michel123456

We are currently observing UDFy-38135539. In this Galaxy there is (was) a star with a planet and an alien waving his hand. That event (the alien waving his hand) happened 13 billions years ago. At that time, this alien was observing a CMBR closer to him (in time) than what we are observing today from the Earth. Correct?

If the answer is yes, it means that a young Galaxy is closer IN TIME to the CMBR than we are. Correct?

Let's focus on this. CMBR happened everywhere on Spyman's diagram. O.K. But CMBR happened in a definite time: correct?

After a few thoughts and reading some about S.Hawking & Leonard Mlodinow's book, I believe they are doing a great job. At the end M-theory may prove that nothingness is something so unstable that it cannot exist. That should be a definitive step forward in our understanding of the Universe. But I may be wrong on that.

You'll get fooled again.

empty post, I edited my post # 80 to avoid changing page. see page 4 of this thread. Not an empty post anymore. Don't miss previous page to understand the following. What i would propose is something like this: In this diagram: 1.Everything is curved. 2.Any observator observes the same thing, no matter what position in Space and in Time. 3. in each observator's FOR, angles are conserved (the space & time axes are orthogonal, S.O.L. is always 45 degrees) 4.CMBR is something like a horizon. Sysiphus's diagram is compatible. 5.It is a diagram of the observable universe. Each observator has a horizon at the same distance in time from its position. There is no Big Bang.

You see, a last we don't disagree on what represents the BBT. Simply, you agree on the BBT, I don't. _Of course you draw this diagram quickly (thank you for that), and it is not to scale. CMBR is closer to the Bang, and distant galaxy is closer to CMBR. I am not sure the resulting curve would be so smooth when drawing the diagram at proper scale. In other diagrams, there is an abrupt change in the slope representing the inflation phase. and the change is behind CMBR, not in front of it. _The frame of black lines pattern represents space expansion. Why aren't they straight lines? The curve as shown indicates a slowing down expansion. I thought it has been observed expansion was accelerating.? _It is a space-time diagram. As such, all physical phenomenas ruled by Relativity happen along diagonals, like the red lines. Horizontal relations on this diagram have no physical meaning. "distance when light was emitted" and 'distance when light was received" are abstract concepts that cannot be measured. The same goes for the horizontal CMBR. For example, the distance (along diagonals) between each point of the CMBR and the Bang is different. Each particle of the CMBR has traveled a different (red)distance from the Bang, and enlighted at the same time. How come? (simultaneity is the question, again, not the mechanism). _why are there horizontal lines at all? It seems there is an influence from the Mercator projection, and the division of the terrestrial globe in meridians and parallels (although its all about a 2d flat diagram and not a sphere). I see no reason why only the time axes are curved, and not the space ones. In a 4d curved Universe, everything should be curved (or nothing). _I am sure you can find other configurations where there is no necessity for all vertical lines to join at the same point. It looks to me like a setting made on purpose to explain a concept, and not the result of observation. You can for example strighten the curved lines (meridians) and obtain a square diagram, without Bang, of course. _by default, Time intervals are regular. In such a Universe, is that a correct assumption? if Time becomes irregular, maybe the square diagram can stand? _The regularity of time intervals produces a strange result: the "real" distance (red line) is, beginning from Earth, reducing from step to step, and then suddenly increasing in the interval CMBR & Bang. Bizarre. As if the "real" displacement of light was never the same.? _the whole diagram looks like a perspective drawing. A strong similarity with perspective is that "distance when light was emitted" and "distance when light was received" are the same: space has expanded, distance remains the same. Exactly as if it was a perspective. If one keeps in mind that Relativity is the nr one Theory that depicts accurately observation, and that perpective is also a way to represent observation, it may suggest that maybe "parallel lines" do not join at horizon. -Am I the only one to ask such things? _the way CMBR is positionned on the diagram does not seem to be compatible with Sysiphus's post #30. In Sysiphus's post, CMBR is like a horizon, always at the same distance from any observator. In Spyman's, CMBR is an absolute position closer to the distant Galaxy than it is from us. (I cannot attach picture of post #30, page 2 of this thread).

