Floating, nay... falling, on the Space Station.

[ntw0rk]

Consider this...at a mere
200 miles above the surface of the earth the Space Station
is not weightless. In fact, 200 miles will only lessen the
force of gravity by about 9 percent.

In other words...if you weigh 150 lbs on the surface of the
Earth you would still weigh about 136 pounds 200 miles up.

So why is everything, including the astronauts, floating
around in space in today's video? The answer is, they're
not floating, they're falling. It's just like if you went
skydiving. For that minute or two in between the time you
jump and the time you open your parachute you appear to be
weightless (to someone falling at the same speed you are)
not counting all the wind rushing past you.

It is the same thing on the Space Station 200 miles up.
They are in freefall. The reason the whole mess doesn't
come crashing into the atmosphere is that the Space Station
is also traveling in orbit around 17,500 mph. So you might
say they are all 'falling around' the Earth.

Try and wrap your imaginations around what while you watch
the video below.
http://www.evtv1.com/player.aspx?itemnum=14983

 

[FastSRT19]

Cool!

 

[Demon 8]

Thats all orbit is, even thousands or millions of miles out you are "falling" towards the object with the greatest gravitational force. Cool stuff

 

[Django]

You're enertia is too high to allow you to fall......?

D

 

[Begood]

That looks like a lot of fun.

Bill.

 

[ViperJeff]

Very Cool

 

[nycstev]

You're enertia is too high to allow you to fall......?

D

Similar to swinging a ball tied to a string around in a circle.The centripetal force(force of gravity) is pulling the astronauts in twoard the center of rotation and the and the reactive centrifugal force is the equal and opposite force outwards

 

[Texas Yellow Fever]

HUH??? :dontknow: :marchmellow:

 

[Ram From Hell]

Haven't watched the video yet, but the "weightlessness" is the result of a balance between earth's gravity pulling things down, and the force "pushing" out while traveling in a circle (think GIANT skid pad).

"Centrifugal force is one of the "fictional" forces that arrises when you are in a rotating system, and is actually just the consequence of the principle that a body will travel in a straight line if no force is applied. We call this inertia. If you set a ball down on the seat of a car and then make a turn to the left, the ball will appear to roll to the right. Sitting in the car, it looks like something is "pushing" the ball to the right - a centrifugal force. Looking from outside the car, you would see the ball continuing to travel in a straight line with nothing pushing on it, while the car moves underneath it. The real forces are the friction between the tires and the road that causes the car to turn and the friction between the seat and your body that keeps you moving with the car.

The force of gravity is calculated on mass alone because you want to calculate the real force, that which is truly attributable to gravity. The same formula will apply to you on the surface, an astronaut in orbit, or a passing asteroid moving in some arbitrary direction not bound in our system.

When you instead want to quote the "surface gravity" of a planet, meaning the measured inward force on objects sitting on the surface, then you have to take into account that what you are measuring is in a sense the "net" force on you. What is left over beyond what is needed to keep you (and your scale) accelerating in the rotating frame? For the astronaut, the answer is g=0. Gravity balances the fictional centrifugal force. She's weightless, with no apparent acceleration in any direction. For someone on the equator, the answer is g=9.78. Gravity dominates. For someone standing on the asteroid as it swings into a curve around the earth, they feel a net centrifugal force pushing outward, away from the earth, just like you feel sitting in a turning car. g<0. The strength of that acceleration would be dependent on both the force of gravity and the speed of the asteroid. An independent, non-rotating observer would see only the force of gravity in every case, but would also be able to see *all* of the acceleration it causes, including the centripetal part that makes the other people travel in a circle."

 

[ntw0rk]

Haven't watched the video yet, but the "weightlessness" is the result of a balance between earth's gravity pulling things down, and the centripetal force (as mentioned) pushing out while traveling in a circle (think GIANT skid pad).

...right! And since everything is "falling" sideways at the same speed, it looks like it is floating.

 

[GADodgetech]

it'd be fun for the first day or so, then Id lose my fkn mind. :argh:

 

[Ram From Hell]

...right! And since everything is "falling" sideways at the same speed, it looks like it is floating.

Most people confuse that balance with this one:

Earth-Sun L1 Lagrange point

This is the point at which true weightlessness is achieved, where the gravitational pulls of the earth and sun zero out.

 

[TNVIPER]

Interesting....