Wondering about outer space and weightlessness.

[Beachguyj]

If you are in a spacecraft such as the shuttle or at the space station it is pressurized. So how does zero gravity get into a pressurized cabin?

[Scealle]

If I am no wrong gravity only applies when we are on earth. There are not really gravity in space hence why people float when they are in the moon. Sorry just my basic reading knowledge not a science major, some people correct me if I am wrong.

[Beachguyj]

If I am no wrong gravity only applies when we are on earth. There are not really gravity in space hence why people float when they are in the moon. Sorry just my basic reading knowledge not a science major, some people correct me if I am wrong.

Okay, but there is gravity on the moon, it's maybe 4 times less than here.

[IAMTHATIAM]

Umm... I know this question was a strange sort of joke, but the TRUTH: WE ARE EARTH.

When you see the Earth from afar, WE ARE A PART OF THAT.

WE ARE EARTH, SPARKING INTO BEING FOR A SHORT TIME.

Away from this world we shrivel and die...


Dream all you want, but KNOW this is the ONLY world for us and for so many generations to come. Little ones have no problem discerning Fantasy from reality, odd how so many who grow old and well educated fail in this regard.

[Beachguyj]

I found the real answer and it's not because they are in zero gravity. They are only about 200 miles away from earth in the space station and even the moon has a gravitational pull to earth. I will wait to see if anyone know the answer as to why they float in outer space.

[Rayvontae]

GMm/r²

[gsdx]

It's like a magnet. It's always attracting certain metal things, but only if they are close enough. Gravity does the same thing. It attracts people when they are on the Earth, but, in space, it isn't strong enough to pull people toward it. (Not enough mass.) That's why rockets have to go so darned fast on lift-off. They have to fly faster than the gravitational pull to get away from it. Once they're free of the gravitational pull, they can, theoretically, float around up there forever.

[Harke the Boeotarch]

There is gravity aboard the space station. It's just so little we call it 'microgravity'.

The space station is in a state of continuous free falling around the earth (it's called an orbit), just like the earth itself is continuously falling around the sun.

The difference is that earth has an enormous amount of mass and you're standing on the surface, whereas the space station has a relatively tiny mass and also the astronauts are usually on the inside where the gravitational forces would cancel each other out.

[Hard-up1]

The original OP contains a fallacious premise about a pressurized cabin. The inclusion of gas in a container is not relevant when one is contemplating the mass of the planet Earth. The pressure is merely to allow inhabitants to shed the space suits.

Gravity is not a force that can be excluded via bulkheads and gaskets. Its more like a tug on every single thing by every other single thing, and the mass of the Earth is the Big Kahuna when one is measuring the pull force on the inhabitants on the Earth's surface.

As has already been posted, that force weakens dramatically as one gets hundreds of miles away from the planet.

Honest question though. Science is complex, and we don't all absorb it at a young age when it is first thrown at us.

[oakpope]

All the above answers are incorrect.

There is evidently gravity outer space, near Earth or not.
What you observe in 'zero gravity' effect like astronomers sipping goblets of water is simply free fall. The space station is simply free falling towards Earth. But ! But they are also constrained by the centrifugal force. The station inertia forced the station to go away from Earth. The gravity forces the station to move towards Earth. Hence the circular moving of the station.

It's the same thing as the Earth moving around the Sun. If there wasn't a centrifugal force, Earth would plummet to the surface of the Sun.

PS : to the reference to rockets : the majority of the fuel is not to go to space, but to have enough of speed when at the height needed with the speed needed to go with a certain circular velocity. If you propel a rocket just in a vertical motion, then when the thrust is stopped, the rocket would free fall towards Earth. Only centrifugal force will allow the rocket to have the circular motion around Earth to contrebalance gravity.

[bankside]

Gravity is still there in orbit. But you are spinning around very fast in orbit which flings you away from the earth, and at the same time the earth's gravity is pulling you toward the earth. When the pushing and pulling balance each other out exactly, you float around the space station.

If you go farther and get close enough to the moon, then they both have a tug of war which again balances out at just the right spot, called a "Lagrange Point."

If you think about it, the sun's gravity easily reaches as far out as Pluto, so no human ha ever been away from it. But we can get to lots of places where the gravity is cancelled out by something else.

[bankside]

Gravity is still there in orbit. But you are spinning around very fast in orbit which flings you away from the earth, and at the same time the earth's gravity is pulling you toward the earth. When the pushing and pulling balance each other out exactly, you float around the space station.

If you go farther and get close enough to the moon, then they both have a tug of war which again balances out at just the right spot, called a "Lagrange Point."

If you think about it, the sun's gravity easily reaches as far out as Pluto, so no human ha ever been away from it. But we can get to lots of places where the gravity is cancelled out by something else.

