Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Cakespoon on 01/08/2009 08:02:33

Title: How would a stationary object appear to moving observers?
Post by: Cakespoon on 01/08/2009 08:02:33

My question is, If the world is spinning and moving around the sun, the sun in moving within our galaxy, our galaxy is spinning and moving through the universe, and the universe is expanding, how fast would a object that has managed to completely stop all moment seem to be traveling to some one observing it? I have a few other questions about said object, but i will post them later, I'm having troubles putting them into words understandable by others right now.  [:-[]

Title: How would a stationary object appear to moving observers?
Post by: LeeE on 01/08/2009 18:07:55

There appears to be no absolute frame of reference within the universe, so it's not possible to say that something has completely stopped.  Being 'stopped' then, is a relative term and how it will look will depend upon the observer's frame of reference relative to the observed 'stopped' object's frame of reference.

Title: How would a stationary object appear to moving observers?
Post by: lyner on 01/08/2009 18:54:28

There is no absolute position or velocity in space (no xyz 'graph paper'). If I see you moving away at 100km/s then you will see me moving away at 100km/s too. Neither of us is more right than the other - it's just what we see.
However - when you see a huge object like a galaxy and a smaller object moving relative to it, it is frequently tempting to treat the big one as stationary and the small one as moving.

Title: How would a stationary object appear to moving observers?
Post by: Cakespoon on 01/08/2009 22:50:55

Thanks. Dang from what I understand that invalidates my fallow up questions.