
Graphene aerogel takes world’s lightest material crown - Lightning
http://www.gizmag.com/graphene-aerogel-worlds-lightest/26784/
======
joezydeco
So if we wrap this material in mylar and remove the air, we'd have solid
balloons without needing helium? Sounds good to me.

~~~
EthanHeilman
What would be the economic implications of "float stone", that is a solid
material which is lighter than air or at least neutrally buoyant? Say a
molecular structure that creates pockets of vacuum at the micro scale.

~~~
arnarbi
Strap one on your back and you can swim in the atmosphere like a diver in
water.

Although it would have to be over 66 cubic meters for an 80kg person in 20°C
air. If it is spherical, it would be c.a. 5 m in diameter.

~~~
mortenjorck
Thanks for the napkin calculation. How does that compare to the volume
required for the amount of helium or hydrogen that would be required to
achieve the same buoyancy?

~~~
arnarbi
This new material is 0.16 kg/m3, presumably if it's filled with vacuum..
Helium is 0.17 kg/m3 at 20°C and hydrogen is 0.09 kg/m3. At the same time, air
is 1.2 kg/m3.

So, the volume of each needed to lift 80kg (which would have to include the
person and whatever structure to contain the material), is 80/(1.2 - density
of material) m3. So:

Helium: 78 m3, or sphere of diameter 5.3 m

Graphene aerogel: 77 m3, or sphere of diameter 5.3 m

Hydrogen: 72 m3, or sphere of diameter 5.1 m

------
btilly
They claim less dense than helium. Then they show it not floating in air.

Something is not right there.

~~~
DigitalJack
It's porous, so think of it as a sponge soaked with air.

The sponge that one washes a car with will float on water until it is soaked
with water.

~~~
PanMan
So the sponge material itself must be heavier than water, e.g, more than 1
kg/L. Otherwise it would still float. Same holds here

~~~
DigitalJack
Well, sure. It's made of carbon. Carbon isn't going to be lighter than
anything ahead of it on the periodic table.

~~~
tarre
Atomic mass is totally different thing than density

------
ChuckMcM
This should be an interesting experiment, test to see how much charge the
graphene will hold.

Being less dense than air means that its structure won't inhibit
attraction/repulsion and being conductive means that it will be able to
transport charge to its surface. And just like an 'air' balloon you can stick
to the roof after rubbing it to your head, it seems like it should be able to
do the equivalent of a Van de Graf charge transfer inside the "block" to
transfer charge to the graphene.

At which point you can make a balloon which 'repels' the Earth (or is
attracted to it).

Interesting times indeed.

------
eah13
Note that this is the world's least dense material, not the world's lightest.
They mention the density measurements but conflate it with weight in the title
and elsewhere.

Sigh, journalism. Sigh.

------
samstave
I love graphene and aerogel. Graphene aerogel is super interesting.

What I would like to see is a graphene base capacitor/circuit 3d printed and
insulated by regular aerogel. Where you have a circuit which is completely
protected by the insulting aerogel.

~~~
solistice
What did the aerogel do to become insulting?

