[HN Gopher] 'Whitest ever' paint reflects 98% of sunlight
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'Whitest ever' paint reflects 98% of sunlight
Author : pseudolus
Score : 263 points
Date : 2021-04-16 11:34 UTC (10 hours ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| Isamu wrote:
| Combine with Vanta Black for the "greyest grey"
| d33lio wrote:
| I wonder if there's a marked disadvantage to using this on
| aircraft? I'm curious if some form of this tech has existed for
| decades for use on nuclear response TACAMO aircraft? Depending on
| the frequency response, it seems like this _could_ be a horrible
| material to coat an aircraft with, due to IR reflectivity?
|
| My uncle works at Tinker AFB in Oklahoma and always used to
| explain the different unique features of TACAMO [0] aircraft.
| Also, on a side note, he currently has his identical job he held
| in the air-force as a civilian and collects multiple pensions
| (albeit, he was always my "cool engineer uncle" who bought me my
| first soldering iron).
|
| [0] - https://en.wikipedia.org/wiki/TACAMO
| steele wrote:
| and consequences!
| ping_pong wrote:
| This sounds like a waste of energy to me. I think all roofs
| should be covered in solar power generating equipment. Reflecting
| all that sun energy back into the air just heats up our planet,
| better to convert that into electricity
| orev wrote:
| Light turns into heat when it is absorbed by a material.
| Reflecting it back into the air sends it (and the heat) back
| out into space, and since air is mostly clear it does not get
| absorbed so doesn't "heat up the planet", at least not in any
| significant way.
|
| Sure, using the energy for solar would be nice too, but that's
| far more expensive per square meter, so paint is a fine
| solution that's cheap.
| [deleted]
| tyingq wrote:
| I wonder how well this holds up to dust, pollen, UV, etc. At some
| point is the difference negligible? Every white commercial roof
| I've ever seen is much less white after some time passes.
| pfdietz wrote:
| Yes, this is my concern with things of this kind.
| cosmodisk wrote:
| The same problem is with solar panels. I believe it was a
| project in India that struggled with sand particles covering
| the panels way too often.
| cyberlab wrote:
| Someone needs to compile a list of all this fringe tech that I
| see popping up in my feeds, almost daily now. I know there are
| techpress blogs that pump out articles like this, but there
| doesn't seem to be an authoritative compendium of such tech
| anywhere on the net. I could curate this by hand with 3 hours of
| free time and some Red Bull I suppose.
|
| The reason I want this is because we seem to be swimming in
| innovation, but nobody to aggregate and make sense of it all, and
| `join-the-dots` of all this tech so we can make even bigger leaps
| with it. Also: A lot of these articles are great, but too quickly
| shoved into people's bookmarks and forgotten about, without any
| real action taken on them. Put simply: we are addicted to
| innovation, but with little action taken on this innovation!!
| surfpel wrote:
| www.sciencedaily.com is what you're looking for. This story,
| like most others, was published there the same day the research
| came out:
|
| https://www.sciencedaily.com/releases/2020/10/201021112358.h...
|
| And they have an absurd number RSS feeds for every topic too:
|
| https://www.sciencedaily.com/newsfeeds.htm
| aaroninsf wrote:
| I would pay for an Axios-like native app which repackages
| science daily for me in a very pleasant readable way.
| bbaumgar wrote:
| Would $99 + gratitude be enough to motivate you to take that
| time? I got serious value out of this compendium [0] and have
| been looking for more.
|
| Contact info is in my profile if interested.
|
| [0] https://elidourado.com/blog/notes-on-technology-2020s/
| loonster wrote:
| Custom RSS News feed?
| sandworm101 wrote:
| This is nothing new. You are just now hearing more about it
| because of how journalism is being done online. There have
| always been lots of revolutionary things happening in labs.
| They are rarely ever practical, or if they are it will take
| decades to bring to market. How many dozens of new battery
| techs are announced as being "better than lithium ion" only to
| disappear once everyone realized how impractical they are. Such
| announcements were once confined to scientific journals and
| trade mags. Now the great algorithm makes them daily news
| bulletins right beside the Kardashian latest puppy video.
| Bang2Bay wrote:
| I understand that there are scientific discoveries which are
| worth the investment money or otherwise. But I would prefer
| the great algo to pick these up for me rather than which star
| admires who.
| snitch182 wrote:
| oh yes, there was a sort of 3d memory lasered into scotch
| tape(german tesa) rolls. They just could not make it durable.
| EvanAnderson wrote:
| I researched this a few weeks ago and commented here[1]. I
| got a reply from someone with firsthand knowledge of the
| work. I love HN for that kind of stuff!
|
| [1] https://news.ycombinator.com/item?id=26040009
| malloryerik wrote:
| Your point clearly has merit in many cases, but paint seems
| almost the epitome of practicality. Assuming that it could be
| mass producible at a price similar to premium house paints I
| can't see the problem in bringing this to market.
|
| And from the article: > In the US, New York has recently
| coated more than 10 million sq ft of rooftops white. The
| state of California has already updated building codes to
| promote cool roofs.
| obmelvin wrote:
| > Assuming that it could be mass producible at a price
| similar to premium house paints I can't see the problem in
| bringing this to market.
|
| Unfortunately, that's the whole point of this little
| discussion, right? GP is saying how many things like this,
| yes, seem like they have merit, but at the end of the day
| _can 't_ be produced practically outside of a lab.
| kube-system wrote:
| There are a _lot_ of practicality /implementation concerns
| to paint other than what color it is. Just as many if not
| more than there are for battery technologies.
|
| Does the paint stick to the surface you want to paint, how
| is it applied, what is the coverage, is it durable, does it
| repel contaminants, can it withstand the environmental
| conditions, is it chemically compatible with the surface,
| it is chemically a concern for the other
| items/humans/animals that may come in contact with, can it
| be produced at scale, does it (and it's vehicle for
| application) meet regulatory standards? etc...
| clairity wrote:
| one thing i've learned from doing little home improvement
| projects over the past few years is that paint is a
| 2-part product, primer and topcoat, and neither should be
| skipped if you want good results. generally speaking,
| primer sticks and seals while topcoat colors and
| protects. this isn't made obvious in any way to the
| novice, and big box store workers seem as ignorant about
| it as anyone.
| kube-system wrote:
| And that's just for home improvement store paint. More
| sophisticated painting processes, like for automobiles,
| can be 5+ different types of coatings.
|
| i.e. electroplate > primer > base > mid pearl > clear
| mauvehaus wrote:
| Depending on the application, the primer coats can
| fulfill a couple other requirements as well:
|
| If you want a really smooth topcoat, you usually want to
| sand past what you can
| reasonably/economically/effectively do on the substrate.
| Some primers are formulated to sand nicely to a powder
| (as opposed to balling up in clumps on the paper). You'll
| see this spraying higher quality paint grade work. You
| have to have a decent surface before you prime, but the
| primer can really smooth it out for the topcoat.
|
| If you're finishing pine with knots in it, you'll want a
| primer that will seal the knots, otherwise the pitch will
| eventually bleed through and discolor the topcoat.
| Shellac excels at this.
