What name has been given to the two days of the year when the length of a "day", i.e. time between sunrise and sunset, is the shortest at the equator?

DarcyJ

Equinox equinox (noun) 1 : either of the two points on the celestial sphere where the celestial equator intersects the ecliptic; 2 : either of the two times each year (as about March 21 and September 23) when the sun crosses the equator and day and night are everywhere of equal length Jun 22 04, 8:35 PM

in my opinion

Quite a tropical question. The solstice is the point in the sky where the ecliptic is furthest from the celestial equator by 23.5°. When the Sun is at the solstice point we have either the longest amount of daylight (summer: June 21 for northern hemisphere) or the shortest amount of daylight (winter: December 21 for northern hemisphere). http://www.astronomynotes.com/glossary/glosss.htm Jun 22 04, 9:01 PM

harish_256

Solstice is the correct answer, that is when ecliptic is furthest from the equator, as IMO said. No, this isn't a trick question ... the day and night is equal on the equator only during the equinoxes (March 21 and September 23). (All this is assuming that the Sun is a point source of light, which I should've mentioned in the question; sorry about that.) Jun 23 04, 7:57 AM