NASA creates groundbreaking super black light absorbing material(geek.com)
geek.com
NASA creates groundbreaking super black light absorbing material
http://www.geek.com/articles/geek-cetera/nasa-creates-groundbreaking-super-black-light-absorbing-material-2011119/
45 comments
A lot of those potential applications will hinge pretty heavily on what kind of durability this coating demonstrates. What works great on metal may never give rise to a product suitable for fibers. And what works in space may wear away surprisingly quickly under the constant assault of airborne particulates.
All that said, it does provide a convenient justification for "slightly darker black" turtleneck jokes.
All that said, it does provide a convenient justification for "slightly darker black" turtleneck jokes.
If it is cheap enough, it could be used to easily bypass infrared motion sensors.
I don't think that would work. When it absorbs light, it converts that energy into heat, then re-radiates that heat. That re-radiated heat will show up to the infrared motion sensors.
I see one way you might be able to work around this: if you made a suit out of this stuff, and were somehow able to rig it so that all of the heat is dumped inside the suit, then it would be "invisible" to IR sensors. However, it would get really uncomfortable inside that suit really fast.
Also, even if it somehow magically absorbed all of the IR without re-radiating, it would still be possible to build IR sensors that detect it: if it's perfectly black in IR, it will show up as a "shadow" against a warmer background. To be invisible to IR, you need a suit that matches its temperature to the surroundings.
I see one way you might be able to work around this: if you made a suit out of this stuff, and were somehow able to rig it so that all of the heat is dumped inside the suit, then it would be "invisible" to IR sensors. However, it would get really uncomfortable inside that suit really fast.
Also, even if it somehow magically absorbed all of the IR without re-radiating, it would still be possible to build IR sensors that detect it: if it's perfectly black in IR, it will show up as a "shadow" against a warmer background. To be invisible to IR, you need a suit that matches its temperature to the surroundings.
[quote]if you made a suit out of this stuff, and were somehow able to rig it so that all of the heat is dumped inside the suit, then it would be "invisible" to IR sensors. However, it would get really uncomfortable inside that suit really fast.[/quote]
That gave me an idea... if it were possible to make a sphere that had this coating on the outside and dumped the heat to the inside, you'd have a great heat source for a Stirling engine. This could work exceptionally well in space if you can use the light-absorbing sphere oriented so that it shaded the cool side of your engine, thus maximizing the temperature difference.
That gave me an idea... if it were possible to make a sphere that had this coating on the outside and dumped the heat to the inside, you'd have a great heat source for a Stirling engine. This could work exceptionally well in space if you can use the light-absorbing sphere oriented so that it shaded the cool side of your engine, thus maximizing the temperature difference.
But if it absorbs IR and irradiates a considerable amount of heat at the same time, wouldn't it be considered a lousy, lousy IR absorbent?
Infrared is not all the same. For one thing the frequency depends on the temperature.
But more importantly it absorbs infrared light, and converts it to heat. Heat and light are not the same thing! True, hot things emit light, but that doesn't make them the same thing.
Most practically you can cool the device once the energy is heat. Or just dilute it in a heatsink.
But more importantly it absorbs infrared light, and converts it to heat. Heat and light are not the same thing! True, hot things emit light, but that doesn't make them the same thing.
Most practically you can cool the device once the energy is heat. Or just dilute it in a heatsink.
On that note, it sounds like you could make a really good heat ex-changer with this stuff. I wonder if this would make for improvements in fields like refrigeration and energy production.
Indeed. In fact, if this low albedo extends over such a wide range in wavelength, this material might be as close to the theoretical concept of a "blackbody" we have seen.
Car body paint shops could offer it for the darkest matte black on the block.
This might not be such a good idea when you consider that "black cars are 47 per cent more likely to be involved in road accidents".
Source: http://www.telegraph.co.uk/motoring/news/7845366/Black-cars-...
This might not be such a good idea when you consider that "black cars are 47 per cent more likely to be involved in road accidents".
Source: http://www.telegraph.co.uk/motoring/news/7845366/Black-cars-...
Context is vary important:
During daylight hours, black cars were up to 12 per cent more likely be involved in crashes than white vehicles, while at dawn and dusk, the figure rose to 47 per cent.
There is simply not enough information to say how bad black cars based on that article. If they where significantly safer at night then everything in that article could be true even though black cars where safer overall. Also, because they are using the 'worst case numbers' some makes and or models could be safer when panted black etc. Let alone changes in the type of drivers that chose specific colors. Let alone more complex situations ex: Yellow might be the least safe color for a given driver, but if it's only chosen by safety contentious people due to it's reputation it might have the best record.
Edit: I suspect black cars are moderately less safe, but less than a 10% difference overall otherwise they would just give the actual numbers.
During daylight hours, black cars were up to 12 per cent more likely be involved in crashes than white vehicles, while at dawn and dusk, the figure rose to 47 per cent.
