[/caption] Ephemerides is the plural form of ephemeris; one ephemeris, two (three, four, …) ephemerides. Why such a strange word? Why not ‘ephemerises’? Because of its Greek-via-Latin origin, and because it’s a word rarely used outside an academic/technical setting (there are only a few other words in English which form plurals in this way, one … Continue reading "Ephemerides"