Let's pretend that gravity stopped. It is only make-believe. But it shows what gravity does for us.
Gravity is the invisible pull that makes things fall down. It keeps you on the ground. If it stopped, nothing would hold you down.
When you throw something up, gravity pulls it back down. With no gravity, nothing would pull a thrown ball back.
Your weight is how hard gravity pulls on you. The pull comes from all of Earth's mass. With no gravity, you would have no weight.
Your mass is how much stuff you are made of. It stays the same even when your weight changes.
On the Moon you weigh about one-sixth as much. That is because the Moon pulls less.
Astronauts on the space station look like they float. That is because everything inside is falling together.
A roller coaster can feel a bit like this. Free fall gives you a brief feeling of weightlessness. That happens at the top of a drop.
Gravity holds down the air we breathe. So Earth keeps its blanket of air. Without gravity, Earth would not keep it.
The Moon's gravity pulls on the seas. That makes the ocean tides go up and down. Without that pull, there would be no such tides.
Gravity keeps the Moon going around Earth. It keeps Earth going around the Sun.
The Sun's gravity keeps Earth at a comfortable distance. That distance suits its light and warmth.
Words to know
- gravity: invisible pull
- weight: gravity's pull
- mass: amount of stuff
- tides: rising falling sea
- weightlessness: feeling of floating
