Here Comes the Sun

Technically, George Harrison got it wrong in the Beatles song “Here Comes the Sun.” In the heavens, the Sun doesn’t move. Relative to us the Sun’s position is fixed at the center of the Solar System. Instead of the Sun coming to us, we on the planet Earth move along the with Earth as it revolves around the Sun.
One revolution around the Sun takes 365 days or one year. During a year we on the Earth experience the seasonal change between the period of longer days and warmer temperatures known as summer and the period of shorter days and cooler temperatures known as winter.
This seasonal change is caused by the fact that the Earth is tilted on its axis by 23.5° relative to its orbit around the sun. Because of this tilt, for a half year--or winter--the Northern Hemisphere is tilted away from the Sun, while the Southern Hemisphere is toward the Sun. Then the tilt reverses for the other half year--or summer.
From our viewpoint on the Earth, the Sun appears to traverse between north and south as the Earth's tilt toward/from the Sun changes during a year. Thus, George Harrison got it right in terms of how we experience the changes in the Earth's relative position to the Sun. In the Northern Hemisphere, the Earth's tilt from the Sun is at maximum on winter solstice or December 21. The day is at its shortest. There is variation in the length of the day according to your geographical position on the Earth. The further up north you are on the Earth, the greater the tilt from the sun and less sunlight you receive during the winter.
How one’s geographical position affects the variation in day length is illustrated by the difference in the length of days in Helsinki and New York. Helsinki lies about 40 degrees higher up in the north than New York. The charts below illustrate how the effect of this difference. The charts show the times for sunset and sunrise. In the middle of the bars is in the length of the day in hours and minutes.

On December 21, when day is at its shortest in the Northern Hemisphere, it is 5 hours and 56 minutes long in Helsinki, which lies roughly at the same latitude as Anchorage, Alaska. In New York the day is 9 hours and 18 minutes long or about 50 percent longer than in Helsinki. At the other extreme on the summer solstice on June 21, the day is 19 hours and 5 minutes in Helsinki and 15 hours and 9 minutes in New York. So in both locations there is marked difference in the length of the days due to seasonal changes.

This webpage was created by Juhana Rossi. More info about me can be found behind this link. Data and notebooks used to gather it can be found in this GitHub repository.