The Inquiring Minds Program

Online Newsletter for Inquiring Minds

The Reason for the Seasons

Unless you live near the equator you will likely have noticed that the seasons change throughout the year. On our planet Earth the year can be separated into four distinct seasons: summer, autumn, winter, and spring. Each season brings with it physical changes in weather, temperature, and the length of daylight. We also mark the change of seasons with special events and activities, with changes in fashion and food -- even our attitudes may change.

Throughout history many different cultures have created stories and reasons to explain the seasons:

The annual seasons happen because of two reasons:

Try this!
To help understand the tilt of the Earth as it goes around the sun, point at an object across the room that isn't moving and walk in a circle around a friend while he or she remains in place. Remember to keep pointing at the object across the room; this way you are always pointing in the same direction, no matter how you move. As you "orbit your friend", observe that the direction you are pointing sometimes goes directly toward your friend, sometimes directly away from him and sometimes to the side; the Earth behaves in the same way toward the sun.
Source: National Geographic Xpeditions

Other Activities & Web Sites to Help Explain the Seasons:

Because the direction of the Earth's tilt changes in relation to the sun, the northern and southern halves (hemispheres) of our planet get different amounts of sunlight throughout the year. When the Northern Hemisphere of the Earth is leaning toward the sun, it receives direct rays of sunlight and is warmer, while the Southern Hemisphere receives more indirect rays. When the northern part of the Earth is leaning away from the sun, the situation is reversed—the Northern Hemisphere gets cooler, more indirect sunlight while the southern half receives direct rays and experiences warmer temperatures. Because of this, the seasons in the Northern and Southern Hemispheres are reversed.

The summer solstice is the first day of summer and the longest day of the year. In the Northern Hemisphere the summer begins on or near June 21st, when the North Pole is leaning more directly toward the sun than it does on any other day. In the Southern Hemisphere summer begins on or near December 21st.

Celebrations:
The Summer Solstice
World Humanist Day

 

The winter solstice is the first day of winter and the shortest day of the year. In the Northern Hemisphere the winter begins on or near December 21st, when the North Pole is leaning away from the sun. In the Southern Hemisphere winter beings on or near June 21st.

Celebrations:
The Winter Solstice
HumanLight
Human Rights Day
Reality Revival
Darwin Day

 

The autumn equinox marks the beginning of fall and is a transitional period between the summer and winter seasons. In the Northern Hemisphere autumn begins on or near September 22nd, when the North Pole begins to lean away from the sun. In the Southern Hemisphere autumn beings on or near March 20th.

Celebrations:
The Autumn Equinox
Banned Books Week
Separation of Church
& State Week

Halloween

The vernal equinox marks the beginning of spring and is a transitional period between the winter and summer seasons. In the Northern Hemisphere autumn begins on or near March 20th, when the North Pole begins to lean toward the sun. In the Southern Hemisphere autumn beings on or near September 22nd.

Center for Inquiry | CSICOP | Inquiring Minds | ©2005 Committee for the Scientific Investigation of Claims of the Paranormal