Has there ever been a sunrise that was not followed by a sunset?
In the history of sunrises and sunsets, has there ever been a sunrise that was not followed by a sunset?
— Henry, Joliet
No, there has not. It is a matter of geography: The Earth rotates on its axis and every spot on its surface experiences a sunrise that is followed by a sunset. However, the Earth’s axis of rotation is tilted 23.5 degrees to the plane of its orbit around the sun. Consequently, the hours of daylight and darkness at a given location on the planet vary during the course of the year. In the polar regions, the “day” is six months in length; that is, the sun remains above the horizon for half of the year and is below the horizon for the other six months. At the equator, the hours of daylight and darkness are almost exactly 12 hours each through the year.