the.com/cosmic rays
the universe's stray bullets, fired billions of years before you were born, hitting you right now.
means high-energy particles, mostly protons, flung through space by exploding stars and black holes, that constantly slam into earth's atmosphere.
from named in the 1920s by physicist robert millikan, who assumed they were gamma rays from outer space; turned out to be charged particles, but the cosmic part stuck.
discovery cluevictor hess found radiation increases in balloon flights, 1912
energy scalesome outpace anything human particle colliders can make
biological effectthey mutate dna, possibly speeding up evolution and cancer
tech hazardthey occasionally flip bits in computer memory chips