Redefining "Up"
Redefining Up is a Grade 5 science concept from Amplify Science (California) that challenges the intuitive notion of a fixed "up" direction. Because gravity pulls toward Earth's center and Earth is a sphere, the direction up — directly away from Earth's center — points in different directions in space depending on where you stand. Someone in Australia and someone in the United States both point "up" toward the sky, but their up directions diverge in space. Covered in Chapter 2, this concept builds spatial reasoning and an understanding of gravity's role in defining orientation.
Key Concepts
If "down" is toward the center, then up is the opposite direction. "Up" always points away from the center of the Earth and out toward the sky.
No matter where you stand on the globe, gravity ensures that you feel upright. This explains why we don't feel like we are hanging upside down, even if we are on the southern half of the planet.
Common Questions
Why is up different depending on where you are on Earth?
Up is always defined as directly away from Earth's center, opposite to gravity's pull. Because Earth is a sphere and gravity pulls toward the center from every direction, the direction up points differently in space for people in different locations — yet everyone consistently experiences up as away from the ground.
Do people in Australia experience up the same way as people in the USA?
Both experience up as pointing away from Earth's surface into the sky above their heads. But relative to space, an Australian's up and an American's up point in very different directions — they diverge by nearly 90 degrees when comparing their actual spatial orientations.
How does gravity define up?
Gravity pulls toward Earth's center. So up is the direction opposite to gravity — directly away from Earth's center. Wherever you stand, up is always the direction gravity is not pulling you, which is away from the ground and toward the sky above your specific location.
Would objects fall differently on different sides of Earth?
No, objects fall the same way on all sides of Earth — straight down toward Earth's center. A dropped object in Australia falls toward the Australian center of Earth, and a dropped object in Canada falls toward the Canadian center of Earth. Both fall down because of gravity.
When do 5th graders learn about gravity and the meaning of up?
This concept is covered in 5th grade science. Amplify Science California Grade 5 Chapter 2 explores what up and down mean using Earth's spherical shape and gravity, challenging students to think beyond simple fixed directions.
How does understanding up and down help with space science?
Understanding that up and down are defined by local gravity helps students grasp why astronauts in space experience weightlessness (no strong local gravity) and why planets and stars are spherical (gravity pulls equally from all sides toward the center).
Which textbook covers redefining up for 5th grade science?
Amplify Science (California) Grade 5 covers this concept in Chapter 2, using Earth's spherical shape and gravitational force to challenge students' understanding of what up and down really mean.