Shouldn’t it decrease gradually as we go up?
In: Physics
>Shouldn’t it decrease gradually as we go up?
It does. Gravity depends on your distance from the earth’s center of mass (i.e. basically its center). It’s gradual. You’d weigh less at the top of Everest than you would at sea level. The higher you go, the lower the force of gravity until in space it gets so close to zero that you can float.
It doesn’t.
The ISS experiences about 90% of the gravity that is experienced on the ground. What is happening is that the lateral velocity of the ISS, and other orbiting bodies, keeps them falling OVER the horizon. If the ISS was to fire up its rockets and slow this lateral movement it would fall to the ground.
The weightless effect of being in orbit is NOT due to “being in space”, but is a consequence of being in perpetual freefall while in orbit. That’s what being in orbit means, that you are constantly falling around the earth but never getting any closer. So, you are quite literally freefalling, and that appears to make you weightless.
But, in actuality there is almost just as much gravity at that altitude as there is on the surface. You are correct, it gradually fades away over a MUCH larger distance than typical orbital distance.
It doesn’t. Gravity gradually fades as we get further away.
Gravity is a specific function of acceleration caused by enormous mass.
Things in orbit around the planet have a constant velocity with little to no acceleration. No acceleration == no gravity
^(oversimplification, but that’s what you’re seeing with the astronauts)
You seen the video of a bowling ball on fabric? They toss in a golf ball and it “orbits” until it falls to the center. Gravity bends space. Earth is the bowling ball. As you get further away from the bowling ball/earth the fabric/space is less curved/bent. Get far enough and the bending fades until you are actually weightless. Gravity is like an invisible dimension we can’t see but we can experience it.
There’s so many big objects in our solar system that if you tried to stay in one place with no force to keep you there I would assume you would eventually fall toward a big object. I’m not an authority on the subject by any means.
When I was flying we would put the plane into an aerodynamic stall on purpose. We would often drop a small object in the plane and it would appear to float or be weightless momentarily.
Gravity doesn’t change much. When you’re in a stable orbit, you’re falling in a circle so fast that you’re constantly missing Earth.
To expand on the other points:
If you simply : “went to space”, that is, you went a hundred miles or so straight up, you would not feel “weightless”. You would feel almost as much gravity as you feel on the surface. And then you would start to fall. You would “feel” weightless as you fell, because you always feel weightless when falling, but a glance out the window would prove that you’re feeling all that gravity.
… I hope you brought a parachute on this hypothetical.
> Shouldn’t it decrease gradually as we go up?
It does. Specifically, it follows an inverse square law – if you double your distance from the center of the Earth, the force of gravity is four times weaker. Gravity does not suddenly drop off when you enter space – you have to go a *long* way away from the Earth to be outside of its gravitational influence.
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