from the how-ever-do-you-keep-it-clean? dept.
Whitest paint in world created at Purdue, may help curb global warming:
The paint has now made it into the Guinness World Records book as the whitest ever made.
So why did the scientists create such a paint? It turns out that breaking a world record wasn't the goal of the researchers: Curbing global warming was.
[...] Making this paint really reflective, however, also made it really white, according to Purdue University. The paint reflects 98.1% of solar radiation while also emitting infrared heat. Because the paint absorbs less heat from the sun than it emits, a surface coated with this paint is cooled below the surrounding temperature without consuming power.
Using this new paint to cover a roof area of about 1,000 square feet could result in a cooling power of 10 kilowatts. “That’s more powerful than the air conditioners used by most houses,” Ruan said.
[...] Two features make this paint ultra-white: a very high concentration of a chemical compound called barium sulfate – also used in photo paper and cosmetics – and different particle sizes of barium sulfate in the paint, scientists at Purdue said.
Will the reflected sunlight cause more global warming or less ?? And, what happens on cloudy days ?
(Score: 0, Funny) by Anonymous Coward on Saturday September 18 2021, @09:48PM
Scare the black right off of you
(Score: 4, Insightful) by Runaway1956 on Saturday September 18 2021, @09:49PM (7 children)
Turning off, or even turning down, the air conditioners beneath that roof will lead to less global warming. Cloudy days? The clouds are absorbing a lot of the sun's energy, just like they would with or without man around. Meanwhile, that whitest of white roofs is still reflecting UV and IR radiation that reaches the ground. At least some of that radiation is reflected right back out into space, thereby helping to reduce global warming.
(Score: 4, Funny) by krishnoid on Saturday September 18 2021, @11:58PM (1 child)
Or duh, you just paint the clouds instead.
(Score: 3, Interesting) by SunTzuWarmaster on Monday September 20 2021, @12:02PM
(Score: 2) by driverless on Sunday September 19 2021, @02:10PM (1 child)
More importantly, what happens the minute any airborne matter like dust and dirt lands on the world's whitest paint? In most cities it'd be the world's third-whitest paint by the end of the day, the world's greyest paint by the end of the week, and some sort of urban camouflage DPM by the end of the month.
(Score: 2) by bzipitidoo on Sunday September 19 2021, @03:11PM
Took a white car into L.A. once, a long time ago, and was shocked to see it covered in a sort of brownish gray crust the next morning. Things have improved greatly, and that would not happen today.
Another disconcerting experience was the one time I visited London, for a day, in the 1980s. Near the end of my stay, blew my nose on a white tissue, and it turned black, thanks to all the soot in the air. Never had that happen before or since.
I heard also that acid rain was corroding stonework. That too has been largely cleaned up in the US, and I believe Europe.
Anyway, yes, the paint would become dirty very quickly in China. But in the West, it could stay clean enough for a good while.
(Score: 0) by Anonymous Coward on Monday September 20 2021, @02:35AM (2 children)
Yes, I've gotten sun burn at the beach on a cloudy day.
(Score: 2) by Runaway1956 on Monday September 20 2021, @03:09AM (1 child)
Clouds don't block all of visible light, they certainly don't block all UV and IR. Talk a ginger into sunbathing on a cloudy day, and see if he/she doesn't burn. With all the redheads in my family, I've seen it happen.
(Score: 0) by Anonymous Coward on Monday September 20 2021, @03:40AM
I was being serious, not sarcastic. But I see how it could have been interpreted either way.
Prefer to take Ginger [wikipedia.org] sunbathing ;-)
(Score: 5, Interesting) by Thexalon on Saturday September 18 2021, @10:00PM (11 children)
This new pigment will be freely available, but with one noted exception:
context for the uninitiated [thecollector.com]
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 0) by Anonymous Coward on Saturday September 18 2021, @10:31PM
Things that matter? Vantablack is no longer the blackest black, so Kapoor has to settle for second best.
(Score: 3, Informative) by c0lo on Sunday September 19 2021, @12:03PM (7 children)
That would be White 2.0 [culturehustle.com]
Which is in the beta phase and may have already lost the race to whiteness to this one - (this one is patented [google.com]).
