Five Odd Science-Inspired Units of Measurement
The metric system is great, but sometimes it simply doesn't do justice to what you're trying to describe. These highly-specialized units of measurement might be of use!
Sagan. Inspired by and in tribute to astrophysicist and science communicator Carl Sagan, the "Sagan" plays off Sagan's tendency to say "billions and billions," often in reference to stars, galaxies, or planets in the Universe. It's defined as a "large quantity of anything."
Banana equivalent dose. A little considered fact: bananas are radioactive. The potassium-40 in your average banana imparts roughly 0.1 microsieverts of ionizing radiation when consumed. "Banana equivalent dose" (BED) refers to that amount. For refence, it would take about 35,000,000 BEDs to kill a human.
Barn. If you can't hit the broad side of a "barn", don't feel too bad about yourself. Nuclear physicists regularly use the term to describe a cross section of 10-24 cm2, roughly equal to the cross section of an atomic nuclei. The term originated out of the Manhattan Project back in 1942, and was actually kept classified until 1948. It's been widely used by nuclear and particle physicists ever since.
Foe. A stellar supernova is one mighty blast. In an instant, a dying star explodes, expelling its guts out into space at up to 10% of the speed of light. As you might imagine, the process releases an awesome amount of energy, so much, in fact, that astrophysicists Gerald Brown and Hans Benthe created a unit of measurement for it. Your average supernova releases about one "Foe" of energy, equal to 1044 joules.
Beard-Second. The light-second is defined as the distance a particle of light travels in exactly one second, and is equal to roughly 186,282 miles. That's quite a distance. As Kemp Bennet Kolb espoused in the humorous book This Book Warps Space and Time, there ought to be a comparable unit for defining things on the small-scale. He proposed the beard-second: "the distance that a standard beard grows in one second." It's equal to roughly ten nanometers.