

New micro-lattice material is world's lightest at 0.9mg/cm^3 - zacharyvoase
http://www.gizmag.com/ultralight-micro-lattice-material/20537/

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tomkinstinch
Does the 0.9mg/cm^3 number seem strange? The density of air is about
1.2mg/cm^3 at STP[1]. Can it be less dense than air? Wouldn't that make it
float?

1\. <http://pdg.lbl.gov/2007/reviews/atomicrpp.pdf>

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dmak
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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ars
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?)

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pyrhho
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.

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Retric
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

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TylerE
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.

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Retric
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>) _

