OT Anybody seen the articales about the ultra white paint?

The John Doe troll stated the following in message-id <sdhn7c$pkp$ snipped-for-privacy@dont-email.me:

And the John Doe troll stated the following in message-id <sg3kr7$qt5$ snipped-for-privacy@dont-email.me:

And yet, the clueless John Doe troll has itself posted yet another incorrectly formatted USENET posting on Sat, 30 Oct 2021 08:10:34 -0000 (UTC) in message-id <sliulp$sgs$ snipped-for-privacy@dont-email.me.

XrJJ/PaAht1O

The John Doe troll stated the following in message-id <sdhn7c$pkp$ snipped-for-privacy@dont-email.me:

And the John Doe troll stated the following in message-id <sg3kr7$qt5$ snipped-for-privacy@dont-email.me:

And yet, the clueless John Doe troll has itself posted yet another incorrectly formatted USENET posting on Sat, 30 Oct 2021 08:13:39 -0000 (UTC) in message-id <sliuri$sgs$ snipped-for-privacy@dont-email.me.

DfTOyg4Bf8AU

Martin Brown <'''newspam'''@nonad.co.uk> wrote in news:sljg52$1c3h$ snipped-for-privacy@gioia.aioe.org:

It may be an otientation thing. With vanta black, the nanotubes are grown (applied) like a forest of trees all pointing perpendicular to the surface to which it is applied, and long enough to trap photons that "enter" the tubes. Supposedly, they now have something "even blacker" called "musou".

On the white side, however, it has to be about the reflection of a broad spectrum of visible light and IR light. I would think them quite emissive in the IR, just like water at like 0.98. But therein lies the crux of the matter. The Death valley lake bed is pretty white, but the photons likely reflect further into the medium like in the vanta black case. Some gets radiated as white reflected light, but a lot gets absorbed because the medium is a flakey surface. These white paints must have a property of the pigment particulate that reflects the light, but has no transparency to allow any to be absorbed, and the particle size might be a factor as well as that would play into the final makeup of a "paint layer". The binder used as well. There are some pretty white silicone rybber (RTV) High voltage potting mediums... I wonder how a half inch thick mat of that would work as a roof material.

I'll bet they do. Remember what a few industries did to hemp and cannabis back in the '30s and it has affected the economy and culture of the nation since? I remember. They asked La Guardia to do a study on the affects in the NYC school system and his report came back stating there was no detrimental effect. It wasn't the answer they were looking for so it and then LaGuardia got buried, and it was never considered as they plastered cannabis as some great evil. They grow thousand acre fields of it in Sweden so closely spaced that they fight for the sun to 14 and 16 foot heights of the strongest plant fiber known to man. They then take it and make a particle board building sheet material that has a higher R factor than pine chip based particle boards AND hemp grows two feet per month and pine only grows two feet per year and yields far less per acre.

The seed meat is second only to soy in protien content and has the highest omega 3 *and 6* content of all. Beats coffee, covfefe, chocolate, fish oil... all of it. Could feed s the world's unfed masses with it, but NOooooooo! The US even went so far as to demand and get every UN member nation to draft anti cannabis laws. In other words, the idiotsin this nations morphed the cultural complexion of the entire planet with their agendas. Oh... right... what's new?

And they still push back against it. It should not even be on schedule 1. Do 50 million Americans look like they are in a narcosis to you (well some do but it ain't from pot)?

Oddly enough, that is exactly what they said in the video, the paint emits more heat than it absorbs and cools the surface below ambient! My understanding is the coefficient in the two directions MUST be the same and a difference violates the laws of thermodynamics. Otherwise an object could potentially cool itself and allow the production of energy from nothing other than a heat sink *at the ambient temperature* no matter what that temperature is!

I believe you are over thinking the problem. A large percentage of the heat reflected (is that the right term?) from such surfaces will be directly into space. Use an IR thermometer on a clear sunny day and you will read the sky as a very low temperature. That's the heat sink for these surfaces. So maybe that's why they don't violate the laws of thermodynamics, the surrounding air is only part of the ambient. In the IR range the ambient is as much space as anything.

Rick C snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

If a photon reverses direction would the term not be called reflection? However, if a surface and therefore underlying medium captures a photon and those emitted back out are spawned from the medium itself it would be called a radiator not a reflector.

Absolutely not. The atmosphere attenuates IR. That means it is the resistor making heat from the 'work' of the Sun's incoming, bombarding rays. That is how the Earth warms its atmosphere. Some of that atmospheric warming comes from heated ground surface too, so ground IR emission, even if perpendicular does not "go directly into space". But you knew that... one would think.

That also means that anything we reflect back up ALSO has to pass through that same medium on its way back out. It is spectrum dependent too. Some frequencies pass through the air better than others.

