[JurijD]

Originally posted by geoschmo:

quote:

---

Originally posted by Suicide Junkie:
Assuming everything stays inside the station, the center of mass will remain in a consistent position.

No, I don't think this is right either. Loser is right when he says there will be some reaction to people walking around the inside of the station. As they exert force against the deck plates to go in one direction the station will have an equal reaction in the opposite direction. I just think he's way over estimating the amount the reaction will affect the station. The difference in mass between the person and the station means that almost all the energy moves the person and almost none of it moves the station. So while there will be a force applied to the station it would be imperceptable I believe.

Geoschmo

---

Oh no you're totally wrong here geoschmo, and Suicide Junkie is completely right. The center of mass (gravity) of the whole system (station+people inside) cannot be changed by movements inside the station.

Think of it this way: when we exert force on the deck plates in one direction we also have to exert the equal but opposing amount on some other deck plate to stop ourselves from flying out of the space station...

so... we bounce off one wall: we start moving in one direction FAST and the space station in the other just SLOWER as it has greater mass. But the POINT of gravity doesn't change.

Say you're holding a rock in space and you throw it away... that action pushes you back when the rock flies away... BUT. The center of gravity of the rock flying away and your body flying away in the opposite direction (just more slowly) DOESN'T CHANGE .. EVER!.

Now say you and the rock are tied together with a piece of string (similar situation as if you were inclosed in a hollow sphere). When the rock is so far away that the string is taught the rock will stop as the string will pull it in the opposite direction of its movement ... BUT so will u! the rock will stop your movement throught the string too! So the result is just a change in the geometry of the system NOT in its center of gravity. And if the rock and you and the string were in orbit the orbit would't change either.

[ December 19, 2003, 08:39: Message edited by: JurijD ]