Scotty99 Posted August 18, 2016 Posted August 18, 2016 http://www.digitaltrends.com/cool-tech/largest-structure-in-universe-discovered/ I stumbled across this today and thought to myself, didnt i hear about this a while ago...and after a bit of searching yes the original story was reported a year ago by royal astronomical society: https://www.ras.org.uk/news-and-press/2693-5-billion-light-years-across-the-largest-feature-in-the-universe Has any headway been made on this particular discovery? Sorry but after reading the original article a few times over, i cannot get over this line: Most current models indicate that the structure of the cosmos is uniform on the largest scales. This ‘Cosmological Principle’ is backed up by observations of the early universe and its microwave background signature, seen by the WMAP and Plancksatellites I have tried to keep up with CMB data as much as i can, and none of what this particular article states can even be jokingly taken as fact. Nothing about the CMB is homogeneous at all. Max Tegmark is someone at the center of the CMB research and the last thing he would admit is that the the universe is homogeneous.
Strange Posted August 18, 2016 Posted August 18, 2016 I have tried to keep up with CMB data as much as i can, and none of what this particular article states can even be jokingly taken as fact. Nothing about the CMB is homogeneous at all. Max Tegmark is someone at the center of the CMB research and the last thing he would admit is that the the universe is homogeneous. Do you have a reference to support this? As far as I know, the CMB is an almost perfect black body spectrum and almost perfectly homogeneous.
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 Do you have a reference to support this? As far as I know, the CMB is an almost perfect black body spectrum and almost perfectly homogeneous. Is that a serious question strange? Have you seen the pictures captured by wmap and planck? I find your question trollish if i am honest. Literally google "cosmic microwave background" and tell me all of those images you see are homogeneous. -1
Strange Posted August 18, 2016 Posted August 18, 2016 Is that a serious question strange? Have you seen the pictures captured by wmap and planck? I find your question trollish if i am honest. Literally google "cosmic microwave background" and tell me all of those images you see are homogeneous. What is the scale of those variations? (Homogeneous is, of course, a relative term. Hence my use of "almost perfectly".) 2
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 What is the scale of those variations? (Homogeneous is, of course, a relative term. Hence my use of "almost perfectly".) Go away. -2
ajb Posted August 18, 2016 Posted August 18, 2016 Nothing about the CMB is homogeneous at all. It is very nearly homogeneous and the scale of the fluctuations is very small compared to the average temperature. It is all a question of scales. As for the possible structure you ask about - I have no idea, it is far from my area of knowledge. 1
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 It is very nearly homogeneous and the scale of the fluctuations is very small compared to the average temperature. It is all a question of scales. As for the possible structure you ask about - I have no idea, it is far from my area of knowledge. "A question of scales" you say eh? Why did they send up so many satellites then? If it was as minor as you and strange say, why didnt they write it off in 1982 or whenever the first time they mapped the CMB? -1
ajb Posted August 18, 2016 Posted August 18, 2016 "A question of scales" you say eh? Yes - the CMBR has very small fluctuations in temperature when compared to the average. This is well established science. Why did they send up so many satellites then? To carefully measure these small fluctations... and remember there has also been balloon made measurements. If it was as minor as you and strange say, why didnt they write it off in 1982 or whenever the first time they mapped the CMB? Because the details of these small fluctuations are important in understanding models of cosmology. They are like the fingerprint of the Universe and allow us to rule out certain cosmological models. So right now the best model is the Lambda CDM model with inflation. I think you are misunderstanding the fact that these fluctuations are small with the idea that they are not important. None of us has said that these fluctuations are not important - just that they are small and that the CMBR is near homogeneous. 1
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 Nah, sorry. You cant have both ajb its either the cosmological principle or nothing, there is no in-between here bud...no matter how much you and strange want to minimize the findings. That is the CMB, how about we talk about the actual thread at hand. Is this as big of a story as the CMB? Im not sure, but it sure is something that deserves a closer look.
ajb Posted August 18, 2016 Posted August 18, 2016 Nah, sorry. You cant have both ajb its either the cosmological principle or nothing, there is no in-between here bud...no matter how much you and strange want to minimize the findings. I am talking about the CMBR and the scale of the fluctuations. The ring of gamma ray bursts is something else. If these bursts really are all connected then they form a larger structure that the current models really allow - and the details of the CMBR support the current models. So, either it is chance that they formed in this way they have, or some of the data on their positions is poor, or we have to think more about the models. Interesting stuff either way.
