David Levy Posted January 20, 2016 Posted January 20, 2016 (edited) Let's assume that we all have just landed at Mother Earth. We don't know anything about the Universe and how it looks like. We don't know what is a galaxy or cluster. We also don't know anything about the BBT, Expansion and all the other relevant theories. So, they put us in a closed room and give us the following information about the CMB: All of the CMB comes from the same distance and therefore all of it is affected equally. There is a single red-shift for all the frequencies in the CMB. All frequencies are shifted equally. All wavelengths are scaled by the same amount. The red-shift affects all frequencies by the same amount. The radiation is scaled (red-shifted) by 1,100. They also explain that the CMB is based on wavelength radiation which comes evenly from all the directions. This wavelength radiation is linear. It also has a very unique feature - it can cross very long distance (much more than light). They specify that the CMB redshift is 1089, and they also give us full explanation about the meaning of the redshift. They tell us that this redshift represents a wavelength radiation from a distance of 45 Billion LY. So, the question is: Please draw the shape of the universe based on those features of the CMB. I assume that for some of you it might be quite difficult to participate in that kind of exercise. But please, try. It is only an exercise. The Sun will not fall over our head... Edited January 20, 2016 by David Levy
imatfaal Posted January 20, 2016 Posted January 20, 2016 Let's assume that we all have just landed at Mother Earth. We don't know anything about the Universe and how it looks like. We don't know what is a galaxy or cluster. We also don't know anything about the BBT, Expansion and all the other relevant theories.... Going to be difficult - but a good gedanken. I am not sure you have given enough scope for your putative scientists to discover/deduce anything They also explain that the CMB is based on wavelength radiation which comes evenly from all the directions. This wavelength radiation is linear. It also has a very unique feature - it can cross very long distance (much more than light). They specify that the CMB redshift is 1089, and they also give us full explanation about the meaning of the redshift. They tell us that this redshift represents a wavelength radiation from a distance of 45 Billion LY. Your phrasing shows how little you understand this topic - and why so many posters are frustrated at your continued attempts to pick holes in a theory you seem to have no real grasp of. 1. The CMBR is isotropic - which I think is what you mean from your first sentence 2. No idea about second sentence 3. Wah? The CMBR is light - it started off as ultraviolet and is now microwave - but that is all still light. If you are positing new special characteristics - then the question is why? 4. OK 5. Still not entirely sure about this sentence i. We are told the surface of last scattering beyond which we see only opaqueness is at a distance of 45 Gly ii. We know that a minimally cool opaque plasma universe would give off light in the ultraviolet at around 3000k. iii. We are seeing light in the microwave with a temperature of just below 3k. iv. We know that an expanding background "stretches" light by increasing its wavelength and in effect cooling. v. We would note that the redshift given agrees with our predictions of a universe-wide opaque plasma (3000k) leading to a universe-wide background radiation which has been cooled (to <3k) by an expanding universe. vi. We would estimate (not knowing about accelerated expansion) that the expansion which has caused the redshift was simple and linear. vii. We would also estimate that the limit of the light observable universe (ie the surface that is now the CMBR and is/was the surface of last scattering) was of radius about 40 Mly when the universe stopped being opaque and started to transmit light
David Levy Posted January 20, 2016 Author Posted January 20, 2016 3. Wah? The CMBR is light - it started off as ultraviolet and is now microwave - but that is all still light. If you are positing new special characteristics - then the question is why? That is correct. But, it isn't visible light. I assume that the furthest distance of galaxy that we can see is no more than 13 or 15 Billion light years. So the wavelength radiation is very special. We can still detect its energy after crossing a distance of 45 Billion LY. Do you agree?
