Does that mean the time that the sun starts to set or does that mean the sun has completely set? If it means that the sun is beginning to set, how long does it take for the sun to completely set?
2006-09-25 08:48:22 · 4 answers · asked by M C 2 in Science & Mathematics ➔ Astronomy & Space
The times listed for sunrise and sunset refer to the time when the upper edge of the Sun is at the horizon, so the time stated for sunset would be the time that the Sun has completely set.
Keep in mind that even within one town, there are observable differences in the horizon's appearance, based on whether you are standing in front of city hall downtown, or sitting in the top of a bell tower. So, the time of the sunset can differ by several minutes in each location within the same town.
As far as how long it takes for the sun to set, the time fluctuates throughout the year, but it's around 3 minutes.
Hope this helps!
2006-09-25 09:19:22 · answer #1 · answered by norcalirish 4 · 0⤊ 0⤋
Normally sunset is considered to be when the last little part of the Sun disappears below the horizon.
The Sun appears 1/2 degree wide in the sky, and the whole sky is 360 degrees around, including the half below the horizon, so the sun is 1/720th of the sky wide. It moves around the sky in 24 hours so it takes 24/720 = 1/30 of an hour, or two minutes, to travel its own diameter. So it takes 2 minutes from the time it touches the horizon until is is completely below the horizon. That is just approximate, there are many complications, the biggest of which is that the Sun is not normally not moving straight down to the horizon as it sets, unless you are at the equator, so real sunsets at high latitudes take longer. At the north pole it takes many hours to set, and then it stays set for the whole winter.
2006-09-25 16:08:20 · answer #2 · answered by campbelp2002 7 · 1⤊ 0⤋
The newspaper time for sunset usually means the time the sun has dipped below the horizon. Twilight persists for about 25 minutes after this.
Here is a site that will give you times for twilight as well as sunset, so you can know not only when the sun will set, but when it will get dark: http://www.cmpsolv.com/los/sunset.html
2006-09-25 17:06:21 · answer #3 · answered by Jack D 2 · 0⤊ 0⤋
good question! It's the difference between astronomical twilight, nautical twilight, etc. I don't know exactly so I'll let someone else answer.
2006-09-25 15:51:57 · answer #4 · answered by Matt 3 · 0⤊ 0⤋