September 2021 — Sun in Chicago

September 2019

However, technically, the three stages of dusk are as follows:

• At civil dusk, the center of the Sun’s disc goes 6° below the horizon in the evening.
• At nautical dusk, the Sun apparently moves to 12° below the horizon in the evening.
• At astronomical dusk, the Sun’s position is 18° below the horizon in the evening.

Civil Twilight is when the sun is 6 degrees below the horizon and lasts through sunrise for dawn – or sunset to 6 degrees below the horizon for dusk. Nautical Twilight is when the sun is 6-12 degrees below the horizon. Astronomical Twilight is when the sun is 12-18 degrees below the horizon.

Ask Tom: What’s the difference between words dawn/sunrise and dusk/sunset? “Sunset” is the opposite. It occurs the moment the disc of sun completely disappears below the western horizon. Technically, “dusk” is the period of twilight between complete darkness and sunrise (or sunset).

This morning twilight before sunrise is divided into three categories depending on the amount of sunlight that is present in the sky, which is determined by the angular distance of the centre of the Sun (degrees below the horizon) in the morning. These categories are astronomical, nautical, and civil dawn.

In the evening, it begins at sunset and ends when the Sun reaches 6 degrees below the horizon. Civil dawn is the moment when the center of the Sun is 6 degrees below the horizon in the morning. Civil dusk is the moment when the center of the Sun is 6 degrees below the horizon in the evening.

Period before the rising of the sun. The time just before dawn.

Dawn suggests the notions of illumination and hope, the beginning of a new day and thus a chance for happiness and improvement. Sunrise is a symbol of birth and rebirth, of awakening. The coming of light, resurrection.

As a cemetery symbol, the sun represents eternal life, as well as the eternal light of heaven. When you think of it as a sunset, it symbolizes the end of our earthly life. On the other hand, as a sunrise it also reminds us of the promise of new beginnings in the afterlife.

Dawn is a feminine given name. It is of Old English origin, and its meaning is the first appearance of light, daybreak.

1 : the apparent rising of the sun above the horizon also : the accompanying atmospheric effects. 2 : the time when the upper limb of the sun appears above the horizon as a result of the diurnal rotation of the earth. Sunrise. geographical name. Sun·​rise | / ˈsən-ˌrīz /

: the time of day when sunlight first begins to appear : dawn I woke at (the) break of day.

Sunrises and sunsets can appear identical as there is no difference in the light coming from the sun itself at those times and it passes through the same distance of atmosphere. Arguably there are more aerosols and pollutant particles in the air at the end of the day than the start.

At sunrise, the color temperature of the light is always going to be cooler with more bluish tones, because light bounces off less particles in the air, as explained above. Sunsets can produce more colors than sunrises, which is why you do not want to skip on those either.

Because of the spherical geometry of the earth, the sunlight travels longer distance in the thick of the earth’s atmosphere during sunset and sunrise when the Sun is at the horizons than when the Sun is at the zenith (midday). Hence, the Sun (and sunrise and sunset) appears reddish orange during sunset and sunrise.