Experiment - How Long Is The Day?
What time was sunrise today? When will the Sun set tonight? Will those times be the same tomorrow? Are they the same everywhere in the world?
With the help of volunteers, we kept track of the times of sunrise and sunset in several cities around the world. We collected this data each day for a period of a few weeks from August through October, 1998.
Our volunteers provided this data was gathered by watching the Sun rise and set and recording the times, or by checking in the local newspapers. Sunrise and sunset data for anywhere in the world and for any day can be obtained from the Web site of the Australian Surveying and Land Information Group .
Look at our results to see the data from around the world that has been accumulated. What patterns do you see?
What's next?
Learn about how an ancient librarian used observations of the Sun to measure the cricumference of the Earth in How Round Is the Earth?
Result/Solution(s)
We asked volunteers to help us learn about the times of sunrise and sunset around the world. Here are the results received by SEED from several locations around the globe. The data were collected from August 30 to October 25, 1998. What patterns do you see?
September 23, 1998, was the Equinox, the first day of spring in the Southern Hemisphere and the first day of autumn in the Northern Hemisphere. On this day, the Earth's angle to the Sun was perpendicular to its rotational axis, so that the Sun shone equally on the Northern and Southern Hemispheres. Every spot on the Earth was in the Sun for one-half a rotation, or half a day. You may notice that the locations in our experiment all reported a few minutes more than 12 hours. Why do you think this is?
Date
Sunrise
Sunset
August 30
6:21 a.m.
7:32 p.m.
August 31
6:22 a.m.
7:30 p.m.
September 1
6:23 a.m.
7:29 p.m.
September 2
6:24 a.m.
7:27 p.m.
September 3
6:25 a.m.
7:26 p.m.
September 4
6:26 a.m.
7:24 p.m.
September 5
6:27 a.m.
7:22 p.m.
September 6
6:28 a.m.
7:21 p.m.
September 7
6:29 a.m.
7:19 p.m.
September 8
6:30 a.m.
7:17 p.m.
September 9
6:31 a.m.
7:16 p.m.
September 10
6:32 a.m.
7:14 p.m.
September 11
6:33 a.m.
7:12 p.m.
September 13
6:35 a.m.
7:09 p.m.
September 14
6:36 a.m.
7:07 p.m.
September 16
6:38 a.m.
7:04 p.m.
September 17
6:39 a.m.
7:02 p.m.
September 18
6:40 a.m.
7:00 p.m.
September 19
6:41 a.m.
6:59 p.m.
September 20
6:42 a.m.
6:57 p.m.
September 21
6:43 a.m.
6:55 p.m.
September 22
6:44 a.m.
6:54 p.m.
September 23
6:45 a.m.
6:52 p.m.
September 24
6:46 a.m.
6:50 p.m.
September 25
6:47 a.m.
6:49 p.m.
September 26
6:48 a.m.
6:47 p.m.
September 27
6:49 a.m.
6:45 p.m.
September 28
6:50 a.m.
6:44 p.m.
September 29
6:51 a.m.
6:42 p.m.
Data submitted by Mary Wyatt
Date
Sunrise
Sunset
August 31
6:29 a.m.
9:13 p.m.
September 1
6:32 a.m.
9:10 p.m.
September 2
6:35 a.m.
9:06 p.m.
September 3
6:38 a.m.
9:02 p.m.
September 8
6:53 a.m.
8:44 p.m.
September 9
6:56 a.m.
8:40 p.m.
September 10
6:59 a.m.
8:37 p.m.
September 11
7:02 a.m.
8:33 p.m.
September 14
7:11 a.m.
8:22 p.m.
September 15
7:14 a.m.
8:18 p.m.
September 16
7:17 a.m.
8:15 p.m.
September 18
7:23 a.m.
8:07 p.m.
September 20
7:29 a.m.
8:00 p.m.
September 21
7:32 a.m.
7:56 p.m.
September 22
7:35 a.m.
7:53 p.m.
September 23
7:38 a.m.
7:49 p.m.
September 24
7:41 a.m.
7:45 p.m.
September 25
7:44 a.m.
7:42 p.m.
September 26
7:47 a.m.
7:38 p.m.
September 27
7:50 a.m.
7:34 p.m.
September 28
7:53 a.m.
7:31 p.m.
October 3
8:08 a.m.
