Gravity Pulls Things Down
Understand gravity as a force that pulls objects towards the centre of the Earth, that 'down' means towards Earth's centre regardless of where you stand on the sphere, and that gravity keeps the Moon orbiting Earth and planets orbiting the Sun
What a learner can do afterwards
- Define gravity as a pulling force that attracts objects towards the centre of the Earth
- Explain that 'down' points towards Earth's centre, so people on opposite sides of the globe both feel pulled 'down'
- State that gravity keeps the Moon orbiting Earth and planets orbiting the Sun
1 · Read
Gravity is a pulling force. It pulls every object toward the center of the Earth, all the time, even though you cannot see it or hear it working.
Leo lives in Canada. His pen pal Ana lives in Australia, on the opposite side of the world. When Leo drops a ball, it falls down toward Earth's center. When Ana drops a ball, hers falls down toward Earth's center too, even though she is standing on what looks like the 'other side' of the globe. Both of them feel 'down' the same way, because gravity always points toward the middle of the Earth.
Gravity does more than pull things down. It also keeps the Moon circling around Earth, and keeps every planet, including Earth, circling around the Sun. The same force that drops an apple keeps whole worlds moving in their paths.
Gravity pulls everything toward Earth's center, so down always means toward that center, and this is the same pull that keeps the Moon circling Earth and the planets circling the Sun.
More to read
5.5: Newton's Law of Universal Gravitation
Gravity is a pulling force that attracts objects toward each other. Every object with mass pulls on every other object. The more mass something has, the stronger its pull. The closer objects are, the stronger the pull. Earth is huge, so its gravity pulls everything toward its center. That is why we feel pulled down. Down just means toward Earth's center. People on the opposite side of the world also feel pulled down toward the center. Gravity also keeps the Moon orbiting Earth and the planets orbiting the Sun. Without gravity, everything would fly off in straight lines.
How Our Solar System Formed
Gravity built our solar system. About 4.6 billion years ago, a cloud of gas and dust started to collapse. Gravity pulled the material tighter and tighter. As it spun faster, it flattened into a disk. The center got so hot it became the Sun. In the disk, gravity clumped dust into rocks, rocks into boulders, and boulders into planets. The same force that keeps your feet on the ground also gathered the planets.
Explore more
2 · Watch
به انگلیسیTake it off screen
Where it sits
Learn first
Optional connections
This opens up
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.