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 (edited) I am talking about the CMBR and the scale of the fluctuations. The ring of gamma ray bursts is something else. If these bursts really are all connected then they form a larger structure that the current models really allow - and the details of the CMBR support the current models. So, either it is chance that they formed in this way they have, or some of the data on their positions is poor, or we have to think more about the models. Interesting stuff either way. Riiiiight, but you aren't dense enough not to understand the implications of the CMB being anisotropic. Edited August 18, 2016 by Scotty99
ajb Posted August 18, 2016 Posted August 18, 2016 Riiiiight, but you aren't dense enough not to understand the implications of the CMB being anisotropic. Sure - the anisotropies are small but very important, for instance they are linked to structure seeding in the early Universe. I think that Strange also knows this.
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 Sure - the anisotropies are small but very important, for instance they are linked to structure seeding in the early Universe. I think that Strange also knows this. I want you to say why the anisotrophies could potentially be important, just so i know we are speaking the same language. I dont want to make the about the CMB but one more question, do you and strange say the anisotropies are small because of the temperature variations alone? I just dont understand how someone can look at pictures of the CMB and call those anomalies "small".
ajb Posted August 18, 2016 Posted August 18, 2016 I just dont understand how someone can look at pictures of the CMB and call those anomalies "small". [/size][/background] The temperature fluctuations are something like 1:100,000. We think this is quite small - but what we expect from theory.
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 The temperature fluctuations are something like 1:100,000. We think this is quite small - but what we expect from theory. So i understand what you mean by this, there was a 1 in 100,00 chance that temperatures would be variant in the pattern they were described? To me temps werent the thing that caught my attention, it was the massive zones created by the temperature differences that seemed to be at odds with the cosmological principle...but hey maybe thats just me.
ajb Posted August 18, 2016 Posted August 18, 2016 (edited) So i understand what you mean by this, there was a 1 in 100,00 chance that temperatures would be variant in the pattern they were described? No, this is the scale of the differences in temperature as compared with the average. This means that the CMBR is quite uniform until you get to 1 part in 100,000. There are also some hot and cold spots in the CMBR that are unexpected and may just be down to not subtracting the local environment properly. On the subject to this ring structure, you can read the paper here http://arxiv.org/abs/1507.00675 The point is that it seem to be too be larger than the scales that we would expect the Universe to appear homogeneous and isotropic. This violates the cosmological principle, which is of course an approximation - though thought to be a good one. Edited August 18, 2016 by ajb
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 Lots of weird stuff in the paper you linked. Do people regularly refer to the outer reaches of space as "sky"? What does "projection of a shell" mean? "voids and string-like formations are common outcomes in a large scale structure" Even tho you get through all of that stuff that makes my brain hurt they came to this conclusion: This ring-shaped feature is large enough to contradict the cosmological principle. Why again do i post articles that are a rather big deal in science, but you almost never see them talked about?
ajb Posted August 18, 2016 Posted August 18, 2016 Do people regularly refer to the outer reaches of space as "sky"? Yes. You point your telescope at the sky. What does "projection of a shell" mean? You will have to read the paper carefully - I would need some more context to answer that properly. "voids and string-like formations are common outcomes in a large scale structure" Yes, both models and observations give us a structure like a spounge or something like that on quite large scales. Only on larger scales again does the Universe really start to look uniform. I forget the numbers here, you can google for details. Why again do i post articles that are a rather big deal in science, but you almost never see them talked about? I am not sure in this case. In general, lots of interesting science is just too specialised for this forum. In this case, I guess it is the fact that people here don't like to jump on things that are outside of there interests or expertese. I mean, it is not totally clear if this ring is real- if it is do we have a mechanism for its formation? Or do the cosmological models need more work?
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 Well i think it would have to be the latter here ajb. Cosmological principle is something that is not questioned very often in science, if it were to be changed we would have to consider entirely new possibilities of reality without that filter. Someone could easily argue the CMB is at odds with the cosmological principle as well. That is two examples from someone who does not pay attention to science as much as he should shedding light on a possible scientific revolution? (id assume if the cosmological principle were falsified that could be classified as a revolution yes?). This is what i love and hate about science, so much to learn but so few willing to.
