The problem with white and yellow is that they tend to attract bees, and without a flamethrower I’m completely defenseless against them.
I wish I had seen this at the beginning of Summer and the foreknowledge of what I would see walking around southern California all summer. I would print this out and hand it to every idiot I see wearing black on scorching sunny days. A majority of people walking around wearing black all summer! What is going on? Black is apparently in style lately because the world is falling apart & everyone is miserable
but are people this uneducated? White reflects light & keeps internal temperatures down! Black does the exact opposite! 🤦🏼♀️
Bedouins wear black robes, the guardian did some tests and they found out the amount of heat the wearer is exposed too is the same with black and white robes.
Taylor, Finch, Shkolnik, and Borut measured the overall heat gain and loss suffered by a brave volunteer. They described the volunteer as “a man standing facing the sun in the desert at midday while he wore: 1) a black Bedouin robe; 2) a similar robe that was white; 3) a tan army uniform; and 4) shorts (that is, he was semi‑nude)”.
Each of the test sessions (black-robed, white-robed, uniformed and half-naked) lasted 30 minutes. They took place in the Negev desert at the bottom of the rift valley between the Dead Sea and the Gulf of Eilat. The volunteer stood in temperatures that ranged from a just-semi-sultry 35C (95F) to a character-building 46C (115F). Though he is now nameless, this was his day in the sun.
The results were clear. As the report puts it: “The amount of heat gained by a Bedouin exposed to the hot desert is the same whether he wears a black or a white robe. The additional heat absorbed by the black robe was lost before it reached the skin.”
Bedouins’ robes, the scientists noted, are worn loose. Inside, the cooling happens by convection – either through a bellows action, as the robes flow in the wind, or by a chimney sort of effect, as air rises between robe and skin. Thus it was conclusively demonstrated that, at least for Bedouin robes, black is as cool as any other colour.
Depending on of the fabric and how tight it is to the body black can keep you as cool.
This study paid for by The Bad Guys ™️
But seriously
The additional heat absorbed by the black robe was lost before it reached the skin."
Thick multi-layer robes.
A different effect than single-layer black t-shirts & casual apparel that westerners wear. Returning our focus to OP’s diagram.
I feel like this is incomplete because the pigments could change the long wave emissivity of the shirts and affect the ir measurement.
NEEEEERD
They see me mowin’
My front lawn
I know they’re all thinking I’m so
and nerdy
It’s crazy how much hotter the “almost white” is compared to the actual white
There is no scale, maybe it’s just 0.1 degree
This guy sciences
yes, but because I’m fat, the loose clothing provides updrafts as my sweat evaporates…
is what I tell my metalhead/goth fat ass.
The study is a little old, but this is why Bedouins wear loose black clothing in the desert.
That is pretty cool. We should have seen a robe trend on golf courses around 2012. It’s too bad we didn’t, it would have been funny.
The results were clear. As the report puts it: “The amount of heat gained by a Bedouin exposed to the hot desert is the same whether he wears a black or a white robe. The additional heat absorbed by the black robe was lost before it reached the skin.”
Bedouins’ robes, the scientists noted, are worn loose. Inside, the cooling happens by convection – either through a bellows action, as the robes flow in the wind, or by a chimney sort of effect, as air rises between robe and skin. Thus it was conclusively demonstrated that, at least for Bedouin robes, black is as cool as any other colour.
Interesting 🤔
P.S. I like how my dumbass just kept reading and got confused why Bedouins eat bones.
Black still isn’t a bonus in that case
“Black, it’s cooler than green” ~marketing
They need to add heater packs underneath and thermocouple readings. While white is good at rejecting external thermal radiation, it is also poor at emitting thermal radiation. A white surface can be hard to keep cool if the heat comes from within. In particular, white will look like it has a much better comparitive advantage when imaged in IR than is likely to be the case in real usage conditions.
Yellow, red, and gray may be more comfortable in practice.
But most heat we reject isn’t rejected radiatively, so you need a sweaty heater pack for a better test. You’re right that the clothes will also affect how well the person underneath removes heat, a confounding variable, but pigment alone might be a small part compared to weave and fiber choices
I’m not convinced about the “black makes you look slimmer” part.
Black does make you look tougher though, dark colours do subconsciously.
red is doing pretty well, and I’m surprised with the other colors
I assume because of infrared reflectivity. I wonder if there are black fabrics with high IR reflectivity. I can find paints/pigments, but nothing obvious for fabric.
Tone also plays a factor. Light green vs a dark green. So it’s not just the color itself.
Neat spectoscopy experiment. Notice how yellow is not receiving the heat? It’s because the atmosphere is refracting/absorbing it because “yellow sun.”
The one perk of black is the sweat might get evaporated by the shirts light collection.
Lol, yesterday was (hopefully) the last t-shirt day this year.
What this neglects to show is the amount of time different colors retain that heat.
It’s not just the absorption, I heard black dissapates heat faster than other colors for instance. And how much you feel that heat has the most to do with how loose your clothing is.
That’s not measuring body temp, it’s measuring the heat radiating off the shirts. The fact white isn’t radiating heat off the shirt means that if you are inside the shirt producing heat then it’s not letting your heat out
No
It means white is not absorbing the heat so it doesn’t radiate as much. White reflects the heat while black absorbs it. The more you absorb the more you radiate.
If what you said was true the heatmap would be even across the shirt. It isn’t
Or the manequin holding up that shirt in the sunlight doesn’t have as much heat to give off as the others do because the lighter shirt reflected more heat away prior to that.
I’m not aware of any heat-trapping properties of the colour white, other than it’ll reflect visible light. Though I think how it handles IR and UV light might be more relevant than visible. Like would a black shirt that reflects UV light well feel cooler than a white shirt that doesn’t?
I’m not aware of any heat-trapping properties of the colour white, other than it’ll reflect visible light.
It reflects emr in the visible spectrum. It probably reflects emr slightly beyond the visible spectrum too, like infrared. Then you make a tube out of it and put a hot body in the tube. It will reflect the war back at the body.
Ok yeah, you’re right that that is a factor. Though when in direct sunlight, the amount of heat reflected will be much more significant than the amount trapped. But it could be more significant in low light situations.
That doesn’t make any sense, sure it will reflect slightly more heat from your body back inside but that is negligible because the vast majority of body cooling happens due to convection and/or evaporative cooling and/or “contact cooling” depending on heat/humidity/how loose your clothes are. Radiation plays very little effect in that cooling.
Basically consider this: your body is emitting black-body radiation at 310K, and the sun is emitting black-body radiation at 6000K (+ a bunch of other radiation coming from all the fusion happening inside). Which one is a more important factor when you’re deciding the reflectivity of the shield between yourself and the rest of the universe?
It depends on whether you’re standing in direct sunlight for extended periods of time or not. Generally, staying in direct sunlight for extended periods of time is going to do so much to you that the albedo of your shirt isn’t going to really do too much.
I have a black long-sleeve and a white long-sleeve which both promise SPF-50 (I don’t really trust them fully but they do seem to work well enough). The black one definitely feels hotter in the sun.
Basically it’s either ambivalent (if you’re not in direct sunlight or the clothes are thick and loose so they don’t transfer most of the absorbed heat to you) or white wins.
Grey all day
