David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) This is not a secret. Google reporrts half a million results: https://www.google.co.uk/search?q=cmb+redshift Google Scholar has thousands of papers: https://scholar.google.co.uk/scholar?q=cmb+redshift Arxiv has so many it won't list them all: http://arxiv.org/find/all/1/all:+AND+cmb+redshift/0/1/0/all/0/1 Yes, there is. For example, it says: "The photons that existed at the time of photon decoupling have been propagating ever since, though growing fainter and less energetic, since the expansion of space causes their wavelength to increase over time" "The intensity of the radiation also corresponds to black-body radiation at 2.726 K because red-shifted black-body radiation is just like black-body radiation at a lower temperature." "As the universe expands, the CMB photons are redshifted" "The temperature Tr of the CMB as a function of redshift, z, can be shown to be proportional to the temperature of the CMB as observed in the present day (2.725 K or 0.235 meV)" "the cosmic microwave background will continue redshifting until it will no longer be detectable" So there is no conspiracy to hide this information. No, they don't say clearly that the CMB redshift is 1100. Why they give us all those kinds of information without clearly specify that the CMB redshift is 1100? How can we know it? I had no clue about it. So I still think that they must add immediately this vital info. Not hid it in between long explanation. So instead of: "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] " It should be: The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089. So simple! Edited January 20, 2016 by David Levy
Strange Posted January 20, 2016 Posted January 20, 2016 No, they don't say clearly that the CMB redshift is 1100. Why they give us all that kind of information without clearly specify that the CMB redshift is 1100? How can we know it? Really? It says "Since decoupling, the temperature of the background radiation has dropped by a factor of roughly 1,100[77] due to the expansion of the universe." I had no clue about it. I don't think it is reasonable to blame your ignorance on a conspiracy. But maybe this isn't surprising. You think that if you, personally, don't understand something then all the world's scientists must be wrong. And if you have failed to read and/or learn something then it is some sort of military secret. So I still think that they must add imidiatly this vital info. Not hid it in between long explanation. So instead of: "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] " It should be: The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089. So simple! It is Wikipedia. You can add that if you want to. You will need to add a link to the page where the scale factor of 1089 is explained. (There are already links to that on the page. So an intelligent reader can find all the information they need.) But maybe it is irresponsible of me to encourage someone who is so wilfully ignorant to edit Wikipedia!
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) The other problem is that they mix evidences with theories. If they give us info about the CMB it must includes only pure evidences about the CMB. Why it is stated: "the cosmic microwave background will continue redshifting until it will no longer be detectable" This is a theory by definition. It might be correct, but it also might be incorrect. Really? It says "Since decoupling, the temperature of the background radiation has dropped by a factor of roughly 1,100[77] due to the expansion of the universe." Really? They speak about the temperature, not about the redshift. How could I know that this 1100 represents the redshift? Sorry - it is my fault. I'm so wilfully ignorant. Edited January 20, 2016 by David Levy
Strange Posted January 20, 2016 Posted January 20, 2016 Almost the only "fact" about the CMB is that it is a black body spectrum with a temperature of 2.3K. Oh no, wait: "black body" is a theoretical concept. "Temperature" is a theoretical concept. You cannot separate facts from theory. You just want to do that because you think theory is wrong. But as you have just demonstrated (again) that you are profoundly ignorant and unwilling/unable to learn, I don't think your opinions on theory are worth anything.
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) Almost the only "fact" about the CMB is that it is a black body spectrum with a temperature of 2.3K. Oh no, wait: "black body" is a theoretical concept. "Temperature" is a theoretical concept. You cannot separate facts from theory. You just want to do that because you think theory is wrong. But as you have just demonstrated (again) that you are profoundly ignorant and unwilling/unable to learn, I don't think your opinions on theory are worth anything. No - I totaly disagree. We know for sure that: "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089." That all are pure evidences. How can anyone estimate what will happen in the future: "the cosmic microwave background will continue redshifting until it will no longer be detectable" How can we be so sure about it? We even don't know a simple question as - what came first in a galaxy - stars or black hole? This is a pure theory. They can add a theory. I'm not against it. But they have to state: "We assume that the cosmic microwave background will continue redshifting until it will no longer be detectable" I have one more question about the following statement: "the cosmic microwave background will continue redshifting until it will no longer be detectable" Let's assume that this is incorrect. Let's assume that the cosmic microwave background will continue redshifting forever. What can we learn from that? Edited January 20, 2016 by David Levy
Strange Posted January 20, 2016 Posted January 20, 2016 (edited) No - I totaly disagree. We know for sure that: "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089." The red shift is purely theoretical. It is not a directly observed fact. The spectrum of the CMB is an observational fact but identifying it as a "black body spectrum" is theoretical. That all are pure evidences. How can anyone estimate what will happen in the future: We know what is happening now. We have no evidence currently to indicate that will change. So all we can do is extrapolate based on what we know. Of course, in future, more observations might change that. But they have to state: "We assume that the cosmic microwave background will continue redshifting until it will no longer be detectable" That is implicit in every single scientific statement. Every time you read a sentence about science you need to add "As far as we know, according to current best theories ..." to the start and "... this may be subject to change as we learn more" to the end. It would make things unnecessarily cumbersome to write every sentence like that. especially as everyone know that sceince is provisional and based on our current best theories. I have one more question about the following statement: "the cosmic microwave background will continue redshifting until it will no longer be detectable" Let's assume that this is incorrect. Let's assume that the cosmic microwave background will continue redshifting forever. What is the difference? It will continue redshifting for ever. At some point it will become undetectable. Edited January 20, 2016 by Strange
David Levy Posted January 20, 2016 Author Posted January 20, 2016 What is the difference? It will continue redshifting for ever. At some point it will become undetectable. No, the question is - if it will continue to be detectabale forever, and at the same features as it is today. "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089." What is the impact of that?
