Yea, so for kicks and giggles I looked up Sunsets on Wikipedia, and yes, they DO have an article about sunsets! They have just about everything on wikipedia, so check out this from Wikipedia:

Sunset or sundown is the daily disappearance of the Sun below the horizon in the west as a result of Earth’s rotation.

The time of sunset is defined in astronomy as the moment the trailing edge of the Sun’s disk disappears below the horizon in the west. The ray path of light from the setting Sun is highly distorted near the horizon because ofatmospheric refraction, making astronomical sunset occur when the Sun’s disk is already about one diameter below the horizon. Sunset is distinct from dusk, which is the moment at which darkness falls, which occurs when the Sun is approximately eighteen degrees below the horizon. The period between the astronomical sunset and dusk is called twilight. (Not to be confused with story books about homo vampires)

Locations north of the Arctic Circle and south of the Antarctic Circle experience no sunset or sunrise at least one day of the year, when the polar day or the polar night persist continuously for 24 hours.

Sunset creates unique atmospheric conditions such as the often intense orange and red colors of the Sun and the surrounding sky.

I think there is a time to say, ok, we get it, just about everything that can be written, is written on wikipedia.