When something goes up it always comes down.
Why can’t it be the other way around?
"What goes up, must come down!”
You’ve probably heard this saying before,
but did you ever think about what it really means?
The answer, in a word, is gravity.
Okay, so what’s gravity? I’m so glad you asked! Gravity is a force that attracts matter together.
Planets and stars are so large that they have their own gravitational pull, and the Earth is no exception.
The reason a dropped object will fall to the ground, the reason we don’t fly off into space, and even the reason the Moon revolves around the Earth are all because of the force of Earth’s gravity. But it doesn’t stop there:
The Sun also has a strong gravitational pull,
which is what keeps all the planets in our solar system revolving around it.
Have you ever seen video of astronauts floating in the space station?
They float because they are so far away from any planet that they are not affected by gravity.
See for Yourself: DEFY GRAVITY!
You need a Styrofoam or paper cup, some water, and a place where it’s ok to get wet (outside, probably).
Toward the bottom of the cup, use a pen or pencil to poke a hole in the side.
Holding your finger over the hole, fill the cup with water.
When you take your finger away, the water pours out in a steady stream,
due to gravity creating water pressure in the cup when it is being held still.
Put your finger back over the hole and fill the cup again.
Now drop the whole cup to the ground, from about 4-5 feet up.
Watch the hole as the cup falls.
The water no longer leaks out of the cup on the way down,
because gravity is affecting the whole cup, water and all, not just the water inside.
Congratulations, you just defied gravity!