|
| Shellac is also outstanding as a sanding sealer. You can
| use that in a couple of ways: to fill the pores in the
| wood so they don't get full of sanding dust (which can be
| key if you have inlay of strongly contrasting woods), or
| to stiffen the fibers of softer woods so you can get a
| better/smoother sanded surface for the next steps in the
| finishing schedule.
|
| Shellac is also often used as a barrier coat between
| otherwise incompatible finishes or when you have a
| relatively fragile stain layer. If you're putting an oil
| based finish over an oil based stain, you run the risk of
| picking up the stain as you apply the topcoat, especially
| if you're brushing or wiping the topcoat. Because the
| solvent in shellac is alcohol, you can pretty freely
| brush it over oil or water based stains without risking a
| disaster.
|
| And yes, I do use primers other than shellac from time to
| time if I have a specific need, but dewaxed shellac is
| compatible with basically everything, so I always have a
| can around.
|
| N.B. I'm not a professional finisher. Don't take my word
| on any of this; test your prep and finishing schedule on
| scrap!
| clairity wrote:
| > "If you're finishing pine with knots in it, you'll want
| a primer that will seal the knots, otherwise the pitch
| will eventually bleed through and discolor the topcoat.
| Shellac excels at this."
|
| yes, i learned this the hard way, albeit on a simple set
| of wall shelves as cat stairs that i can easily fix
| eventually with shellac and another topcoat (when i get
| around to it).
| korethr wrote:
| The big box stores employees at the paint counter seem as
| ignorant as a novice about the vagaries of application
| most likely because they themselves are novices. They may
| know quite a bit about colors and matching and how to
| work the mixing machines, but they probably don't have
| much more experience painting than the average homeowner.
| That knowledge comes more from doing, whether its a
| handful of projects as a homeowner, or regularly as a
| professional.
|
| IMO, the stores could do better about offering basic
| information about this, about when one would need a
| primer, or just a topcoat, what kinds of paint bases are
| appropriate for what applications, what kinds of
| application methods are appropriate, etc. Instead, the
| response of the big box stores seems to be to skip the
| question entirely with combined products, e.g. "paint and
| primer in one".
| clairity wrote:
| yes, there's no experience or incentive for better
| knowledge in big box stores unfortunately. i've moved on
| to buying from a local paint specialty store, which is
| owned by a family that i believe is/was in the
| construction/painting business. they cater mainly to
| contractors but also sell to the wider public.
|
| oh, and yeah, paint and primer in one does neither job
| very well.
| blacksqr wrote:
| They used standard acrylic paint manufacture techniques,
| just substituting barium sulfate for the usually-used
| white pigment titanium dioxide. So most such questions
| should be answered simply by looking at previous
| experience with existing white acrylic paint.
| DanBC wrote:
| So, in about 10 years we're going to have yet another
| source of trillions of particles of microplastic?
| Tempest1981 wrote:
| Other factors include how it ages, w.r.t. thermal
| emittance (emissivity) and solar reflectance (SRI). See
| the "3 years" columns here:
| https://coolroofs.org/directory
|
| Many products drop by several % after a few years.
| coding123 wrote:
| Actually that last bit there seems to be more important to
| me than the actual tech here. So without this tech people
| are painting rooftops white. And I'm guessing that's
| already like a 90% reflectivity? -- So there's really
| nothing to wait for if you want to cool your house. Just
| buy... exterior white paint.
|
| If you wanted to wait for this specific product, that's
| fine, but that's almost like waiting for 26% efficient
| solar panels instead of ~23% we already have (even though
| most production panels are 18% - 22%)...
|
| And actually this is also one of those things that also
| helps beat Tesla Solar roof - get a white paint - THEN add
| bifacial solar panels. So the Tesla roof panels is actually
| worse for your overall cooling than regular panels now.
| adrian_b wrote:
| The whole point of the discussed paper and of their
| patent applications is that normal white paint is not
| good enough to cool something exposed to solar light.
|
| The white-painted object will heat less than when painted
| in another color, but it will heat anyway.
|
| The white paints described in the paper and in the patent
| applications, which use either barium sulfate or calcium
| carbonate instead of the normal titanium white pigment,
| actually cool the painted object, even in strong solar
| light.
| fidesomnes wrote:
| Scientific American Magazine. You're welcome.
| macspoofing wrote:
| >The reason I want this is because we seem to be swimming in
| innovation, but nobody to aggregate and make sense of it all,
| and `join-the-dots` of all this tech so we can make even bigger
| leaps with it.
|
| There is. It's called "the market". Each one of those
| innovative ideas gets tested by their inventors and backers
| against real world use-cases. Nothing validates an idea or
| innovation more than someone writing a check to buy it.
| swsieber wrote:
| > Each one of those innovative ideas
|
| On their own though, right? That's not what was being asked.
| They wanted someway to track things that would work really
| well together and bring bigger benefits than things could on
| their own.
| macspoofing wrote:
| >On their own though, right?
|
| Yeah. When I ran a startup, you look for customers, but you
| also look at partnerships all the time to complement
| whatever you're doing. Sometimes the partnership finds you,
| and sometimes you find the partnership. You attend
| tradeshows and conferences. Sometimes your customers will
| point you at another company you should work with. That's
| all part of the market. People behind innovative
| technologies (inventors, and investors) are constantly
| looking to find ways for their tech to gain traction.
|
| >They wanted someway to track things that would work really
| well together and bring bigger benefits than things could
| on their own.
|
| OP is advocating for a top-down system where they can get a
| list of innovative technologies and just put them together
| like lego. It doesn't work that way. It's why a top-down
| command economy with a central authority doesn't work.
| There's a lot of trial and error (and failure) that happens
| at the bottom level and from the top, you just don't know
| what ultimately is worth expanding effort on and what is a
| waste of time. Any decision you make about what should go
| with what is going to be wrong. That's why the market is so
| powerful for innovation.
| jamifsud wrote:
| Completely agree. I'm working on something to solve this
| problem and I'd love chat more about your thoughts on this.
| Contact info in profile if you're interested!
| duxup wrote:
| I think ultimately what you want is some measure of say it's
| practicality / viability to really make change?
|
| I think the catch is that if you really knew that... you'd be
| out making an insane amount of money as you'd be able to pick
| and choose winners / make them work ;)
|
| I'm reminded of the old TV series "Connections" where lots of
| individual innovations are cobbled together over surprisingly
| long periods of time to really have an impact. Mostly... it
| seemed like a combo of inspiration and happenstance when
| someone strung them together.
| dmoo wrote:
| For those that haven't seen it I would highly recommend it.
|
| https://youtu.be/XetplHcM7aQ
| divbzero wrote:
| Wikipedia's "List of emerging technologies" [1] provides a
| glimpse of the breadth of our ongoing innovations.
|
| [1]:
| https://en.m.wikipedia.org/wiki/List_of_emerging_technologie...
| cyberlab wrote:
| Thanks for the share. Great list that.
| FredPret wrote:
| Speaking of joining the dots, did you know that both the train
| and steam power (albeit a toy version of it) were invented in
| ancient Egypt?
|
| Think what could have been had we joined those two dots in
| 2000BC instead of 17-1800 AD.
|
| I should note that their train was of course pulled by slaves
| and not a locomotive.
