Non interacting regions of the universe.

Does the universe contain regions that cannot have any interaction with each other?I'm not thinking about event horizons derived from a black hole but regions of space that are so far apart that they could never shared information from each other?What I mean is is there a specific circumstance where something happening at point a can never (i.e. given as much time as you like) affect somthing a point b.I was wondering about the expansion of the universe and how things seem to be getting father apart (on the very macro scale); would we ever get to a point where every partical in the universe was so far from every other partical that there would be zero interaction and it got me thinking if this could be happenig with regions of the universe.I guess I'm thinking only spatially (as I think time is just another distance like point of reference) but I guess there could be time 'evet horizons', too.BB and cosmology, please.Edited by Larni, : routine editing

Thread copied here from the Non interacting regions of the universe. thread in the Proposed New Topics forum.

Yes

Cute.Would it also be correct to say that a from our position we would (most likely) only ever be able to observe one of the two mutally exclusive points?If two point are not seperated spatially but in time would there also be point where they cannot interact?Edited by Larni, : most likely

No. (Percy, we need a sketch pad facility here)In flat space, you can have two observers approaching each other at near c, decelerating all the way to zero relative velocity and accelerating away from each other again, and they will never be in causal contact. They will never be aware of each other's existence. But a third observer stationary wrt to the two, sitting between them, will suddenly be aware of them arriving, and from then on will be able to see both of them accelerating away for as long as he cares to watch.This is analagous to the situation in an expanding universe, where two galaxies in opposite directions can be seen from Earth, but neither is aware, nor ever will be, of the other. You can always just view this situation at some velocity such that they will be separated in space *and* time. But they are in one another's light cone. But they could be dragged out of each other's light cone by virtue of the expansion, if they are not at zero spatial separation wrt to the reference frame defined by the expansion (the comoving frame)

If objects are so far apart that the recessional velocity is greater than the speed of light, no new info can be exchanged between the objects. But since the universe expanding at an accelerating rate, light that left one object in the past may still reach the other object even if the objects are too far apart for continued interaction. Perhaps, but I don't believe this could be happening right now. Expansion happens on a cosmic scale and things that are bound together by gravity or stronger forces are showing essentially no expansion. Maybe if the expansion accelerates to some huge quantity in the future, all matter will get ripped apart and separated beyond the point of no interaction.

Is that heat death?ABE: welcome to the club house!Edited by Larni, : welcome

Heat death is max entropy. What he's talking about is the Big Rip, one of three possible outcomes for the universe.- Oni

That is likely completely wrong, but it's an interesting idea at least (I think so anyway).Would it be possible for a "big rip" to create a "big bang"?What I mean is, in the higher order of things (like branes and stuff), could the action of ripping apart spacetime actually cause a new big bang to form?

I thought that things got so far away and the lamda thingy got so great that a new universe would spark up spontaneously.

I read from an atheist that reality is what humans know that affects humans.And his attitude is that if anything or any idea at all does not affect humans, then he should not concern himself with it.If you are an atheist who subscribe to that attitude, then you should not be at all be curious about the subject of your thread.Remember, your fellow atheists adopt a mantra of "We don't know" when they are asked what comes outside and beyond the Big Bang, and they are very humble about not knowing anything that might at all come from outside or beyond the Big Bang.So, on the one hand I must congratulate you that you are not of that attitude of not being concerned about anything at all which to your mind does not affect you or mankind at large.But on the other hand, I am asking you, do you also adhere to the mantra that outside and beyond the Big Bang you don't know anything, or you cannot know anything, notwithstanding however the presumably above average intelligence you possess?Yrreg

hogwash!!that is the reality that we can see, we also hypothesise and theorise about other realities and dimensions try to prove them or disprove them i think the current theory says that there are 11 dimensions and that we can only see 3 but we dont go arround saying that god is in the 11th dimension cause there is nothing pointing to that that is more of a theist reasoning sin is the cause of disease so pray and you will be healed its true dont go looking for anything under a microscope you will not find anything and you will get burned for being a heretic that was the churches opinion for about 1500 years god is the cause of everything so dont go looking for some other cause our mantra is more like we don't YET know but we are very sure that god dint do it [qs] But on the other hand, I am asking you, do you also adhere to the mantra that outside and beyond the Big Bang you don't know anything, or you cannot know anything, notwithstanding however the presumably above average intelligence you possess? [\qs]we dont know yet there are some theories and hypothesis that make more logical sence than god.Edited by frako, : No reason given.

If you would like to start another thread, please do.It's not the point of this one, though.

No need to get emotional.Yreg

haahahahlol well i do tend to get emotional when someone tries to put me in a box that doesn't fit me.i dont think you would stay calm if i told you all theists are brainwashed and incapable of logical thought.