confocal (not comparable)
(optics, mathematics) Having the same foci
confocal (plural confocals)
Any of a pair of confocal mirrors or lenses
Source: Wiktionary
Con*fo"cal, a. (Math.)
Definition: Having the same foci; as, confocal quadrics.
Source: Webster’s Unabridged Dictionary 1913 Edition
7 June 2025
(noun) a unit of astronomical length based on the distance from Earth at which stellar parallax is 1 second of arc; equivalent to 3.262 light years
Coffee dates back to the 9th century. Goat herders in Ethiopia noticed their goats seem to be “dancing” after eating berries from a particular shrub. They reported it to the local monastery, and a monk made a drink out of it. The monk found out he felt energized and kept him awake at night. That’s how the first coffee drink was born.