| quickthrowman wrote:
| You need machine tools capable of tight tolerances and
| quality metals/alloys to make useable (for work) steam
| engines. The Egyptians, Greeks, Romans, Abbasid, Persians,
| Europeans, etc all lacked these, thus no usable steam engines
| in antiquity/Middle Ages. Usable engines followed consistent
| quality metal production and machine tools pretty closely,
| it's not like older people were just stupid, they didn't have
| the technology necessary to create steam engines capable of
| real work.
|
| It's like asking "Why wasn't there a chess engine as good as
| stockfish for the PDP-11?" It simply wasn't possible with the
| technology in 1970.
| ouid wrote:
| Also worth mentioning that a lot of what is considered
| technology is actually mathematics.
| samatman wrote:
| That's a conventional response with a lot of merit to it.
|
| But then I watch Clickspring recreating the Antikythera
| mechanism, and I wonder.
|
| Yes, there is a big leap between what is effectively
| clockwork and, say, making a pressure boiler. But I wonder:
| if Francis Bacon had been a student of Euclid and derived
| the scientific method in 3rd century BC Alexandria, and
| Rome had been better governed, devoting more energy to
| science and less to war, speed-walking the tech tree 1500
| years early isn't impossible to contemplate.
|
| Fun to think about anyway!
| macleginn wrote:
| As one of my uni professors said, if the Persians had not
| annihilated Miletus, the humanity would've walked on the
| Moon much sooner.
| trhway wrote:
| Romans had copper and that would be enough to run the
| Empire using the telegraph. They just didn't know about the
| electricity and how to make a voltaic pile in particular
| even though they had the sufficient technology.
| FredPret wrote:
| Good point regarding tooling, metal, and tolerances.
|
| But in this hypothetical timeline they would've hand-made
| the first leaky and inefficient engine if someone with some
| clout had the idea for a piston back then.
|
| These people didn't blink at moving mountains to build
| burial crypts, so it's conceivable that they might've
| experimented with steam if that notion struck, say, the
| pharaoh.
| aksss wrote:
| Smil's book about Making the 20th Century has some good
| context for this type of discussion. Highly recommended
| if interested in how technical leaps happen.
| yetihehe wrote:
| They didn't have one important dot: cheap good steel or other
| durable materials. Steel for them was more expensive and hard
| to get than titanium now.
| VBprogrammer wrote:
| This reminds me of the 2.8kg pyramid which sits atop the
| Washington Monument. At the time it was cast, it was the
| largest single casting of an exotic metal which cost more
| than silver, known to you and I as Aluminium.
| FredPret wrote:
| I think Napoleon had a set of aluminium cutlery... to
| show off his extreme wealth.
| Red_Leaves_Flyy wrote:
| I think part of they problem is that whoever invented this
| paint is going to want a massive premium for its sale. So it'll
| get some niche industry use until the patent expires and people
| start painting their desert roofs with it, or whatever else.
| Apply to this virtually every technical innovation that is
| iterative. Fundamental breakthroughs allow for a shakeup of the
| incumbents, iterative ones don't, due to the archaic IP laws
| that only serve to stifle innovation. I think a better solution
| would be arbitrated profit sharing as a percentage of the cost
| of the product proportional to the value added with no
| requirement for the consent of the rights owner. Decay the
| percentage to 0 over the same timespan as current patents.
| bwestergard wrote:
| This is a very insightful comment. Perhaps you are aware, but
| some economists have designed mechanisms to "split the
| difference" in a manner similar to what you describe:
|
| https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2744810
| Red_Leaves_Flyy wrote:
| I was not aware, though I am not the least bit surprised to
| discover that economists have explored this before I tapped
| it out. Thanks for the link!
| dismalpedigree wrote:
| I'm pretty sure this is developed and patented by Purdue
| University (or perhaps a partnership). They don't really try
| to extract extreme fees for usage.
| bsanr2 wrote:
| The Two Minute Papers YouTube channel covers new research
| related to (visual) simulation and AI. It's like a weekly mini-
| Siggraph.
|
| https://youtube.com/c/K%C3%A1rolyZsolnai
| cosmodisk wrote:
| Such a good idea! There's so much stuff being invented, some of
| it outright insane and yet it's almost impossible to find
| anything, unless you are very knowledgeable in a particular
| field.
|
| For instance,I've been subscribing to materialdistrict.com for
| years and some materials they showcase are simply mind
| boggling.
| thinkingkong wrote:
| What sources are you using for fringe tech that you would
| compile from? Even a list would go a long way to expanding mine
| and other peoples concepts of innovation.
| brentjanderson wrote:
| The field you're looking for is called "tech transfer" - many
| universities have technology transfer offices that help
| research connect from a lab to industry, usually enriching
| researchers through the sale of patents or consulting
| contracts.
|
| I don't know of any compendium on the web, but if someone were
| looking to get started there is a field to dig into where
| people do this kind of work full time. It's essentially a two-
| sided market making process of curating useful innovations and
| building up a sales function to close deals.
| pjungwir wrote:
| In _The Chip_ , T. R. Reid talks about how Kilby and Noyce
| (inventors of the integrated circuit) spent time reading
| through new patent applications every day/week. As programmers,
| we spend a lot of time reading blog posts, but it's possible to
| take it further than that. For a couple years I attended a
| database reading group every Friday at a local university,
| where each week we would discuss a paper someone was interested
| in. You may also have alumni access to interesting journals. Or
| A Morning Paper[0] is a more Readers Digest approach. It takes
| some intentional work, but it's fun and you learn a lot.
|
| [0] https://blog.acolyer.org/
| [deleted]
| Xplune13 wrote:
| I agree. Such a compendium would be great and more so if that
| would be the only place where we can get the information about
| inventions and innovations.
| apples_oranges wrote:
| How does black paint work anyway? What happens to the energy of
| the photons? (Will google, but perhaps someone here can explain?)
| ohazi wrote:
| Absorbed, adding energy to the paint molecules, then reradiated
| at a lower wavelength (IR), heating up nearby things.
| mrob wrote:
| Some is conducted into the object that's painted, and some is
| radiated away as infrared. See:
|
| https://en.wikipedia.org/wiki/Black-body_radiation
| Bayart wrote:
| It dissipates as heat into the paint and it's substrate, I
| assume. At least that's what I always thought we wore dark
| clothes in winter and bright ones in summer.
| pfdietz wrote:
| Some black paints/surfaces for solar heating applications are
| the opposite of the white paint in this thread: absorb strongly
| in visual and near IR, but only weakly in far IR (and so have
| low thermal emissivity at those wavelengths.)
| mannykannot wrote:
| "An infrared camera (right image) shows how a sample of the
| whitest white paint (the dark purple square in the middle [of the
| infrared image]) cools the board below ambient temperature."
|
| So... Maxwell's demon?
| Groxx wrote:
| Yeah... "ambient temperature" is very different than "other
| nearby surface temperatures".
|
| Still, it's pretty cool.
| cryptonector wrote:
| Well, if something can only radiate, and will absorb much less
| than it radiates... the only way it could stay at ambient
| temperature would be via contact transmission. I would expect
| an object painted in this whitest paint to cool below ambient
| temperature unless it had a heater inside it, say, or unless it
| was submerged in water rather than air.
