@@itoibo4208 Yes, In order to cool off you have to transfer heat that is made in the body to the environment. If most of the heat is coming from one direction you want to block the transfer by wearing something reflective like white or silver. In the other direction though black wins as it can absorb and radiate more energy.
I have worked outside in the heat (90-105) a lot from jobs before. The biggest difference in being hot or cool is the material. It's far cooler to wear light breathable material with long sleeves to keep the sun off but allow sweat to evaporate. I started wearing t shirts but learned that things like light hooded joggers made me feel coolest. The color didn't matter.
@@westonding8953 I think it would have more to do with sweat evaporating. In a humid climate that would matter much less since the air is already very saturated so the fabric matters less. In dry air, that compensates for any color difference by a lot, but in a wet environment the color probably wins out. My guess.
You also have to consider, in general, the _non-linear spectral response_ of different materials and coloring agents. Some materials which are black in visible light are white in infrared, and vice-versa. That can have an extremely profound effect upon the observed affect.
@@arvana Infrared is the only one that really matters for this discussion. I think their point is that you may be surprised to find that some material you thought was white (because it reflects the visible spectrum) actually absorbs infrared
@@ericwazhung AFAIK, yes you are supposed to calibrate IR cameras for the emissivity of the object you're measuring. I would expect if you got the three bottles to be the same temperature, the black bottle would be (incorrectly) reported as a hotter temperature than the others
Some white objects, especially white paints and plastics, can have high emissivity (high absorptivity) despite their color. Look for tables showing emissivity of different substances - the higher the emissivity the more absorptive.
Fun fact: navy/dark blue is the best color to wear in the sun because it has the best balance of UV-absorbing qualities while not warming up as much as black. Maybe the UV aspect is one reason the Bedouins like to wear black because it helps protect them from sunburns better than wearing white!
This makes sense. I live in Israel, and navy blue is by far the most popular color among Orthodox Jewish women. The poor guys are stuck wearing heavy black coats.
@@pigeonlove often the black is a blue. its just very dark indigo. you see this on rugs too, what looks like a black is just very dark blue, and with age it softens in tone. another way to know is moths, they love indigo dye, madder too, they won't touch chrome black chemical dye, so if you see an old yurt, the moth damage is only on some colors. rugs too.
@@YochevedDesigns lol that's more like.. about.. Back then, people make the violet color like something that so expensive. Like.. Royal color thing. It's either from indigo plant or the lapis lazuli. Only for rich people. About the beduin, they're the ones that do that for practical purpose. About jewish blue, it is purely about the ancient dumb belief about violet-indigo-blue color thing Not just jews that believe in that. It's also ancient egyptian and roman empire. That's why u can see so many drawings in egyptian stuff that use the violet-blue color
The black clothes are seriously the weirdest and coolest thing I've ever seen. I kinda want to make my own and go walking town, day and night. It's like the deepest, darkest shadow ever walking around.
2:33 I love how casually you say "it's about 45 degrees" 🤣 I was thinking in Celsius and my reaction was "wow he's taking that rather well. He's in his element, unperturbed"
my experience (mostly outside deserts) is quite different when wearing single layer blacks feels significantly warmer, sometimes even feels hot like sunbathing even if it's cold outside when there's no wind
The basic gist is that the clothing in question works because it's heavy, layered, and loose, and is a robe, so it basically promotes airflow across the body, and draws away the excess heat while accelerating evaporative cooling.
@@seigeengine yes, if you have a tight black shirt on, it will absorb a lot of heat, and release it into your body. If you have a flowing black robe, it will absorb a lot of heat, but release it into the air.
In the Jurassic Park novel one character asks Ian Malcolm why he would wear black clothes to a tropical island, and he answers back questioning whether they understand black body radiation. I always enjoy those little scientific asides in Crichton's books.
I'll probably be proven wrong later, but TheActionLab is one of the TH-camrs still with a sense of honor. I respect him for putting sponsors at the very end. an advertisement is more efficient when the viewer doesn't feel punished.
I appreciate it but there's nothing wrong with people who use midroll sponsorships, you can just fast forward past them and some sponsors probably require it or pay more for it.
Interesting. I lived in the tropics for several years and dark was always terrible to wear. My wardrobe became all light colours. So from my experience I would say if the fabric is the same, then a lighter colour is definitely cooler when in the sun.
"It depends... on literally everything." Are you exposed at short periods? Do you pass by reflective materials like sand or water? Have you measured it or is a feeling? Does lighter clothes make your eyes color pop and bring that extra zing?
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I have experienced a major difference in temperature when wearing different color latex gloves. Maybe it's because Latex gloves are in direct contact with my skin, that I feel the black gloves instantly heat my hand when in the sun light opposed to white gloves. Maybe that's why the difference between black and white loose clothing doesn't matter too much. Have someone put a black and white glove on your hands while not looking and walk out into the sun. Because of the skin tight contact, you'll guess which hand has the black glove.
He's definitely messing up the actually relevant info. The bedouin clothing in question achieves this effect because it's loose, thicker, sometimes layered, and promotes airflow across the body. This makes the external temperature and therefor color largely irrelevant. It doesn't apply to tightly fitting, thinner, single-layered or more conventional modern clothing. He also contrasts two entirely different outfits, which really makes him appear a clown.
Neat Steve. A windproof black jacket will warm faster in the Sun. The wind won't cool you as fast. I like to hike in winter and if there is Sun, I wear black water/windproof jackets so the Sun warms me up and my warmth holding sweater under the outer jacket, dark clothing is good in winter!
wouldn't it make sense in cold places to still have it black outside, but white inside, and in hot placed the other way around? I even heard of white paint used to buildings to reflect the sunlight
I don't think layering the colors actually does anything. It seems like it would at first, but when you think about it, it shouldn't actually matter. White buildings are generally better because they change temperature slower. They heat up slower in the day and cool down slower at night. Generally speaking you don't want living spaces to experience large swings in temperature. It's important to remember, however, that things like buildings (or people) don't only exchange heat through emission and absorption of radiation.
