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Meatball

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Wikipedia is in fact, an unreliable source. Do you know what would happen to my english grade if i used wikipedia as a source on a paper? "thermal" damage even from the sun.... isn't it also caused by the IR heat from the sun? I think that why they say to never look into the sun just like we say to be careful with IR lasers.. But perhaps I am wrong. We haven't covered the whole chapter on light in physics yet.. :p
 

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thanks for the "tag"-info. never heard of these. is it pure friction-caused irritation, which would go by itself again?
No its like a mole, but soft..like skin. You get them when you get older. If they are small enough you can pick them off, but they bleed a lot. I cut mine off with a sterilized cuticle cutter. Why pay the doctor when you can do it yourself? LOL Sometimes they get a little bigger with age, but they don't go away. You will more than likely get them. They are very common, but no one seems to talk about them. I didn't know what they were either at first, and I was around 25 at the time.
 

Switch

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Wikipedia is in fact, an unreliable source. Do you know what would happen to my english grade if i used wikipedia as a source on a paper? "thermal" damage even from the sun.... isn't it also caused by the IR heat from the sun? I think that why they say to never look into the sun just like we say to be careful with IR lasers.. But perhaps I am wrong. We haven't covered the whole chapter on light in physics yet.. :p
Yes you are wrong.Sunburns aren't thermal damage.If you never noticed, you can't get sunburns on the palms of your hands because you have no pigment there.Also, darker colored people are more resistant to sunburns, and if they were caused by plain heat, they would actually sustain more damage since their skin absorbs more of the light.
And the reason you're told not to look at the sun is pretty obvious: it's too damn bright! It's not because of the IR.Yes, sunlight contains some near infrared too, but it's the visible light that damages your eyes when you stare at it with the naked eye.
The sun emits a lot of types of radiation, but as far as I know(correct me if I'm wrong) only visible light, near IR and near UV reaches the surface of the earth.I'm not sure what you mean by "IR heat" but it's the UV that does the tanning.I bet that if you had a huge UV filter you could stand in the middle of the desert a whole day and not get any tan.
 

Cyparagon

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Standard glass is a barrier to UV light under about 350nm I think (makes me giggle when sunglasses are advertised as "UV filtered").

you can't get sunburns on the palms of your hands because you have no pigment there.Also, darker colored people are more resistant to sunburns
Er... that's BECAUSE they have more pigment.
 

Benm

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Depends a bit on what you call 'standard glass' as well... the usual glass for home windows is soda-lime glass, which will transmit uv all the way down to about 300 nm. It's actually possible to get a tan indoors, it just doesnt happen often because people move away from the heat when the sun in strongest in summer. It also happens in cars, though many have tinted windows that reduce the effect.
 




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