| ryannevius wrote:
| This is mostly off-topic, but the title instantly made me think
| of this quote from Invisible Man:
|
| > "Our white is so white you can paint a chunka coal and you'd
| have to crack it open with a sledge hammer to prove it wasn't
| white clear through."
|
| Of course, I'm not implying any connection to this 'whitest ever'
| paint, but the book is quite good.
| milleramp wrote:
| I have mixed barium sulfate with white paint, for making cheap
| reflective integrating boxes. The tricky part is maximizing the
| amount of powder to paint, without it getting too thick for
| painting. I have also used the Labsphere, integrating sphere
| white paint, it is also so expensive:
| https://www.labsphere.com/labsphere-products-solutions/mater...
|
| On another note, the building rooftop outside my office window
| was painted white, within 1.5 years its gone from from blinding
| white to a very dark gray, I am not sure this does much good over
| time.
| gypsyharlot wrote:
| Isn't this kind of racist?
| fnord77 wrote:
| materials engineering is a fascinating and really
| underappreciated field. I love stuff like this
| torgian wrote:
| Damn. That's whiter than my best friend.
| jbverschoor wrote:
| Can someone explain the difference between this and a mirror? A
| mirror reflects also something like 98%, right?
| buran77 wrote:
| I would expect it's twofold. This paint acts like a "diffuse
| mirror" so doesn't create any bright spots like specular
| reflection. This is great particularly in cities where every
| building would become a giant mirror. On the other hand a
| mirror finish is harder to achieve on rough surfaces that the
| paint would presumably be used on.
| Arnt wrote:
| Adding:
|
| Mirrors don't have to reflect very much, they have to reflect
| as a picture. That's why one-way mirrors work -- people
| generally don't notice that the light mirrored is much less
| than 100%. White paint is free to reflect the photons in any
| direction, so that >98% is a harsher requirement on the share
| of incoming photons, but a laxer requirement on the photons'
| direction.
| buran77 wrote:
| Some mirrors can reflect a lot more light even if in
| narrower wavelength ranges. But that only makes the matters
| worse from a practical human perspective, when trying to
| use them on large surfaces outside. It would feel like
| staring into the Sun far too often.
| Arnt wrote:
| Which mirrors are that, and why are they made, what are
| they used for? Just giant telescopes on remote
| mountaintops, or is there more?
| buran77 wrote:
| Lasers! :)
|
| I'm talking about dielectric mirrors. Wikipedia suggests
| 99.999% or better reflectivity over a narrow range of
| wavelengths.
| Arnt wrote:
| Of course. Duh.
| cigaser wrote:
| Aluminium coating (most mirrors) only reflects between 80% to
| 90%. It reflects light in single direction. White paper
| reflects more, but scatters light in several directions.
| mrob wrote:
| A mirror reflects with specular reflection. When parallel rays
| of light hit a flat mirror they remain parallel after being
| reflected:
|
| https://en.wikipedia.org/wiki/Specular_reflection
|
| Paint reflects primarily with diffuse reflection. The rays of
| light are scattered in all directions:
|
| https://en.wikipedia.org/wiki/Diffuse_reflection
| snug wrote:
| I was going to ask this same question, thinking it would be a
| dumb question, glad this got answered! Thank you
| appleflaxen wrote:
| That's an awesome learning point; thank you.
|
| What percent of the light does a mirror reflect in a specular
| way?
| analog31 wrote:
| Like the design of paint, the design of a mirror can affect
| its reflectivity. For an extreme example:
|
| https://www.semrock.com/maxmirrors.aspx
|
| Mirrors that are a cheaper coating on glass or metal can be
| in the 95% range without too much effort. If you don't care
| about actually forming an image with a mirror, it can be
| quite cheap, e.g., plain aluminum (with whatever oxide
| forms on its surface) or aluminized mylar film.
| SamBam wrote:
| I assume this could be useful to shield something in space with
| extremely specific temperature tolerances.
|
| I'm not sure about the suggestion that people are going to paint
| their roofs with it. People already have the opportunity to paint
| their roofs with cheap white paint which would provide nearly all
| the benefits this would, and still choose not to do it.
| purple_ferret wrote:
| NYC roofs are definitely painted with reflective paint. They're
| usually silver-ish though.
| nerdponx wrote:
| Disappointingly few of them, still. It's always depressing to
| fly over an area and see nothing but black rooftops, devoid
| of anything but HVAC equipment. I know green roofs have
| engineering issues but I hope one day I will instead look out
| my airplane window and see a sea of solar panels, small wind
| turbines, and rooftop gardens.
| JackFr wrote:
| The thing is, tar is an inexpensive and excellent sealant.
| yetihehe wrote:
| Not as much benefits as their paint
|
| > Commercially available white paints reflect between 80% and
| 90% of sunlight, according to lead researcher Prof Xiulin Ruan
| from Purdue, in West Lafayette, Indiana. "It's a big deal,
| because every 1% of reflectance you get translates to 10 watts
| per metre squared less heat from the Sun," he explained.
| SamBam wrote:
| Yes, sure, but if you painted just two roofs white with
| regular paint, you're already doing much better than painting
| a single roof white with super-fancy paint.
|
| And yet it's hard enough even to do that.
| rtkwe wrote:
| White roofs don't look great which is why I think they're
| largely relegated to commercial buildings instead of
| residential ones. They get dirty fast, are super bright and
| don't fit with the traditional look for houses. On commercial
| flat top roofs they are hidden so it doesn't matter if they're
| blindingly bright or stained because they're not visible.
| bryanrasmussen wrote:
| >They get dirty fast
|
| do they get dirty fast in both humid and not humid climates?
| I would think in not humid, dry climates it might be more
| useful?
| rtkwe wrote:
| They show any dirt really clearly so for houses it's a
| crummy choice because it's not hidden on out of view (on
| most houses, if it's a modern house with a flat roof you
| could potentially use a flat white painted roof) which
| means cleaning a lot.
| bryanrasmussen wrote:
| architecturally is a non-flat roof good for dry, hot
| environments? I think I tend to associate flat roofs with
| a dry and hot environment.
| iamthepieman wrote:
| It's bad for wet environments and snowy ones. You need to
| be super vigilant about inspection and maintenance if you
| have a flat roof where I live in northern U.S. While two
| feet of snow on the roof will provide a small amount of
| insulation, every material in contact with it needs to be
| rubberized or sealed every couple of years or both.
|
| Shovelling your roof with a flexible waterproof membrane
| can lead to gouges which defeat the impermeability. And
| one small leak can go unnoticed until it has seeped into
| the visible part of the house and rotted rafters and
| supporting timbers. Drainage on flat roofs get clogged
| and need to be cleaned or you end up with standing water.
|
| A sloped metal roof will last for 30+ years without any
| maintenance. A flat roof of any type will require several
| maintenance operations a year and last half that unless
| you have a commercial tar and gravel roof which is heavy
| and imposes additional load bearing requirements on the
| structure.
| frabert wrote:
| Dust would settle on them despite of humidity levels I
| think
| Retric wrote:
| It likely rains enough in humid environments to make dust
| a non issue. Both because you get vastly less dust in the
| air and because it washes away most dust that does show
| up as long as the roof has a significant slant to it.