Working evening and overnight shifts for most of my life, it was impossible to not notice that darker cars got frost on them before lighter cars, and of course, the frost melted on dark cars first in the morning. I’ve heard that painting exhaust headers on race cars white lowered the temperature under the hood by as much as 100 big-ass FAHRENHEIT degrees. I would assume this would also raise the temp at the exhaust tail pipe considerably. It’s been said that painting the fins black on air-cooled engines aids cooling, and it probably does, but not much, judging by the number of unpainted fins out there. An idea - Black Ice Cube Trays! Scientifically Proven to freeze water faster! (Not as effective with freezers that work by convection - which is most of them.)
It's worth considering that air radiators primarily exchange heat through heating the air, not by radiation. It's also important to realize most real world things don't heat up and cool down entirely via radiation. The reason those bedouin robes work is because they promote air flow across the body and accelerate evaporative cooling.
I bet it depends on material, too. I have black cotton polos that feel fine. But the nilon polo gets so hot in the sunlight, I can't wear it in the sun at all.
I wonder what the effects would be if clothing was reversible and white on one side, black on the other. Are there advantages to warming up or cooling off depending on which side is facing out?
I'd be interested to see how the blackest black clothing would look through military grade nvgs at night. If it reflects no light it theoreticly should be invisible to pvs 7, or pvs 14 which were the best night vision devices they had when I was in
It will still give off fresnel reflection. The edge sheen, you can also see in the video. It´s caused by the surface structure. So in case, the person is even slightly lit from the back, the nightvision will pick that light up.
Could the black material act like a heat-sink, by wicking away heat from the body in the parts that are in the shade? If the fabric emits heat from the surface of areas in the shade, won't it then conduct heat from the skin below? I think that the pervasive winds where they live might have something to do with it too...
No. Think about it. The parts facing the sun are also facing space. You lose heat by shooting it into space. If you shoot heat down at the ground, you heat up the ground, but the ground is also emitting infrared to heat you up too.
1 How about black and white cars? In sunlight, the black car is much hotter than the white. 2 Does the black item lose heat faster just because it starts at a higher temperature?
That's a very interesting question there. I had 2 identical cars, one graphite gray and my current one is pitch black, and I will be honest with you. The black car does feel hotter when I get in it in the summer, but when I'm driving I noticed the AC inside the car gets way colder quicker than the gray car did. Again identical makes models and years.
ok I have a question based roughly on this topic... Is this the same in a sealed car. assuming the same internal car color and shape and everything as close as possible. dose the internals of a black or white car get and stay hotter longer, or in winter what car will get colder quicker.
No, he's basically ignored every relevant detail. Black cars get hotter inside than white cars. Significantly hotter. They do however also cool down faster.
@@seigeengine I wonder how that works while driving, does the wind cool down the black car better while driving? and while standing still the white car is better?
If you are only wearing a Tshirt and there is little to no air movement the difference on a sunny day can be rather extreme. I have some shirts that when inside or when not on a very sunny day are feel virtually the same (well they are the same shirts just in different colors after all), but in autumn when sitting outside with a low but strong sun the white ones are too cold, while the black ones make me sweat.
same experience here. also it. could be different when air temperature is way past body temperature. for instance driving with windows open and no AC feels worse than no AC and windows closed...also riding a motorcycle faster will feel even hotter and motorcycle gear will insulate you from the heat. I think it's the same in the desert you need to be insulated by loose clothes and layer of air, probably in this case color doesn't matter as much
@3:17 Haha, that is the exact same question I asked when I was little (well "those people in the desert") when my mom told me I shouldn't wear black out in the sun. But I also learned since that their clothing is just much better suited than ours.
I think that the cold piece of metal, the wind and the temperature of the air are irrelevant in this experience. The cold piece of metal will only absorb the energy by conduction if its colder than the bottles. It do not affect the radiation rate without contact. It is just emitting less light and lower frequency light toward the bottles than hot metal. I think that we could even say that the cold metal is heating the bottles because it is emitting radiation energy toward the bottles. Its just that the bottles emitting radiation rate is greater than the receiving rate at this moment. A breeze will cool you down the same whatever you have a white or a black cloth because its a conduction heat transfert effect and colors have no effects on this. My question now is : what is the most relevant factor for heating a black object, the wavelength or the number of photons received ?
You're wrong. The function of the block of cold metal is that it is emitting less radiation because it's colder. Normally, if you put a bottle beside a wall, the wall would emit as much infrared into the bottle as the bottle does into the wall. In this case, all the bottles would end up the same temperature. The cold metal is emitting less infrared, so it's acting as a sink of heat energy from the bottles. It's also cooling them by cooling the air around it, but it would be cooling them all roughly the same amount, so it's the different in emissivity that's causing the black bottle at play. "What is the most relevant factor in moving a pile of sand. How many workers you have, or how much sand each worker can carry?"
I read, many years ago, that desert dwellers in still air environments generally wore white robes to reflect the sun’s rays whereas in breezy environments they wore black to wick away the bodies heat.
Ive used a thermometer gun like that on my dogs and the black fur was significantly warmer. Like about 20 degree difference compared to brown and about 25 degrees hotter than their white fur.
Your measuring the fur though, not the temperature of their skin underneath. Hair behaves a bit differently as it both absorbs and insulates at the same time.
@@Draconiangem like i said, we can't just carelessly keep black cows in the field if there's no shade for them to hide here in brazil because they die of heatstroke, while the white ones are fine. the dog is hotter underneat the fur, too.
Right; I've noticed this on my black and white dog. Given all the factors described in this video, to me it's still an open question as to what if any difference it makes to the dog underneath. Obvious sweating is not available to the dog's fur.
Just remember that black is gives off more infrared as white at the same temp, so an infrared thermometer will read the black as being hotter. That's why they're inaccurate at reading skin temperature and you need a specially calibrated one for foreheads.
No, they're probably right. The Bedouin robes do become hotter on the outside. They may emit more, but they're also transferring heat into the inside. The reason this doesn't matter much for them is because the robes are thicker and loose, promoting airflow across the body. If color simply didn't matter, and things that were darker simply emitted it all away just as much, then black things wouldn't get hot in the sun.
