Slashdot Mirror
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 ?"
What's blacker than black... ...a new nickel and phosphorous coating with microscopi...
You know? The joke just isn't as funny this way.
Wonder how effective it would be as a solar heating surface ?
That probably depends on the specific heat of the material.
I myself wonder how physically resilient this material is, what it's impedance is, and whether it isn't extremely similar the blackbird surface material.
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."
If it reflected one times less that'd mean it was reflecting nothing at all, so what happens when it reflects 10 times less?
Need I say more?
A)bort, R)etry or S)elf-destruct?
My high school physics teacher had a piece of "black," though not as black as this. He said he'd put it against walls and students sitting at the other end of the room would think there was a hole, he said. By the time I saw it, it was old and had gotten too dusty to be very impressive.
Whale
Why don't they name materials better today? What is interesting in the name "Super-black"? Nothing!
I suggest we call it Darkonium or something...
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."
-Mark
OK, now we know what fuligin is made of.
Sheesh, evil *and* a jerk. -- Jade
Nigel Fox, who heads the optics group at NPL, said: "When you look at the black, it is an incredibly beautiful surface. It's like black velvet."
Who'll be the first schmuck to paint Jesus or Elvis onto this surface?
Welcome to the Panopticon. Used to be a prison, now it's your home.
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!
Is this a material that Ford and Zaphod will marvel at as they cruise space parks looking for a ship to steal and will Marvin be riding a ship made of one into the sun.
Rest In Peace Mr. Adams
I was thinking of the immortal words of Socrates, who said: "I drank what?" - Chris Knight (Val Kilmer)- Real Genius
Hotblack wants to upgrade his spaceship with some new buttons.
Rob.
so I know this material has been here on earth since the "Dawn of Man."
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.
From the lame Ananova article:
I thought that black velvet was 60% Guinness and 40% Champagne...
Might make a cool screen too.
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
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
Well... in physics, the sun is often used as an example of a "black body", so one may even say it's black enough as it is ;-)
"First lesson," Jon said. "Stick them with the pointy end."
Scientists estimate this will be the blackest material ever manufactured, until they perfect the technique of mass-producing Hillary Rosen's soul.
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?
...this is a Good Thing for production instruments, but it won't matter much for research/labwork/prototypes; right now I'm working on laser detection of single atmospheric particles; we needed a *black* coating for the inside of the chamber, but it didn't need to be particularly robust, just dark - so we smoked it with a flame. Carbon black is the least reflective substance known, IIRC it absorbs something like 99.996% of incident radiation...anybody who's seen the inside of an old kerosene lamp chimney knows exactly what they mean in the article when they talk about the 'black velvet' appearance. We did have some problems with it 'popcorning' as we pumped the chamber down, but a staged evacuation with good degassing periods took care of that.
Oh, this would make a great solar heating material - somebody mentioned the specific heat of the material, but as long as you have a thin layer backed by a heatsink, the specific heat doesn't matter (it's just the amount of heat a material can contain per gram; if you have just just a tiny bit of black substance, it doesn't matter how much heat it stores); it's all about the absorbtion.
Facts do not cease to exist because they are ignored. - Aldous Huxley
as a solar heating surface ?"
Ummmmm, much more than black paint?
I don't mean to be snide or anything ( for a change), but you really couldn't figure that out for yourself in about 1/10 of a second?
Not that it'll make much difference in a world that still puts black asphalt products on their roofs (which does everything wrong, being hot in summer and cold in winter) instead of polished aluminum.
In order to make good use of solar radiation one must first learn to use it *properly,* no matter how efficient any particular material is. Otherwise that efficiency just goes to waste.
I recommend a perusal of Rex Robert's classic work "Your Engineered House" for an explaination of how understanding basic thermodynamics can be applied simply and cheaply, with off the the shelf non-propriatary building materials, to a house with remarkable effect.
Just as in software no one makes gobs of money promoting nonpropriatary solutions, even though those solutions may not only be cheaper, but *better.* The whole Open/Propriatary thingummy goes far deeper than the IT industry. It is pervasive in every walk of life.
It's up to you to ignore the advertising material and edumicate yourself I'm afraid.
KFG
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?
Say conventional black paint reflects 1% of the radiation. This stuff reflects, say, 0.1%. If you are building optical instruments then that is a 90% decrease in ambient reflections from internal surfaces, which is really useful.