Strange Posted August 18, 2016 Posted August 18, 2016 Go away. "The cosmic microwave background is the afterglow radiation left over from the hot Big Bang. Its temperature is extremely uniform all over the sky. However, tiny temperature variations or fluctuations (at the part per million level) can offer great insight into the origin, evolution, and content of the universe." http://wmap.gsfc.nasa.gov/universe/bb_cosmo_fluct.html 2
ajb Posted August 18, 2016 Posted August 18, 2016 Cosmological principle is something that is not questioned very often in science, People who work in cosmology do question it - the principle is the backbone of our cosmological models, however people are looking at inhomogeneous cosmologies, usually to see if dark energy can be removed in this way. Anyway, I think it maybe a question of the scale at which we expect the principle to hold well. Other evidence from observational cosmology suggest that we don't want to throw this principle away completley. ...if it were to be changed we would have to consider entirely new possibilities of reality without that filter. It would be hard to work with for sure. Someone could easily argue the CMB is at odds with the cosmological principle as well. I think the CMBR fits okay here - maybe not if we don't include inflation. That is two examples from someone who does not pay attention to science as much as he should shedding light on a possible scientific revolution? (id assume if the cosmological principle were falsified that could be classified as a revolution yes?). I think it is more a question of scales again. Anyway, we need to wait and see what further analysis and observations reveals before getting ahead of ourselves. 1
Strange Posted August 18, 2016 Posted August 18, 2016 Nah, sorry. You cant have both ajb its either the cosmological principle or nothing, there is no in-between here bud...no matter how much you and strange want to minimize the findings. No one is minimizing the findings. You seem to be confusing "small" and "unimportant". We have very small fluctuations that are very, very important. Why again do i post articles that are a rather big deal in science, but you almost never see them talked about? In this case, although I have seen some discussion of this, there isn't a lot to go on. A sample size of 1 doesn't tell us too much.
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 (edited) "The cosmic microwave background is the afterglow radiation left over from the hot Big Bang. Its temperature is extremely uniform all over the sky. However, tiny temperature variations or fluctuations (at the part per million level) can offer great insight into the origin, evolution, and content of the universe." http://wmap.gsfc.nasa.gov/universe/bb_cosmo_fluct.html Strange...i get its all or nothing for you but i will oblige. You love minimizing statistical anomalies especially when they are at odds with a scientific backbone like the cosmological principle. If i am honest it does not matter how small they are, you still cannot explain why they are there when the theory predicts otherwise. I just cannot grasp why i have not seen more of this in mainstream media. I mean shit ive seen everything from nasa needs help to corral an asteroid to how the recent failures of the LHC are actually wins because "nothing" is important. Science is always ready to pat themselves on the back, but how about we take the humble approach for once? Edited August 18, 2016 by Scotty99 -1
Strange Posted August 18, 2016 Posted August 18, 2016 Strange...i get its all or nothing for you but i will oblige. You love minimizing statistical anomalies especially when they are at odds with a scientific backbone like the cosmological principle Again: I am not minimizing it. The various anomalies may be very important. But they are very small in size (that is why so much time and effort needs to spent studying them). If i am honest it does not matter how small they are, you still cannot explain why they are there when the theory predicts otherwise. Some can be explained and some can't. Some of the latter have all sorts of far out speculations associated with them (e.g. Mersini-Houghton's "colliding universes" idea) I just cannot grasp why i have not seen more of this in mainstream media. Dunno. I guess there is just a lot of competition for news space. Science is always ready to pat themselves on the back, but how about we take the humble approach for once? Isn't the admission that the suggestions of a new particle from the LHC being wrong sufficiently humble? Science is the discipline of being consistently wrong. The whole purpose of the scientific method is to try and show that your (or other people's) ideas are wrong.
Scotty99 Posted August 18, 2016 Author Posted August 18, 2016 No that isnt being humble, jesus. Being humble would be able to go back on HUNDREDS year old theories and rethink where we are at in science today instead of trying to make them fit out of pride. I am not claiming the cosmological principle is incorrect in this thread, but if you take a deep hard look to where science is at how can you come to any conclusion other than the framework was warped from the start? Lets trace our steps backwards until things start to make sense, what is the harm?
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