Science in Focus: Shedding Light: Workshop 7

Sun and Seasons

The tilt of the Earth's axis causes the cycle of the seasons. In this workshop we'll discuss how different parts of the Earth receive different amounts of light energy that result in the Earth's seasons. In particular, we will look at the tilt of the Earth's axis and how the hours of daylight change throughout the year. We will also touch on the long-term history of climactic changes on Earth.

Learning Objectives

Participants will be able to:

Describe the apparent motion of the Sun across the sky during a day in winter, spring, summer, and fall using patterns of shadows as supporting evidence.
Explain the reason for varying lengths of daylight in terms of Earth's orbit around the Sun and the angle of Earth's axis relative to the plane of the orbit.
Explain the cycle of the seasons in terms of Earth's orbit around the Sun, the angle of Earth's axis relative to the plane of the orbit, and length of daylight.

Standards

National Science Education Standards

K-4 Standards: http://bob.nap.edu/html/nses/html/6c.html#csck4

The sun provides the light and heat necessary to maintain the temperature of the earth.

Content Standards: K-4: Earth and Space Science: Objects in the Sky
The surface of the earth changes. Some changes are due to slow processes, such as erosion and weathering, and some changes are due to rapid processes, such as landslides, volcanic eruptions, and earthquakes.

Content Standards: K-4: Earth and Space Science: Changes in the Earth and Sky
Weather changes from day to day and over the seasons.

Content Standards: K-4: Earth and Space Science: Changes in the Earth and Sky

5-8 Standards: http://bob.nap.edu/html/nses/html/6d.html#csc58

The solid earth is layered with a lithosphere; hot, convecting mantle; and dense, metallic core.

Content Standards: 5-8: Earth and Space Science: Structure of the Earth System
Water, which covers the majority of the earth's surface, circulates through the crust, oceans, and atmosphere in what is known as the "water cycle." Water evaporates from the earth's surface, rises and cools as it moves to higher elevations, condenses as rain or snow, and falls to the surface where it collects in lakes, oceans, soil, and in rocks underground.

Content Standards: 5-8: Earth and Space Science: Structure of the Earth System
Water is a solvent. As it passes through the water cycle it dissolves minerals and gases and carries them to the oceans.

Content Standards: 5-8: Earth and Space Science: Structure of the Earth System
Clouds, formed by the condensation of water vapor, affect weather and climate.

Content Standards: 5-8: Earth and Space Science: Structure of the Earth System
Fossils provide important evidence of how life and environmental conditions have changed.

Content Standards: 5-8: Earth and Space Science: Earth's History
The sun is the major source of energy for phenomena on the earth's surface, such as growth of plants, winds, ocean currents, and the water cycle. Seasons result from variations in the amount of the sunÕs energy hitting the surface, due to the tilt of the earthÕs rotation on its axis and the length of the day.

Content Standards: 5-8: Earth and Space Science: Earth in the Solar System

American Association for the Advancement of Science (AAAS) Project 2061 Benchmarks

By the end of the 2nd grade, students should know that:

Some events in nature have a repeating pattern. The weather changes some from day to day, but things such as temperature and rain (or snow) tend to be high, low, or medium in the same months every year.

The Physical Setting: 4B The Earth: K-2

By the end of the 2nd grade, students should know that:

Water can be a liquid or a solid and can go back and forth from one form to the other. If water is turned into ice and then the ice is allowed to melt, the amount of water is the same as it was before freezing.

The Physical Setting: 4B The Earth: K-2

By the end of the 5th grade, students should know that:

The earth is one of several planets that orbit the sun, and the moon orbits around the earth. Stars are like the sun, some being smaller and some larger, but so far away that they look like points of light.

The Physical Setting: 4B The Earth: 3-5

By the end of the 8th grade, students should know that:

Energy cannot be created or destroyed, but only changed from one form into another. Most of what goes on in the universeÑfrom exploding stars and biological growth to the operation of machines and the motion of peopleÑinvolves some form of energy being transformed into another.

The Physical Setting: 4E Energy Transformations: 6-8