There is simply not enough information to say how bad black cars based on that article. If they where significantly safer at night then everything in that article could be true even though black cars where safer overall. Also, because they are using the 'worst case numbers' some makes and or models could be safer when panted black etc. Let alone changes in the type of drivers that chose specific colors. Let alone more complex situations ex: Yellow might be the least safe color for a given driver, but if it's only chosen by safety contentious people due to it's reputation it might have the best record.
Edit: I suspect black cars are moderately less safe, but less than a 10% difference overall otherwise they would just give the actual numbers.
> I could finally have the ultimate set of curtains to ensure cave-like darkness on the brightest day.
BTW, If you really do need this, aluminium foil taped to the windows blocks light completely. It's not a curtain, but if you need it really dark, it works very well.
BTW, If you really do need this, aluminium foil taped to the windows blocks light completely. It's not a curtain, but if you need it really dark, it works very well.
NASA article: http://www.nasa.gov/topics/technology/features/super-black-m...
With more information, more pictures, and less confusion about "absorbing light leading to lower temperatures."
With more information, more pictures, and less confusion about "absorbing light leading to lower temperatures."
More confusion though: The advantage over other materials is that our material is from 10 to 100 times more absorbent
There's some snake oil there. If their material absorbs 99%, that would mean that other materials would only absorb 1-10%, which is not true. They even say in the article that black paint absorbs 90%.
What they probably mean is that their material reflects 10-100 times less light. Ie, something 90% absorbent is 10% reflective, and their material is 0.1-1% reflective....
There's some snake oil there. If their material absorbs 99%, that would mean that other materials would only absorb 1-10%, which is not true. They even say in the article that black paint absorbs 90%.
What they probably mean is that their material reflects 10-100 times less light. Ie, something 90% absorbent is 10% reflective, and their material is 0.1-1% reflective....
Thanks. On my iPad, the original link seems to go into an infinite redirect loop. I doubt I missed much.
Same here on iPhone. This drives me nuts when mobile sites "break" the web. I would rather double tap and scroll than put up with a subpar mobile experience. Now with the iOS 5 reader, I think that mobile sites are mostly irrelevant.
Yeah, that wasn't even the only confusion they added. Thanks.
Well, there is super-black light-absorbing material.
And then there is super black-light-absorbing material.
What a difference a couple of hyphens makes.
-- Your Friendly Neighborhood Punctuation Person
EDIT:
Really, there are gobs of possible interpretations. The material could be super (wow, what a material!), black (its color), light (not heavy -- or maybe it's made of light?), and absorbing (soaks up water?). It could be super, black, and light-absorbing. It might absorb black light that is super. It might absorb light that is super-black.
I count 11 possible interpretations in all. For the combinatorially minded out there, it does appear that the Catalan numbers are involved. But I don't get 14 (= C_4) because 3 of the interpretations don't parse; it doesn't work for "light-absorbing" to get a modifier (how could "light-absorbing" be "black" [whether or not the result is "super"], and how could "light-absorbing" be "super-black"?).
And then there is super black-light-absorbing material.
What a difference a couple of hyphens makes.
-- Your Friendly Neighborhood Punctuation Person
EDIT:
Really, there are gobs of possible interpretations. The material could be super (wow, what a material!), black (its color), light (not heavy -- or maybe it's made of light?), and absorbing (soaks up water?). It could be super, black, and light-absorbing. It might absorb black light that is super. It might absorb light that is super-black.
I count 11 possible interpretations in all. For the combinatorially minded out there, it does appear that the Catalan numbers are involved. But I don't get 14 (= C_4) because 3 of the interpretations don't parse; it doesn't work for "light-absorbing" to get a modifier (how could "light-absorbing" be "black" [whether or not the result is "super"], and how could "light-absorbing" be "super-black"?).
Wired had an article a couple of years ago about a similar sounding black material made by Japanese nanotechnologists.
http://www.wired.com/wiredscience/2009/03/ultrablack/
Couldn't it also be used in solar technology? It absorbs the light and I assume it stores it as heat, seems like the next logical step...
PV technology, as far as I know, works less efficiently at higher temperatures, so the heat storage might not be desirable. On the other hand, there's also concentrated solar power, which uses giant arrays of mirrors to heat up water for use in a traditional steam turbine, for which this might be useful.
Your dad's Solar panels weren't PV--they were black panels with water circulating through them. This color would help with that.
There is photovoltaic, and solar thermal. One uses heat, the other uses electromagnetic light.
This black stuff would help with the solar thermal type - but for a power plant a difference of 1% is completely unimportant, so this will never be used for that unless it's extremely cheap.
This black stuff would help with the solar thermal type - but for a power plant a difference of 1% is completely unimportant, so this will never be used for that unless it's extremely cheap.
This material reminds me of asbestos in many ways. Would there be any health problems with repeated exposure to billions of tiny fibres like this?