If you have air pressure or not has nothing to do with gravity. Drop an empty balloon or a full balloon and it will still drop.

[Keeland]

The moon is attracted to the Earth by gravity. If it stopped its movement through space, it would fall to the Earth. If the moon were closer to the sun than to Earth, it would fall into the sun. But it isn't. It's closer to Earth, so much closer that the Earth-moon gravity attraction overwhelms that of the moon-sun.

But if the Earth stops moving through space, it would fall into the sun.

Spin a pail full of water around your body (imagine the pail of water is the moon, the space station or anything orbiting the Earth) attached to your hand by a rope (gravity — Earth, the sun) and watch what happens when you stop whirling it. Wear a body-size condom.

[Harke the Boeotarch]

Are we all aspies in this thread?

[oakpope]

Are we all aspies in this thread?

Didn't know the word. Thank you for letting me learn something today

[Beachguyj]

A few of you were right

It's a popular misconception that astronauts experience weightlessness during space

travel because they are outside the field of gravitational force of a large body. In

fact, weightlessness during space travel is actually achieved because of free fall — the

astronaut and the space shuttle or rocket are both falling (or accelerating) at the same

speeds. The same speed gives the notion of weightlessness or floating. This is the same

concept as a person on a "free fall" ride at an amusement park. Both the rider and the

ride are falling at the same speed causing the rider to seem as though he is falling

independent of the ride. The same feeling can be experienced while riding an airplane or

an elevator that suddenly breaks from its normal rate of decent.
----------

Although the Earth's gravity has a lesser effect on an astronaut orbiting the Earth in a

spaceship than on a person on the surface of the Earth, this is not the reason why an

astronaut experiences weightlessness. The space shuttle, International Space Station and

most other manned vehicles don't get that far from the Earth. The Earth's gravitational

attraction at those altitudes is only about 11% less than it is at the Earth's surface.

If you had a ladder that could reach as high as the shuttle's orbit, your weight would

be 11% less at the top. Put another way, a person who weighs 100 pounds on the Earth's

surface would weigh about 89 pounds at the top of the ladder.

The reason why the person wouldn't feel weightless is because they are being pushed by

the ladder - it is keeping them from falling. If they were to jump off the ladder, then

they would feel weightless, at least up until the time they splatted on the ground. This

is why astronauts feel weightless. The astronaut, the spaceship and everything inside it

are falling towards the Earth. The reason why the astronaut doesn't go splat is because

the Earth is curved and the astronaut, the spaceship and everything inside it are moving

'sideways' fast enough that, as they fall towards the Earth, the surface of the Earth

curves away from them. They are always falling towards the Earth, but they never get

there.

[voyager1994]

Hope I get to travel to space in my lifetime so I don't have to wonder.

[csb999]

thought - gravity - why is it so common to portray spaceships as rockets or modified airplane type things when practically round would work just as well in a gravitationless vacuum ?

[csb999]

my cousin asked this of some physicist who said there were two types of gravity , the first planetary that we are all familiar with , the second another type that for example allows asteroids to retain their shape in a vacuum .

[youfiad]

Theh reason that you float in outer space is because inertia. Since there is not enough gravituational influence by planets or other large bodies of mass, you will continue in motion until acted upon by an outside force, such as the ceiling.

---EDIT---

And yes, presurization has nothing to do with gravity, it's purpose is so that your internal body pressure doesn't explode when faced with a vacuum (a little exagurated). But a neet little experiment I saw where they subjected a ping pong ball to a tube that was about 10 feet long, and sucked out allof the air, creating a vacuum. When the vacuum seal was broken, and the ping pong ball was sucked into it, it was accelerated to 600 miles per hour by the time it left the 10 foot tube. Kind of the opposite would happen if we were put into a vacuum.

[youfiad]

Maybe I'm confused by what you're actually asking??

[xbuzzerx]

Maybe I'm confused by what you're actually asking??

It sounds like he thinks gravity is something that needs to "get into" the cabin so how can it when the cabin is pressurized.

Gravity is the pull of objects with mass. There IS gravity acting on you in space, it's just much weaker from greater distances. But the earth circles the sun because of the sun's gravity. Otherwise it would just fly off on whatever current trajectory it was on.

[youfiad]

It sounds like he thinks gravity is something that needs to "get into" the cabin so how can it when the cabin is pressurized.

Gravity is the pull of objects with mass. There IS gravity acting on you in space, it's just much weaker from greater distances. But the earth circles the sun because of the sun's gravity. Otherwise it would just fly off on whatever current trajectory it was on.

Indeed, I am well aware of universal gravity laws and pysics in general, especially theoretical/partical physics tend to be an interest of mine