How is it possible that certain colours absorb heat and others reflect it? They are just ‘colours’?
Why if you are wearing black pants, you get warm, but with white, less so – even if it’s the same material?
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Colours are our perception of how objects are reflecting light. Light colours, especially white, mean the object is reflecting most of the visible light. Light that’s absorbed causes an object to heat up, so black clothes will generally feel warmer in the sun than white ones. The effect works both ways, so black objects will tend to cool faster in the shade, which is why radiators and heat sinks tend to be black.
Much of the sun’s energy reaches us as infrared light, which we can’t see and so it doesn’t affect colour. This means that you could have a white object that absorbs infrared and so heats up in the sun. You could also have a black object that reflects infrared that wouldn’t heat up as much. The rule that light-coloured things stay cooler in the sun is a reasonable starting point but it’s not always true because we can’t see infrared light.
Colours are our perception of how objects are reflecting light. Light colours, especially white, mean the object is reflecting most of the visible light. Light that’s absorbed causes an object to heat up, so black clothes will generally feel warmer in the sun than white ones. The effect works both ways, so black objects will tend to cool faster in the shade, which is why radiators and heat sinks tend to be black.
Much of the sun’s energy reaches us as infrared light, which we can’t see and so it doesn’t affect colour. This means that you could have a white object that absorbs infrared and so heats up in the sun. You could also have a black object that reflects infrared that wouldn’t heat up as much. The rule that light-coloured things stay cooler in the sun is a reasonable starting point but it’s not always true because we can’t see infrared light.
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