Watch these Harvard men and women fail to grasp the full concept of seasons. This 1989 video asked alumni and faculty at a Harvard commencement why Earth has seasons. A majority of them held misconceptions about the science of the seasons or the phases of the moon.
A sensible explanation for the seasons is that Earth is closer to the sun during the summer, and farther away in the winter. Actually, in the Northern Hemisphere, the opposite occurs.
Seasons are caused by Earth's axial tilt, not its distance from the sun. Earth rotates at a tilt of about 23.4 degrees, so that summer occurs in the hemisphere that's closer while winter happens in the hemisphere that's tilted away. It's true that the entire Earth is closer to the sun during some parts of the year than others (it circulates in an ellipse, not a perfect circle). However, summer actually occurs in the Northern Hemisphere when the Earth is farthest from the sun, simply because it's tilted toward the sun at that time.
One 2002 Estonian study by Eve Kikas asked 198 teachers to evaluate the validity of four explanations of the seasons. Of the 30 physics and chemistry teachers surveyed, 67 percent found explanations based on misconceptions either mainly or totally correct. Yet 93 percent also identified the correct explanation as mainly or totally true. A few researchers claim that the general confusion may stem from the diagram used to show Earth's elliptical orbit around the sun, which may leave teachers to reason that distance determines the seasons.