I am not an expert, but I think the surface of the target is too porous. You need a smoother surface. I would try with very thin glass from microscope equipment, or glass-ceramic, like the babyliss flat iron your girlfriend use to make her hair. And also on the picture, you get the image of reflection from the dust in the air. I am afraid you wont get correct results by photographying from a distance, even in a dust-free room. The target should be a photographic plate. With all the above mentionned inconvenient. Note what i said in previous post: the photograph you get comes from reflected light. If reflection was null, you would not see anything. How do they manage to avoid reflection in this kind of experiment? I voted for you post, rmv. I am touched by your approach. It is much more difficult than simply browsing, as we do all here. Good for you.

I have edited my last diagram. Of course the "curtain" is horizontal. If you turn it upside-down, it becomes a regular space-time diagram. The slope of Observable Universe represents Speed Of Light (the 45 degrees angle). The "curtain" is the second Bang as explained above in post #61 by Spyman (Recombination), and confirmed by Sysiphus in post #68 where he states that "It was already explained how the universe became transparently nearly simultaneously all around. There is nothing in that that contradicts relativity - relativity merely states that events simultaneous in one reference frame are not simultaneous in another.") The fact that the "curtain" is horizontal makes it a phenomenon of simultaneity, in our Frame Of Reference. But also in any other FOR, which is part of my objections. On the other side of the "curtain" happen a lot of strange phenomena's, like the curving, and the slope in the contrary direction. Or please correct me.

Interesting. I learned something today.

Why this obsession with creation? Has real creation ever been observed, somewhere, in some laboratory? As much as i know, the best we can do is transform light into matter: it is transformation, not creation. Or is the whole concept of creation a human myth? A dream. That's what I think. If you look at the question differently, and try to explain a Universe that existed forever, you will realize that the real question is not creation. The question is "forever", the question is Time. And as much as I know, Time is still an open question. All that stuff concerning creation is IMHO like discussing whether angels are male or female. With all my respects to people thinking differently.

I haven't read the book, but from articles, it seems Hawking is talking about M-theory.

I don't. But I have a suggestion to make. If something can arise from nothing, why not trying to make the reversal procedure, and make nothing from something. No kidding. IIRC anihilation produces energy. So it's not nothing. We need pure anihilation.

This picture has been edited.

Correct. That doesn't prove that the circle emitting the past view actually was physically bigger in the past. But IF the past Real Universe was shrinking (looking backward at its expansion), and IF it would be observable, the Observable Universe would be shrinking too. Because the Observable Universe is an open book of what happened in the past. The 'trick" of the BB is to put a curtain exactly at the moment where we should observe the theoretical shrinking (looking backward at its expansion). If you put into a diagram the diameter of the Observable universe versus time, it is always increasing. The BBT consists of telling us that at some time very distant from us and inobservable, the Real Universe gets smaller than the Observable Universe to the point of reaching a singularity. In the diagram, that means a sudden change in orientation, and I really don't see any reason why I should believe such a nonsense Theory. I understand nothing of your Thought experiment, I think it is confusing.

look here

It looks correct to me. I don't understand why Sysiphus don't come and burn you.

I am not saying that the world population is growing. I simply say "wow, i got a lot of letters from a week ago". If i wait, i will get letters from 2 weeks ago, more letters, and so on and so on. It will not go downwards. I have well understood your point. If the universe preexisted, and suddenly the light came of it, on such premises your explanation stands. The premises are under question. How could the whole Universe be enlighted simultanetly all around? IIRC simultaneity is not much compatible with Relativity. But this is not the place to discuss it. My sketch above is a description of my point of vue. The observable universe is a sphere growing function of time. The more I look in the past, the larger is the observable universe. I cannot conceive a situation where the observable universe reduces to a singularity. And I have to correct something: The picture we get from the far away universe is that of a young man (under the BBT). I will laugh when some future astronomer will find a distant three legs galaxy.