Strange Posted January 20, 2016 Posted January 20, 2016 No, the question is - if it will continue to be detectabale forever, and at the same features as it is today. "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.%5B5%5D with a redshift of 1089." What is the impact of that? There is a limit to the sensitivity of instruments. At some point it will no longer be possible to detect photons with that little energy. But do you mean, what if it turns out that the CMB is not due to the changing scale factor? In other words, what if General Relativity is fundamentally wrong? Then GPS satellites would stop working. And we would have to find alternative explanations for all the evidence for GR and the big bang model. That would be pretty exciting. But also extremely unlikely.
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) The red shift is purely theoretical. It is not a directly observed fact. The spectrum of the CMB is an observational fact but identifying it as a "black body spectrum" is theoretical. Why do you claim so? We know exactly the meaning of redshift. It is detectable. So it is fact. I agree that the implementation of that fact might be a theoretical idea. So, based on that redshift fact - we have an idea about the BBT theory. That is perfectly O.K. So, CMB redshift is evidence. The BBT is a theory. Same issue with black body. This is not theoretical. We know for sure what is the spectrum of a black body. Therefore, the CMB is considered as a black body. This is a pure evidence. Again - the implementation of this evidence - is theory. Edited January 20, 2016 by David Levy
Strange Posted January 20, 2016 Posted January 20, 2016 Why do you claim so? We know exactly the meaning of redshift. It is detectable. So it is fact. Because to know the red-shift you have to know the original frequency and the frequency now. We cannot measure the original frequency so that is purely theoretical.
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) Because to know the red-shift you have to know the original frequency and the frequency now. We cannot measure the original frequency so that is purely theoretical. O.K. I'm not going to argue about it, especially as I'm not so cleaver as you are. What is the difference? It will continue redshifting for ever. At some point it will become undetectable. No, the question is - Lets assume that it will continue to be detectable forever, and at the same features as it is today. "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089." What is the impact of that? Edited January 20, 2016 by David Levy
imatfaal Posted January 20, 2016 Posted January 20, 2016 No, the question is - Lets assume that it will continue to be detectable forever, and at the same features as it is today. "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089." What is the impact of that? Our ideas about the universe would be incorrect. But as you have just made the statement up from thin air it is not worth worrying about. David - unless this thread gets back to being about honest inquiry and stops being you (seemingly automatically) gainsaying what ever answers you are given I shall report this thread for a moderator to move to specs or close down.
David Levy Posted January 20, 2016 Author Posted January 20, 2016 Our ideas about the universe would be incorrect. But as you have just made the statement up from thin air it is not worth worrying about. David - unless this thread gets back to being about honest inquiry and stops being you (seemingly automatically) gainsaying what ever answers you are given I shall report this thread for a moderator to move to specs or close down. Thanks That is clear. You can leave this tread open as it is. I have some ideas about the CMB. Therefore I will open a new tread at speculation
swansont Posted January 20, 2016 Posted January 20, 2016 This is the most important feature of the CMB. So, how could it be that it isn't published in all the CMB articles? For example: https://en.wikipedia.org/wiki/Cosmic_microwave_background In that article from Wiki - not even one word about the redshift. In the last several years I have read few hundreds articles about the CMB - none of them have mentioned this vital info. Why? Is it a military secret? I'm in a deep shock about it. It's a big shame for the science community that they hide this supper important information from the public. So instead of: "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] " It should be: The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.[5] with a redshift of 1089. So simple! The information isn't hidden. If you're reading up on it, perhaps it's assumed you know a little bit about it already — it depends on who the target of the article is. Articles aren't tutorials. No - I totaly disagree. We know for sure that: "The CMB has a thermal black body spectrum at a temperature of 2.72548±0.00057 K.%5B5%5D with a redshift of 1089." That all are pure evidences. How can anyone estimate what will happen in the future: "the cosmic microwave background will continue redshifting until it will no longer be detectable" How can we be so sure about it? We even don't know a simple question as - what came first in a galaxy - stars or black hole? This is a pure theory. They can add a theory. I'm not against it. But they have to state: "We assume that the cosmic microwave background will continue redshifting until it will no longer be detectable" How can anyone estimate what will happen in the future? That's what science does! ALL of science. You're acting like predicting future behavior is somehow unique and unexpected, and it's not. It's business as usual. If you drop something, I can predict it wall fall with an acceleration of about 9.8 m/s^2, modified by air resistance. I don't have to say that I will assume that's going to happen. The theory is really well-established.
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