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by driverless on Sunday September 19 2021, @02:07PM (6 children)
Gawd some people get upset at the silliest things. Anish Kapoor, while a talented artist, is also an asshole for what he did with Vantablack, but Quinacridone Gold? Firstly, Daniel Smith is a major art supply chain that buys pigments to, um, "sell it to artists" in the same way that anyone who isn't Daniel Smith would have done, and secondly, just choose one of a million other identical-looking yellows if you want that. It's not like quinacridone is magic fairy dust, it's just another pigment.
(Score: 3, Insightful) by c0lo on Sunday September 19 2021, @02:42PM (4 children)
If you're not a painter, don't be too hasty throwing stones. What you're suggesting may be well like asking musicians to do with another chord, since well there are plenty of other minor or major of them, why such a fuss?
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by driverless on Sunday September 19 2021, @03:32PM (3 children)
Except that this isn't a different chord, it's exactly the same thing, just with a different name. So a better analogy would be "may be well like asking musicians to do with C♯ instead of D♭".
(Score: 2) by c0lo on Sunday September 19 2021, @03:47PM (2 children)
You sure about it? Like, is 3M's canary yellow the same thing as Daniel Smith's quinacridone gold and both of them are monopolizing the same thing, they just don't know it?
(mind you, C♯/D♭ is a note, not a chord)
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 2) by driverless on Sunday September 19 2021, @04:08PM (1 child)
There's various debates about whether quinacridone gold is or isn't distinguishable from any of its alternatives. The sort of people who can hear the colour orange through three closed doors insist there's no replacement for genuine quinacridone gold. So I think an effective solution would be to tell anyone who really insists on quinacridone gold and nothing else that this tube of paint I'm going to sell you at a special never-to-be-repeated price is a rare leftover example of real genuine quinacridone gold found in the estate of a deceased 90-year-old reclusive painter and then they'll be happy with it. As long as they don't take it to a lab for analysis to see what it really is.
Oh, and you can still buy the probably-real thing all over the place from art supply shops, it's not like it's some extinct species.
And the reason for 3M's Canary Yellow is because it's the colour used in Post-It notes and they trademarked it for that, nothing to do with artists. Lots of colours are trademarked, e.g. UPS brown and Barbie pink.
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @08:26PM
https://www.desireherman.com/2017/10/is-daniel-smith-lying-to-us-the-comparison-of-the-new-quinacridone-gold-to-the-old-one.html [desireherman.com] Alone it seems rather similar, but when mixed, it behaves differently. I have some practice with paints but not an expert, and yet can see that the green zones have a natural olive look with the original, and something else with the new. When mixing many pigments, weird things can happen, so painters like to start with single pigment paints. https://www.handprint.com/HP/WCL/palette1.html [handprint.com] The new version is a mix itself.
The fun thing is that https://en.wikipedia.org/wiki/Quinacridone [wikipedia.org] says the family is interesting for new tech, so it should be easier again to get the pigment (divert the right subproduct from general process and finish making PO49). Or not, as the big market was cars, and yellow could have no use at all in optoelectronics. https://www.handprint.com/HP/WCL/watere.html#PO49 [handprint.com]
(Score: 3, Insightful) by Thexalon on Sunday September 19 2021, @03:06PM
An analogy here: Stuart Semple is to pigments what Richard Stallman is to software. In both cases, they believe that the fundamental building blocks of what they do should not be owned by any one person but expressly available to everybody.
What Semple is worried about is that you'll have to pay somebody a nickel every time you use color #2A94C2 on a website. And given the way patent and copyright trolling works these days, I don't consider it a completely irrational worry.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @10:27PM (1 child)
Can this whitest white be mixed with vantablack to get the world's greyest grey? Will it be John Major grey?
(Score: 2) by c0lo on Monday September 20 2021, @12:08AM
In the context of painting, it will be Dorian Gray.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 5, Informative) by HammeredGlass on Saturday September 18 2021, @10:00PM (7 children)
they will not stay clean and the dirt they accumulate will absorb heat.
(Score: 1, Funny) by Anonymous Coward on Sunday September 19 2021, @04:42AM (1 child)
When it gets dirty, wipe it like with a cloth??
(Score: 0, Flamebait) by HammeredGlass on Sunday September 19 2021, @02:28PM
Thanks, Hillary.
