It's hard to believe that the spring equinox was just
yesterday! The weather hasn't shown much springlike
behavior. However, the astronomical seasons progress
regardless of the weather. Yesterday marked the vernal
equinox, when the nights are equal in length to the
days. The photo on the left is sunrise at 7:49 am
EDT. The photo on the left is taken almost 12 hours
later at 7:39 pm EDT, at sunset looking back east where the
sun rose. If you look carefully on the right-hand
photo, sunlight is still shining on the distant mountain
range. The reason these photos miss the 12 hour
interval by about 10 minutes is attributed to the morning
sunrise coming a little later due to the uneven horizon
(mountains) that the Sun must overcome and the evening
sunset is a bit earlier for the same reason.
From the spring equinox until the summer solstice, the days
will become longer and the nights shorter. At North
Carolina's latitude, there will be about 15 hours between
sunrise and sunset at the June solstice.
Happy springtime, everybody!
Physics Photo of the Week is published weekly during the academic year on Fridays by the Warren Wilson College Physics Department. These photos feature interesting phenomena in the world around us. Students, faculty, and others are invited to submit digital (or film) photographs for publication and explanation. Atmospheric phenomena are especially welcome. Please send any photos to firstname.lastname@example.org.
All photos and discussions are copyright by Donald Collins or by the person credited for the photo and/or discussion. These photos and discussions may be used for private individual use or educational use. Any commercial use without written permission of the photoprovider is forbidden.