I have lived in AZ my entire life and I have always worn black clothing whenever i have the option, people always used to ask me "How can you stand to wear all black" and i never had an answer for them, but staying cool in AZ is all about shade, so i bet i was cooler in the shade with my black clothing because it was losing heat faster.
Dark clothing color doesn't mean hot when exposed long enough to sunlight to feel you're getting hot it may depends on what kind of material they use to make that clothing or probably it's the wearer who sweat a lot than average.
Color only has an effect in the visible spectrum. Your setup with bottles has a flaw. The reason your black bottle changes temperature faster is due to differences in materials (even minor in pigment).
Doesn't using an IR thermometer to measure surafaces with different emissivities (which affect the readings) somehow defeat the purpuse? :) I think using contact thermometers would be a better option here.
The different emissivity of the surfaces also distorts your thermal camera reading. Even if all the bottles had the same temperature, the black one would appear hotter on the thermal camera. (Assuming that there are no anomalies in the infrared spectrum, which probably is the case)
No the camera thing is measuring the wavelength of infared light being emmited which directly correlates to temperature, not the quantity of light which would be determined by the emissivity of the material.
@@kennethferland5579 Do you have a source for that? I work professionally with optical metrology, and I have never seen this. Ordinary thermal cameras just measure the optical power over a broad wavelength range. (Thus integrated over the entire black-body spectrum.) Because the radiation increase by the power of four proportional to the temperature, this works quite well if the emissivities of the materials are comparable. I quote from Wikipedia: "Images from infrared cameras tend to be monochrome because the cameras generally use an image sensor that does not distinguish different wavelengths of infrared radiation."
It seems the best test is to paint three metal plates on one side, one white, one gray, one black and measure the temperature of each sheet on the bare metal side.
0:10 - depends... If the black tee is baggy and the white tee is tight fitting, then the baggy loose fitting black tee will keep you cooler due to airflow vs the tight fitted white tee.
Has any one who lives on the east coast USA ever noticed its harder to find clothes to keep you warm in the winter than it is to find clothes that keep you cool in the summer?
Great video! Would the black be cooler if you are sweating because it would evaporate faster? What would the sensible temperature of the bottles be checked with a thermocouple or other type of thermometer? Do you get the same reading on the white bottle with the infrared thermometer if you put a piece of black tape on it and check the tape? What about white tape on the black bottle?
I remember reading about this research and if I'm remembering correctly, you left out some pertinent information/data points. Traditional Bedouin garb often involved somewhat thick, woolen robes i.e. they were somewhat thermally insulating. That had the effect to minimize thermal transfer from the outside surface to the inside, near skin. The thinner the material, the less this will be the case, because the heat will get conducted through faster. In other words, it was not just about black body radiation. I have noticed this in my own everyday observations. There is a big difference between black and white in thin, t-shirt type materials. I definitely over heat in very dark clothes in the sun when it is warm to hot out. But if the clothes are a thicker and more insulating type, I don't notice the color difference much. Then consider that if you are in an environ wherein the ambient air temps, not even including Solar gain, are significantly above your core body temp, then having some thermal insulation will be a good thing, because it can help to create a micro climate as long as you are sweating and the sweat is evaporating efficiently. (Course if the humidity starts to get high, then this will backfire and make things worse). Oh, and btw, sheep's wool has the highest moisture regain of any normal/typical textile fabric. This may also affect things. In any case, you gave a somewhat incomplete picture of the issue.
Regarding the Beduins: I am guessing they will often also use some sort of sun shade, like an umbrella or a tent. In that case, you don't get hit with direct solar radiation, so the emitting properties of black colors might be better.
If they went on an expedition on horses or camels, having tents above them all the time won't be efficient. However, they cover their head well so that the sun doesn't hit it directly. It also has lose ends so that they can cover their face in case of a sandstorm
That is a great demo, however black is black in the visible spectrum we see.. not everything is "black" depending which spectrum you are at...for exemple, black anodized aluminum is reflective in IR
I was just deciding to get free black hoodie or white hoodie yesterday from Google after certification, how are you so good at reading minds of people?
What might be the most effective insulating blackout curtain for an RV? Silver Reflectix on one side and IR Flock Sheet on the other? During day, silver side out and at night, black side out?
Not to be picky, but infrared thermometers are bad at reading temperatures of reflective materials... I get the point of the explanation though, it's a good one - too many variables. How hot or cold clothing feels when out on a sunny day depends on a whole lot of factors other than just it's color... thickness, how breathable it is, how much wind you have, how tight they are, etc. And several of those affects more how you feel other than color by itself. Living in a tropical country and having gone through a metal head phase in my teens, I can tell you that in general black clothing will feel hotter than white clothing though. But I guess it's not so much because it's black, it's because they are generally made of less breathable and thicker materials - particularly the metal band t-shirts. xD They mostly print the entire front and back with some metal band album cover or something... which makes it less breathable. Wax based transfer, so it's super water resistant. xD I think thicker materials are also used so that they don't get faded and last a bit longer - it's less of a deal or less visible when a white T-shirt goes a bit thin, gets a bit yellow, logos a bit faded, in comparison to a black t-shirt going grey.... particularly when the wear and tear is not uniform.
I question that white reflects heat better regardless to weather its true or not. To me, it depends on several factors. So, I will use a choice between a black or a white golf umbrella on a hot sunny day in my example. Have you ever been at a outdoor Football game in the blazing sun while its 88°F outside? I always prefer the shade that a black umbrella provides over a white umbrella. It feels as though the white umbrella allows the sun to beam right through it and provides much less shade. Whereas the black umbrella reflects it and creates a much darker shade and the reduced light better on the eyes. And we all know that cooler temperatures always exist in the darkest shade. Even cattle knows this. Put up a white canopy and a black one on the hottest summer days and watch as all the cattle gather under the black one. That's just my personal opinion your results may vary.
That has always been my take on it too. Dark cloth blocks more uv and light from your skin than white cloth. I live on a tropical island and have worked in the full sun for weeks on end. Preferred wearing black long sleeves to white or other colors.
