A Globe Walk Modeling the Reasons for the Seasons

Models are tentative schemes or structures that correspond to real objects, events, or classes of events, and that have explanatory power……. The National Science Education Standards (Page 117); National Academy Press 1998.

A Class of Events Earth Rotates on Its AxisEarth Rotates on Its Axis Earth is Tilted on its AxisEarth is Tilted on its Axis Earths Revolves in an Orbit around the SunEarths Revolves in an Orbit around the Sun Earths Orbital Radius is Constantly Changing.Earths Orbital Radius is Constantly Changing. The Lengths of Daytimes Gradually Change as the Seasons Change.The Lengths of Daytimes Gradually Change as the Seasons Change. The Altitudes of the Sun Gradually Change during a Day and as the Seasons Change.The Altitudes of the Sun Gradually Change during a Day and as the Seasons Change. Seasonal changes are most dramatic in the Polar Regions.Seasonal changes are most dramatic in the Polar Regions.

Most students are aware of seasonal changes in lengths of daytime but may not know that they depend on Latitude.

Students are probably less aware of seasonal changes in the altitude of the sun. Today, the midday altitude of the sun in Kotzebue, Alaska is 44.8º at 1:55 PM Alaska Standard Time. Today, the midday altitude of the sun in Kotzebue, Alaska is 44.8º at 1:55 PM Alaska Standard Time. The Distant Horizon A U.S. Naval Observatory web site provides the suns altitude on any day at any Latitude.

Kotzebue, Alaska is located 33 miles north of the Arctic Circle You can learn more about Kotzebue by visiting their web site You can learn more about Kotzebue by visiting their web site.

Today, the midday altitude of the sun in Amherst is 69.4º at 11:50 AM Eastern Standard Time Today, the midday altitude of the sun in Amherst is 69.4º at 11:50 AM Eastern Standard Time. The Distant Horizon A U.S. Naval Observatory web site provides the suns altitude on any day at any Latitude.

Diagrams have limited value illustrating seasonal changes in the altitude of the sun and lengths of daytime

Animations can more effectively reveal aspects of seasonal changes such as the lengths of daytimes in the Polar Regions. mations/01_EarthSun_E2.html

The Globe Walk A classroom, a model of the sun, a model of Earth, a representation of Earths orbit, two straws, and a protractor can be used to demonstrate a variety of daily and seasonal changes. A classroom, a model of the sun, a model of Earth, a representation of Earths orbit, two straws, and a protractor can be used to demonstrate a variety of daily and seasonal changes.

A Demonstration of Solstices and Equinoxes The 2010 Astronomical Seasons (for the Northern Hemisphere) Spring began at 12:32 PM EST on March 20 th Summer began at 6:28 AM EST on June 21 st Autumn will begin at 10:09 EST on September 21 st \ Winter will begin at 6:38 PM EST on December 21 st

Other Globe Walk Demonstrations Include: Changes in the altitude of the sun at different Latitudes as the seasons change.Changes in the altitude of the sun at different Latitudes as the seasons change. Changes in the Lengths of Daytimes at different Latitudes as the seasons change.Changes in the Lengths of Daytimes at different Latitudes as the seasons change. Summer Solstice at the North Pole.Summer Solstice at the North Pole. Daily changes in the Altitude of the Sun.Daily changes in the Altitude of the Sun.