The Lightest Metal Ever (2015) [video] | Hacker News Reader

The Lightest Metal Ever (2015) [video]

boeing.com

54 pointslisper47 comments

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I thought this was familiar, and a search revealed it was posted here twice back in 2011... so, not exactly new.

http://insights.dice.com/2011/12/13/ultralight-metallic-micr...

http://newatlas.com/ultralight-micro-lattice-material/20537/

Even this article is a year old (2015) but yes this has been around for a while.

Interesting none the less.

Does it bother anyone else that the audio is so highly edited? They're literally stitching together sentences that she did not say. I'm used to videos cutting phrases together, but they're cutting individual words together in a way I've never see^B^B^B heard before.

You probably just don't notice when it is done in stuff with higher production values.

To me the most likely explanation is that they wanted a certain (short) run time and she only did 1 take.

So my response is don't do that.

Don't do one take? Uh, if I was her I wouldn't do more than one take. I might not do the shoot at all. I wouldn't get paid more by doing a promotional video shoot. Why would I care? Why would she?

Presenting your ideas is an important part of most, if not all, high complexity works. If you're an engineer - present your ideas and results, so you can get better feedback, if not more appreciation. If you're a product person, explain the results to practically anybody - improves conversations which lead to better mutual understanding. For executives it's even more straightforward - remember how many hours Steve Jobs spent preparing demoing first iPhones?

What you describe is the type of stuff that is largely unimportant. This is not a commercial for a retail product, it is for an unapplied manufacturing technique. It doesn't mater who you wow with this stuff. It has an application or it doesn't. In fact, for all the good this video does, they should have just wrapped an egg it the stuff and dropped in from a building. 15 seconds of potentially viral video would have done a better job than this video. The video is fine for telling an engineering story, however. She and the hack videographer did a fine job for a low-stakes presentation. It's fine, really

I'm not blaming the engineer for the poor production quality--that's not her job. Presumably there's a video producer involved here, or someone at Boeing who didn't hire a proper video producer.

Oh, man what a high bar you have set for no reason. This video is the equivalent of an internal company newsletter. It doesn't matter the quality. Do the shoot, tell the story, wrap. They did exactly what they should have done if they wanted to get an engineering story out there. There is no pleasing some people

> This video is the equivalent of an internal company newsletter.

I'm part of Boeing now? This is great news! When do I get my first paycheck?

> Do the shoot, tell the story, wrap.

Okay, so don't edit it so much that it's incredibly distracting.

> There is no pleasing some people

Meh, in the end I liked the video, but that doesn't mean we have to pretend the video was edited well.

You actually see (hear) this a lot on YouTube lately. It's usually not so bad when professionals do it, but often amateurs have tendency to go a little overboard and it can really spoil a video for me.

Probably clipping out gaps and 'um' type filler words. It really is jarring in this case.

The title should say "lightest metal structure".

Lithium is the lightest metal. (Though technically Li-6 isotope is even lighter)

http://scitation.aip.org/content/aip/journal/jcp/27/5/10.106...

When someone talks about 'light' metal, I assume they incorrectly refer to the weight of a solid cube (cm^3) of the metal, that is, the density. A wireframe, to me, is not a metal. It consists of metal but its structure, including air, is not a metal. I don't say my cupboard is made out of the lightest wood in existence because if I divide its volume (including the air inside!) by its weight, it's lighter than any cube of wood.

Ironically, balsa wood, pine, and oak are all just boring same ole cellulose and lignin composite surrounded by varying amounts of nothing. Used to be surrounded by water when the tree was alive.

Yes yes there are trivial details in that pine is 1% pine tar and oak has 1% whatever dyes and stuff to make it darker color, but to one sig fig or to 10% accuracy, its all the same.

