Strange Posted January 20, 2016 Posted January 20, 2016 So, a redshift of 11.9 represents a distance of 13 Billion LY. As the article says, that is "13 billion years ago". That is not the same as 13 billion light years away. The scale factor and red-shift are related to how far away the galaxies were when the light was emitted. The relationship between the light travel time and that distance is non-linear (because of expansion).
David Levy Posted January 20, 2016 Author Posted January 20, 2016 As the article says, that is "13 billion years ago". That is not the same as 13 billion light years away. The scale factor and red-shift are related to how far away the galaxies were when the light was emitted. The relationship between the light travel time and that distance is non-linear (because of expansion). . Please - don't use a theory (the expansion) as an argument against evidence (CMB redshift). My question is very simple - Is it correct that a redshit of 11.9 represents a distance of 13 B ly? If so, I still do not understand why a redshift of 1100 in the CMB can't represent a distance of 1,300 Bly?
Strange Posted January 20, 2016 Posted January 20, 2016 Is it correct that a redshit of 11.9 represents a distance of 13 B ly? No. Please stop assuming that if you, personally, have failed to understand something then it must be wrong. The problem is with your lack of understanding, not the theory. Please - don't use a theory (the expansion) as an argument against evidence (CMB redshift). We only know the CMB is redshifted from theory. You can't measure the redshift directly.
swansont Posted January 20, 2016 Posted January 20, 2016 Sorry, that is the main fault of the modern science![/size] Your misunderstanding of science is not the fault of science. They actually band the evidences in order to meet their speculation![/size] The expansion and the big bang are theories by definition.[/size] I'm not against any theory. I'm not against the Big bang or the expansion.[/size] But those theories must be correlated with the CMB evidences.[/size] The CMB redshift is evidence.[/size] Based on redshift we know for sure that there are galaxies at a distance of 13 Bly.[/size] As you have stated:[/size] "[/size]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.[/size] I stated that, but I thought I was clear that I was paraphrasing your apparent position. That's not an endorsement that it's correct. Quite the opposite: you are wrong. However, my call for you to come up with evidence still stands. What evidence do you have?
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) With regards to my question: Is it correct that a redshit of 11.9 represents a distance of 13 B ly? Your answer was: No. Why? So based on what evidence the science had decided that those galaxies are located at a distance of 13 Bly? Edited January 20, 2016 by David Levy
Strange Posted January 20, 2016 Posted January 20, 2016 So based on what evidence the science had decided that those galaxies are located at a distance of 13 Bly? What makes you think they are? Please provide some evidence for this.
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) It is stated clearly: "The greater the observed z value for a galaxy, the more distant it is in time and space, as observed from our position in the Milky Way". "the improved and extended dataset has allowed the scientists to shed unexpected new light on this object, showing that it either lies at an even greater distance than previously thought (at a redshift of 11.9, handing it back the distance record)" Therefore, there is full correlation between redshift and distance. Why do you ignore that? Edited January 20, 2016 by David Levy
Mordred Posted January 20, 2016 Posted January 20, 2016 David you really need to grasp a few concepts. First redshift is only calculatable if you know the emitter frequency. (For this we note the Rayleigh scale on specific elements) Secondly there is several types of redshift. (Cosmological, gravitational, Doppler). Thirdly we must filter out our own environment influences ( galaxy, solar system and planetary movement). Local radiation etc. It took years of expiremental research to correlate the average redshift in the CMB. It took years of experimental research to develop the redshift formula. (Previously it was hypothesized as "tired light" or alternatively referred to as "spectral shift" As mentioned you cannot separate theory and evidence. Evidence is a fundamental part of a working theory It is stated clearly: "The greater the observed z value for a galaxy, the more distant it is in time and space, as observed from our position in the Milky Way". "the improved and extended dataset has allowed the scientists to shed unexpected new light on this object, showing that it either lies at an even greater distance than previously thought (at a redshift of 11.9, handing it back the distance record)" This has more to do with how early can galaxies form than the CMB itself.
swansont Posted January 20, 2016 Posted January 20, 2016 So based on what evidence the science had decided that those galaxies are located at a distance of 13 Bly? You're the only one making this statement. Why should science have to back you up? It's your job to make your case. What evidence do you have that an object that emitted light 13 billion years ago is 13 billion LY away?
