Is the universe "flat" ?

Erik B

I am only casually interested in astronomy so its rather difficult for me to articulate my thoughts, but I will try my best. Consider me a layman and please accordingly use layman's terms if possible when you write your answer. When I see planetary systems, galaxies etc. depicted all objects in the systems appear to be at the same... um.. altitude (I know that that is a terrible word to describe it but as I said its difficult for me to articulate this) and everything is on the same "level". That is what i mean by the question Is the universe "flat". If so, why is this ? Is there anything above or below the Earth? for instance if i was to take a spacecraft and fly directly upwards from the north pole or directly downwards from the south pole?

Drakkith

The universe is far from flat in this sense. Planets and other major bodies typically orbit stars in approximately the same "plane" (the word you were looking for) because it is a result of the way the gas and dust clouds collapse during the formation of stellar systems. If we look far out into space we see many many different galaxies spread out in every direction, up and down, from one side to the other approximately equally. We refer to this as the universe being "homogenous" at the largest scale.

See this thread for more information: http://physicsforums.com/showthread.php?t=417310

urmother

planets align in a plane around sun so does stars around settled galaxies ,considering that sequence, galaxies might be in an alignment around something that lies far beyond the horizon of our comprehension of cosmic neighborhood .and it is logical to extend our thoughts in this manner.local movements of galaxies may not be in direct correlation to that central mass considering the mere distance


→if universe is infinite it would be flat
→if universe is finite , flatness have 1/3 chance

i'd say universe is infinite and flat

phinds

It is possible, but unlikely, for something like this to happen with galactic clusters, but for it to happen is just nonsense