Nyctophiles and Night

Night image from Pixabay

I came across the word nyctophile and had to look it up. Nyctophile (noun) is a person who has a special love for night and darkness. I think I am one of those people.

This word has Greek origins – nyktos literally means night and‎ philos stands for love. We have a lot of words using phile from phileein meaning to love or to show a love of something. Bibliophiles love books. Cinephiles love the cinema. Astrophiles love astronomy and the stars. I am all of those things.

I do like (love?) nighttime and I am more active at night (nocturnal? not really). But I started to wonder what the actual difference is (if there actually is a difference) between words like night, dusk, evening, nightfall, twilight, eventide, and sundown. When is it officially "night"?

Dusk, evening and twilight are commonly used interchangeably to mean the period from sunset/sundown until nighttime. But I've also seen nightfall, eventide used for that period. I don't think anyone would correct you if at sundown you said "I love the light at dusk." 

Looking up these terms it seems that "dusk" is a period of time occurring at the end of the day during which the sunsets. "Evening" is the time of the day between dusk and night, when it gets dark. Dusk occurs when the geometric center of the Sun is 18° below the horizon in the evening.

In the 48 contiguous U.S. states, it takes anywhere from 70 to 100 minutes for it to get dark after sunset and the further north you are, the longer it takes for true darkness to arrive after sundown.

What about twilight? That is the time between daylight and darkness and seems to be applied to the time after sunset and also before sunrise when the light appears diffused and often pinkish. The sun is below the horizon, but its rays are still scattering because of the Earth's atmosphere to create the colors. So, there are two twilights - the periods between the dawn and sunrise, and the time between sunset and dusk.

Is that clear or more confusing? By the way, sunrise and sunset are defined as the exact times when the upper edge of the disc of the Sun is at the horizon. That's an easy one to identify.