Strange Posted January 20, 2016 Posted January 20, 2016 They also explain that the CMB is based on wavelength radiation which comes evenly from all the directions. What do you mean by "wavelength radiation"? This wavelength radiation is linear. What do you mean by it being "linear"? It also has a very unique feature - it can cross very long distance (much more than light). It is light. It can cross exactly the same distance as light. Why do you think otherwise? They tell us that this redshift represents a wavelength radiation from a distance of 45 Billion LY. What do you mean by "wavelength radiation"? So, the question is: Please draw the shape of the universe based on those features of the CMB. I don't think you have given enough information to say anything about the shape of the universe. What information do you think says anything about the shape of the universe? I'm not sure anyone knows what the shape of the universe is. So I doubt it could be worked out from the vague and confusing information you have provided. That is correct. But, it isn't visible light. I assume that the furthest distance of galaxy that we can see is no more than 13 or 15 Billion light years. So the wavelength radiation is very special. We can still detect its energy after crossing a distance of 45 Billion LY. Do you agree? The only difference is that there are no galaxies at the distance that the CMB comes from. There is nothing "special" about the radiation that allows it to travel further - it just started further away. Also, much of the light from the most distant galaxies is not visible light. It will have been shifted into the infra-red or beyond.
swansont Posted January 20, 2016 Posted January 20, 2016 I'm not sure what the point of a "what would you conclude if you had far less information available to you" exercise is.
ajb Posted January 20, 2016 Posted January 20, 2016 I don't think you have given enough information to say anything about the shape of the universe. You are right. If you want to measure the curvature of the Universe then you can do this using the CMBR, but you need to look at the power spectrum and temperature anisotropy very carefully. Th generic features of the CMBR are not enough. Anyway, both the CMBR and estimates of the total matter-energy content of the Universe are consistent with a flat Universe.
imatfaal Posted January 20, 2016 Posted January 20, 2016 I'm not sure what the point of a "what would you conclude if you had far less information available to you" exercise is. [ot] I think it can - in very specific circumstances and probably not the OP's - lead to wholly differing approaches. We knew that peptic ulcers were related to bad diet, high stress, specific food types, t2 etc so our research focussed there; but without this knowledge we might have thought to rule out an infective agent first. Warren and Marshall's work was mocked because it ignored so much already known. On the whole I agree with your comment - and the approach is really only available to those who know and understand the topic completely and deliberately choose to ignore ideas rather than those wrongly assuming that their own patchwork knowledge will suffice [/ot]
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) The only difference is that there are no galaxies at the distance that the CMB comes from. There is nothing "special" about the radiation that allows it to travel further - it just started further away. Why are you so sure about it? Why do you claim that there are no galaxies at a distance which is 45 Bly or over? How do we know that? So, do you agree that the redshift of the CMB is about 1100? Do you agree that this redshift represents a distance of 45 Billion LY? Do you agree that if it comes from that distance, then potentially there might be some galaxies/mass at that distance? Edited January 20, 2016 by David Levy
Strange Posted January 20, 2016 Posted January 20, 2016 (edited) Why are you so sure about it? Why do you claim that there are no galaxies at a distance which is 45 Bly or over? How do we know that? Of course we don't "know" that. But that is what our best theories and evidence tells us. You seem to be looking for some bizarre level of certainty that doesn't exist (in science, at least). Do you agree that if it comes from that distance, then potentially there might be some galaxies/mass at that distance? No, because at the time that the radiation was emitted the universe was(*) a uniform hot dense plasma. It took millions more years for stars to form. (*) As far as we know at the moment ... according to our current best theories and evidence ... subject to change ... more information ... yadayada Edited January 20, 2016 by Strange
imatfaal Posted January 20, 2016 Posted January 20, 2016 That is correct. But, it isn't visible light. I assume that the furthest distance of galaxy that we can see is no more than 13 or 15 Billion light years. So the wavelength radiation is very special. We can still detect its energy after crossing a distance of 45 Billion LY. Do you agree? Who cares if it is visible through our second rate monkey-eyes - it is detectable. Your assumption is incorrect (again) - the "light-travel distance" would be around 13.2 billion years. But the light travel distance does not take into account expansion (in light travel distance the size of the observable universe is 13.8 Gly) - I think the further galaxies are at about z=8.5 and about 30Glyr No the radiation is exactly the same as microwave radiation generated in a lab. There was just a universe full of it - so we still detect it. Crossing a distance which we could measure today as 45 Gly Stop trying to push people into corners with silly phrasings like "Do you agree?" - you are not in a courtroom and we are not hostile witness limited to y/n answers - nor are you a mentor trying to draw out students' knowledge. A whole dose of humility would do you the power of good and might allow you to start to learn about a topic which clearly fascinates you. 2
