Recently, I was in an exchange with a girl in London. In my
novel, I mentioned it getting dark around 9:00 PM in mid June. She commented
that it does not get dark in mid June until 10:00PM. So, who was right? If you have a knowledge of physical
geography, you know we both were.
The discrepancy comes from the fact the difference in the
lengths of days by season is greater in the high latitudes (areas closer to the
poles) than the low latitudes (areas closer to the equator).
The novel I was writing takes place in the Ozarks,
approximate latitude 37 degrees north, while London is at latitude 52 degrees north. If you know the latitude of
a location, it's easy to calculate sunrise and sunset for that location by
using an online generator such as the one here: http://aa.usno.navy.mil/data/docs/RS_OneDay.php
. Sunset at 52 degrees north (London, UK) occurs at 8:24 on June 21. At latitude 37 degrees north (Springfield,
MO) the sun sets at 7:23 on this date.
I have compiled a small table mentioning selected cities,
their latitudes, and the time of sunrise and sunset on June 21 and December 21.
No adjustment for how far east or west of their time zone has been made.
City Lat. June 21 Dec. 21
Rise Set Rise
Set
London UK 52 3:40
am 8:24 pm 7:25 am 4:31 pm
New York NY 41 4:28 am 7:36
pm 6:50 am 5:06
pm
Springifeld MO 37 4:41 am 7:23
pm 6:40 am 5:16 pm
New Orleans LA 30 4:59
am 7:04 pm 6:25
am 5:32 pm
As you can see from the table, the sun rises an hour
earlier in London than it does in Springfield and sets an hour later. In winter
it's nearly reversed, with sunrise forty-five minutes later in London and
setting forty-five minutes later. Furthermore, the length of days varies more
for high-latitude locations than low-latitude locations.
It does not get instantly dark the moment the sun sets. There
is a period of twilight. As a general rule there is enough twilight to read a
book a half hour before sunrise or after sunset, there's enough twilight to
make out basic land features a full hour before sunrise or after sunset. Twilight lasts longer the closer to the poles
you get. Of course, this assumes a clear sky.
Depending on cloud cover, the twilight could be nonexistent.
While studying to make your novel as authentic as possible,
don't forget about the effects of latitude on your setting. Now that you know
the secret, you have the knowledge to make your novel that much more realistic.
Fascinating. That's something I never thought about directly, although I did look up the sunrise and sunset times for the date and location of my novel as I was writing, so I indirectly took that into account.
ReplyDeleteA lot of authors wouldn't have thought to do that. It's why I wrote the article in the first place.
ReplyDeleteGood tips. Thanks for sharing.
ReplyDeleteWhen I've edited books, I've often looked up sunrise or sunrise, or moonrise and phases for authors. It's something that is a good attention for detail and while it might not lose you a reader, it can give you an opportunity to raise a reader's confidence in your storytelling.
ReplyDelete