(Score: 2) by FatPhil on Sunday September 19 2021, @11:24AM (4 children)
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 1, Insightful) by Anonymous Coward on Sunday September 19 2021, @12:29PM (1 child)
(Score: 2) by FatPhil on Monday September 20 2021, @06:20PM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 1) by HammeredGlass on Sunday September 19 2021, @02:30PM (1 child)
With a hydrophobic coating, it won't get clean.
and what the AC said below if you didn't see it:
"Reflect, not absorb and re-emit. They don't want IR to be absorbed to start with. This is reflection, not radiation."
(Score: 2) by FatPhil on Monday September 20 2021, @06:23PM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 0) by Anonymous Coward on Saturday September 18 2021, @10:04PM (5 children)
Barium sulfate is very dense and the buildings will collapse under its weight.
(Score: 2) by takyon on Saturday September 18 2021, @10:27PM (2 children)
How thick is it going to be, 100 microns?
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by Runaway1956 on Saturday September 18 2021, @11:06PM
Forget microns, we want it layered on 3 feet thick!
(Score: 5, Informative) by seeprime on Sunday September 19 2021, @11:38AM
As a former Technical Director of a coatings company, the coating will need to be at least 6 microns thick. A thinner film reduces hiding and reflectance. Also, you can just keep adding pigment to a formulation as levels much above a pigment to binder ratio of 1.2 to 1.0 causes flocculation, which means the pigment is no longer ideally dispersed and opacity actually decreases. Another issue is that exterior films applied to roofs will thin out over time due to the effect of weather. So, a fresh coat will be needed every 4 or 5 years to keep the reflectance up. Also, flat roofs will not benefit from this more costly pigment choice since dust and grime build up over time and will not naturally wash off when it rains. Titanium dioxide, or a blend of the two white pigments, woudl be better. Sloped roofs will be ideal, though.
(Score: 2) by FatPhil on Sunday September 19 2021, @11:43AM (1 child)
And of course, let's not forget that *copper plates* were used as roofing material. That's not just a film on the surface, that's solid. And copper has a density of nearly 9.
The densest thing in your post wasn't the barium sulfate.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: -1, Troll) by Anonymous Coward on Sunday September 19 2021, @12:37PM
(Score: 4, Funny) by Gaaark on Saturday September 18 2021, @10:27PM (7 children)
in Canada, we switch our roofs from the whitest white in summer to the blackest black in winter????
Imma gonna build me a house that's half black and half white (but none of that half white and half black shit)...that would be my last battlefield fo' sho'!
--- Please remind me if I haven't been civil to you: I'm channeling MDC. ---Gaaark 2.0 ---
(Score: 5, Informative) by Anonymous Coward on Saturday September 18 2021, @11:22PM (3 children)
Paint the roof white, and the walls dark. That way you'll reflect a lot of Sun in the Summer when the rays come down more, and you'll absorb more in the Winter when the angle is more shallow. This effect generally works well if you have eaves or awnings. It's basic passive Solar design. It can get complicated based not only on latitude but also the orientation of your house. It's best considered before the house is even built, but there might be some low-hanging retrofit fruit. I'm sure there are professionals out there that can analyze it all, or perhaps even software where you can plug and chug data about your house and it spits out recommendations. One of my neighbors seems to get some benefit from a retractable awning. Bottom line though, you're probably going to take what you get. I live much further south. I lucked in to a good orientation with lots of south-facing windows and my water heater on the south side so heating on sunny days takes very little power. In summer I draw the drapes. In Winter it's cooler than it should be because my walls are white. I have no awnings and little eave, so I'm not messing with it.
(Score: 3, Funny) by Runaway1956 on Sunday September 19 2021, @07:10AM
Bonus points for building a house half black and half white - and putting it on jacks so you can turn it around to suit the season.
OK, was being a wise guy, but, it might be doable if only the outer shell turns around the interior of the home. Build round, and put the facade on a track? Double check that no toddlers are caught in the doorways when you're ready to rotate. Don't forget the stupid cat.
(Score: 3, Interesting) by number11 on Sunday September 19 2021, @11:51AM
My house was built around 1900. It's got wide eaves, sized so that in the summer the eaves block direct sun, but in the winter when the sun is lower lets direct sun in. Builder knew what he was doing, even on what was a cheap workman's house. Of course, these days they're too cheap to build with wide eaves.
I dunno about the dark walls bit though. It would help during the winter daytime, but would radiate more at night. And in the winter, there's more night.