Black pigment is more opaque than simply bleaching and common cheap white pigments. Fabric that is pigmented white with zinc or titanium oxide would also be opaque despite being white, but that would be more expensive than other white fabric so it isn't usually done. It's a somewhat apples to oranges comparison. For example, shade provided by a wooden or metal roof would be just as dark if the roof is painted white as it would be if painted black because it wouldn't be any more transparent.
I have a white and a black dog and my black dog spends 90 percent of walks panting from the heat, despite the fact we shave her long fluffy hair down so her coats not as thick. She is definitely absorbing more heat and when I pick her up her belly is always way warmer than the other dogs. I think since isn't a garment and dog hasn't control in these cases the black fur is not as good as white. Or is it the same for animals too as humans with garments?
to have a valid measurment of tempreature using IR camera you have to take into account emissivity (it should be in settings, thou not all IR cameras have that option)
Now the next question...is it better to wear loose fitting clothes or tight fitting clothes? I found I sweat more in loose clothes, is it just me? It would seem that in loose clothes the air traps the heat and it can't evaporate as fast. In tight clothes, there is no air and the material transfers the heat directly to the surrounding.
There was a guy who did a test on that hummer and it took 4 days to fully charge and once he put it into tow mode it only went about 25 miles. Gas will never be replaced
white till it get external hot, then black for giving an internal. for ideal situation take some water for wetting the cloth, when that cloth will vaporize water temp will go down, chameleon cloth with some capillaries, that can drink water from capsules inside the close would be cool
I have a possible experiment for you. My research says that the same person perspires the same amount in both high and low humidity. In high humidity the body isn't able to evaporate the perspiration and isn't as comfortable as they are at the same temperature in low humidity. But people still insist that they sweat more in Florida than in Arizona while I disagree. Thanks for another one of my questions answered about black colored objects and the temperature differences.
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For the hummer it’s 0-60 mph in 3 seconds, not 60 😂
Lol what is it, a freight train? Might be impressive then.
Must have been made out of lead....takes 60 seconds to start and 60 seconds to stop.
Stealthy 🥷
try this with a tshirt and you will find your skin burning in a black one.
@@itoibo4208 Yes, In order to cool off you have to transfer heat that is made in the body to the environment. If most of the heat is coming from one direction you want to block the transfer by wearing something reflective like white or silver. In the other direction though black wins as it can absorb and radiate more energy.
I have worked outside in the heat (90-105) a lot from jobs before. The biggest difference in being hot or cool is the material. It's far cooler to wear light breathable material with long sleeves to keep the sun off but allow sweat to evaporate. I started wearing t shirts but learned that things like light hooded joggers made me feel coolest. The color didn't matter.
Must have been low humidity. In high humidity white clothing is always cooler.
@@ChrisG1392 true it was a very dry environment most of the time. Never worked much in high humidity.
Thank you! Been having this argument with my wife for years.
@@ChrisG1392 does water vapor affect convection?
@@westonding8953 I think it would have more to do with sweat evaporating. In a humid climate that would matter much less since the air is already very saturated so the fabric matters less. In dry air, that compensates for any color difference by a lot, but in a wet environment the color probably wins out. My guess.
*"It depends... on literally everything."*
words to live by
answer to 99.99% of all questions: "it depends..."
Only quantum mechanics is exception...
...where the answer to every question is "It's uncertain".
@@ShlokParab more accurately uncertain until measured..
@@niks660097 "until measured.."
More accurately until after the uncertain part of the information is kicked out and lost forever.
@@niks660097 no, no... Even when you measure. Ask Heisenberg.
Not the meth dealer, the scientist.
You also have to consider, in general, the _non-linear spectral response_ of different materials and coloring agents. Some materials which are black in visible light are white in infrared, and vice-versa. That can have an extremely profound effect upon the observed affect.
So to stay cool in hot sun you'd want a material that's white in the visible spectrum and black in infrared? Is there such a material?
@@arvana Infrared is the only one that really matters for this discussion. I think their point is that you may be surprised to find that some material you thought was white (because it reflects the visible spectrum) actually absorbs infrared
@@Zaros262 Wouldn't things like this effect the measurements taken by an IR thermometer diferently than other types of thermometers?
@@ericwazhung AFAIK, yes you are supposed to calibrate IR cameras for the emissivity of the object you're measuring. I would expect if you got the three bottles to be the same temperature, the black bottle would be (incorrectly) reported as a hotter temperature than the others
Some white objects, especially white paints and plastics, can have high emissivity (high absorptivity) despite their color. Look for tables showing emissivity of different substances - the higher the emissivity the more absorptive.
Fun fact: navy/dark blue is the best color to wear in the sun because it has the best balance of UV-absorbing qualities while not warming up as much as black. Maybe the UV aspect is one reason the Bedouins like to wear black because it helps protect them from sunburns better than wearing white!
Re Bedouins black is cheaper than blue
This makes sense. I live in Israel, and navy blue is by far the most popular color among Orthodox Jewish women. The poor guys are stuck wearing heavy black coats.
@@pigeonlove often the black is a blue. its just very dark indigo. you see this on rugs too, what looks like a black is just very dark blue, and with age it softens in tone. another way to know is moths, they love indigo dye, madder too, they won't touch chrome black chemical dye, so if you see an old yurt, the moth damage is only on some colors. rugs too.
It also about... The night it can be SO COLD. So.. The black color helps them to stay warmer in the night
@@YochevedDesigns lol that's more like.. about.. Back then, people make the violet color like something that so expensive. Like.. Royal color thing.
It's either from indigo plant or the lapis lazuli. Only for rich people.
About the beduin, they're the ones that do that for practical purpose.
About jewish blue, it is purely about the ancient dumb belief about violet-indigo-blue color thing
Not just jews that believe in that. It's also ancient egyptian and roman empire.
That's why u can see so many drawings in egyptian stuff that use the violet-blue color
The black clothes are seriously the weirdest and coolest thing I've ever seen.
I kinda want to make my own and go walking town, day and night.
It's like the deepest, darkest shadow ever walking around.
