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## Engineers Create World's Lightest Material177

ackthpt writes "A team of engineers claims to have created the world's lightest material. Made from a lattice of hollow metallic tubes, the material is less dense than aerogels and metallic foams, yet retains strength due to the small size of the lattice structure (abstract). The material's density is 0.9 milligrams per cubic centimeter. Among other things, it's potentially useful for insulation, battery electrodes, and sound dampening."
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## Engineers Create World's Lightest Material

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• #### Unlikely (Score:4, Insightful)

by Anonymous Coward on Friday November 18, 2011 @11:39AM (#38099608)

0.9mg/cm^3 is 0.9kg/m^3, i.e. lighter than air (1.2kg/m^3). I call shenanigans.

• #### Re:Unlikely (Score:5, Insightful)

on Friday November 18, 2011 @11:45AM (#38099674) Homepage

You're obviously going to have tared the measuring against air. Making it .9mg above the weight of the air. But, if there is no air, it would weight .9.

• #### Re:Unlikely (Score:5, Insightful)

on Friday November 18, 2011 @11:47AM (#38099714) Journal

If that is the case, then aerogel wins
aerogel is 1.9mg/cm^3 in a normal atmosphere, only 0.7mg above the weight of the air.

Can someone settle the discrepency beside speculating like we are?

• #### Re:Unlikely (Score:5, Insightful)

on Friday November 18, 2011 @11:59AM (#38099918)

The lightest Aerogel when evacuated has a density of ~1mg/cm^3

It is porous, and when air is allowed into its structure to goes up to 1.9mg/cm^3.

http://en.wikipedia.org/wiki/Aerogel

It doesn't have the strength to resist 1 atmosphere of pressure when sealed. But helium can be used to equalize the pressure and the material will float in air.

http://www.youtube.com/watch?v=HoCAxS4vqwQ

• #### Re:I like it but (Score:5, Insightful)

on Friday November 18, 2011 @11:59AM (#38099922)

Due to its expense I can't see this being used as a drywall replacement. Drywall is used to due to how cheap it is, not because it is the best at its job.

If it was used in the same fashion as drywall then the actual lattice would be covered by a paper layer and then acoustic mud, just like drywall.

• #### Re:Hello, Computer... (Score:5, Insightful)

on Friday November 18, 2011 @12:06PM (#38100026)

Um, Scotty gave us transparent aluminium, i.e. the thinnest transparent material. Not the lightest material. Light and thin aren't the same thing yet, at least not before a few coordinate system transformations.

• #### Re:This is getting ridiculous... (Score:5, Insightful)

<dadinportland@yah o o .com> on Friday November 18, 2011 @12:07PM (#38100036) Homepage Journal

All of which would be interesting. Some of us like science and engineering.

• #### Re:I like it but (Score:5, Insightful)

by Anonymous Coward on Friday November 18, 2011 @12:07PM (#38100044)

What?! Your comment does not compute. Thats like saying NASA just built this new rocket, I bet it would work great to heat my house with it!

Drywall's sole purpose is to be a flat surface (ie: a wall) for painting and as a fire resistant to give occupants of buildings slightly more time to get out. Hence the reason they often use double or triple layers of drywall between shared walls. It offers virtually no insulation value whatsoever, which is why its paired with actual insulation on exterior walls.

This material doesn't share [b]any[/b] of those properties in a practical sense. Its obviously porous and would be impractical to paint, not to mention it would probably cost thousands of times more than drywall and be much more difficult to work with.

• #### Re:Unlikely (Score:5, Insightful)

on Friday November 18, 2011 @12:42PM (#38100564) Journal
So they aren't measuring the volume properly. They are measuring the bounding box, and not doing an Archimedes-style immerse-it-in-a-fluid-and-measure-the-displacement volume measurement. If they did that, I'm sure the density would be the same as the metal from which it is made.

But if you're going to cheat, and measure the volume of the envelope, then I'm sure I've got a lighter than air tent. And what about all those air supported sports domes? Zepplins and hot air balloons? Been there. Done that.
• #### Re:Unlikely (Score:5, Insightful)

on Friday November 18, 2011 @12:44PM (#38100598) Homepage

0.9mg/cm^3 is 0.9kg/m^3, i.e. lighter than air (1.2kg/m^3). I call shenanigans.

Yes, and if you wrapped an impermeable skin around it and evacuated the air using the lattice material as a support for the skin then it probably would float (assuming that the skin didn't tip the balance of the stuff into being too dense and assuming the material was strong enough to resist collapse from the atmospheric pressure). BUT it is a lattice material and the spaces in between the hollow metallic tubes are typically, brace yourself... full of air! So on it's own it does not float.

It's amazing to me that the parent got modded insightful. Sure he can google the density of air, but clearly he couldn't reason his way out of a paper bag.

• #### Re:Floating furniture? (Score:2, Insightful)

on Friday November 18, 2011 @12:56PM (#38100720)

Re (1): it won't work. The material would instantly collapse from the atmospheric pressure.

• #### Re:I like it but (Score:2, Insightful)

by Anonymous Coward on Friday November 18, 2011 @02:09PM (#38101648)

Perhaps RTFA instead of spreading ignorance. It indicates this stuff is stronger than Aerogel. There's pictures of a square inch of aerogel not being crushed by a 10 pound weight sitting on it. As the article states, when you start getting down to nano sized structures, it tends to get stronger, not weaker.

"When people are least sure, they are often most dogmatic." -- John Kenneth Galbraith

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