alexro

@ACG52You say:"The only 'theories' incuding the expansion of matter are from cranks."Really? Well, a lot of guys in the quantum are looking for this. Even Dirac asked himself that question at some point. @ACG52 You say: "This is not the case." Actually, this is the case. But if that's not the case, please explain acceleration then. @ACG52 You say: "I'm tending to agree with Arch." You mean you tend to agree with the fellow who doesn't even know the topic of the discussion? Then you also don't know the topic. Why don't you find out what you're taking about before actually talking. This is supposed to be a science forum, isn't it? @pwagen: "Which Nobel prize, specifically, was given to someone who showed the universe's expansion is decelerating?"I disn't say that (on the contrary). You arrived at your own conclusion.

I don't know what happens, lately I can't even use citations. Please excuse me.@ACG52You say:"Please provide a citation for this."In the late years I read quite a few theories of expansion including the matter.I suppose you won't expect me to remember where exactly I read it, would you?Anyway, you can search online by yourself, I suppose.Now, about gravity, you may have a point there, but there's a point even larger: think about dark matter.@pwagenYou ask:"is the original question about the accelerated expansion AFTER inflation?"Obviously not, since after inflation the expansion could ONLY decelerate (compared to inflation). No, I'm talking about what they're currently seeing. They were even awarded a Nobel prize, you know...@Arch2008You say:"I believe that someone (quite) obviously is just trolling."An why exactly would you think that?@SpymanThanks again for your illustrations, but I don't think they work. I don't think that's what they would see. They might see that independently, but the question is: will they see that AT THE SAME TIME? Because expansion (apparent movement) FROM observer 1 is TOWARD observer 2.And an accelerated expansion detected by observer 1 will be perceived by observer 2 (at least on the line of sight directly towards observer 1) as deceleration.Thanks to all.If again all my posts will be joined together, please be aware that I replied above to everybody. Thanks. If again all my posts will be joined together, please be aware that I replied above to everybody. Thanks.

@Arch2008:You say:"everything you posted is about inflation."Actually, nothing of what I said is about inflation. Accelerated expansion is dark energy, not inflation. Compared to inflation, accelerated expansion is nothing.You say:"Two scientists will observe the same thing."Actually, I don't know of any scientists who would claim they can observe inflation. Not only was so short in time (EXTREMELY), but it was long ago and far away...You say:"However, the matter within the gravity of a galaxy is not expanding."Actually, there are theories whether the expansion of matter also takes place or not.If you know for sure they settled it, I would like the source, please.You say:"Within galaxies stars and planets are still forming."Well, for me it's obvious THEY CAN'T FORM in the conditions of even a constant expansion that pulls everything away form all the rest, let alone an accelerated expansion. That's why I'm puzzled.Thank you.@SpymanI really want to thank you for taking the time with those illustrations. You are very nice indeed.I tried to figure it out, but I suppose I'm too tired right now. I'll come back on this. At first look, seems it might work, but I'm still not convinced about it in 3d. Things get very complicated in real space.Even more with an accelerated expansion. At that time, I think I read something like "the further away, the faster it moves away", but I will have to check that.So, see you tomorrow, and thank you so much again. Spyman: My reply to you is above. I really don't know what happens, and all my sentences are pulled together (even different paragraphs) almost gravitationally...

@Arch2008:Thank you for both your welcome & reply, but what I asked has nothing to do with inflation.Im puzzled however that you said:Alan Guth proposed that the very early universe underwent inflation on an epic scale.Well, to my knowledge, it wasnt epic at all. When it ended, the universe wasnt larger than a golf ball. If Im wrong, please correct me.You also said:Inflation has met some predictions, so even if you cannot figure it out, it does not mean that it cannot happen.Mute, since I didnt talk about inflation at all.Then, what you say in the last part of your comments, in my view, cancels evolution of stars, planets, etc. How could they have formed? Because, remember, the universe is STILL expanding at an accelerated rate,So, Im still puzzled.Thanks for the comments though, you were kind to reply.Now I think its your turn to understand what I meant: in an accelerated expansionary universe, 2 separate observers simply cannot see the same thing. Thus, although for one of them the universe may look isotropic & homogeneous, for the other it wont.For the first observer (if his universe is isotropic & homogeneous), wherever he looks (any line of sight) he would detect accelerated expansion (outwards from his location). Another observer would see very different things: inward expansion along the line of sight towards the first observer, and in all other directions varying according to the angle to that first line of sight. @SpymanThank you for your reply. But you stick to only one point of observation. What I meant was multiple observers. Once you introduce another observer in the universe (different location), he cant possibly observe what we observe. Remember, the further away, the faster things appear to move from the observer. So the second observer not only will not see WHEREVER he looks the universe appearing isotropic (as the first observer), but also looking straight towards the first observer (along the line uniting them) will see something very different.How can that be?See also my last comments for Arch2008.Thanks.

Could anyone please explain to me how can an accelerated expansion take place in a homogenous & isotropic universe? I really can't figure that out - at all. Not only cannot happen radial, but not even linear. Unless I'm terribly wrong - and there's where you'll probably come in. If you even take the time for an (simple !) illustration, I would thank you even more. By the way, not only I cannot figure out dark energy, but I cannot imagine expansion even before DE - how could even a constant expansion, or a deccelerating one, could take place in a homogenous & isotropic three-dimensional universe? As soon as I think of several points in space and try to imagine what would happen (the observations should be the same, but they can't be!), well... I'm really waiting for your input. Thank you so much.