<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
Why does the sun make our hair lighter but make our skin darker?
<|assistant|>
The sun makes our hair lighter because the hair absorbs the UVA rays from the sun and the melanin in our hair absorbs the UVA and UVB radiation from the sun causing the hair to lighten.  Meanwhile, the skin is darkened by the UVB radiation while the UVA rays reflect off the skin unchanged. This difference in absorption of different types of radiation leads to the skin darkening while the hair lightens.