You make a very good point, but we can amend (http://paulgraham.com/disagree.html) the GP's argument to say that such macroscopic holes are not very impressive. Now if they were as small as those in balsa, and invisible to the eye... then on a macroscopic level it would appear to be superlight metal. It could also help that the holes are sufficiently small as to not percolate (https://en.wikipedia.org/wiki/Percolation_theory).

When I was writing the post, I thought about balsa but I was too lazy to adjust my metaphor. I could have just said "gun safe" and made the point about metal again.

Question: will it ever be possible to wrap a thin impermeable film around a structure like that, suck out the air inside and end up with a lighter-than-air solid in order to build vacuum airships?

Theoretically yes, practically no. But why bother? Supporting the walls by filling the space with a gas lighter than air would be more efficient.

Theoretically, no, not this particular substance.

But anyway, the reason people are fascinated with the idea is that vacuum is a renewable and abundant resource. Heck, space is almost completely full of it.

All of the lighter-than-air gases I'm aware of have downsides, like hydrogen's permeability and flammability, or helium's rarity and price.

If the container is going to be metal, then hydrogen is an option. I wonder about flammability. This substance is metal with an extremely high surface area/volume ratio. It may be very flammable, and potentially contain much greater energies, when mixed with air.

> If the container is going to be metal, then hydrogen is an option.

Afaik hydrogen tends to slowly diffuse through metals and embrittle and corrode them in the process. And a solid-metal hull probably is ideal for airships anyway.

Pure hydrogen doesn't burn, it needs oxygen. The Hindenburg disaster was so spectacular because the ship was made out of highly flammable canvas and wood. The hydrogen itself burned up very quickly once escaping.

If the ship had been made out of metal it would've sprouted a brief jet of flame, then crunched to the ground in a fairly ungraceful manner, but it wouldn't have exploded.

Maybe a graphene hydrogen containment cell could work? That would be strong enough to deal with the pressure, plus provide a flame resistant barrier.

Graphene is flammable, as are pretty much all arrangements of pure carbon.

Everything is flammable if you can heat it up enough and get it ready to party with oxygen. It could be treated with some kind of fire-retardant chemical, though.

Hot air is lighter than air, and aerogel like low density materials have some weird property where the thermal conductance is lower than bare gas when the mean free path in the aerogel is shorter than the mean free path in bulk gas. In other words they're better hot air balloons than actual hot air balloons.

Something interesting to think about is if they don't leak heat energy very well, and the exterior is something heat proof (steel foil?) you can heat up the air inside to arbitrary temps until radiative glow exceeds the other thermal losses. So if you think nylon hot air balloons are high performance, imagine balloons with much higher lift per volume. A liter of air weighs about a gram so its always going to take a large piece of aerogel to lift me (I weigh quite a few grams) but ...

A hot air balloon sized piece of aerogel is not economically viable right now, even for the military... or is it?

Low-density materials surrounded by a thin shell are still going to weight a lot more than air surrounded by a thin shell. Also, you have to look into how this is going to be heated. For a hot air balloon to work, all the air inside has to be hot. If your balloon is filled with an amazingly efficient insulator....

Also, the reason airships use lighter-than-air gas is because then they don't have to carry lots of heavy fuel for heating air. Things like fuel, and pipes to carry heat throughout your aerogel, will rapidly eat up any efficiencies you gained.

Helium is not that rare, it's just that we choose not the capture it when digging for oil or gas. The US mine that is "running out" is a store not a source. It's just not economical to collect it from gas wells while the US is selling off the Helium reserve 'cheap'.

http://m.phys.org/news/2013-04-probing-helium.html

Helium is still dirt cheap despite its relative rarity on Earth. In the universe at large it's ridiculously abundant.

A gaz is not a solid. Think about a what you could build with a solid that is lighter than air. That would make the expression "the sky is the limit" pretty much literal.

No, this is not nearly strong enough for that. 1 square foot at 1 ATM ~= 1 ton of weight, in the video she was crushing a square in of this stuff between her fingers with relative ease.

Basically cardboard made out of metal?