(Score: 2) by FatPhil on Sunday September 19 2021, @03:14PM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves
(Score: 3, Insightful) by bzipitidoo on Sunday September 19 2021, @12:41AM (1 child)
The answer is louvers.
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @02:50AM
so the beatles were right? "all you need is louvers ..."
(Score: 2) by SunTzuWarmaster on Monday September 20 2021, @12:05PM
(Score: -1, Troll) by Anonymous Coward on Saturday September 18 2021, @10:35PM
and the toast complained not.
Cells.
Within Cells.
Interlinked.
"My dick is great for taking a piss." - King Terry A. Davis
(Score: 0) by Anonymous Coward on Saturday September 18 2021, @10:46PM (4 children)
really? "the world's whitest paint". in today's political climate? seems to me these people either have their head in the sand or are purposely trying to stir shit.
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @01:56AM
It turned out to be the average skin color of Vermont.
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @04:01AM
Your political climate seems fucked.
White is a colour, not a race.
(Score: 0) by Anonymous Coward on Monday September 20 2021, @04:52AM (1 child)
Don't worry, that isn't the name of the paint. They're calling it Überpaint: the final solution to the warming question, they even have a cute Charlie Chaplin mascot. They'll make a killing with it, and promise to use part of the profits to help whiten the regions of the world most affect by heat, like Africa.
(Score: 0) by Anonymous Coward on Monday September 20 2021, @06:08AM
👌👌
(Score: 2, Insightful) by Beryllium Sphere (r) on Saturday September 18 2021, @10:50PM (8 children)
Emits infrared?
Stoves are black for a reason. Sloppy writing, counting reflection as "emission"?
(Score: 2, Insightful) by Anonymous Coward on Sunday September 19 2021, @12:47AM (4 children)
Emissivity and absorptivity are always equal at a particular wavelength. The material could be optically white, but black in the IR range.
(Score: 2) by c0lo on Sunday September 19 2021, @06:00AM (3 children)
Say... what? From a black that absorbs visible and emit infrared to non-linear laser medium which absorbs IR and emits UV [wikipedia.org]
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Insightful) by rleigh on Sunday September 19 2021, @02:08PM (2 children)
The Stokes shift between absorption and emission means that the absorption spectrum and emission spectrum usually overlap. At the crossing point (or points, for complex spectra), the absorption and emission are indeed equal.
Examples: https://micro.magnet.fsu.edu/primer/lightandcolor/images/excitationemissionfigure2.jpg [fsu.edu] and https://www.researchgate.net/profile/Pengfei-Zhang-17/publication/321697315/figure/fig1/AS:667189447237636@1536081768625/absorption-and-emission-spectra-of-fluorescein.png [researchgate.net]
For vantablack, the shift and overlap will still be there. It's atypical in having a very broad absorption spectrum, but it's still going to have a shift with overlap somewhere in the IR range. The datasheet is on their website, but you have to sign up to get access.
For the NIF link, second or third harmonic generation to double or triple the frequency occurs before interaction with the target, so doesn't really apply to the original point. It's a very cool technique though. I used to use it with a femtosecond-pulsed tuneable Ti-sapphire laser to image collagen fibres in tissue in the 800-1100nm range (400-550nm effective after second-harmonic generation within the tissue, using the highly-structured collagen as the combiner).
(Score: 2) by c0lo on Sunday September 19 2021, @02:37PM (1 child)
You have a point here, my wrong in taking your "are always equal at a particular wavelength" as "are always equal at any particular wavelength
Oh, but it is applicable to the original point. Granted, not for the target, but for the interaction with the frequency converter, in which the UV-VIS photons were not absorbed but were emitted, the absorbed radiation IR transformed in heat will emit lower wavelengths and the monochromatic IR radiation that's transmitted is weaker with the losses - you get a non-intersecting spectrum between emission and absorption.
Granted, thermodynamic doesn't apply very well to lasers, which require the "negative temperature" [wikipedia.org] trick to force the lasers on its throat (a laser can heat the target beyond the temperature of its source, which is a nono cf second law).
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Monday September 20 2021, @04:28PM
Take two materials.
