4 ms·

I'm not sure the same consideration applies to sunblock. The article makes the case that plants always "want" to let through the same quantity of light, but not

I'm not sure the same consideration applies to sunblock. The article makes the case that plants always "want" to let through the same quantity of light, but not necessarily the same proportion, while we ideally want to block 100% of UV all the time.

dieselerator 4y ago
I think this might be a good place to add this reminder: "Vitamin D is made when UV (more precisely, UVB rays) react with a compound (7-dehydrocholesterol) in the skin. The best rays for UV synthesis have wavelengths between 270–300 nm." [1] [1] https://www.sciencelearn.org.nz/resources/1313-vitamin-d-and-uv https://www.sciencelearn.org.nz/resources/1313-vitamin-d-and...
- lightedman 4y ago
  270nm is UVC territory. Did you mean 280nm instead?
  - dieselerator 4y ago
    That is a fair question. This is what I find. [1] Ultraviolet B UV‑B 280–315 Ultraviolet C UV‑C 100–280 [1] https://en.wikipedia.org/wiki/Ultraviolet https://en.wikipedia.org/wiki/Ultraviolet My read is "UVB" is the popular medicine way of saying UV is needed for the body to synthesize vitamin D. It was not considered necessary to point out part of the useful spectrum is in "UVC" territory.
- hinkley 4y ago
  Also kills microbes on surfaces.