› added 28 minutes ago

TIL that swell sharks and catsharks glow underwater so they can "talk" to each other. The glow can also protect them from bacteria.

Read more universityofcalifornia.edu

via reddit.com

XEROj TIL that Inuit in northern Greenland were using iron blades for centuries without knowledge of metallurgy. They made them by breaking pieces off of a huge iron meteorite and shaping them with heavy stones. They built their settlements close to the meteorite and used its iron for generations.
epdGk TIL that Sharpie can’t make a white permanent marker
kp5m TIL prior to WWII in Nazi Germany, a group of German teens known as the Edelweiss Pirates rebelled against the authoritarian Nazi regime.They intermingled with the opposite sex, grew their hair long, and wore outlawed clothes.During WWII,many spread Ally propaganda and assisted German army deserters
OwaX TIL Police officers are blue because they were originally surplus US army uniforms after the civil war
wLvAo TIL the worlds smallest playable guitar is 10 microns long (about the size of a red blood cell). It has six strings each about 100 atoms wide and is played by aiming lasers at the strings. Its tone is about 130,000 times higher than a regular guitar supposedly the highest pitch ever recorded.