One with an emissivity of 0.6 and an absorptivity of 0.4, another with an emissivity of 0.4 and an absorptivity of 0.6
Fashion a cube of each, and insulate 5 sides as well as you can. Put the two uninsulated sides facing each other a short distance apart. Assume any reasonable starting temperature you like, and work out the equilibrium temperature of each block. You will find you have a temperature difference that can be used to extract energy.
You have just violated thermodynamics, and the Nobel prize committee would like to talk to you.
(Score: 2) by c0lo on Sunday September 19 2021, @06:18AM (2 children)
Yes, whatever VIS is not absorbed is converted into IR by increased entropy, which is in excess of what the environment emit towards it.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Monday September 20 2021, @03:14PM (1 child)
You mean converted into heat, not converted into IR?
(Score: 2) by c0lo on Tuesday September 21 2021, @03:48AM
Yes, converted into heat.
For the isolated black body (no atmosphere, no thermal contact), heat will eventually leak out mainly by IR radiation.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 5, Interesting) by SparkyGSX on Saturday September 18 2021, @11:07PM (9 children)
"Because the paint absorbs less heat from the sun than it emits, a surface coated with this paint is cooled below the surrounding temperature without consuming power."
That would violate the laws of thermodynamics, as it would be a heat-diode, while moving thermal energy from a cold reservoir to a hot reservoir without energy input. That's telling the ball to roll uphill.
You can reduce the absorbed energy and reduce the need for air conditioning, which is great.
If you do what you did, you'll get what you got
(Score: 4, Informative) by Anonymous Coward on Sunday September 19 2021, @12:22AM (1 child)
Its not a heat diode when you consider the total system. The absorption properties are tuned to target those wavelengths put out by the Sun that reach the Earth's surface while also allowing high emissivity on infrared wavelengths. If you had two bodies exchanging heat using radiation in a thermodynamic system and one was painted with this and the other wasn't, they would still reach thermodynamic equilibrium.
(Score: 0) by Anonymous Coward on Tuesday September 21 2021, @07:14PM
So like a reverse greenhouse effect?
(Score: 1) by khallow on Sunday September 19 2021, @01:43AM
Think about what is the cold sink here. Protip: it's not the air!
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @01:59AM
I don't see how this violates any thermodynamic principles. It absorbs some energy, but the total of the energy absorbed and reflected doesn't add up to more than the amount incoming. How much is absorbed versus reflected is something that should be measurable to settle the matter.
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @03:29AM
This video gives a good explanation of how it works. https://www.youtube.com/watch?v=Ay6ckBojc_0 [youtube.com]
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @05:47AM
it emits its absorbed energy a IR frequency range ("color") that is not absorbed by the atmosphere or water vapor.
you know, like how shortwave radio bounces off the ionosphere, but Ku-band microwaves pass right through that and the rest of the atmosphere without much attenuation?
(Score: 2) by c0lo on Sunday September 19 2021, @06:25AM (1 child)
Surprise [wikipedia.org], surprise [wikipedia.org], you can even buy them [apricus.com.au]
In spite of no law of thermodynamics being raped.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @09:42AM
You don't even need to get that fancy in this case. As the video another post links points out, this is basically the opposite of greenhouse glass. Instead of allowing visible light through and reflecting infrared, it allows infrared through and reflects visible light.
(Score: 1) by NPC-131072 on Sunday September 19 2021, @12:13PM
No, it's just badly worded. https://www.technologyreview.com/2017/09/12/149205/a-material-that-throws-heat-into-space-could-soon-reinvent-air-conditioning/ [technologyreview.com]
(Score: -1, Flamebait) by Anonymous Coward on Sunday September 19 2021, @04:48AM
And the knees go jerking.
(Score: 0) by Anonymous Coward on Sunday September 19 2021, @06:29AM (1 child)
We could just make the walls thicker. Can't let common sense get in the way of patented designer chemicals!
(Score: 2) by Runaway1956 on Sunday September 19 2021, @07:19AM
Depends on what you make the walls of. Adobe, rock, cement, etc, tend to store energy during the day, and release it at night, keeping the house nearer equilibrium. But, that equilibrium might be higher than you would wish, if you happen to live in the desert. So, paint it white to lower that day/night equilibrium. Don't forget the roof while you're painting. Since you're painting anyway, you might as well go with the whitest white you can afford!
(Score: 0) by Anonymous Coward on Monday September 20 2021, @02:12AM
Where I live, after one day, it will be covered in brown dust.