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) Thanks Mordred Evidence is a fundamental part of a working theory Fully agree As mentioned you cannot separate theory and evidence. Theories should be based on evidences and not vice versa. David you really need to grasp a few concepts.First redshift is only calculatable if you know the emitter frequency. (For this we note the Rayleigh scale on specific elements)Secondly there is several types of redshift. (Cosmological, gravitational, Doppler).Thirdly we must filter out our own environment influences ( galaxy, solar system and planetary movement). Local radiation etc.It took years of expiremental research to correlate the average redshift in the CMB.It took years of experimental research to develop the redshift formula. (Previously it was hypothesized as "tired light" or alternatively referred to as "spectral shift" That is fully clear. So can you please explain when we should use a redshift to verify a distance, and why a galaxy redshift can't be used as an evidence for the distance from that galaxy. Edited January 20, 2016 by David Levy
Mordred Posted January 20, 2016 Posted January 20, 2016 (edited) You can't rely on just redshift. Let's say I want to measure a star. First I know hydrogen gas a specific spectrum on the Rayleigh scale. So from this I can estimate the frequency of the emitter. Good so far now let's follow the light path from that star to Earth. First question to answer, is that light path a straight line? Surprisingly enough due to universe geometry influence the path can be curved. Just as spacetime curvature can alter the path of a light Ray. So we must compensate for this change. (Distance change in light path) 2) did the light path enter a gravity well? This causes gravitational redshift/blueshift. 3) what's is the stars movement compared to our. (Doppler shift) You cannot from measure alone distinquish cosmological redshift, from gravitational redshift or Doppler shift. You require further details and measurements to seperate how much each has influence upon your light Ray. For these reasons distance measurements requires mountains of data to fine tune them. They require multiple methods. Parallax being one of them. Here these will help. Site Articles (Articles written by PF and Site members) http://cosmology101.wikidot.com/redshift-and-expansion http://cosmology101.wikidot.com/universe-geometry Edited January 20, 2016 by Mordred
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) You're the only one making this statement. Why should science have to back you up? It's your job to make your case. What evidence do you have that an object that emitted light 13 billion years ago is 13 billion LY away? It takes about 8 min for the sun light to get the Earth. This time frame represents the distance between us. As I have already stated - the expansion is a theory. So, just for one moment, let's try to ignore that theory. Hence, if the light of an object had been emitted x ly ago, than by definition the distance to that object represents a distance of x ly. Off course, we can then claim that based on the expansion, this isn't the real distance when the light had been emitted. But as a straight forward answer - Then yes, a light which had been emitted x Billion ly represents the distance of x Billion light years Edited January 20, 2016 by David Levy
swansont Posted January 20, 2016 Posted January 20, 2016 It takes about 8 min for the sun light to get the Earth. This time frame represents the distance between us. As I have already stated - the expansion is a theory. So, just for one moment, let's try to ignore that theory. Hence, if the light of an object had been emitted x ly ago, than by definition the distance to that object represents a distance of x ly. Off course, we can then claim that based on the expansion, this isn't the real distance when the light had been emitted. But as a straight forward answer - Then yes, a light which had been emitted x Billion ly represents the distance of x Billion light years You need some other evidence to corroborate that. You can't just assume it's true.
Strange Posted January 20, 2016 Posted January 20, 2016 It is stated clearly: "The greater the observed z value for a galaxy, the more distant it is in time and space, as observed from our position in the Milky Way". "the improved and extended dataset has allowed the scientists to shed unexpected new light on this object, showing that it either lies at an even greater distance than previously thought (at a redshift of 11.9, handing it back the distance record)" Therefore, there is full correlation between redshift and distance. OK. Let's use that information to calculate the distance, rather than making up numbers. The distance to the source of the CMB is about 45 billion light years. That has, as you know, a red shift of about 1100. That is about 100 times greater than the redshift of this galaxy. So the distance to this galaxy is about 45 billion / 100 = 500 million light years. Does that make sense?