2:33 I love how casually you say "it's about 45 degrees" 🤣 I was thinking in Celsius and my reaction was "wow he's taking that rather well. He's in his element, unperturbed"
my experience (mostly outside deserts) is quite different when wearing single layer blacks feels significantly warmer, sometimes even feels hot like sunbathing even if it's cold outside when there's no wind
The basic gist is that the clothing in question works because it's heavy, layered, and loose, and is a robe, so it basically promotes airflow across the body, and draws away the excess heat while accelerating evaporative cooling.
@@seigeengine yes, if you have a tight black shirt on, it will absorb a lot of heat, and release it into your body. If you have a flowing black robe, it will absorb a lot of heat, but release it into the air.
Loll
In the Jurassic Park novel one character asks Ian Malcolm why he would wear black clothes to a tropical island, and he answers back questioning whether they understand black body radiation. I always enjoy those little scientific asides in Crichton's books.
Only he's pretty wrong about the tropical weather. if you wear black in high humidity high sunlight you will suffocate
I wish they ever made a movie based on hes book. Not some i like this i like this and lets change this.
@@r4v3nboy The book was pretty boring.
@@r4v3nboy The movie and the book being different means we have two different versions of JP, which is great.
"0-60 mph in 60 seconds" typical hummer
"The answer is that it depends, on literally everything"
My favorite answer.
Don't answer "Are you a pedophile?"
I'll probably be proven wrong later, but TheActionLab is one of the TH-camrs still with a sense of honor. I respect him for putting sponsors at the very end. an advertisement is more efficient when the viewer doesn't feel punished.
I appreciate it but there's nothing wrong with people who use midroll sponsorships, you can just fast forward past them and some sponsors probably require it or pay more for it.
I use the ad time at the end to browse comments
There are heaps. TH-cam is freaking enormous. Perhaps broadening your horizons may help you find others.
NileRed has a good sense of humour. I think there are plenty more too.
Is it really more efficient? I imagine the amount of people who simply end the video right there is tremendous compared to midroll ads.
4:57 That really looks like an edit because of the smooth, textureless black...
Interesting. I lived in the tropics for several years and dark was always terrible to wear. My wardrobe became all light colours. So from my experience I would say if the fabric is the same, then a lighter colour is definitely cooler when in the sun.
"It depends... on literally everything." Are you exposed at short periods? Do you pass by reflective materials like sand or water? Have you measured it or is a feeling? Does lighter clothes make your eyes color pop and bring that extra zing?
No no no no no jb uk ik hm jb bm kbhi ni ho rha hai to the next two weeks ago and the other days I want to the other day And it was and want to be very special to be a great👏👍just don't don't have to go on a Saturday night🌃 want a goodbye👋👋👋👋👋👋 to be very much as possible to the new one is🇧🇷🇧🇷 for me and you can get some of I don't knowing that Indian🇮🇳 Army and I'm so I can some reason I don't have to the next day And I'm still waiting for my birthday🎂 is a great👍👍👍 day And it will be very very very very good day And night and it will make you🤣🌹 feel bad👎 for me to the new friends with my new favorite😍😍 color🎨 is🇧🇷🇧🇷 a new car🚘 and I don't have time
Hahaa that was cool
That study was done in a bone dry desert environment so I think air humidity can change things a lot
It's probably also psychological in hot humid places as lighter colours are perceived as cleaner/more hygienic
Excellent video. Heat transfer can be rather complex and you show this perfectly.
I have experienced a major difference in temperature when wearing different color latex gloves. Maybe it's because Latex gloves are in direct contact with my skin, that I feel the black gloves instantly heat my hand when in the sun light opposed to white gloves. Maybe that's why the difference between black and white loose clothing doesn't matter too much. Have someone put a black and white glove on your hands while not looking and walk out into the sun. Because of the skin tight contact, you'll guess which hand has the black glove.
He's definitely messing up the actually relevant info.
The bedouin clothing in question achieves this effect because it's loose, thicker, sometimes layered, and promotes airflow across the body. This makes the external temperature and therefor color largely irrelevant. It doesn't apply to tightly fitting, thinner, single-layered or more conventional modern clothing. He also contrasts two entirely different outfits, which really makes him appear a clown.
Neat Steve. A windproof black jacket will warm faster in the Sun. The wind won't cool you as fast. I like to hike in winter and if there is Sun, I wear black water/windproof jackets so the Sun warms me up and my warmth holding sweater under the outer jacket, dark clothing is good in winter!
wouldn't it make sense in cold places to still have it black outside, but white inside, and in hot placed the other way around? I even heard of white paint used to buildings to reflect the sunlight
I don't think layering the colors actually does anything. It seems like it would at first, but when you think about it, it shouldn't actually matter.
White buildings are generally better because they change temperature slower. They heat up slower in the day and cool down slower at night. Generally speaking you don't want living spaces to experience large swings in temperature. It's important to remember, however, that things like buildings (or people) don't only exchange heat through emission and absorption of radiation.
But you would have to be in the shade for the emitting to take full effect. Therefore the black clothing would be hotter in direct sunlight.
You emit constantly, not just while in the shade.
Working evening and overnight shifts for most of my life, it was impossible to not notice that darker cars got frost on them before lighter cars, and of course, the frost melted on dark cars first in the morning. I’ve heard that painting exhaust headers on race cars white lowered the temperature under the hood by as much as 100 big-ass FAHRENHEIT degrees. I would assume this would also raise the temp at the exhaust tail pipe considerably. It’s been said that painting the fins black on air-cooled engines aids cooling, and it probably does, but not much, judging by the number of unpainted fins out there.
An idea - Black Ice Cube Trays! Scientifically Proven to freeze water faster! (Not as effective with freezers that work by convection - which is most of them.)
It's worth considering that air radiators primarily exchange heat through heating the air, not by radiation.
It's also important to realize most real world things don't heat up and cool down entirely via radiation. The reason those bedouin robes work is because they promote air flow across the body and accelerate evaporative cooling.
Do your neighbors ever wonder what you're up to?
"What the heck was that???"
"Calm down. It's just Jimbo doing one of his experiments."
I bet it depends on material, too.
I have black cotton polos that feel fine. But the nilon polo gets so hot in the sunlight, I can't wear it in the sun at all.
Nilon?
