Why astronauts float in space, even though gravity is still there
Weightlessness: why falling feels like floating
On a drop tower ride, for a few seconds, your body feels as light as an astronaut's. Gravity has not switched off. So what did you stop feeling, and why does a falling bottle of water stop leaking?
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1
Rono wants to feel what the astronauts feel. So he goes up the drop tower, the tallest ride at the fair. Its seat falls straight down a tall pole.
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2
But first, what is weight? Gravity pulls you down all the time. The ground does not let you go down, so it pushes back up on your feet. That push is what you feel as your weight.
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3
Then the seat drops. Gravity still pulls on Rono, as hard as before. But the seat falls just as fast as he does, so it no longer pushes on him. For a few seconds, Rono feels no weight at all.
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4
Down below, Miva has a bottle of water with a small hole near the bottom. When she holds it still, water pours out. When she drops it, the water stops. Water and bottle fall together, so the water no longer pushes out through the hole.
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5
This is called free fall: you, and everything around you, fall together. Up in space, the same thing happens. The station falls, with the crew, their pens and their food. Nothing pushes on anyone, and that is why they float.
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6
But the ride stops after a few seconds, close to the ground. Every fall we see down here ends on the ground. Yet people have floated in the station without a break since 2000. Why does their fall never end?
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Quick check
Think of what you really feel as your weight.
Show the answer
No. The tower holds the station up, so the floor pushes on their feet. They would feel about 90% of their weight.
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Go further
You do not need a rocket to feel free fall.