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) Of course we don't "know" that. But that is what our best theories and evidence tells us. Sorry, I disagree. The CMB is pure evidence. All the others theories - are just theories. We must distinguish between theory and evidence. Somehow - the science mix it up. No, because at the time that the radiation was emitted the universe was(*) a uniform hot dense plasma. It took millions more years for stars to form. That is a theory. You claim - No, because it doesn't meet the current theory. However, it doesn't contradict any real evidence which we might have. If you wish, please highlight just one real evidence which contradicts that issue. In any case, please answer the following: Is it correct that the redshift of the CMB is about 1100? Is it correct that this redshift represents a distance of 45 Billion LY? Edited January 20, 2016 by David Levy -1
ajb Posted January 20, 2016 Posted January 20, 2016 All the others theories - are just theories. We must distinguish between theory and evidence. Somehow - the science mix it up. Rather generally it is impossible to separate completely the theory and observations. One needs some theory to have an idea of what one is looking at. A theory is needed in the design of experiments as well as in the interpretation. A clear cut as you would like is not really possible.
Strange Posted January 20, 2016 Posted January 20, 2016 That is a theory. You claim - No, because it doesn't meet the current theory. However, it doesn't contradict any real evidence which we might have. The current theory is based on a mountain of evidence. The discovery of galaxies with an age of 13.8 billion or more years would therefore contradict all that evidence. Is it correct that the redshift of the CMB is about 1100? Is it correct that this redshift represents a distance of 45 Billion LY? You have another thread where these questions have been answered multiple times already. Why do you keep asking the same thing? What do you mean by "wavelength radiation"?
swansont Posted January 20, 2016 Posted January 20, 2016 All the others theories - are just theories. Anyone who uses "just theories" in this context obviously doesn't understand what a theory is. 1
David Levy Posted January 20, 2016 Author Posted January 20, 2016 Rather generally it is impossible to separate completely the theory and observations. This is a severe mistake! We must clearly distinguish between evidences and theories One needs some theory to have an idea of what one is looking at. A theory is needed in the design of experiments as well as in the interpretation. A clear cut as you would like is not really possible. Yes, I fully agree. But, we always need to confirm our theories. We shouldn't ignore any new evidence which might contradicts our current theories. We always need to open our mind for any idea which could be more acurate than the current approch.
swansont Posted January 20, 2016 Posted January 20, 2016 This is a severe mistake! We must clearly distinguish between evidences and theories Again, you don't understand what a theory is. It includes the evidence. It's not possible to separate the evidence from the theory; it wouldn't be a theory anymore. Conjecture or hypothesis, perhaps, but not a theory. 1
Klaynos Posted January 20, 2016 Posted January 20, 2016 David Levy, can you please define what you mean when you use the word theory?
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) David Levy, can you please define what you mean when you use the word theory? Theory = a supposition, an uncertain belief or a system of ideas intended to explain something. Evidence = the available body of facts or information indicating whether a belief or proposition is true or valid. The BBT is a theory. The Expantion is a theory.Those theories are uncertain belief. If those ideas were evidences, then they had to call it the BB evidence or Expantion evidence. What do you mean by "wavelength radiation"? Please see the following: Even though we call it the CMB 'temperature', it isn't like a gas temperature which decreases as the cube of the volume increase. It is actually the wavelength of the radiation which makes up the CMB that increases linearly with the same scaling factor as the expansion of the universe. So the scaling factor 1100 is the relevant one for the CMB. Edited January 20, 2016 by David Levy
swansont Posted January 20, 2016 Posted January 20, 2016 Theory = a supposition, an uncertain belief or a system of ideas intended to explain something. Maybe you should use supposition, hypothesis, or conjecture. In science a theory is a well-supported explanation/model of the behavior of the natural world. https://en.wikipedia.org/wiki/Scientific_theory (And, just in case this comes up, theories do not "grow up" to become laws.) The big bang theory is not mere supposition.