The jury is still out on exactly how bad nano-tubes are but the good news is that they are generally too small to block your lungs in the same was a soot particles and too soft to cause any mechanical damage.
Asbestos fibres are much larger and much stronger - it's like comparing steel drill swarf to chocolate flakes!
Asbestos fibres are much larger and much stronger - it's like comparing steel drill swarf to chocolate flakes!
This has been known a while. The earliest paper that I can find describing this phenomenon is from 2009 [1] but I distinctly recall seeing some slides describing R&D results corroborating this at least as far back as 2007.
This is neat stuff in general but sometimes I think people oversell the utility of structured forests of nanomaterials. There are even startups promising the sky based on nanostructured silicon. [2]
[1] http://www.pnas.org/content/106/15/6044.full
[2] http://www.bandgap.com/contactus.html
This is neat stuff in general but sometimes I think people oversell the utility of structured forests of nanomaterials. There are even startups promising the sky based on nanostructured silicon. [2]
[1] http://www.pnas.org/content/106/15/6044.full
[2] http://www.bandgap.com/contactus.html
Well done NASA!
This sounds like the same futuristic material coating the super-fast spaceship that Zaphod and Ford Prefect were admiring outside Milliways in Hitch Hiker's Guide to the Galaxy.
This sounds like the same futuristic material coating the super-fast spaceship that Zaphod and Ford Prefect were admiring outside Milliways in Hitch Hiker's Guide to the Galaxy.
So, this is the paint for the monolith in 2001: A.S.O.
I wonder how well it absorbs radar.
The features of this material are way to small to have any direct effect on radar.
It might be used to make a stealthy surface even stealthier though.
It might be used to make a stealthy surface even stealthier though.
It probably does really well, and is probably already being used in some applications ;)
> Because the light absorption level is so high, the super-black material will also keep temperatures down
Can someone with more physics knowledge explain how absorbing more energy will result in reduced temperatures. I would assume the opposite.
Can someone with more physics knowledge explain how absorbing more energy will result in reduced temperatures. I would assume the opposite.
If you are facing something really cold and black - like space then the blacker your radiator is the more power you can emit at a given temperature.
In theory a perfectly reflective silver object would never cool down and a perfectly black one would cool to -270C however much power you dumped into it
In theory a perfectly reflective silver object would never cool down and a perfectly black one would cool to -270C however much power you dumped into it
That is not true. A perfectly reflective silver object still emits blackbody radiation.
And a perfectly blank one will absorb light, heat up and also emit blackbody radiation.
And a perfectly blank one will absorb light, heat up and also emit blackbody radiation.
A Mr Kirchof would disagree with you if he wasn't dead.
A perfect emitter facing an infinite cold sink is in perfect equibirium at the temperature of the cold sink.
A perfect emitter facing an infinite cold sink is in perfect equibirium at the temperature of the cold sink.
Of course - but that's not what you said.
You said: "...would cool to -270C however much power you dumped into it" and that is not true.
And in any case you don't need to be a perfect emitter to be in equilibrium with the temperature of the cold sink, all you need is infinite time, but any emitter, no matter how bad will eventually equilibrize.
You said: "...would cool to -270C however much power you dumped into it" and that is not true.
And in any case you don't need to be a perfect emitter to be in equilibrium with the temperature of the cold sink, all you need is infinite time, but any emitter, no matter how bad will eventually equilibrize.
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It'd be cool to have a robe made of this. Like the one that that extra evil MF Dexter Quinn from Neutronium Alchemist had :)
Probably a good article if it weren't impossible to read due to broken mobile detection "logic" in infinite redirect.
^f Tycho. sigh
I immediately thought of Hotblack Desiato's limo.
"It's so ... black!" said Ford Prefect, "you can hardly make out its shape ... light just seems to fall into it!" Zaphod said nothing. He had simply fallen in love. The blackness of it was so extreme that it was almost impossible to tell how close you were standing to it.
"It's so ... black!" said Ford Prefect, "you can hardly make out its shape ... light just seems to fall into it!" Zaphod said nothing. He had simply fallen in love. The blackness of it was so extreme that it was almost impossible to tell how close you were standing to it.
I'm sure there are many applications as an interior coating in optics, such as photography, cinematography, telescopy and microscopy, leading to sharper images. E-Ink displays could use it on the dark side of their "pixels" for higher contrast. Car body paint shops could offer it for the darkest matte black on the block. I could finally have the ultimate set of curtains to ensure cave-like darkness on the brightest day. Ninjas will appreciate it for moving undetected through the shadows (and slightly more commonly with special forces and swat teams, who might also appreciate the coating on their gear). I could get an ultra-black turtleneck to make it look like my disembodied head and hands are animating themselves. My cell phone could be blacker than anyone else's. And finally, this could make for really high-contrast black-light posters.