I think it's worth noting that a magnifying glass actually blocks/filters out UVB, and substantially reduces UVA. Feynman famously watched Trinity with only a t

I think it's worth noting that a magnifying glass actually blocks/filters out UVB, and substantially reduces UVA. Feynman famously watched Trinity with only a truck windshield to protect him. https://en.wikipedia.org/wiki/Trinity_(nuclear_test) https://en.wikipedia.org/wiki/Trinity_(nuclear_test)