The color of our T-shirt we wear in summer

[fresh]

who can help me explain this ? why is the darker color ?

 

Clothing

Loose-fitting long-sleeved shirts and long pants made from tightly woven fabric offer the best protection from the sun's UV rays. A wet T-shirt offers much less UV protection than a dry one.

Darker colors may offer more protection than lighter colors.

 

http://www.cdc.gov/cancer/skin/basic_info/prevention.htm

Edited January 8, 2014 by fresh

[StringJunky]

Cloth is not perfectly smooth - it has gaps in it - so UV rays can reflect between individual light-coloured threads, following a complicated path of internal reflections through to the skin, more than dark fibres which will be less internally reflective between threads in total.

Edited January 8, 2014 by StringJunky

[Strange]

Fabrics are dark because they absorb light. The idea is that if they absorb visible light then they may be more likely to absorb UV as well.

[DimaMazin]

Fabrics are dark because they absorb light. The idea is that if they absorb visible light then they may be more likely to absorb UV as well.

To reflect off better than to absorb in my region in summer.

[fresh]

wearing dark clothes makes me sweat more.

[Strange]

wearing dark clothes makes me sweat more.

 

Because they absorb infra-red as well as light.

[CaptainPanic]

Dark clothes absorb most, reflect little light

Light clothes absorb little, reflect most light

 

If your light clothes were made of aluminium foil, it would reflect everything away from you. But they are not. They are made from thin threads of cotton (or something else - but it's almost always woven). Light may reflect away, but some light gets through, and that's how light clothes protect less against UV. Because some UV light bounces off the threads until it ultimately is absorbed by your skin.

[fresh]

Dark clothes absorb most, reflect little light

 

so when dark clothes absorbs most of UV rays, it is like a wall which prevents us from being exposed to UV rays ?

 

Does it also mean our skin absorb less UV rays, because the dark clothes already absorbs most of light, and the UV rays cant penetrate through our dark clothes ?

 

Is it reliable to infer the dark people can absorb less UV rays than the white people even thought they feel hotter ?

Edited January 9, 2014 by fresh

[xyzt]

Dark clothes absorb most, reflect little light

Light clothes absorb little, reflect most light

 

If your light clothes were made of aluminium foil, it would reflect everything away from you. But they are not. They are made from thin threads of cotton (or something else - but it's almost always woven). Light may reflect away, but some light gets through, and that's how light clothes protect less against UV. Because some UV light bounces off the threads until it ultimately is absorbed by your skin.

Scientific research, peer reviewed and published in Nature shows that black or white..... it makes NO difference. Surprise!

[DimaMazin]

Scientific research, peer reviewed and published in Nature shows that black or white..... it makes NO difference. Surprise!

Completely wrong comparison with our discussion.White wool is transparent.Thick white cotton isn't so transparent.Woolen clothes for night weather in desert. Light cotton or linen is better for cooling than dark cotton or linen,but thin light cotton Is a bad obstacle for UV.

Edited January 10, 2014 by DimaMazin

[fresh]

Can i conclude it is the type of clothing materials matters, not the color of it ?

we need a conclusive answer.

[StringJunky]

Have a read of this: http://en.wikipedia.org/wiki/Sun_protective_clothing

 

On a side but related note, make sure any sunglasses you wear have the sides blocked, or are wraparounds, because UV rays can bounce off the inside of the glasses into your dilated pupils. The combined effects of dilated pupils, which increases the acceptance angle, and internal reflection originating from the unblocked sides cause your pupils to take in more UV than if they were naked where they would be very constricted and thus protecting your eyes better.

Edited January 10, 2014 by StringJunky

[xyzt]

Can i conclude it is the type of clothing materials matters, not the color of it ?

we need a conclusive answer.

correct

[fresh]

correct

i have no worries about wearing white T-shirt in summer now

[DimaMazin]

i have no worries about wearing white T-shirt in summer now

Visible light has 55% of solar energy on Earth surface. UV light has 5%. You can choose heatstroke or sun tanning.

[StringJunky]

xyzt, on 09 Jan 2014 - 5:28 PM, said:

Scientific research, peer reviewed and published in Nature shows that black or white..... it makes NO difference. Surprise!

The abstract is about solar heat loads and says there is no difference in heat absorption not UV absorption, where white hair and feathers is inferior.

 

Survival in hot deserts has always posed a problem for man; Moses had to solve it in order to lead the children of Israel through the wilderness of the Sinai—a formidable hot desert. It seems likely that the present inhabitants of the Sinai, the Bedouins, would have optimised their solutions for desert survival during their long tenure in this desert Yet, one may have doubts on first encountering Bedouins wearing black robes and herding black goats. We have therefore investigated whether black robes help the Bedouins to minimise solar heat loads in a hot desert. This seemed possible because experiments have shown that white hair on cattle1,2 and white feathers on pigeons3 permit greater penetration of short-wave radiation to the skin than black. In fact, more heat flowed inward through white pigeon plumage than through black when both were exposed to simulated solar radiation at wind speeds greater than 3 m s−1 (ref. 3). We report here that 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.

Quote

 

[DimaMazin]

Cotton don't cause irritation of skin. White T-shirt protects from solar heat by reflection and evaporation.Dark T-shirt protects by evaporation,therefore you should more drink and sweat, therefore the dark T-shirt will been dirty and wet.Wet thin cotton is bad protection from UV.

Edited January 11, 2014 by DimaMazin