|
| However you don't need white to see significant benefit
| over a black roof, even just green helps.
| bryanrasmussen wrote:
| I think they mean in non-humid environments the dust
| would be an issue.
| everybodyknows wrote:
| I'm recalling a technology from 70s Southern California: low-
| slope, tar paper for water seal, half-centimeter fragments of
| broken light-colored rock scattered on top. Dust falls
| through the gaps onto the tarpaper.
|
| One downside being that after a heavy rain, some fraction of
| the gravel makes its way down from the roof.
| ebiester wrote:
| What we really need is white paint in the summer, black paint
| in the winter - reversible roofs, if you will.
|
| That said, in the desert southwest and many places in the
| world, white roofs are common. I wish it were more common in
| the southeast...
| fullstop wrote:
| Couldn't solar panels be used to achieve both benefits?
| beauzero wrote:
| If you look at old architecture in rural Georgia and Alabama.
| Houses are on rocks raised above the ground (air circulates
| underneath), 10 ft ceilings, a huge attic fan to pull cool
| air in in the evening, tall trees planted next to the house
| for shade (we have 4 pecan trees), and reflective tin roofs
| (if still shiny). This helped significantly to cooling in the
| summer. Winters aren't cold enough to warrant more than a
| fireplace in the common area. We have an old farm house built
| in the 1920's...the old original part of the house doesn't
| get uncomfortable until the temperatures outside get above
| 100. A newer part of the house with standard 9ft ceilings
| built in the 70's gets very warm and uncomfortable.
| quercusa wrote:
| Wide eaves help as well to keep summer sun off windows and
| to provide a place for a porch. A gentle rain on a tin roof
| is a sure ticket to sleep; a strong one not so much.
|
| I'd never thought about ceiling height - that makes a lot
| of sense.
| theluketaylor wrote:
| Well designed buildings for passive cooling/heating in
| the higher latitudes can also take advantage of wide
| eaves. Since the sun is lower in the sky during winter
| you can design a home with eaves that block the summer
| midday intensity but allow sunlight to flood in
| throughout the winter with some careful calculations and
| site placement. Houses built to suit their location can
| slash the amount of energy required to regulate the
| temperature.
| gerikson wrote:
| The same kind of ideas were present in bungalows in British
| India and other parts of Asia.
|
| In general I think a lot of energy savings can be realized
| by accommodating buildings to the prevailing climate, and
| using passive means of heating and cooling.
| Tade0 wrote:
| Black in the winter would make the building lose heat faster
| - especially during the night.
| dieortin wrote:
| How so? It would absorb more radiation from the sun. In
| cold European cities the roofs are traditionally black.
| goodcanadian wrote:
| Things that readily absorb energy readily emit it also.
| throwaway0a5e wrote:
| Corrugated material could provide a white surface to the mid-
| day sun in the summer and a black surface to the mid-day sun
| in the winter. Of course you'd need to take latitude and roof
| slope into your calculations but I bet if you made the
| materials in 10-deg increments you could get something "good
| enough" for most use cases. Or you could just make the
| material change color based on temperature.
|
| This is all known science but getting it cheap enough to be
| used as roofing is the trick.
| diggernet wrote:
| Oh, nice, a lenticular roof. Make it show white from summer
| sun angle, black from winter sun angle, tile roof images
| from ground level, and a "Pull Up" sign for aircraft
| overhead.
| [deleted]
| loonster wrote:
| I'm really curious about the energy savings that roof mounted
| solar provides (not including electricity that the panels
| produce).
|
| In the summer, they shade the roof keeping it cooler.
|
| In the winter, they provide an additional ventilation area
| that allows heat to escape without melting snow (thus
| mitigating risk of ice dams). Even a snow covered solar panel
| provides a benefit.
| beauzero wrote:
| There are even tax benefits for doing this in the USA.
| https://www.energystar.gov/about/federal_tax_credits/roofs_m...
| We decided to not use shingles on our new roof but go with
| silver galvalum. Galvalum does not provide the initial
| reflectivity but over a 5 year period shingles lose much of
| their reflectivity
| https://homeenergysaver.lbl.gov/consumer/help-popup/content/...
| https://web.ornl.gov/sci/buildings/tools/cool-roof/ ...there
| are many other resources out there. It made a huge difference
| in our home in rural Georgia.
| williesleg wrote:
| That's racist, why call paint white?
| [deleted]
| robomartin wrote:
| Yeah, no, 98% percent reflectance paint has been available for, I
| don't know, 30 years. I was using it about 15 years ago for a
| product that required high optical efficiency.
|
| The problem with such paints or coatings is that they don't
| perform well over time outside of a clean room environment. On a
| roof this 98% would likely only exist for 1.2 microseconds. Dust,
| dirt, aging an bird shit will make sure of that.
|
| Climate change? Oh please. Ridiculous.
| btbuildem wrote:
| White roofs are great -- just like snow, the high albedo means a
| lot of the heat energy is reflected not absorbed.
|
| But.. the ultra-white paint, on a roof? Perhaps it will be ultra-
| white on the first few days. Rain, pollution, dust, smog, and a
| myriad of other particulates (esp. in an urban setting) will
| quickly render it off-white, and bring it on par with existing
| finishes.
| toss1 wrote:
| It seems the existing finishes would also degrade along exactly
| the same curve. Starting at a higher point on the curve might
| leave this finish, in it's environmentally degraded state,
| still brighter than the other white finishes when new, and
| certainly brighter after both are exposed.
|
| Also, if this were that big a problem, it seems that solar
| panels would fail. It seems that rain often counteracts the
| pollution, dust, & smog items on your list, washing them off.
| cwkoss wrote:
| Solar panels will drop in effectiveness as they get dusty and
| dirty. They need to be cleaned periodically.
| toss1 wrote:
| Of course, and the cleaning interval depends on conditions,
| sometimes years. Similarly, windows and buildings are also
| periodically cleaned.
|
| I'm not seeing a problem here that supports GP's
| implication that the new 98% reflective paint is somehow
| rendered useless vs existing extra-bright ~85% white paint,
| which already demonstrably works. It seems that the new
| paint would work better on any cleaning schedule, up to the
| point where the pollutants fully covered both surfaces. Am
| I missing something?
| apinnes wrote:
| This would be great for a projector screen on a wall, surrounded
| by black 3.0.
| digitalsin wrote:
| Also it can't dance.
| f6v wrote:
| > "It's a big deal, because every 1% of reflectance you get
| translates to 10 watts per metre squared less heat from the Sun,"
| he explained.
|
| In the apartment I rent there's a huge 1.5x1.5m ceiling window
| for letting the sun in. In addition to huge 2m-high windows. The
| number of buildings not suitable for the present-day climate is
| astonishing.
| begun_hazardly wrote:
| Too early for this.
| [deleted]
| a4isms wrote:
| Reminds me of "anti-flash white," developed for bombers during
| the early years of the cold war. The theory was that the
| specially formulated white paint would reflect enough of a
| nuclear explosion's thermal energy to allow the aircraft to
| survive the explosion as the bomber departed the scene.
|
| https://en.wikipedia.org/wiki/Anti-flash_white
|
| It was also used on interceptors like the Avro Arrow prototypes.
