When exposed to the sun, why does your skin darken but your hair lighten?

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Discussion Overview

The discussion explores the phenomenon of skin darkening and hair lightening when exposed to sunlight, focusing on the biological mechanisms behind these changes. It touches on concepts related to pigmentation, UV light effects, and societal perceptions of these changes.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants propose that skin darkens to absorb sunlight and protect against burns.
  • Others argue that hair lightens because the pigment breaks down under UV light, with the caveat that hair is dead and cannot regenerate pigment.
  • A participant questions whether hair should turn completely white instead of blonde, given the breakdown of pigment.
  • Another participant clarifies that blonde hair retains some pigment, as UV rays do not completely degrade it to a white state.
  • One participant introduces a tangential question about which hair color has the strongest pigment, suggesting ginger hair as a contender.
  • A later reply comments on the cultural implications of tanning and hair lightening, noting the popularity of these looks and their impact on salon businesses.

Areas of Agreement / Disagreement

Participants express differing views on the specifics of how hair pigmentation changes in response to UV exposure, and there is no consensus on the strongest hair pigment. The discussion remains unresolved regarding the exact nature of these changes.

Contextual Notes

Participants do not fully explore the biochemical processes involved in pigmentation changes, and assumptions about the effects of UV light on different hair colors are not explicitly defined.

wasteofo2
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I know that when your skin is exposed to a lot of sunlight it turns darker in order to try to absorb some of the light's energy, which can help avoid burns, but why does your hair become blonde?
 
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Because the pigment in the hair breaks down under influence of the UV light, and since hair is dead no new pigment can be made.
 
Monique said:
Because the pigment in the hair breaks down under influence of the UV light, and since hair is dead no new pigment can be made.
doesnt this mean the hair should turn to white and not blonde?
 
White is the complete lack of pigment, blonde hair has very light pigment, the UV rays aren't strong enough to completely degrade all the pigment, so the hair will just become lighter than it originally was.
 
so (a little bit offtopic) which hair has the strongest pigment: black or ginger?

i go for ginger :surprise:
 
it's ironic too because this tan look with sun kissed highlights is a look most women (and some men too) strive for, thus keeping the tanning salons and hair salons in business...
 

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