HD Felix Baumgartners space jump

[SpontaneousOrder]

my point exactly.
it cant be much different, do the sums.

so why didnt felix float about, or why DO the astronauts float about ?

Astronauts are in constant free fall, as you would be if you imagined the cable snapping in a lift and you would be a little floaty (if you imagine little to no friction) until you hit the bottom.

Felix wasn't in freefall - a baloon was holding him up in the air.

[EternalOptimist]

Astronauts are in constant free fall, as you would be if you imagined the cable snapping in a lift and you would be a little floaty (if you imagine little to no friction) until you hit the bottom.

Felix wasn't in freefall - a baloon was holding him up in the air.

free falling, but not TOWARDS the earth. with lots of gravity


this is one of them physics things that makes yer head explode isnt it

[KentPhilip]

After Baumgartner jumped out of the stationary capsule, he started free-falling towards earth. At that point he was weightless, just as the people in the international space station are weightless. They are both accelerating towards the earth.
The difference with the space station is that it is moving at 18000 mph horizontally, and the effect of the acceleration falling towards the earth is simply to bend that horizontal movement around the curve of the earth. So they are falling down towards the earth, but due to the earth curving as they travel horizontally they never quite fall down in reality.

[EternalOptimist]

After Baumgartner jumped out of the stationary capsule, he started free-falling towards earth. At that point he was weightless, just as the people in the international space station are weightless. They are both falling towards the earth.
The difference with the space station is that it is moving at 18000 mph horizontally, and the effect of the acceleration falling towards the earth is simply to bend that horizontal movement around the curve of the earth. So they are falling down towards the earth, but due to the earth curving as they travel horizontally they never quite fall down in reality.

so if the space station was geo stationery, the astronauts would be able to walk around normally, but the space station would hit the ground ten minutes later ?

[SpontaneousOrder]

so if the space station was geo stationery, the astronauts would be able to walk around normally, but the space station would hit the ground ten minutes later ?

No

[EternalOptimist]

No

he used to be a sweet boy

[KentPhilip]

so if the space station was geo stationery, the astronauts would be able to walk around normally, but the space station would hit the ground ten minutes later ?

If the space station was geostationary at the height of 120,000 feet (similar to Baumgartner and a bit less than the actual space station) then you are right they would fall down and hit the ground.
But the real ISS is going at 18,000 mph or so horizontally, and so is going fast enough that it "falls down the curve of the earth" to invent a phrase.

Geostationary orbit is a different thing again. This is where the satellite is much further out - 22,236 miles to be precise, where due to the distance out the strength of earth's gravity is much less. That means that it does not have to go as fast in order to stay up. Once you reach 22,236 miles up then the speed happens to be the same as the speed at which the earth itself rotates, so although you are still going round the earth, since the earth is itself rotating, it looks like you are stationary relative to the earth.

Of course that speed is far too slow to support orbit at the low altitudes of Felix what's his face.

[VectraMan]

Reading this thread, it seems physics is in freefall.

[suityou01]

The resolution of the forces between the anglular rotation of the orbit, and the direct pull of the earth cancel out. If the force of the angular rotation was greater or less than that of the gravitational pull, ie not in perfect balance then sustained orbit would not be possible and one of the forces would win, ie the module would fall to earth, or spiral off into space.

It is a force equilibrium that generates weighlessness.

[SpontaneousOrder]

Orbits are just altitudes @ such a speed that although you're constantly in free fall towards the centre of gravity, you're also moving forwards around that center of gravity at the right speed so that you constantly are falling around it - rather than flying off into space, of falling to the ground.

Just imagine throwing a tennis ball - it free falls to the ground, but takes an arc passage through space. If you judge it right you could get a perfect quarter circle path.

Now imagine that the ground beneath your feet was a single point centre of gravity - when that tennis ball completes it's first quarter circle it is not moving straight 'down' (as we'd imagine it), yet the gravity is pulling it sideways back to you. So now it's in exactly the same state as it was when you first threw it, except starting a quarter of a circle round already - now it'll happily do another quarter circle, and so on.

That's why shuttle missions, etc, take off and fly east - we're already hurtling eastward at high speed, so if they tried to fly west they'd have to use a lot more energy to get to such a speed that they can find an orbit.