› added 4 years ago

297

TIL that although it is believed that serotonin deficiency plays a role in depression, there have not been any studies proving that brain levels of this or any neurotransmitter are in short supply when any mental illness develops

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xV6Gb TIL that in 1975, Gary Dahl invented the pet rock. He took rocks from a Mexico beach and, over the course of only half a year, would sell each rock for $4, making himself over $1.5M.
a0vM TIL Teddy Roosevelt was a staunch conservationist and banned Christmas trees from the White House
N7w8P TIL that barbers in the Middle Ages performed surgery such as limb amputation, bloodletting and tooth pulling in addition to cutting hair. They were known as ‘barber surgeons’ and the red and white barber pole signified blood and bandages.
GBYN TIL Germany has ‘Tauchgondeln’ [diving gondolas]. They’re tourist attractions where a pressurized room on a pole gets lowered down into the sea. They’re unique to Germany and there are only four of them.
4XD4X TIL Friction ridge skin impressions (fingerprints) were used as proof of a person’s identity in China over 2000yrs ago.