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Nanotubes Form The Darkest Material Yet Created
Posted by
samzenpus
on Thu Jan 17, 2008 03:08 AM
from the none-more-black dept.
from the none-more-black dept.
toxcspdrmn writes "Bad news for Spinal Tap fans. The BBC reports that researchers at Rensselaer Polytechnic Institute in Troy, New York, have produced the darkest known material by manufacturing "forests" of carbon nanotubes. This forms a surface that absorbs or scatters 99.9% of all incidental light."
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Don't tell John Carmack! (Score:5, Funny)
(and you just thought you saw all possible shades of black and brown in Doom 3!)
Re:Don't tell John Carmack! (Score:5, Funny)
Parent
Re: (Score:3, Insightful)
Such a pity more young people havent read it.
There are so many references to the books everywhere.
Such a pity that so many people think Hitch-Hikers guide is just a book, and don't know about the Radio show from which it came.
Re:Don't tell John Carmack! (Score:4, Insightful)
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Re:Don't tell John Carmack! (Score:4, Insightful)
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Paint (Score:5, Funny)
Re:Paint (Score:4, Funny)
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Re:Paint (Score:5, Funny)
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Oh wow - an darker shade of black... (Score:5, Funny)
Re: (Score:3, Funny)
Re:Oh wow - an darker shade of black... (Score:5, Informative)
Parent
Re: (Score:3, Funny)
None. None more dark.
Re: (Score:3, Informative)
Here ya go. [ibiblio.org]
Re:Oh wow - an darker shade of black... (Score:5, Informative)
Pretty cool stuff. The sample on the left is carbon black, which is reasonably black, but the surface still texture stands out clearly with the flash. The sample of the new material looks like a black hole - which I guess it almost is. Except for the suckage.
Parent
Re:Oh wow - an darker shade of black... (Score:4, Funny)
Parent
Re:Oh wow - an darker shade of black... (Score:5, Funny)
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Re:Oh wow - an darker shade of black... (Score:5, Funny)
"Y'ar. I've seen it meself with me one good eye. It be blacker than pitch, darker than a black cat on a moonless night, and dim as the stygian depths of Davey Jones' locker itself. As murky and inscrutable as an hoor's arsehole. Not well-lit, I am telling thee. Opaque, if ye catch my drift. As inky as a squid's, er, ink. Ye keen well what I mean."
Parent
wouldn't scattered light still be light? (Score:4, Insightful)
Re:wouldn't scattered light still be light? (Score:5, Informative)
Parent
Re:Collects, actually. Solar panels, anyone? (Score:5, Funny)
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Re: (Score:3, Interesting)
I was going to ask... (Score:5, Funny)
Unfortunately, posting on Slashdot provides me with the perspective to see how stupid a question it was.
Re: (Score:3, Interesting)
Still, if even one photon in a hundred escapes, it can't be too black, now can it?
Re: (Score:3, Funny)
How much more black? (Score:5, Funny)
Re:How much more black? (Score:5, Funny)
Parent
mapping this darkness on a scale (Score:4, Funny)
from 1 to 10 would yield us, what? 11?
Mr Desiato would like a word with them... (Score:5, Funny)
Absorbtion (Score:5, Interesting)
Black body radiation (Score:5, Interesting)
Parent
Re:Black body radiation (Score:5, Informative)
Although Planck's formula predicts that a black body will radiate energy at all frequencies, the formula is only applicable when many photons are being measured. For example, a black body at room temperature (300 K) with one square meter of surface area will emit a photon in the visible range once every thousand years or so, meaning that for most practical purposes, the black body does not emit in the visible range.
My, possibly incorrect, interpretation (assumption?) of the article was "light" in the broad sense of all electromagnetic radiation. This, however, does not make your link less interesting; in fact, in makes it more interesting. Thank-you.
Parent
Re:Absorbtion (Score:4, Interesting)
"The application will be to things like more efficient solar cells, more efficient solar panels and any application where you need to harvest light," he added.
There was an earlier article on
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Another article with a pic of the substance (Score:4, Informative)
Where to put it (Score:5, Interesting)
Case in point - I was once in a room that had contained a fire. The walls, floor, ceiling, and windows were all coated in a soft black soot that was perfectly uniform and ate all the light. The effect was very disconcerting and disorienting. None of the normal visual cues of highlights, textures, or reflections existed. Only the open door gave a reference point so that you didn't feel like you were floating in a void.
The article posits several uses, but can you imagine a person clothed in this black in full sunlight? Could we even see them? or a building covered in it? or a car? Sight requires a least some photons to hit the retina. Anyone? I know I sound repetitive, its 0430 and didn't want to lose the train of thought to sleep.
Re:Where to put it (Score:5, Informative)
Even if your brain couldn't handle pure blackness, the rods still fire randomly, ensuring that some form if input is always present. You can verify this by closing your eyes in a very dark room - you should see a color that is not black. This color is called eigengrau [wikipedia.org].
