• Support an argument that the gravitational force exerted by Earth on objects is directed down. (5-PS2-1)

• Each force acts on one particular object and has both strength and a direction. An object at rest typically has multiple forces acting on it, but they add to give zero net force on the object. Forces that do not sum to zero can cause changes in the object's speed or direction of motion. (Boundary: Qualitative and conceptual, but not quantitative addition of forces are used at this level.) (3)
• The patterns of an object's motion in various situations can be observed and measured; when that past motion exhibits a regular pattern, future motion can be predicted from it. (Boundary: Technical terms, such as magnitude, velocity, momentum, and vector quantity, are not introduced at this level, but the concept that some quantities need both size and direction to be described is developed.) (3)

• The gravitational force of Earth acting on an object near Earth's surface pulls that object toward the planet's center. (5)

• The orbits of Earth around the sun and of the moon around Earth, together with the rotation of Earth about an axis between its North and South poles, cause observable patterns. These include day and night; daily changes in the length and direction of shadows; and different positions of the sun, moon, and stars at different times of the day, month, and year. (5)

• Patterns can be used as evidence to support an explanation. (4)

• Science assumes consistent patterns in natural systems. (3-5)

• Constructing explanations and designing solutions in 3–5 builds on K–2 experiences and progresses to the use of evidence in constructing explanations that specify variables that describe and predict phenomena and in designing multiple solutions to design problems. (3-5)
  • Use evidence (e.g., observations, patterns) to construct an explanation. (3)
  • Identify the evidence that supports particular points in an explanation. (4)

• Constructing explanations and designing solutions in 3–5 builds on K–2 experiences and progresses to the use of evidence in constructing explanations that specify variables that describe and predict phenomena and in designing multiple solutions to design problems. (3-5)

• 3-5: 4B/E1. Things on or near the earth are pulled toward it by the earth's gravity.
• 3-5: 4B/E2bc. The rotation of the earth on its axis every 24 hours produces the night-and-day cycle. To people on earth, this turning of the planet makes it seem as though the sun, moon, planets, and stars are orbiting the earth once a day.
• 6-8: 4B/M3. Everything on or anywhere near the earth is pulled toward the earth's center by gravitational force.

• 3-5: 4G/E1. The earth's gravity pulls any object on or near the earth toward it without touching it.

• 3-5: 11C/E4. Some things in nature have a repeating pattern, such as the day-night cycle, the phases of the moon, and seasons.

• 3-5: 12E/E3. Seek reasons for believing something rather than just claiming "Everybody knows that…" or "I just know" and discount such claims when made by others.

How did scientists first directly demonstrate that the Earth rotates? This short video, seen through the eyes of a child, explores the work of French scientist Leon Foucault -- a pendulum seems to rotate as it swings, but there is no external force that would cause the rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern). Through experiments, Foucault showed that it's not the pendulum doing the rotating. It's the steady, predictable movement of the Earth's rotation on its axis.

• Physical Sciences K-8 Planetary Motion Unit

How did scientists first directly demonstrate that the Earth rotates? This short video, seen through the eyes of a child, explores the work of French scientist Leon Foucault -- a pendulum seems to rotate as it swings, but there is no external force that would cause the rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern). Through experiments, Foucault showed that it's not the pendulum doing the rotating. It's the steady, predictable movement of the Earth's rotation.

• Physical Sciences K-8 The Universal Law of Gravitation Unit

This 4-minute video stars a boy who is concerned about spinning off into space, until he is introduced to a Foucault pendulum. The video does an excellent job of explaining how the motion of a pendulum demonstrates that the Earth is rotating on its axis. The pendulum is located at the Lexington, KY, public library, and is itself a thing of beauty.

• Physical Sciences K-8 Conservation of Energy and Forces on a Spring Unit

How did scientists first directly demonstrate that the Earth rotates? This short video, seen through the eyes of a child, explores the work of French scientist Leon Foucault -- a pendulum seems to rotate as it swings, but there is no external force that would cause the rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern). Through experiments, Foucault showed that it's not the pendulum doing the rotating. It's the steady, predictable movement of the Earth's rotation on its axis.

• Physical Sciences K-8 Astronomy: An Historical Perspective Unit

How did scientists first directly demonstrate that the Earth rotates? This short video, seen through the eyes of a child, explores the work of French scientist Leon Foucault -- a pendulum seems to rotate as it swings, but there is no external force that would cause the rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern). Through experiments, Foucault showed that it's not the pendulum doing the rotating. It's the steady, predictable movement of the Earth's rotation on its axis.

• Physical Sciences K-8 Astronomy Resources for the K-8 Classroom Unit