Terminology[edit]
For the terms "civil twilight" and "astronomical twilight", see Twilight#Definitions
Sunset is the point at which the Sun is first completely below the horizon marking the start of twilight. It should not be confused with dusk, which occurs at the end of twilight.
Historically[edit]
The 16th-century astronomer Nicolaus Copernicus was the first to present to the world a detailed and eventually widely accepted mathematical model supporting the premise that the Earth is moving and the Sun actually stays still, despite the impression from our point of view of a moving Sun.[1]