But if you are interested in harvesting energy then the absorbancy has gone up from 99% to 99.9%, which is an increase of just 0.9% over what we had before. Gee.
Paul.
You are lost in a twisty maze of little standards, all different.
Here is another example.
/syle
offtopic, yes, but somewhat more in the vein of discussion, how does it do on reflecting, say, radar?
- Entertaining Bits from the Ancient Kernel Tree
great, as soon as Lars Ulrich gets word of this they'll re-release their black album for more profits.
There\'s no place like ~
The problem with solar power today isnt about efficiency since modern panels have about 70-80% efficiency in heating water. The incoming power is about 1000W per m2. A better absorber wouldnt make the panel that much more efficient.Chromium Oxide have an efficiency of about 92%. Much of the problems lie in how you transport the heat from the panel to the energy storage.Insulation of the panel is something that you have to take into consideration. Cost is also of utter importance since you often have a roof capable of housing more than 30 m2 of panels which in most houses is overkill. To generate water you typically would need about 5 m2 from mars to november.
If this material can make the total cost smaller then its good but if it makes it more expensive it isnt of any use. Robustness and price is what we should look into and not efficiency. A cheap solar panel that lasts for as long as it have to be functional to return the investment is possible today.
The main problem with solar power is that when you need the power most (night/winter) there arent much sun around. Solar Power can never be anything but a valuable complement to something else. All trials of storin the energy longer times have failed miserably so far.
Im not just rambling here, i was a partner in a company manufacturing solar panels some years ago.
HTTP/1.1 400
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?
this may alleviate the greenhouse effect ... maybe ...
I'd rather hope not
As my old Professor used to say "its the ENHANCED Greenhouse Effect thats the environmental problem, the normal Greenhouse Effect is what keeps us alive"
If our Atmosphere didn't 'trap' a certain amount of the incident energy from the sun, and the Oceans didn't transport this around the surface then out little planet would resemble a snowball.
This is what happens in an ice age when the Ocean/Atmosphere system flips into another metastable state and the large amount of ice and snow on the surface significantly changes the reflective properites of the planet and the whole system cools.
First we need to understand how this delicate balance actually works before we try and fix it. One thing we are learning is that the Ocean/Atmosphere system is not the safe stable thing we assumed it was, but its very dynamic with a number of metastable states. It can and has switched between states on a geologically quick (5000 years) timescale without much provocation. The bad news is that sustaining life is easy in the current state, it gets much harder in some of the others.
Like a pH buffered solution its quite possible that our environment can tolerate and compensate for all the stuff we chuck into it, and then suddenly flip to another state.
Oh, and the increment improvement in absorbtion will do very little to help solar collectors - the problem with solar collectors is doing something useful with the heat once you've got it, not getting it in the first place. Find me a material thats twice as good as a thermocouple than current technology and we may be on to something...
HCl acting on Zinc plate can produce a very black surface. In about 1980 I experienced the chemical effect and read about it. The article I read had a microscopic view of its surface and it indeed had striking peaks and valleys.
The intent was to use it in cameras in to enhance the already black shrouds fore of the camera lenses in space.
It was very odd looking at something so black.
I'm so goth my black is blacker than your black. I call it "black black."
I'm so goth, I don't say "black," I say "blahhwwwkkk."
I'm so goth I have actually seriously uttered the phrase, "the darkest dark of the dark darkness."
;)
My favourite one is a bit off topic but it has to be mentioned..
I'm so goth that bats hang little plastic me's from their ceiling.
My other account has a 3-digit UID.
"As you would expect a100 year old house and to hear all
kinds of footsteps upstairs"
How come in America it only takes a house to be 100 years old to be very likely haunted, and in the UK you don't reach "probably haunted" levels until the house is about 300 or 400 years old?
Do Stateside ghosts get bored of the Ethereal Plane faster and come looking for trouble?
graspee
Super-black
Technoli
Martin Marietta (now Lockheed Martin) has produced a proprietary "super black" coating for years now. I've seen it, and it is _very_ non-reflective. The coating mentioned in the article sounds similar.
"Martin Black" is proprietary though, so if you want a part coated you have to send it to Lockheed.
To get it even darker, plate a bunch of razor blades with this material, and then stack them.
My father used stacks of razor blades as a heat dump for lasers in his fusion research at University of Wisconsin.
He showed with pencil and paper how the razor blades successively reflect the light into the gaps between the blades, without turning it around. Thus, they absorb all the light, and make a great blackbody.