The observable universe. The sketch is about If (IF) we could see behind the curtain. If your letter was a picture of you, the picture would represent you as you were a week ago. The picture we get from the far away universe is that of a young man.

thank you Spy for your time. Instead of discussing one by one all of your points (I am sure it won't drive nowhere), I just want to explain my point and maybe why I disagree with the BBT. You are describing the Universe like something much bigger than what we are observing, and I have no problem with that. My problem begins when you are explaining that this Universe, much bigger than the observable one, is already in place when observation begins. IMHO it is a difficult point to swallow. But that is not the most important. My problem gets crucial when I look at observations (the part of the story we can actually see): if I want to look in the past, I just have to look far away. The more far away I look, the bigger is the radius of the circle of the observable Universe. You can't disagree on that, you said exactly the same thing, more professionaly. What I say is simply that the circle of the past is always bigger than the circle of the present. Is that so wrong? I thought it was almost tautology. The small casserole is inside the big one, and the big one is the youngest. On this part of the curtain it is always true. What BBT is about, is exactly the contrary. On the other side of the curtain, the small casserole contains the big one, and the small casserole is the youngest. Where am I wrong?

And how is it possible that the 'curtain" opened everywhere at the same time? If it is part of the horizon problem, it is not addressed in the wiki article.

Sysiphus is clearer than Spyman. I don't swallow anything of his explanations, but at least he was clear. I have read tons of books (well, maybe exagerating a bit) about the BB, it is the first time I realize the Theory stands without expansion. Sorry for the ridicule, I thought expansion was the alpha-omega. I have never read that everything was created in place. It looks such an insanity to me that I have some difficulty to understand how this theory has been admitted by the scientific community but anyway. The phrase "the Big Bang happened everywhere" is also something that looks like word-salad, but anyway again, nobody can fight that with philosophical concepts. So. Universe were created roughly in place we see it today. One day, 13,7 billion years ago, "lux fuit". Behind the curtain, where no observations are available, laws of physics can change. Superluminal speed is common sense, and negative gravity is the law. There is no way to fight that. If laws of physics change when there is complete lack of evidence, there is no rule of the game anymore. What else? Spyman wrote: That is much confusing. All diagrams I know concerning the BBT have 2 axis, Space & Time. And there is a very accurate relationship between space & time. Space expands with time, and objects get closer to each other as much we go back in time.Like this one (from wiki) Or this one (the image is too large to load) Where the hell is Sysiphus explanation? Or this one Spyman wrote: I agree that we don't know how distant they are now, but I don't understand why we don't know how distant they were back then when the light was emitted. To me, if they are in opposite directions, at the same distance, we must be able to calculate their mutual distance at the time light was emitted. And anyway what imports to this discussion is that those 2 galaxies, because they are at the same distance from us, are simultanate events. How can, we don't disagree at all! I never said it was a simulation of reversal time. If i did, sorry, not my intention. What i meant is that Universe was huuuuuuuuuge a long time ago, and that I cannot conceive it came out of a singularity. From the moment Sysiphus presents BB like an already-in-place-creation, it cancels everything, logic included. And finally: Do you have any evidence to provide?

after a while, i just realize you are explaining the BBT without expansion. Which is resumed in "stars & galaxies have been there where there are, and we are discovering a universe that preexisted but was opaque." Horror. I guess you will answer that our horizon cannot increase because we have reached the "blindness point". Horror squared. also, what you are saying is that the Observable Universe is roughly the same, independently of the place in space, but not the same in function of time. An Alien living upon a planet 13 billion years ago ( somewhere in UDFy-38135539) was observing a different Universe. Horror.

Doesn't that sound "ad hoc" to you? You are undoubtedly a smart person. So: if I understand your point, stars & galaxies were created approximatively in place & state of motion as they are observed today. The observable Universe of Ancient Mesopotamians is smaller than ours. And our observable Universe is growing of one LY a year, probably more due to expansion. (I never heard of anything like that). And why is UDFy-38135539 called a "young galaxy"? (edit.O.k. this one i can figure out. If your point is part of the standard explanation of the BB, then the BBT is more monstruous than I ever thought of.