Ancient Roman concrete arches contained volcanic ash, which helped them self-heal when cracks formed by reacting with water. This made them incredibly durable, lasting for millennia.
In Japanese mythology, Oni can mean a variety of things like demon, troll, orc or ogre. Children play "oni gokko", which is the same as Tag, but who is "it" is called "the oni"
Various observations of distant galaxies have shown that the universe is expanding at an enormous rate. Other data show that it is gradually cooling, leading to the possibility that the universe will end when it freezes.
The first photo of a person was an accident. In 1838, Louis Daguerre took a photo of a Paris street that appeared empty due to the long exposure time—except for a man getting his boots shined, who stood still long enough to appear in the image.