I feel like the video was a bit sales-oriented. Is it just me?

Yeah, call when you have a really cool application / problem solved. Also the Astrodome is probably 99% air.

tough crowd! no love for basic R&D.

I'm not saying I don't like basic R&D. Quite the opposite actually.

21st Century Chainmail! Our forefathers would be proud.

Does the lack of centering with the play button bother anyone else?

#AllAlignmentsMatter?

That, and the constant background hiss in the audio. I get that they are going for a windy/airy feel, but it comes off as a poor recording.

It's... 3D chicken wire? Not terribly impressed. From the video it shows that it's also super weak. You won't be building airplanes with this stuff.

This obsession with super light materials that "are strong for their weight" seems a bit useless to me. It never seems to scales to something that weighs a medium amount while maintaining its strength to form something actually useful. Supposedly, spider silk is incredibly strong. But if you can't scale that strength there is no point to it.

At least aerogel has purposes for extreme insulation, but as this is made out of metal I don't see use there either.

Nevertheless, I applaud progress.

If the exterior is rigid and the inside is filled with this material it could be strong enough for many structural projects. As was shown in the video our bones are created in the same way. I think the issue will be cost.

Yeah, when I read about this before, I think they were making it with a 3D laser sintering technique, which comes with some baggage. Mainly it's slow and with current technology I don't know if you'd be able to print a continuous sheet of it versus the cubes they showed in the video.

"Supposedly, spider silk is incredibly strong. But if you can't scale that strength there is no point to it."

Actually there's a Japanese company that scaled it using all kinds of genetic engineering and biochemistry and supposedly North Face is shipping a jacket made of it in Japan for $1K "around now" although I can't find it on the website (only exists as press releases claiming it'll be released right about now).

Two days ago according to this press release Kraiglabs started commercial production in the USA under a variety of interesting licenses and patents.

http://www.kraiglabs.com/kraig-biocraft-laboratories-new-spi...

Spider silk is right on the cusp of wide availability. Very interesting material. Unless its discovered to cause cancer or something, you'll probably own some in a decade.

You can do weird and interesting things with low density materials. I can think of some interesting applications for a Zeppelin sized piece of aerogel with embedded bars of conductive metal foam carrying a (solar generated?) current to resistively heat it. A Zeppelin sized piece of aerogel would be kinda expensive, right now. But someday we could make an island sized platter and cover it with solar cells dumping heat into it during the day and make a halfway decent eternally flying island. In my infinite spare time.

The military industrial complex options are interesting. So there are some projectile weapons that ignore low density materials and go right thru (tank sabot round, etc) and others that crumble when they hit anything (some high velocity small caliber rounds, perhaps a HEAT tank round could be triggered by impact no matter how low the density). Meanwhile I'm sure its not very good for the aerogel but I wonder how much energy it dissipates blowing apart in a shock wave, that has some interesting shielding effects for soldiers. Here's a helmet liner that makes you concussion proof exactly once while it turns to dust. Or maybe not.

>obsession with super light materials that "are strong for their weight" seems a bit useless

You couldn't be more wrong. Most of aerospace design is about optimizing ratios. Thrust/weight; strength/weight; specific impulse for rockets (∂momentum/∂fuel); lift/drag; lift,drag/velocity.... etc. etc. etc.

Aircraft structures also have an amplification factor. For every 1 pound of stuff in the aircraft you'll need 5 pounds of structure. Saving small amounts of weight can have big consequences in the range/fuel economy/speed/etc. metrics.

This material wouldn't just be used by itself, it would be compounded with a few other materials to get the right strength characteristics desired. Compare it to the honeycomb material that's all over aircraft today; the honeycomb itself is barely more than shaped paper, but glued to thin sheets on either side, it's incredibly strong.

Imagine that a big sheat of this material is put on a structure made of beams (e.g. Sphere). You then get a very solid and light object that has also some flexibility so that it doesn't break under high stress or hits.

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