10,690 kg, with a payload of 1,900 kg.(http://en.wikipedia.org/wiki/Zeppelin_NT)

Strength is the key part they didn't mention. DARPA probably wants that bit for themselves :) However one must assume this has some strength, otherwise what would the point be. Very cool stuff

DARPA might well be funding the research for the possibility of a future alternative to FOGBANK in nuclear weapons, which isn't as dangerous to produce.

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