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) You can't rely on just redshift. Let's say I want to measure a star. First I know hydrogen gas a specific spectrum on the Rayleigh scale. So from this I can estimate the frequency of the emitter. Good so far now let's follow the light path from that star to Earth. First question to answer, is that light path a straight line? Surprisingly enough due to universe geometry influence the path can be curved. Just as spacetime curvature can alter the path of a light Ray. So we must compensate for this change. (Distance change in light path) 2) did the light path enter a gravity well? This causes gravitational redshift/blueshift. 3) what's is the stars movement compared to our. (Doppler shift) You cannot from measure alone distinquish cosmological redshift, from gravitational redshift or Doppler shift. You require further details and measurements to seperate how much each has influence upon your light Ray. For these reasons distance measurements requires mountains of data to fine tune them. They require multiple methods. Parallax being one of them. Here these will help. Site Articles (Articles written by PF and Site members) http://cosmology101.wikidot.com/redshift-and-expansion http://cosmology101.wikidot.com/universe-geometry Thanks It is stated clearly: http://cosmology101.wikidot.com/redshift-and-expansion "The further away an object is the greater the amount of redshift." So, with all the difficulties to verify accurate distance based on redshift (which you have fully explained), - we should be able to get some sort of distance estimation. Even if it is not fully correct - we still should have some basic knowledge about the distance. So, I still do not understand why some claim that the following distance of 13 Bly is not correlated with the redshift: "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" If the distance of 13 Bly had not been based on redshift, what kind of elements they have used in order to estimate this distance? Never the less, it shows clearly a linkage between redshift and distance. OK. Let's use that information to calculate the distance, rather than making up numbers. The distance to the source of the CMB is about 45 billion light years. That has, as you know, a red shift of about 1100. That is about 100 times greater than the redshift of this galaxy. So the distance to this galaxy is about 45 billion / 100 = 500 million light years. Does that make sense? Thanks I'm really confused. It is stated that a redshift of 12 represents a distance of 13 Bly. So how could it be that a redshift of 1100 represents a distance of only 45 Billion ly? It took years of expiremental research to correlate the average redshift in the CMB. That message is very important! Does it mean that we see different values at the CMB redshift? If it is average, does it mean that some redshift are greater than 1100? Could it be that some are closer to 2200? Wow, that could be great news! Edited January 20, 2016 by David Levy
imatfaal Posted January 20, 2016 Posted January 20, 2016 ... I'm realy comfused.... Finally you say something we can all agree with (spelling excepted). You cannot just jump into this topic and expect to understand everything. Frankly I disagree with some of the things said by others above in the thread - and I don't understand other bits that have been said; but one goes away to think and calculate, to reread and digest, and to check and recheck. You seem to feel that everything deserves an instant response - and you are responding to people who work in research physics, forum experts, well-respected members and non-nothing bozos (like yours-truly). And almost every response tell someone that they are wrong - do you really think you are this good? 1
Mordred Posted January 20, 2016 Posted January 20, 2016 Initial redshift will give us an estimated distance. Keep in mind both those articles I wrote several years back. Let's take that star example again. If Say that star was moving away from us extremely fast. One would think it's further away than what it really is. If it was moving toward you at the same speed you would think it's closer than it really is. (Based solely upon redshift measurement) That message is very important! Does it mean that we see different values at the CMB redshift? If it is average, does it mean that some redshift are greater than 1100? Could it be that some are closer to 2200? Wow, that could be great news! I'm almost hesitant to answer this part given you tendency to get distracted. Yes you will measure different redshift to a certain degree at various points. Those variations are due to other redshift interference. (NO THIS IS NOT BIG NEWS). Any physicist working on the data knows what type of influences can be involved. So they will take other data to filter out those influences. Remember the Planck 2012 Right hemisphere "axis of evil". Where one axis appears hotter than the other.? That was simply due to not having enough filter to compensate for Earths movement. Calibration on the Planck data is published in their papers including the calibration settings. Several of their papers deals just with their calibration.
