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Blacker Than Black
An anonymous reader writes "British scientists at the National Physical Laboratory in London have invented the darkest material on Earth. 'It could revolutionise optical instruments because it reflects 10 to 20 times less light than the black paint currently used to reduce unwanted reflections. The key to the nickel and phosphorous coating's blackness is that its surface is pitted with microscopic craters.' Wonder how effective it would be as a solar heating surface ?"
I would say that the solar surface is hot enough as it is!
Enig? Det alt for hot det smor!
Goths just got scarier. "Black as night, faster than a shadow" -Judas Priest- "Hell Bent For Leather"
"Suburbia is where the developer bulldozes out the trees, then names the streets after them."
None.
None more black.
NIGEL: I think he's right, there is something about this, that's that's so black, it's like; "How much more black could this be?" and the answer is: "None, none... more black."
The light that is neither transmitted nor reflected is absorbed. If it is totally opaque too it has to be also a good solar heating surface. That said, one might be a very good absorber at particular wavelengths, but transparent or reflective at others. The cavities should act as a blackbody and operate at a wide range of frequencies though.
Gentlemen, you can't fight in here, this is the War Room!
Wonder how effective it would be as a solar heating surface ?
It wouldn't make much difference, because changing from absorbing 97.5% of the sunlight to 99.65% isn't going to change the economics of your solar collector much.
However if you are building a telescope and you want to reduce the stray reflections, going from reflecting 2.5% to reflecting 0.35% is a huge improvement
Darkenite!
we could even go around saying it affects superheroes or something.
"Luck is my middle name," said Rincewind, indistinctly. "Mind you, my first name is Bad." -- Terry Pratchett
I would love to see this used to coat the vanes that support the secondary mirrors of reflector type telescopes. Diffraction spikes (the little spikes on relatively bright stars) are really the reflection of light on these little supports. If you are into photographing nebulae, having a bright star in view can be a real photo killer.
The book 'The Hubble Wars' mentions a coating called 'Martin Black' developed by Lockheed-Martin for use in spy satellites - I wonder how this stuff compares. I found some info Here : The 'Martin Black' is not a paint at all, but a specially etched aluminum surface that acts like an anechoic chamber on a microscopic scale. The surface looks like an array of very steep pyramids a few wavelengths of light apart. It's extremely fragile & expensive to produce, but was never a classified process. Mostly used in aerospace optical hardware such as star trackers & imaging systems that have to work in direct sunlight. Ball Aerospace has a version of this process. It's considered to be a 'proprietary' process, ie they won't tell you how it's done for commercial reasons.
There's a little more detail and a few pictures at http://www.npl.co.uk/optical_radiation/superblack. html
no llamas were harmed in the making of this sig
Don't Touch It! It's Evil!
Well, now all those people wearing t-shirts saying "I'm only wearing black until they invent something darker" will be very happy! Any idea as to when we'll be able to get it in t-shirt form?
Pictures are mirrored here: dev/null
A pizza of radius z and thickness a has a volume of pi z z a
This will prove to be useful, for two reasons:
First, it is a better absorber then what we have now, which, as someone pointed out, would make an incremental improvement for things such as solar collectors.
Second, it may find some powerful uses as a black body emitter, which would have some applications for cooling. Specifically, there is a window in the atmosphere where energy can leave the atmosphere ( around one of the IR ammonia lines, IIRC) this may alleviate the greenhouse effect ... maybe ...
As one of my Professors used to say "Progress is measured by progress in Materials Science". He might have been biased, however...
I would be very interested to find out the wavelengths where this is effective.
There are three types of reflectance that I am aware of: mirrors; diffuse reflectors (lambertian surfaces) and a special case of reflectance as found on a dusty surface, such as the moon( which is an aggragation of spherical lambertian surfaces, with special properties). Anyone else know of any others?
This is progress?
Blacker than the mood of a web master who just found out that his page was posted on slashdot.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
Super-black
Technoli