| TorKlingberg wrote:
| This makes me wonder, does "anti-flash white" reflect more than
| polished mirror-like metal?
| Duralias wrote:
| Maybe not more, but different wavelengths.
|
| The Wikipedia page does say "The purpose of the colour was to
| reflect some of the thermal radiation from a nuclear
| explosion", as far as my experience goes polished metal can
| still get extremely hot.
| m463 wrote:
| wouldn't it just be different directions?
|
| A mirror would reflect light directionally, but white paint
| would seem to be diffuse.
|
| Or said in another way, seeing a laser in a mirror might
| cause retinal damage, but on a white wall you would just
| see a dot. (although probably a speckly coherent dot)
| dcanelhas wrote:
| Indeed, a friend of mine who designs playgrounds told me
| that one of her constraints is for slides not to be
| oriented such that they heat up too much from the sun.
| legulere wrote:
| The felt sensation of temperature depends not only on the
| temperature but also on thermal conductivity. With a low
| conductivity you feel less of a temperature difference to
| your body temperature. Most stuff in your apartment should
| have the same temperature, go and touch some metal objects
| and ceramic tiles or so.
| dcanelhas wrote:
| https://www.researchgate.net/figure/Spectral-reflectivity-
| of... apparently most polished metals tend to absorb quite a
| lot of light in higher frequencies (shorter wavelengths).
| walrus01 wrote:
| The E-6 Mercury is painted in anti flash white
|
| https://en.m.wikipedia.org/wiki/TACAMO
| legulere wrote:
| You wouldn't want it to be reflective in infrared though, so it
| can emit heat well into space.
| FredPret wrote:
| "We did a very rough calculation," said Prof Ruan. "And we
| estimate we would only need to paint 1% of the Earth's surface
| with this paint - perhaps an area where no people live that is
| covered in rocks - and that could help fight the climate change
| trend."
|
| LMAO me I love living in the future. This sentence could've been
| lifted from the Hitchiker's Guide to the Galaxy.
| xjlin0 wrote:
| Or, please cover Earth's surface with plant, which may already
| cover more than 1% of the surface, and can convert sun energy
| to something we can use.
| hinkley wrote:
| Heat in cities causes us to produce more heat trying to cool
| indoor spaces. You paint the roofs with this stuff.
| FredPret wrote:
| I get it, it's just a funny quote. "Paints" a rather absurd
| picture - scientists furiously painting a mountain somewhere
| Ultra-white(r) in a last-ditch attempt to cool down the
| planet.
|
| If you haven't yet read Douglas Adams, I can highly recommend
| it.
| jeffbee wrote:
| Wouldn't the reflectivity degrade almost immediately, as dust
| landed on said painted surface?
| marksbrown wrote:
| Naturally you paint a few million floating balls and throw
| them into the ocean!
| earthscienceman wrote:
| Geo-engineering is an extremely flawed way to approach the
| climate change problem, for a million reasons including this
| one.
| FredPret wrote:
| The Nazi's had an idea of launching a sun gun
| (Sonnengewehr) made of sodium metal I think. It would then
| fry the Allies with focused sunbeams. They were also on
| meth by the way.
|
| However maybe we could build a bunch of similar mirrors in
| the Earth-Sun L1 Lagrange point (reflecting light straight
| back at the Sun of course!)
| rednalexa wrote:
| I feel like it would cause some strange local weather patterns
| too if you localized all of the high albedo paint in one area.
| Would be a funny consequence, but I'm sure they've considered
| it!
| contemporary343 wrote:
| To claim this is the whitest ever is dubious. First, things like
| spectralon have existed for a while. Second, a team at UCLA
| already demonstrated a barium sulfate paint last year:
| https://www.intelligentliving.co/amp/ultra-white-paint-refle...
|
| I'm sure there's some good incremental improvements here but this
| is over the top marketing.
| djoldman wrote:
| "And we estimate we would only need to paint 1% of the Earth's
| surface with this paint - perhaps an area where no people live
| that is covered in rocks - and that could help fight the climate
| change trend."
|
| "...only need to paint 1% of the Earth's surface..."
|
| https://postimg.cc/fJ2TJHqh
| jonny_eh wrote:
| The area gets smaller if it can be somehow raised, perhaps in
| orbit? (See:
| https://en.wikipedia.org/wiki/Who_Shot_Mr._Burns%3F)
| Tade0 wrote:
| I wonder how well it reflects in the atmosphere's transparency
| window?
|
| I've been following news about materials which reflect in this
| spectrum so much, that they effectively cool their surroundings,
| but I understand that this paint, while probably less effective,
| should be much cheaper.
| jonplackett wrote:
| I'm now imaging some dystopian future where the polar ice caps
| have melted but we saved the planet by just painting all the bare
| rock white...
| lm28469 wrote:
| You can tell we collectively lost it when white paint is
| presented as a solution for climate change...
|
| You know what's big, white and help with climate change ? The ice
| caps we're destroying. We won't replace them with paint
| qwertywert_ wrote:
| Just because something sounds silly doesn't mean you should
| just dismiss it right away, cynicism doesn't really help.
| driverdan wrote:
| It's not a solution but it helps improve some of the causes.
| Painting buildings white reduces the energy needed to cool
| them. Reducing peak energy demand generated by air conditioning
| is a positive step. Peak generators use fossil fuels.
| abootstrapper wrote:
| I don't agree with your cynicism. This is a very practical,
| potentially accessible, inexpensive solution to save literally
| tons of power. It's an easy win. Let's take it and move on to
| the next area we can make gains in the fight against climate
| change.
| lm28469 wrote:
| > practical, potentially accessible, inexpensive
|
| Painting 1% of the world in white paint is everything but
| that.
|
| It's a cool gadget that will be experimented in a few niche
| places and quickly and quietly abandoned when real life kicks
| in.
|
| How often will it need to be cleaned ? repainted ? How much
| will it cost to paint your building's roof, is you building
| roof even paintable in the first place ? What is the paint
| made of exactly ? Is it going to leak in the environment ?
| How much energy/resources are needed to make/transport it ?
| What impacts does it have on a multi storey building ?
|
| Time will tell but I bet it's going to end up in the same bin
| as the "massive lithium battery breakthrough" news. /reminder
| 10 years
|
| They've been talking about this since at least 2005 by the
| way. Good old hype cycle in effect:
|
| https://www.osti.gov/servlets/purl/10172670
|
| https://www.bbc.com/news/10333304
|
| http://archive.iwlearn.net/unep.org/paint4planet/default.htm
|
| https://www.theguardian.com/environment/2009/jan/16/white-
| pa...
| abootstrapper wrote:
| Presumably most buildings are painted. My house for
| example. If painting it white saves %10 of my energy costs
| in the summer, how is that anything but a net positive?
| BTW, I'm in the market for a new roof. I'm going white
| painted metal.
|
| Are double pane windows, solar panels, and insulation also
| gadgetry hype?
| adrian_b wrote:
| You raise some valid concerns, but this cooling paint has
| far more chances of being applied in reality than any of
| the "breakthroughs" you are alluding to.
|
| There are really no disadvantages of using this as a white
| paint.
|
| Barium sulfate is abundant and the cost of a paint based on
| this pigment should be very similar to the cost of the
| current titanium white based paints, once the pigment is
| produced at industrial scale using the process developed by
| this team.