I think this will be of limited value for personal stealth measures - being that dark, you'd stand out even aginst regular dark surfaces. However, as another article pointed out, a stealth plane could profit from being able to absorb radar beams. Research into the absorption of non-visible wavelengths is already underway.
Parent
But (Score:5, Funny)
The new macbook is all about being seen.... (Score:3, Interesting)
A great use for this would be the border area around my home cinema screen. The projector leaks a bit of light there...
Finally (Score:3, Funny)
Stack of razorblades (Score:4, Interesting)
(Because of the potential for dangerous reflections, please don't shine lasers into a stack of razors trying to test their reflectivity--unless you know what you're doing and, hopefully, have an appropriate pair of laser goggles.)
Re:Stack of razorblades (Score:5, Funny)
The fact that the razors are sharp and pointy can be safely ignored.
Parent
Great, now I have to update my livejournal! (Score:4, Funny)
Perfect for Priests' Socks (Score:5, Funny)
DOUGAL: Anyway, what else did you order?
TED: Priest socks. Really black ones.
DOUGAL: I read somewhere, I think it was in an article about priest socks that priest socks are blacker than any other type of socks.
TED: That's right Dougal. Sometimes you see lay people wear what look like black socks but if you look closely you'll see they're very, very, very, very, very, very, very dark blue.
DOUGAL: Actually that's true. I thought my uncle Tommy was wearing black socks but when I looked at them closely they were just very, very, very, very, very, very, VERY, very, very, very dark blue.
TED: Never buy black socks in a normal shop. They'll shaft you every time!
A Room Without A view... (Score:5, Interesting)
I wonder what it would cost to do? It would be wicked cool to do this to a bedroom!!!!
Re:A Room Without A view... (Score:4, Interesting)
It would be great for photography. You can take pictures with no background, at all.
Parent
That's incident light, and asymptotic to boot (Score:4, Insightful)
It just means instead of using cheap carbon black, 99.6% blac, you use expensive and fragile nanotubes, 99.9% black.
Not a significant increase in energy absorption, and not economical either.
Re:That's incident light, and asymptotic to boot (Score:5, Informative)
Parent
Re:Why wont this change the world? (Score:4, Interesting)
But while his material would undoubtedly be very efficient for absorbing heat, it does not represent any revolution in that area: we can already absorb sunlight for heat with reasonably high efficiency with just basically black paint. This invention is better, by many percentage points, but it is still only an incremental step up from what we can already easily get per square meter.
Also, as always, the economics come into play: it will often be a lot more attractive to use a cheaper and much simpler solution, and spend slightly more surface area to compensate for the lower efficiency.
Extruded black plastic will probably still be hard to beat in the real world for a while.
I think it will be much more useful in light sensitive applications.
Parent
Re:Why wont this change the world? (Score:4, Informative)
Well, let us do some math on the trivial boiling of water with black containers.
Take a container with 1 kg of water. For ease of calculation we will take a 0.1 m x 0.1 m x 0.1 m container.
Let us assume one side of the container faces the sun. Area is 0.1 x 0.1 = 0.01 m2
The staring temperature is 20C, boiling temperature is 100C. Delta t is also 80 C. Specific heat of water is about 4200 J/K/kg.
To make the 1 kg of water boil you need 80 x 4200 = 336 kJ.
Energy received on the side of the container is 0.01 x 1366 = 13.66 W.
Time needed to get 336 kJ with this power is 336000/13.66 = 24597 s (=6 hours and 50 min).
Oops, not so trivial after all...
If you make a large area (1m2) container containing 1 kg water you need get a container of 1 m x 1 m x 0.001 m. This container would boil water in 336000/1366 = 245 s (about 4 min). Problem with such a container is a large area at the cool side of the container and the specific heat of the container is a lot higher than the specific heat of the water it contains. So you need to design a container with a very low specific heat compared to the specific heat of the water it contains, a large surface area to collect the solar energy and good isolation at the shade side to minimize heat losses. Welcome to the interesting world of designing solar collectors.
And for the very black material: going from 99% black to 99.9% black gives only (99.9-99)/99 = 0.9% increase of efficiency. The problem of solar collectors is not the black not being black enough. A new blacker black won't revolutionize solar collectors.
Nyh
Parent
Re:Why wont this change the world? (Score:5, Informative)
You are wrong here. The 1366 W/m2 is indeed at the upper atmosphere. Lower in the atmosphere it is less, how much depends on the current state of the atmosphere. About 1000W/m2 is the right value.
The 100W/m2 is the energy output of a not so good photovoltaic module.
Nyh
Parent
Re:Superblack? Hardly. (Score:4, Interesting)
Well, I thought I was being funny...
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