@@MrEazyE357Nylon
Zero to 60 miles an hour in 60 seconds? That sounds really good.
Meh, only around a factor of 20 off...
Sign me up lol
I can run faster than this car for 5 seconds or so lolz
Finally something I can race in a Geo Metro (other than another Metro).
😂😂😂 i thought the same
Thank you for making this video. I always had questions about the black and white temperature difference.
05:45, can go 0-60 in 60 seconds… I think those figures need an Action Labs investigation 😂
Oops, I think you missed the 0-60 mph on the Hummer. Generally they would go 0-60 in 5 or less seconds not 60 seconds.
I bet he did that on purpose, maybe to see if anybody would catch it....The Hummer has over 1000 HP and does 0-60 in 3.3 Seconds !!
@@Nick-Matchem he was probably reading a script for his sponsor, I’d bet the sponsor doesn’t have a clue what they’re talking about.
@@BryceKimball7.3 I feel like he would've caught it if it was in the script, sounds like he just did it in a single take and brainfarted
That black outfit would make a great Halloween costume: "Invisible Pedestrian"
This will not end well.
All teenagers already knew black was cooler
😂😊
Get it
He's walking around like he hasn't been unlocked yet.
I wonder what the effects would be if clothing was reversible and white on one side, black on the other. Are there advantages to warming up or cooling off depending on which side is facing out?
Light and shadow?
.
Call it "Day n night"
thats literally how the colours on penguins work lol
@@malinatof but it's not lol
The darkest robe was reflecting a surprising amount of light out in the open :P
I'd be interested to see how the blackest black clothing would look through military grade nvgs at night. If it reflects no light it theoreticly should be invisible to pvs 7, or pvs 14 which were the best night vision devices they had when I was in
well, actually it could be TOO black, showing up as a shadow against the background.
@@insertphrasehere15 it'd be very interesting to see. Also extremely fun to play with in various backgrounds. Makes me wonder about thermals too.
damn that's actually a really good idea.
It will still give off fresnel reflection. The edge sheen, you can also see in the video. It´s caused by the surface structure. So in case, the person is even slightly lit from the back, the nightvision will pick that light up.
@@sikliztailbunch so basicly stay low to the ground, or close to objects larger than you. That'd be very interesting to play with.
as the winter is about to start this video was helpful thankyou
Could the black material act like a heat-sink, by wicking away heat from the body in the parts that are in the shade? If the fabric emits heat from the surface of areas in the shade, won't it then conduct heat from the skin below? I think that the pervasive winds where they live might have something to do with it too...
No. Think about it. The parts facing the sun are also facing space. You lose heat by shooting it into space. If you shoot heat down at the ground, you heat up the ground, but the ground is also emitting infrared to heat you up too.
Admit it, you inherently want to say "degrees celsius" but something's stopping you. 😂
Great Video.
1 How about black and white cars? In sunlight, the black car is much hotter than the white. 2 Does the black item lose heat faster just because it starts at a higher temperature?
That's a very interesting question there. I had 2 identical cars, one graphite gray and my current one is pitch black, and I will be honest with you. The black car does feel hotter when I get in it in the summer, but when I'm driving I noticed the AC inside the car gets way colder quicker than the gray car did. Again identical makes models and years.
My gothic ass needs to get her hands on a bolt of that fabric.
ok I have a question based roughly on this topic... Is this the same in a sealed car. assuming the same internal car color and shape and everything as close as possible. dose the internals of a black or white car get and stay hotter longer, or in winter what car will get colder quicker.
No, he's basically ignored every relevant detail.
Black cars get hotter inside than white cars. Significantly hotter. They do however also cool down faster.
@@seigeengine I wonder how that works while driving, does the wind cool down the black car better while driving? and while standing still the white car is better?
@@saidakil9721 Color only effects radiation, so no.
2:56 why not wear that for Halloween and scare some kids sh*tless 😂
If you are only wearing a Tshirt and there is little to no air movement the difference on a sunny day can be rather extreme. I have some shirts that when inside or when not on a very sunny day are feel virtually the same (well they are the same shirts just in different colors after all), but in autumn when sitting outside with a low but strong sun the white ones are too cold, while the black ones make me sweat.
same experience here. also it. could be different when air temperature is way past body temperature. for instance driving with windows open and no AC feels worse than no AC and windows closed...also riding a motorcycle faster will feel even hotter and motorcycle gear will insulate you from the heat. I think it's the same in the desert you need to be insulated by loose clothes and layer of air, probably in this case color doesn't matter as much
only wearing a tshirt is called public indecency
@@Blox117 not if it's long enough.
@@Blox117 nah - i should charge for that :)
@3:17 Haha, that is the exact same question I asked when I was little (well "those people in the desert") when my mom told me I shouldn't wear black out in the sun. But I also learned since that their clothing is just much better suited than ours.
I think that the cold piece of metal, the wind and the temperature of the air are irrelevant in this experience. The cold piece of metal will only absorb the energy by conduction if its colder than the bottles. It do not affect the radiation rate without contact. It is just emitting less light and lower frequency light toward the bottles than hot metal. I think that we could even say that the cold metal is heating the bottles because it is emitting radiation energy toward the bottles. Its just that the bottles emitting radiation rate is greater than the receiving rate at this moment. A breeze will cool you down the same whatever you have a white or a black cloth because its a conduction heat transfert effect and colors have no effects on this. My question now is : what is the most relevant factor for heating a black object, the wavelength or the number of photons received ?
You're wrong.
The function of the block of cold metal is that it is emitting less radiation because it's colder. Normally, if you put a bottle beside a wall, the wall would emit as much infrared into the bottle as the bottle does into the wall. In this case, all the bottles would end up the same temperature. The cold metal is emitting less infrared, so it's acting as a sink of heat energy from the bottles. It's also cooling them by cooling the air around it, but it would be cooling them all roughly the same amount, so it's the different in emissivity that's causing the black bottle at play.
"What is the most relevant factor in moving a pile of sand. How many workers you have, or how much sand each worker can carry?"
