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TIL human fingers can discriminate between surfaces patterned with ridges as small as 13 nanometers in amplitude & non-patterned surfaces. This means that if your finger was the size of the Earth, you could feel the difference between houses from cars

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KYwda TIL the poles on Saturn are hexagons
Egx1X TIL "1" wasn't considered a number by Ancient Greeks (even Aristotle & Euclid). Numbers were multitudes of units (1 was the unit). "One is the seed of number but not number." This view didn't change til 1701 AD, when 1 was defined as a number in the first math dictionary: "Mathematicks Made Easie"
x64kk TIL Stars appear to twinkle because their light passes through our atmosphere and is bent and distorted by varying temperatures and densities of air
ObX4 TIL that NASA has employed George Aldrich for 40 years as a ‘chief sniffer’. His job being to smell items before they go up to space to make sure no harmful smells will end up on the ISS. His nose also gets 'calibrated’ every 4 months.
wLXdP TIL that the figure in "The Scream" isn't actually screaming; he's listening to a scream passing through nature.