Just as an interesting note: This was back in the early 70's, at a time when cost-efficient fusion was only a decade away, and had been only a decade away for 20 years. As part of his defense, he was asked whether it would be practical any time soon. His answer was no. When asked why, he pointed out that the reaction that was giving them some success was the D-T reaction, and that Tritium was so rare that it would never be a practical fuel.
That essentially did not earn the pleasure of others in the field, and kept him out of that field -- perhaps a blessing, since success might have doomed his life to failure.
Correct Horse Battery Staple: 72 bits of entropy. Enter "Correct H" into google. When it generates the phrase, that's
There's an amusing story by Jack ("Call of the Wild") London entitled "The Shadow and the Flash." It's one of about a dozen stories he wrote that would be categorized as science fiction had the genre existed then.
Two competitive brothers both seek the secret of personal invisibility via divergent, and completely bogus methods. One of them finds some way to make his entire body perfectly transparent (!) in the belief the perfect transparency equals invisibility, and apparently gets his index of refraction close to unity but still has some dispersion, because although he is invisible, he produces telltale rainbow-colored flashes.
The other one searches for a perfect black, in the even stranger belief that an object covered in perfect black reflects no light and is therefore invisible. According to the story, this works except that, of course, he casts a shadow--and when he's present, even when not casting a shadow his presence creates an ill-defined sense of darkness or gloom.
"How to Do Nothing," kids activities, back in print!
The problem with solar power today isnt about efficiency since modern panels have about 70-80% efficiency in heating water. The incoming power is about 1000W per m2. A better absorber wouldnt make the panel that much more efficient.Chromium Oxide have an efficiency of about 92%. Much of the problems lie in how you transport the heat from the panel to the energy storage.Insulation of the panel is something that you have to take into consideration. Cost is also of utter importance since you often have a roof capable of housing more than 30 m2 of panels which in most houses is overkill. To generate water you typically would need about 5 m2 from mars to november.
If this material can make the total cost smaller then its good but if it makes it more expensive it isnt of any use. Robustness and price is what we should look into and not efficiency. A cheap solar panel that lasts for as long as it have to be functional to return the investment is possible today.
The main problem with solar power is that when you need the power most (night/winter) there arent much sun around. Solar Power can never be anything but a valuable complement to something else. All trials of storin the energy longer times have failed miserably so far.
Im not just rambling here, i was a partner in a company manufacturing solar panels some years ago.
Linux, because my mother says so!
... how long before /. reports that someone has a case mod made of this?
Tuus crepidae innexilis sunt.
Actually this "black paint" would probably help for those LIDAR guns the cops are using. Painting front and rear ends of your car along with a good laser detector should help reduce your chances of getting caught spe... um... going just a little bit to fast.
In fact I remember reading an article in "Car and Driver" several years ago that did some testing with LIDAR guns and driving with you headlights on. IIRC driving with your high beams on would reduce the effectiveness of the LIDAR gun by a couple hundred feet. C-n-D even suggested installing high power off road lights with IR filters on them to even further reduce the effective range (giving you some time to slow down before the LIDAR is able to get a reading.)
Of course it seems those damn reflective license plates screw the whole thing up.
Life moves pretty fast; if you don't stop and look around once in a while, you could miss it. -FB
This is the same stuff used on the Spinaltap album. "How much more black can it be??? The answer is none. None more black"
WWJDFAKB - What would Jesus do for a Klondike Bar?
A slightly more informative article is here.
They give the recipe.
Free book: Science Toys You Can Make
NPL Super Black In order to make accurate measurements in the UV, IR and visible regions, optical instruments and sensors need surfaces with very low reflectance. These black surfaces are used as efficient radiation detectors or may reduce stray light in an instrument. Highly efficient black surfaces allow smaller, lighter instruments to be made, which is an important advantage in aerospace applications. NPL has successfully developed a very high quality optical black ] known as NPL Super Black. The process uses an adapted nickel phosphorus electroless plating technique followed by finely controlled etching and gives probably the blackest surface known in the visible region. NPL has successfully and repeatedly produced the Super Black coating on a small-scale ecottage industryf basis for a number of years. It is now for upgrading and validating the process for plating much larger substrates with this high quality optical black. The upgrade has led to an opportunity to collaborate with CNES, Astrium and Sodern, the major space contractors for the European Space Agency, on the space evaluation of the black. If successful this will open up many new opportunities for supplying coated optics to the aerospace industry.