Well this scientifically confirms what i have thought my whole life. Yet most ppl always thought i was the one that was wrong 🤣
Imagine playing hide n seek in that
Especially in night your can literally stand in open and be invisible
@@ShlokParab Actually, it's *_too_* black. You would stand out against the background as a black blob.
I read, many years ago, that desert dwellers in still air environments generally wore white robes to reflect the sun’s rays whereas in breezy environments they wore black to wick away the bodies heat.
Ive used a thermometer gun like that on my dogs and the black fur was significantly warmer. Like about 20 degree difference compared to brown and about 25 degrees hotter than their white fur.
Your measuring the fur though, not the temperature of their skin underneath. Hair behaves a bit differently as it both absorbs and insulates at the same time.
@@Draconiangem like i said, we can't just carelessly keep black cows in the field if there's no shade for them to hide here in brazil because they die of heatstroke, while the white ones are fine. the dog is hotter underneat the fur, too.
Right; I've noticed this on my black and white dog. Given all the factors described in this video, to me it's still an open question as to what if any difference it makes to the dog underneath. Obvious sweating is not available to the dog's fur.
Just remember that black is gives off more infrared as white at the same temp, so an infrared thermometer will read the black as being hotter. That's why they're inaccurate at reading skin temperature and you need a specially calibrated one for foreheads.
4:00 This is why when people say "I'm getting hotter then you because I have a black shirt" I just laugh inside
No, they're probably right. The Bedouin robes do become hotter on the outside. They may emit more, but they're also transferring heat into the inside. The reason this doesn't matter much for them is because the robes are thicker and loose, promoting airflow across the body.
If color simply didn't matter, and things that were darker simply emitted it all away just as much, then black things wouldn't get hot in the sun.
A question: wouldn’t the emissivity of the differently colored bottles affect the reading of the infrared thermometer?
Thermal cameras are bad with reflective objects too
I have lived in AZ my entire life and I have always worn black clothing whenever i have the option, people always used to ask me "How can you stand to wear all black" and i never had an answer for them, but staying cool in AZ is all about shade, so i bet i was cooler in the shade with my black clothing because it was losing heat faster.
Dark clothing color doesn't mean hot when exposed long enough to sunlight to feel you're getting hot it may depends on what kind of material they use to make that clothing or probably it's the wearer who sweat a lot than average.
Yo your videos have increased quality man
I dont think that clothing is actually very dark. Pretty easy to see the texture compared to some of your other black projects
@@tripplefives1402 yeah. That got me thinking.
"They absorb almost all light in the visible and infrared spectrum."
What more do you want from me.MP4
@@RETYQ it’s just a normal comment. U act like NK leader, throwing tantrum over an ant
@@tripplefives1402 that makes sense i bet thats true and the other tests he did might have been artificial lighting
And that is just visible spectrum!!!
Color only has an effect in the visible spectrum. Your setup with bottles has a flaw. The reason your black bottle changes temperature faster is due to differences in materials (even minor in pigment).
Doesn't using an IR thermometer to measure surafaces with different emissivities (which affect the readings) somehow defeat the purpuse? :) I think using contact thermometers would be a better option here.
That ninja trick tho! Magnificent :)
The different emissivity of the surfaces also distorts your thermal camera reading. Even if all the bottles had the same temperature, the black one would appear hotter on the thermal camera. (Assuming that there are no anomalies in the infrared spectrum, which probably is the case)
No the camera thing is measuring the wavelength of infared light being emmited which directly correlates to temperature, not the quantity of light which would be determined by the emissivity of the material.
@@kennethferland5579 Do you have a source for that?
I work professionally with optical metrology, and I have never seen this.
Ordinary thermal cameras just measure the optical power over a broad wavelength range. (Thus integrated over the entire black-body spectrum.) Because the radiation increase by the power of four proportional to the temperature, this works quite well if the emissivities of the materials are comparable.
I quote from Wikipedia: "Images from infrared cameras tend to be monochrome because the cameras generally use an image sensor that does not distinguish different wavelengths of infrared radiation."
It seems the best test is to paint three metal plates on one side, one white, one gray, one black and measure the temperature of each sheet on the bare metal side.
0:10 - depends... If the black tee is baggy and the white tee is tight fitting, then the baggy loose fitting black tee will keep you cooler due to airflow vs the tight fitted white tee.
Has any one who lives on the east coast USA ever noticed its harder to find clothes to keep you warm in the winter than it is to find clothes that keep you cool in the summer?
I can hear your neighbor say, "honey that science nut is outside in black cloths." Anyway love your videos!
I’d say you’d get chased by many because of how hot your clothes are, so be careful.
Happened to me so often...
Heat transfer is my favorite topic along with thermodynamics
Poor shadows. 💀 If these clothes are so hot, what about our shadows? How much warmth do they bear to be with us?
"The Shadow knows!"
That ninja thing at the end got me. It was impossible to see him beforehand.
Great video! Would the black be cooler if you are sweating because it would evaporate faster? What would the sensible temperature of the bottles be checked with a thermocouple or other type of thermometer? Do you get the same reading on the white bottle with the infrared thermometer if you put a piece of black tape on it and check the tape? What about white tape on the black bottle?
I remember reading about this research and if I'm remembering correctly, you left out some pertinent information/data points. Traditional Bedouin garb often involved somewhat thick, woolen robes i.e. they were somewhat thermally insulating. That had the effect to minimize thermal transfer from the outside surface to the inside, near skin. The thinner the material, the less this will be the case, because the heat will get conducted through faster. In other words, it was not just about black body radiation.
I have noticed this in my own everyday observations. There is a big difference between black and white in thin, t-shirt type materials. I definitely over heat in very dark clothes in the sun when it is warm to hot out. But if the clothes are a thicker and more insulating type, I don't notice the color difference much.
Then consider that if you are in an environ wherein the ambient air temps, not even including Solar gain, are significantly above your core body temp, then having some thermal insulation will be a good thing, because it can help to create a micro climate as long as you are sweating and the sweat is evaporating efficiently. (Course if the humidity starts to get high, then this will backfire and make things worse).
Oh, and btw, sheep's wool has the highest moisture regain of any normal/typical textile fabric. This may also affect things. In any case, you gave a somewhat incomplete picture of the issue.