IR starlight in space even gets obscured by gas clouds in some bands while others pass right through. The JWST is ALL IR spectrum. Not a visible light telescope at all. See dem Gold mirrors? But the shield inder it will always face the Earth as even that "dark side" residual heat would interfere with its imagery gathering.

It is at the pad and will be getting shot pretty soon.

Check it out sitting in the largest (and cleanest) clean room in the world. (single room, not some chip fab factory floor).

You missed the good part. Ricky just proved that colored objects can't exist.

NIF is bigger and cleaner.

Typical Larkin. He doesn't really explain what he means and is also very snarky. I must have offended him very badly at some point. Most likely I tripped him up while he was espousing his typical BS.

Actually, it is a complement that he will only respond to my posts through third parties. He is clearly intimidated by anyone capable of showing he is full of it. He much prefers to troll those with poor debating skills.

snipped-for-privacy@highlandsniptechnology.com wrote in news: snipped-for-privacy@4ax.com:

That's racist!

snipped-for-privacy@highlandsniptechnology.com wrote in news: snipped-for-privacy@4ax.com:

Boom Shaka Laka Laka! |...........................|...........................| Billionths of a second.

This "lab" is pretty cool too... Nice hi res image to put in your collection.

Rick C snipped-for-privacy@gmail.com wrote in news:a96495c8-8790- snipped-for-privacy@googlegroups.com:

You are having this habit of popping off insults.

I guess that constitutes "good debating skill".

My son-in-law (one of them) works at Sandia. He won't tell me what he does.

He has a PhD in Engineering Mechanics, but it's an insult if anyone calls him a mechanical engineer.

snipped-for-privacy@highlandsniptechnology.com wrote in news: snipped-for-privacy@4ax.com:

medium

The mechanics of engineering are different than mechanical engineering.

He tells the engineers of more than one discipline what direction to go. :-)

He is the Devo of engineers...

Pretty good reference for pre-screening type gun control. :-)

Just reporting the fact...

Sounds like a computer scientist. ;)

Cheers

Phil Hobbs

(Who just acquired a son-in-law, and is pretty jazzed about it.)

The John Doe troll stated the following in message-id <sdhn7c$pkp$ snipped-for-privacy@dont-email.me:

And the John Doe troll stated the following in message-id <sg3kr7$qt5$ snipped-for-privacy@dont-email.me:

And yet, the clueless John Doe troll has itself posted yet another incorrectly formatted USENET posting on Sat, 30 Oct 2021 20:44:37 -0000 (UTC) in message-id <slkarl$ihc$ snipped-for-privacy@dont-email.me.

AoE5aR/7hXeA

The John Doe troll stated the following in message-id <sdhn7c$pkp$ snipped-for-privacy@dont-email.me:

And the John Doe troll stated the following in message-id <sg3kr7$qt5$ snipped-for-privacy@dont-email.me:

And yet, the clueless John Doe troll has itself posted yet another incorrectly formatted USENET posting on Sat, 30 Oct 2021 20:44:59 -0000 (UTC) in message-id <slkasb$ihc$ snipped-for-privacy@dont-email.me.

sNypNtSlMRfL

That is because your understanding of thermodynamics is superficial and inadequate to understand what is going on here. The painted surface is in thermodynamic equilibrium with the air around it, ground below it and the sky and sun above it.

Sun overhead is about 1kW of incident radiation per square metre. If it reflects 98% of that back then it receives 20W of thermalised heating.

Outgoing thermal emissivity is determined by its properties in the thermal band IR 5-20um where it has almost perfect emissivity(*). The outgoing thermal radiation carries away more then the 20W that it absorbs from the sunlight so it cools by radiative transfer in direct sunlight. Designer metamaterials can do even better.

(*) in that waveband almost anything that isn't shiny metallic is a very good approximation to a black body.

The snag is that the surface has to be kept scrupulously clean to maintain these properties (which might be possible in a laboratory) but is never going to happen in a desert. Once there is a thin layer of desert dust on its surface the properties of this magic paint will be indistinguishable from any other white paint. It is also likely to be incredibly fragile according to my paint technologist since the only way they can get BaSO4 to behave like this is to have almost no binder.

Kirchoff's law applies for every wavelength it can absorb and emit but on a per wavelength basis. That is fundamental to what is happening.

You haven't understood the system. The painted surface is in equilibrium with one sun 6000K as a disk 0.0001 steradians and 2pi-0.0001 steradians of clear sky at ~200K (effective) and underneath it 2pi ground at 330K. Clouds if present would be ~270K.

It is also in equilibrium with the any reflected sunlight and thermal radiation from the ground and the rest of its environment at ~330K. The ambient air carries comparatively little heat energy to it.

The crucial thing here is that in the thermal band IR at relevant Earth like temperatures almost every common material that isn't shiny metallic is almost black. A few plastics and fabrics are somewhat transparent.

John Doe snipped-for-privacy@message.header wrote in news:slldur$t69$5@dont- email.me:

F*ck off and die, retarded troll putz.