The World's Lightest Material.

[peter]

Just a quick question guys - was looking at this stuff claimed to be 'The lightest matereal' ever made earlier (lighter even than aerogel apparently) and it looks like a sort of Brillo Pad constructed of micro-fine metalic micro-tubules (couldn't find a replacement word for 'micro' that sounded better ). A thing occured to me that both aerogel aqnd this new stuff are not really the lightest stuff around in that all they are really doing is trapping air into their structure and using the 'composite' density figure obtained thereby to claim the record. It occured to me that unless the size of the contained space was limited in some way I might just as easily claim the status for say, the biggest cardboard box I could seal up and get to hold into a firm structure if some weight was placed on it.

Can anyone tell me what actually is the lightest matereal that is solid at room temperature and does not have air pockets in its structure contributing to it's lightness? Seems ridiculously simple a question and I'm probably gonna look a real jerk when the obvious answer is thrown at me .....but I just can't seem to suss it out!

[Hashi Lebwohl]

I can't actually think of anything that would be lighter than an aerogel, but a good way to get an accurate measure of an aerogel density would be to create a known volume of it, obtain the mass, measure the humidity of the air in the lab, then compare the aerogel mass to the mass of that volume of air at the lab's temperature and density.

I did find this article on metallic nanomesh, which appears to be the substance you mean. I also saw a couple of other articles talking about carbon nanotubes being used to make lighter versions of aerogels.

Neat stuff.

[Vraith]

I love the quirky questions you ask peter.
You're correct they're measuring the "web," making it as thin, in many ways, as possible.
But if you mean "what would really be lightest, without making a web and including space/volume." and still being solid...that's tough, cuz you can make lots of stuff...but a lot of it falls apart if not treated tenderly...
so, actually being solid, normal temps, and not "cheating," and being fairly survivable, it would have to be one of the carbon/lithium compounds.
For "structural" material...I have no idea, it gets too complicated, but it almost has to have carbon cuz of the combo of really light and super strong bonds...

In fact, it might be that graphene best fits what you are looking for...or maybe a variation of graphene with lithium in the mix.

[wayfriend]

My answer is: Very hot Helium.

Which might point out that the question you probably want isn't "what's the world's lightest material", but "what's the world's lightest material that can <something>". You need to say what the <something is> in order to decide.

[peter]

My answer is: Very hot Helium.

Which might point out that the question you probably want isn't "what's the world's lightest material", but "what's the world's lightest material that can <something>". You need to say what the <something is> in order to decide.

I refer my learned friend to the penultimate sentance of the post I made above (By the way Hi Wayfriend - haven't crossed threads with you for a while but I was kind of hoping for to draw you out with my remarks on the copulatory tecniques of the Haruchai over in the 1st Chrons forum!).

Thanks Vraith and Hashi - I thought you would come up easily with something like amber or another well known material, but it seems that once again the world is more complex than I thought I was going to buy a sample of aerogel the size of a matchbox or there abouts but the cost of $90 and it's apparently highly fragile nature put me off. Shame - it would have been a good party trick to have been able to pull it out and watch it float to the ground at 1/4 normal speed.

[Ur Dead]

micro-tubules (couldn't find a replacement word for 'micro' that sounded better

Nanotubes maybe...

[peter]

Would there not be a difference of order to the tune of 10 to the minus six here?

[Vraith]

I was tooling around the 'net, found this, and thought of you, peter. I think the first thing is the stuff you were talking about, and this is new....maybe?? It's pretty cool stuff, anyway.

Last November, we told you about a metallic microlattice that was light enough to rest on the seed heads of a dandelion. At the time, it had just supplanted NASA's aerogel as the lightest material on Earth by a mere tenth of a milligram per cubic centimeter (the former has a density of just .9 mg/cm3; the latter an even 1 mg/cm3.)

Now, researchers at the Hamburg University of Technology have created a material that beats out both of these ultralight substances handily. They call it Aerographite, and it has a density of less than 0.2 mg/cm3. The researchers grow the material through a novel twist on a synthesis technique known as chemical vapor deposition, a process which gives rise to a network of ethereal-looking, yet surprisingly resilient, hollow carbon microtubes.

"Despite its low density," write the researchers in the latest issue of Advanced Materials, "the [Aerographite's] design leads to remarkable mechanical, electrical, and optical properties. The first experiments with Aerographite electrodes confirm its applicability." According to New Scientist, the material's structure allows it to be compressed "by a factor of a thousand, only to spring back to its original size" — a property it shares with the world's now second-lightest material.

[Hashi Lebwohl]

I recently saw that article via DVICE, myself. Fascinating stuff, to be certain.

[peter]

Thanks Vraith. The compressability of the stuff and it's ability to regain it's original shape is surely going to be a big plus over aerogel which was, I understand, very fragile as well as being very light.

The question now is "Where can I get some!". I can buy a sample of aerogel but it's over £100 for a sqare inch sample of the stuff and it threatens to fall apart every time you try to show it off to your mates.