7:13 p.m.
October 4
8:11 a.m.
7:09 p.m.
October 6
8:17 a.m.
7:02 p.m.
October 8
8:23 a.m.
6:55 p.m.
October 9
8:26 a.m.
6:51 p.m.
October 10
8:29 a.m.
6:47 p.m.
October 11
8:32 a.m.
6:44 p.m.
October 12
8:35 a.m.
6:40 p.m.
October 13
8:38 a.m.
6:37 p.m.
October 14
8:42 a.m.
6:33 p.m.
October 15
8:45 a.m.
6:29 p.m.
October 16
8:48 a.m.
6:26 p.m.
October 17
8:51 a.m.
6:22 p.m.
October 18
8:54 a.m.
6:19 p.m.
October 19
8:57 a.m.
6:15 p.m.
October 20
9:00 a.m.
6:12 p.m.
October 21
9:04 a.m.
6:08 p.m.
October 22
9:07 a.m.
6:05 p.m.
October 23
9:10 a.m.
6:01 p.m.
October 24
9:13 a.m.
5:58 p.m.
October 25
8:17 a.m.
4:54 p.m.
Data submitted by Susan van Gelder
Date
Sunrise
Sunset
August 31
6:14 a.m.
7:37 p.m.
September 1
6:15 a.m.
7:35 p.m.
September 2
6:16 a.m.
7:33 p.m.
September 3
6:19 a.m.
7:29 p.m.
September 4
6:20 a.m.
7:27 p.m.
September 6
6:22 a.m.
7:24 p.m.
September 8
6:25 a.m.
7:20 p.m.
September 9
6:26 a.m.
7:18 p.m.
September 10
6:27 a.m.
7:16 p.m.
September 11
6:28 a.m.
7:14 p.m.
September 12
6:30 a.m.
7:12 p.m.
September 13
6:31 a.m.
7:10 p.m.
September 14
6:32 a.m.
7:08 p.m.
September 15
6:33 a.m.
7:06 p.m.
September 16
6:34 a.m.
7:04 p.m.
September 17
6:36 a.m.
7:02 p.m.
September 18
6:37 a.m.
7:01 p.m.
September 19
6:38 a.m.
6:59 p.m.
September 21
6:40 a.m.
6:55 p.m.
September 22
6:41 a.m.
6:53 p.m.
September 23
6:43 a.m.
6:51 p.m.
September 27
6:48 a.m.
6:43 p.m.
September 28
6:49 a.m.
6:41 p.m.
September 29
6:51 a.m.
6:39 p.m.
September 30
6:52 a.m.
6:37 p.m.
October 2
6:54 a.m.
6:34 p.m.
October 3
6:56 a.m.
6:32 p.m.
October 4
6:57 a.m.
6:30 p.m.
October 6
6:59 a.m.
6:26 p.m.
October 7
7:01 a.m.
6:24 p.m.
October 8
7:02 a.m.
6:22 p.m.
October 9
7:03 a.m.
6:21 p.m.
October 10
7:05 a.m.
6:19 p.m.
October 12
7:07 a.m.
6:15 p.m.
October 13
7:08 a.m.
6:13 p.m.
October 14
7:10 a.m.
6:12 p.m.
October 15
7:11 a.m.
6:10 p.m.
October 16
7:12 a.m.
6:08 p.m.
October 17
7:14 a.m.
6:06 p.m.
October 18
7:15 a.m.
6:05 p.m.
Data submitted by Jeff Richardson
Date
Sunrise
Sunset
September 1
6:42 a.m.
5:58 p.m.
September 2
6:41 a.m.
5:59 p.m.
September 3
6:39 a.m.
6:00 p.m.
September 4
6:38 a.m.
6:01 p.m.
Data submitted by Horacio and Natalia Reggini
Date
Sunrise
Sunset
September 17
6:52 a.m.
6:46 p.m.
September 21
6:44 a.m.
6:49 p.m..
September 22
6:43 a.m.
6:50 p.m.
September 23
6:41 a.m.
6:50 p.m.
September 24
6:40 a.m.
6:51 p.m.
September 25
6:39 a.m.
6:52 p.m.
September 27
6:36 a.m.
6:53 p.m.
September 28
6:35 a.m.
6:54 p.m.
September 29
6:33 a.m.
6:55 p.m.
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