prompt: Why does the sun make our hair lighter but make our skin darker?
chosen: Why does the sun make our hair lighter but make our skin darker?
chosen: user
chosen: The sun produces ultraviolet radiation which has two different effects depending on the depth of penetration. The shorter wavelengths (UVA) penetrate deep into the skin and cause tanning, while the longer wavelengths (UVB) are responsible for burning. UVB affects mainly the scalp, which has thinner skin than the face, so it produces more protection against the sun by making the hair lighter. Meanwhile, the longer wavelengths of UVA cause aging and wrinkles, since it can penetrate deeper and reaches the dermis, or inner layer of the skin. Thus, this explains why the skin around the eyes, and on the lips, stays darker despite being exposed to the same amount of radiation as the rest of the skin.
chosen: assistant
rejected: Why does the sun make our hair lighter but make our skin darker?
rejected: user
rejected: assistant