Strange Posted January 20, 2016 Posted January 20, 2016 (edited) Theory = a supposition, an uncertain belief or a system of ideas intended to explain something. OK. So that is not what "theory" means in science. A scientific theory is a well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation. https://en.wikipedia.org/wiki/Scientific_theory A theory is as far from "uncertain belief" as it is possible to get. Please see the following: That doesn't help. That refers to the wavelength of the radiation, which makes perfect sense. Whereas "wavelength radiation" seems to be entirely meaningless. Edited January 20, 2016 by Strange
ajb Posted January 20, 2016 Posted January 20, 2016 Theory = a supposition, [/size]an uncertain belief [/size]or a system of ideas intended to explain something.[/size] Okay, I misunderstood what you were saying. To me a theory is a mathematical model and disentangling mathematical models from observations is generally impossible.
David Levy Posted January 20, 2016 Author Posted January 20, 2016 With regards to the redshift: In cosmology, it's actually the size of the universe when that light was emitted. Hence, distance. For example: In the following article it is stated that a redshift of 11.9 means a distance of 13 billion LY. Hubble census finds galaxies at redshifts 9 to 12https://www.spacetelescope.org/news/heic1219/"Astronomers using the NASA/ESA Hubble Space Telescope have uncovered seven primitive galaxies from a distant population that formed more than 13 billion years ago. In the process, their observations have put forward a candidate for the record for the most distant galaxy found to date (at redshift 11.9), and have shed new light on the earliest years of cosmic history." So, a redshift of 11.9 represents a distance of 13 Billion LY. This is evidence. In the same token, a redshift of 1100 should represents a distance of 1,300 Billion LY. This is also EVIDENCE. So, we can easily claim that the CMB represents a radiation which had been emitted from a distance of 1,300 Billion LY. Why not?
swansont Posted January 20, 2016 Posted January 20, 2016 "Astronomers using the NASA/ESA Hubble Space Telescope have uncovered seven primitive galaxies from a distant population that formed more than 13 billion years ago. In the process, their observations have put forward a candidate for the record for the most distant galaxy found to date (at redshift 11.9), and have shed new light on the earliest years of cosmic history." So, a redshift of 11.9 represents a distance of 13 Billion LY. This is evidence. No, that's conjecture. The redshift is evidence. You have a model that (apparently) treats the universe such that something that emitted light X years ago is X light years away. What you need is evidence that this model is correct. It's certainly not consistent with the big bang cosmology.
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) No, that's conjecture. You have a model that (apparently) treats the universe as static — no expansion — so something that emitted light X years ago is X light years away. What you need is evidence that this model is correct. It's certainly not consistent with the big bang cosmology, which has expansion. It also fails to explain why you would have a redshift in the first place. Sorry, that is the main fault of the modern science! They actually band the evidences in order to meet their speculation! The expansion and the big bang are theories by definition. I'm not against any theory. I'm not against the Big bang or the expansion. But those theories must be correlated with the CMB evidences. The CMB redshift is evidence. Based on redshift we know for sure that there are galaxies at a distance of 13 Bly. As you have stated: "something that emitted light X years ago is X light years away. " Therefore, based on the same knowledge that we have on redshift - the CMB redshift represents a distance of 1,300 Bly. If it doesn't meet the current theories - then its the time to look for different ideas. Edited January 20, 2016 by David Levy
Mordred Posted January 20, 2016 Posted January 20, 2016 No they don't band the evidence to support theory. If evidence shows up that proves the theory wrong they rethink the theory. This has happened to me several times lol. I develop a hypothesis, work on the math. Look for evidence and experimental data. If I find data that conflicts I try to explain it with my hypothesis. If I cannot then I know something is wrong. So I try to figure out how wrong my hypothesis is. (Note at no time did I consider the above a working theory). One of the steps to test a theory is a diligent effort to prove that theory wrong. Otherwise you will never develop a strong long lasting theory.
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