|
| There are no environmental concerns, because barium sulfate
| is as inert as titanium dioxide. Actually there are various
| living beings which use barium sulfate as a bio-mineral,
| instead of the more frequently used calcium salts, like in
| our bones.
|
| So both in cost and environmental properties and also in
| maintenance properties the proposed white paint should
| match the currently used titanium white paints, with the
| difference that it can ensure that any painted surface
| exposed to solar light is cooled instead of being heated.
|
| Only this will certainly not be enough to save the world,
| but it will certainly be a useful product.
| zipotm wrote:
| Combine it with vantablack, will be cool!
| sdwvit wrote:
| https://www.peachpit.com/articles/article.aspx?p=2449031&seq... I
| was wondering how is white the most reflective color, since there
| is also a thing called silver mirror
| khazhoux wrote:
| Interesting times for new paints. This, vantablack, and that
| amazing new blue pigment a few months ago:
|
| https://www.smithsonianmag.com/smart-news/first-blue-pigment...
| JoshTko wrote:
| Won't this rapidly lose reflectively anyway on top of any city
| building due to soot/dirt? Lowering cost or increasing durability
| probably matters far more for reflecting sunlight using white
| paint.
| makotoNagano wrote:
| you can consider it the same as solar panels, which need
| periodic cleaning to maintain high performance
| qart wrote:
| While Vantablack is blacker, it is not all that usable. For
| example, it can't be used for clothing. IR flock sheet is better
| for general use: https://www.youtube.com/watch?v=N9VaJKIO1JA
| chatman wrote:
| This is a racist paint.
| tediousdemise wrote:
| I bet this would look fantastic mixed with some vantablack, for
| the greyest grey achievable.
| m463 wrote:
| I think what might be interesting is like two-sided louvers
| over your roof. black on one side, white on the other.
|
| Flip from one side to the other to help maintain temperature by
| absorbing or reflecting sunlight.
| driverdan wrote:
| You joke but it's interesting to think about what mixing them
| or mixing their components would do.
|
| Mixing them as-is would ruin the effect of Vantablack. Since
| carbon nanotubes are black you probably would get a boring grey
| color with a gloss surface due to barium sulfate.
|
| I'm curious what the effect would be if you coated Vantablack
| with barium sulfate. A highly reflective surface with an
| extreme black paint underneath.
| gbolcer wrote:
| My next model rocket is vanta and superwhite. No room for
| shades of grey. :-)
| khazhoux wrote:
| "The paint mix, named MegaGray, reflects a jaw-dropping
| 50.000001% of sunlight."
| mealkh wrote:
| Or the most extreme zebra.
| eatingCake wrote:
| The most jarring Dazzle camouflage[1] imaginable.
|
| 1: https://en.wikipedia.org/wiki/Dazzle_camouflage
| godelski wrote:
| Honestly I want to see this. Would your head hurt seeing it
| in person? Or would your eyes balance it out
| layer8 wrote:
| The next step is using the combination in e-ink fashion, so
| that you can smoothly regulate the thermal profile as needed.
| godelski wrote:
| You could probably more easily do this with just a flat
| surface that you can rotate. Smaller the squares the better
| uniform distribution you can get but if you don't have those
| strict requirements then why go super small (e-ink)?
| Turing_Machine wrote:
| You could probably use a scaled-up version of the cable
| mechanism used in mini-blinds.
| tediousdemise wrote:
| Genius. Just imagine.
|
| _Honey, it's going to be -27degC (-16.6degF) tomorrow, can
| you turn the reflectivity to 0% after brewing the coffee?_
| polishdude20 wrote:
| Pretty fly for a white dye
| the8472 wrote:
| If the goal is to keep buildings cool you don't want your paint
| to be as reflective as possible in the whole solar spectrum. You
| want it to have a low reflectivity (thus high
| absorption/emissivity) in the infrared window[0] where you'll
| emit more into space than you'll absorb and high reflectivity in
| the rest of the spectrum.
|
| [0] https://en.wikipedia.org/wiki/Infrared_window
| ping_pong wrote:
| It won't get reflected back into space. It will get reflected
| back to us because of the Greenhouse effect, and it will just
| keep warming us up. We need to have solar panels to convert
| that into electrical energy.
| com2kid wrote:
| Better article over at https://phys.org/news/2021-04-whitest-
| hereand-coolest-litera... says that lots of energy saving
| paints already reflect tons of IR, a large portion of their
| (incremental!) improvement over previous paints in this area is
| specifically because they expanded the range of wavelengths
| that are reflected.
| the8472 wrote:
| Ah, great. Paper with an emissivity graph:
| https://arxiv.org/abs/2011.01161
|
| Without that you can't really judge the news article.
| ArcturianDeath wrote:
| OMG, can these so-called "scientists" read the room and realize
| this isn't what we need right now. Its only furthering a culture
| of supremacy
| jessepinkman wrote:
| finna be kanselled cause we live in 2021
| thesuitonym wrote:
| Is Anish Kapoor allowed to buy it?
| irrational wrote:
| So, now we have the blackest black paint
| (https://mymodernmet.com/stuart-semple-black-paint/) and the
| world's whitest white paint. There must be something cool we
| could do with the two of these.
| nicbou wrote:
| What happens if you mix them?
| goda90 wrote:
| What we need is a paint that turns white when air temperature is
| high, and black when air temperature is low to reduce our heating
| and cooling needs.
| devenson wrote:
| Though black surfaces radiate energy more easily due to higher
| emissivity, and white radiate less due to low emissivity. So
| the benefit may be less than you think.
| buran77 wrote:
| Notably, the benefit may be "less" than expected but for all
| intents and purposes any building or vehicle painted black
| will be consistently warmer than the equivalent in white.
| Unless your item is built for purpose it's highly unlikely
| painting something black will make a visible difference in
| the cooling rate compared to the white one, at least not in
| conditions that might be relevant for our discussion.
| icedistilled wrote:
| "Darker materials also emit radiation more readily than light-
| colored materials, so they cool faster."
| hinkley wrote:
| Only if they are warmer than their environment and don't have
| a huge influx of radiant energy incident on their surfaces.
| dejj wrote:
| Also: Black 3.0, the purchasable variant of Vantablack
|
| For sale at: https://www.culturehustleusa.com/
| cyberlab wrote:
| That's a great site. Thanks for the share.
| walrus01 wrote:
| see also, color manufacturers that will sell to anybody who
| ISN'T Anish Kapoor
|
| https://www.dezeen.com/2017/07/07/anish-kapoor-banned-from-u...
| nerdponx wrote:
| I know this is such a small microcosm of the world, but I
| really love to see, just once in a while, that someone with
| power uses their power for the greater good and not for
| selfish benefit (realistically "we won't sell to Kapoor" is a
| marketing spin but it's still a risk and a strong statement).
| JKCalhoun wrote:
| FTA:
|
| > In response, UK-based artist Stuart Semple created a
| pigment that he claimed to be the world's "pinkest pink" and
| made it available to purchase on his website for "everyone
| but Anish Kapoor".
|
| I love artists.
| ceejayoz wrote:
| He managed to get his hands on some.