0:40 yo dis nigg@h sayin we have super pwers n shit
😂
Regarding the Beduins: I am guessing they will often also use some sort of sun shade, like an umbrella or a tent. In that case, you don't get hit with direct solar radiation, so the emitting properties of black colors might be better.
If they went on an expedition on horses or camels, having tents above them all the time won't be efficient. However, they cover their head well so that the sun doesn't hit it directly. It also has lose ends so that they can cover their face in case of a sandstorm
So far, this is the most interesting thing I’ve actually learned from this TH-cam channel.
That is a great demo, however black is black in the visible spectrum we see.. not everything is "black" depending which spectrum you are at...for exemple, black anodized aluminum is reflective in IR
I was just deciding to get free black hoodie or white hoodie yesterday from Google after certification, how are you so good at reading minds of people?
What might be the most effective insulating blackout curtain for an RV? Silver Reflectix on one side and IR Flock Sheet on the other? During day, silver side out and at night, black side out?
Not to be picky, but infrared thermometers are bad at reading temperatures of reflective materials... I get the point of the explanation though, it's a good one - too many variables. How hot or cold clothing feels when out on a sunny day depends on a whole lot of factors other than just it's color... thickness, how breathable it is, how much wind you have, how tight they are, etc. And several of those affects more how you feel other than color by itself.
Living in a tropical country and having gone through a metal head phase in my teens, I can tell you that in general black clothing will feel hotter than white clothing though.
But I guess it's not so much because it's black, it's because they are generally made of less breathable and thicker materials - particularly the metal band t-shirts. xD
They mostly print the entire front and back with some metal band album cover or something... which makes it less breathable. Wax based transfer, so it's super water resistant. xD
I think thicker materials are also used so that they don't get faded and last a bit longer - it's less of a deal or less visible when a white T-shirt goes a bit thin, gets a bit yellow, logos a bit faded, in comparison to a black t-shirt going grey.... particularly when the wear and tear is not uniform.
I question that white reflects heat better regardless to weather its true or not. To me, it depends on several factors. So, I will use a choice between a black or a white golf umbrella on a hot sunny day in my example. Have you ever been at a outdoor Football game in the blazing sun while its 88°F outside? I always prefer the shade that a black umbrella provides over a white umbrella. It feels as though the white umbrella allows the sun to beam right through it and provides much less shade. Whereas the black umbrella reflects it and creates a much darker shade and the reduced light better on the eyes. And we all know that cooler temperatures always exist in the darkest shade. Even cattle knows this. Put up a white canopy and a black one on the hottest summer days and watch as all the cattle gather under the black one. That's just my personal opinion your results may vary.
That has always been my take on it too. Dark cloth blocks more uv and light from your skin than white cloth. I live on a tropical island and have worked in the full sun for weeks on end. Preferred wearing black long sleeves to white or other colors.
Black pigment is more opaque than simply bleaching and common cheap white pigments. Fabric that is pigmented white with zinc or titanium oxide would also be opaque despite being white, but that would be more expensive than other white fabric so it isn't usually done. It's a somewhat apples to oranges comparison. For example, shade provided by a wooden or metal roof would be just as dark if the roof is painted white as it would be if painted black because it wouldn't be any more transparent.
Thanks for this answer!!! I’ve been getting mixed stories on this topic since I was little.
He's slightly right but mostly wrong lol.
@2:56 I think it's funny that even the world's darkest black still shows Fresnel's white lines around the edges
Ok but it doesn't in previous shots, so... What's going on here?
I have a white and a black dog and my black dog spends 90 percent of walks panting from the heat, despite the fact we shave her long fluffy hair down so her coats not as thick. She is definitely absorbing more heat and when I pick her up her belly is always way warmer than the other dogs. I think since isn't a garment and dog hasn't control in these cases the black fur is not as good as white. Or is it the same for animals too as humans with garments?
to have a valid measurment of tempreature using IR camera you have to take into account emissivity (it should be in settings, thou not all IR cameras have that option)
Well I learnt something new today
Awesome video again! Could you please put Celsius and Metric systems as well in your videos?
I always wondered why they would wear those outfits out in the desert now we know and how fun to win a car
I made a joke in your previous video where you showed off the blackest fabric in the world. It turns out that I was wrong. 😹
Very interesting, I like to wear black shirts when dancing salsa this prevents me from overheating salsa is a very intens workout.
White reflective jacket with aerogel inner lining = great winter clothing drip.
*now I know what what I’m wearing on my next hit…tha action lab* 👍🏾
Neat. I say go for it, be a ninja. Maybe in the next video we'll see some ninja star experiments.
The robed figures on the sand dunes was an evocative image
i like the ninja thing like a shadow..... good idea wearing this during night while strolling as a ninja
4:16 idk why but this cracked me up
"You haven't unlocked this character yet "
This video was life changing
Now the next question...is it better to wear loose fitting clothes or tight fitting clothes? I found I sweat more in loose clothes, is it just me? It would seem that in loose clothes the air traps the heat and it can't evaporate as fast. In tight clothes, there is no air and the material transfers the heat directly to the surrounding.
4:56 thank you for this 😂
There was a guy who did a test on that hummer and it took 4 days to fully charge and once he put it into tow mode it only went about 25 miles. Gas will never be replaced
I agree that the shiny silver part of my school bag in direct sunlight is still cold while the black plastic part feels hot.
I've been wondering about this for awhile now! Thanks for clearing it up!
Standing on the hood road like a slenderman 🤣🤣🤣🤣
white till it get external hot, then black for giving an internal. for ideal situation take some water for wetting the cloth, when that cloth will vaporize water temp will go down, chameleon cloth with some capillaries, that can drink water from capsules inside the close would be cool
"In fact, if I take this cold piece of aluminum..." he says like everybody has a block of aluminum just lying around
I have a possible experiment for you. My research says that the same person perspires the same amount in both high and low humidity. In high humidity the body isn't able to evaporate the perspiration and isn't as comfortable as they are at the same temperature in low humidity. But people still insist that they sweat more in Florida than in Arizona while I disagree. Thanks for another one of my questions answered about black colored objects and the temperature differences.