Strange Posted January 20, 2016 Posted January 20, 2016 I'm really confused. It is stated that a redshift of 12 represents a distance of 13 Bly. So how could it be that a redshift of 1100 represents a distance of only 45 Billion ly? You are confused because you don't actually read. The article you quote from says: "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." That is time, not distance. The CMB was created 13.8 billion years ago and the source is 45 billion light years away. This has been explained several times before. Perhaps you should make sure you understand this before making more wild guesses.
swansont Posted January 20, 2016 Posted January 20, 2016 Thanks It is stated clearly: http://cosmology101.wikidot.com/redshift-and-expansion "The further away an object is the greater the amount of redshift."[/size] So, with all the difficulties to verify [/size]accurate[/size] distance based on redshift (which you have fully explained), - we should be able to get some sort of distance estimation.[/size] [/size] Even if it is not fully correct - we still should have some basic knowledge about the distance.[/size] [/size] So, I still do not understand why some claim that the following distance of 13 Bly is not correlated with the redshift:[/size] [/size] "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"[/size] Correlated, yes. Equal, no. If the distance of 13 Bly had not been based on redshift, what kind of elements they have used in order to estimate this distance? Who besides you has stated that the distance was 13 billion LY? Thanks I'm really confused.[/size] It is stated that a redshift of 12 represents a distance of 13 Bly. Where?
David Levy Posted January 20, 2016 Author Posted January 20, 2016 Initial redshift will give us an estimated distance. Keep in mind both those articles I wrote several years back. Let's take that star example again. If Say that star was moving away from us extremely fast. One would think it's further away than what it really is. If it was moving toward you at the same speed you would think it's closer than it really is. (Based solely upon redshift measurement) I'm almost hesitant to answer this part given you tendency to get distracted. Yes you will measure different redshift to a certain degree at various points. Those variations are due to other redshift interference. (NO THIS IS NOT BIG NEWS). Any physicist working on the data knows what type of influences can be involved. So they will take other data to filter out those influences. Remember the Planck 2012 Right hemisphere "axis of evil". Where one axis appears hotter than the other.? That was simply due to not having enough filter to compensate for Earths movement. Calibration on the Planck data is published in their papers including the calibration settings. Several of their papers deals just with their calibration. Thanks for answering. I do appreciate. Why are you so sure that: Those variations are due to other redshift interference. What is the chance that those variations are real? Would you kindly share with us what kind of variations did we discover?
Mordred Posted January 20, 2016 Posted January 20, 2016 (edited) It is published information in the Planck 2015 dataset. The other reason is any good textbook discusses redshift and it's influence upon redshift. Sachs Wolfe effect for example takes advantage of those influences to give us greater detail on expansion as well as the CMB. In Matt Roose "Introductory to Cosmology" the axis of evil" was explainable before the Planck dataset was released. In textbook terminology it's called dipole anisotropy. Matt Roose has a good chapter on it. Any major dataset published will include the calibration data. Most ppl that read it tend to ignore this info. Rather dry and boring I guess. Edited January 20, 2016 by Mordred
David Levy Posted January 20, 2016 Author Posted January 20, 2016 (edited) Who besides you has stated that the distance was 13 billion LY? It is stated: "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."| How do they know that those galaxies had been formed 13 Billion Ly ago? Could it be that they have verified that it took 13 Billion Ly for the light to get to Earth? If so, then this is the answer. Edited January 20, 2016 by David Levy
Strange Posted January 20, 2016 Posted January 20, 2016 (edited) It is stated: "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."| Hence, we see today a light from galaxies that formed more than 13 billion years ago. Therefore - is it correct that it took 13 Billion Ly for the light to get to Earth? Correct. It took 13 billion YEARS. At the time it was emitted, it was much less than 13 billion light years away. It is now much more than 13 billion light years away. You should find out how to calculate these distances and then you will gain a better understanding. Edited January 20, 2016 by Strange
Mordred Posted January 20, 2016 Posted January 20, 2016 No no no. A billion light years is a unit of distance. Not years. During this time the universe has been expanding so the distance of the light path will be GREATER than 13 billion years It is stated: "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."| How do they know that those galaxies had been formed 13 Billion Ly ago? Could it be that they have verified that it took 13 Billion Ly for the light to get to Earth? 1
swansont Posted January 20, 2016 Posted January 20, 2016 Correct. Did you misread his post? He said LY, not years 1
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