|
| https://www.instagram.com/p/BOWz73wgj7R/
| madaxe_again wrote:
| I wonder if you could use this with the white paint mentioned
| to make crookes radiometers capable of doing useful work.
| Timshel wrote:
| Nice they have a White 2.0 too since last year (up to 99.6%
| reflective). And as with Black 3.0 banned for Colour criminals
| ;).
| kube-system wrote:
| Of which, the picture of on the home page has clearly visible
| white text over it.... :D
| skykooler wrote:
| If that's 99.6% reflective, how is this new paint the whitest
| ever at only 98%?
| loonster wrote:
| Could be the spectrum that its tested under. Maybe the
| 99.6% is visible light and the 98% is all energy from sun.
| If that's the case, the 98% is much more impressive.
| tux1968 wrote:
| From the thermal imaging results given in the article,
| i'd say your conjecture is correct.
| [deleted]
| robocat wrote:
| Colour criminals are defined as:
|
| WHY ARE THE COLOUR CRIMINALS BANNED?
|
| Anish Kapoor & the creators of Vantablack for hoarding the
| material and for generally being rotters.
|
| Dupont for the imprisonment of tech consultant Walter Liew
| for espionage, after he stole and sold blueprints for their
| secret titanium white process for over $30million.
|
| T-Mobile & its parent company Deutsche Telekom for claiming
| magenta as their own and suing small businesses for using it.
|
| Scientists at ISIS Neutron and Muon Source who are in the
| process of investigating polar bear fur, insect scales and
| fathers for industrial and commercial applications.
|
| 3M for their ownership of Canary Yellow.
|
| Daniel Smith, for buying up the last reserves of quinacridone
| Gold pigment in the world, so that only they would be able to
| sell it to artists.
|
| https://www.bloomberg.com/features/2016-stealing-dupont-
| whit...
|
| https://sandrinemaugy.com/2018/04/30/the-final-batch-of-
| quin...
| spiritplumber wrote:
| Finding a commercial use for polar bear fur is awesome,
| actually. It would ensure that polar bears never go
| extinct.
| legulere wrote:
| Like how elephants were greatly reduced in numbers to
| make billiard balls?
| dheera wrote:
| I tried it. It's not that black at all. My regular black
| T-shirt was blacker than a piece of cardboard I painted with
| Black 3.0. Super disappointing, to say the least.
| Applejinx wrote:
| Your T-shirt's a 3d structure with microfibers. I'm not
| surprised it was able to be more black than a hard surface:
| fabric's actually a really good way to make an intense black.
|
| The Culture Hustle blacks are also matte, which is very much
| a limiting factor (and part of the concept). I find if you're
| willing to accept highlights, super gloss black is way better
| at being super black everywhere that isn't a highlight. At
| that point you're trying to get the most localized highlight
| as possible, to get it out of the way so everywhere else can
| look blacker.
| atVelocet wrote:
| Ne Joke: Use it on something you prepared before (eg sanded
| down). And use Black 2.0 as a primer. Results are way better
| neurostimulant wrote:
| Maybe it was applied wrong? The website mentioned that porous
| materials must be sealed first before spraying with black
| 3.0.
| dheera wrote:
| I did prepare it with Black 2.0 first.
| whalesalad wrote:
| Neat. I was wondering if you could buy that stuff. There are
| trim pieces in my car I want to paint with it to eliminate
| reflections in the cabin.
| space_ghost wrote:
| Can I get in on that action? I don't understand why
| instrument cluster bezels are universally chromed but I hate
| it and my eyes hate it and I'd really like to look at my
| gauges without getting blinded.
| whalesalad wrote:
| Hah, yep, same situation on both my Ford vehicles.
|
| I think I'll end up removing the trim, masking the pieces I
| dont want to paint, and then hitting the chrome with
| Plastidip spray. It's an aerosol can that contains a
| rubberized coating. It comes out looking like a matte
| finish paint but it can be peeled off of most surfaces so
| it's not permanent.
| teh_klev wrote:
| Sadly, from their FAQ[0]:
|
| _Q. Can I paint my car / bike etc..._
|
| _A. NO - 3.0 is quite fragile and will just scratch off,
| it won't weather well._
|
| _Q. Can I put a topcoat over it then?_
|
| _A. NO that will destroy the matte effect, and many
| topcoats (including our COAT) will react with the paint and
| ruin the finish._
|
| https://culturehustle.com/collections/black/products/black-
| 3... (it's on the right hand side a few scrolls down the
| page)
| tux1968 wrote:
| Should be okay inside the car though...
| dheera wrote:
| Not sure if it's okay in high temperatures though. When
| the air temp in the car can go as high as 60 C, black
| surfaces can go as high as 80 C or more.
| jedberg wrote:
| I want to paint my roof in this ultrawhite paint and then put a
| water tank on the roof and paint it with Vantablack.
| imglorp wrote:
| When can we get rid of black, solar absorbing, fragile, asphalt
| roofs? They should all be sheet metal painted white.
| faceplanted wrote:
| But I live 55 degrees north :o
| nvahalik wrote:
| Yeah it's white but does dust and debris still stick to it?
|
| If it does, it'll only be really effective until the next
| cleaning... and then probably just as good as plain white paint.
| adrian_b wrote:
| They said that they have used an acrylic binder, so this white
| paint should behave like any other acrylic paint, so it should
| need periodic cleaning.
|
| What is novel is that they have discovered some new method for
| preparing the barium sulfate pigment and mixing it with the
| binder, which allows very small pigment particles, possibly
| having a certain form, and also a very large ratio between the
| quantities of pigment and binder in the paint.
| adrian_b wrote:
| Now I have read an earlier version of this paper, which is
| freely available:
|
| https://arxiv.org/abs/2011.01161
|
| The main points are:
|
| 1. The more common white pigment titanium white is not good
| for cooling something exposed to sun, because it strongly
| absorbs ultraviolet light. (Besides generating heat, this
| ultraviolet absorption also causes photo-chemical reactions
| that degrade in time the organic paint binders.)
|
| 2. So they have chosen barium sulfate, which reflects not
| only visible light, but also ultraviolet and near infrared.
|
| 3. Barium sulfate not only reflects solar light, but it also
| emits efficiently in the far infrared, which cools the
| painted surface.
|
| 4. Barium sulfate was traditionally considered a worse white
| pigment, because it has a lower refractive index than other
| pigments, like titanium white.
|
| 5. The Purdue University team has overcome this disadvantage
| of barium sulfate by designing a manufacturing process for
| the pigment that not only ensures a very small average
| pigment particle size but also a broad distribution of the
| particle sizes, which results in good reflection properties
| over the entire solar spectrum.
| dredmorbius wrote:
| Right.
|
| The notion of painting roofs white to increase albedo is an old
| one (look up "Whitecap", which I was familiar with about 30
| years ago). And the practical limit is of behaviour in the
| environment: dirt, grime, damage (hail, wind, birds, insects,
| ultraviolet light, etc.). It's unlikely that a "whitest white"
| substance will _also_ be optimised for those characteristics.
|
| But a durable, easily-cleaned, reflective surfacing material
| could prove useful.
|
| It's all but certain that the actual applications for this
| material _won 't_ be as roofing. At least not for standard
| construction.
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