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Why Planck's Formula For Black Body Radiation Is Used To Measure The Cbr?


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#69 Flummoxed

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Posted 18 May 2019 - 03:31 AM

https://science.scie...t/355/6329/1010

Hubble trouble
  1. Joshua Sokol
Science  10 Mar 2017:
Vol. 355, Issue 6329, pp. 1010-1014
 

 

Summary

There is a vigorous new debate over the Hubble constant, the expansion rate of the universe. New techniques suggest that the Hubble constant

is 8% lower than a leading number that astronomers had mostly settled on. For nearly a century, they have calculated it by meticulously measuring

distances in the nearby universe and moving ever farther out. But lately, astrophysicists have measured the constant from the outside in, based on

maps of the cosmic microwave background, the dappled afterglow of the big bang that is a backdrop to the rest of the visible universe. By making

assumptions about how the push and pull of energy and matter in the universe have changed the rate of cosmic expansion since the microwave

background was formed, the astrophysicists can take their map and adjust the Hubble constant to the present-day, local universe. The numbers

should match. But they don't. It could be that one approach has it wrong. But if the disagreement holds, it will be a crack in the

firmament of modern cosmology that points to new physics.

 

 

Why would it be controversial that the expansion of the universe is not smooth in all directions. The Hubble constant is not a constant it has varied ever since the beginnings of time. The CBR is not even and this would seem to reflect that it is not even. The uniform inflationary stage of the universe by Guth was superceded by Lindes inflationary model which takes into account that inflation was not uniform. 



#70 Flummoxed

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Posted 18 May 2019 - 03:52 AM

OK. Your question assumes that there is a "source", somewhere in the universe, for the CMBR.

 

There isn't.

 

The CMBR pervades the whole of the universe. 

 

That is why it is called "background" radiation. 

 

I have already explained earlier that it was left behind, rattling round the universe, when the universe first became transparent to radiation and ceased to behave like a black body. 

 

I find it extraordinary that you still cannot understand this. 

 

I have no problem with any of this.

---------------------------------------------------------------------------------------------------

I do have a simple question, that maybe someone can answer. 

 

If the CBR is more or less uniform, across the universe at 2.75kelvin, and it has no spikes, allowing predictions to be made ref red shift and distance.

 

How can the depth of the radiation be measured?  

 

Why apply red shift to it other than to support the Big Bang theory, and show the universe was hotter 14billion years ago? There are no spikes indicating red shift.  

 

The CBR was claimed as a relic of particle creation from the Big Bang. Why didn't Hoyle claim it as proof for continual particle creation in the universe?



#71 exchemist

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Posted 18 May 2019 - 05:27 AM

I have no problem with any of this.

---------------------------------------------------------------------------------------------------

I do have a simple question, that maybe someone can answer. 

 

If the CBR is more or less uniform, across the universe at 2.75kelvin, and it has no spikes, allowing predictions to be made ref red shift and distance.

 

How can the depth of the radiation be measured?  

 

Why apply red shift to it other than to support the Big Bang theory, and show the universe was hotter 14billion years ago? There are no spikes indicating red shift.  

 

The CBR was claimed as a relic of particle creation from the Big Bang. Why didn't Hoyle claim it as proof for continual particle creation in the universe?

I can't quite follow what you mean by the "depth" of the radiation. Can you elaborate?

 

As for red shift, the radiation profile (i.e. its intensity as a function of frequency or wavelength) is the same as would be emitted by a black body at 2.7K. Red shift comes into it if one considers the observed expansion of the universe, which we get from red shifts that can be calculated by emissions lines from atoms. Applying that presumed expansion to the CMBR, one gets the result that it would have come from a hot plasma condensing at a certain temperature, in smaller universe. Which is a clean and simple explanation for it. 

 

You are right that there are no emission lines of atoms in the CMBR itself which one can assign and show to be redshifted by a certain amount. (If there were, it would not be black body radiation.) But how would one explain black body radiation, coming equally from every point in the sky, and corresponding to a temperature less than 3 degrees above absolute zero, as due to some matter creation process? What process would that be and why would it produce this ultra-cold radiation?  How could it be "proof" of anything like that?  


Edited by exchemist, 18 May 2019 - 05:34 AM.


#72 Flummoxed

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Posted 18 May 2019 - 08:10 AM

I can't quite follow what you mean by the "depth" of the radiation. Can you elaborate?

 

As for red shift, the radiation profile (i.e. its intensity as a function of frequency or wavelength) is the same as would be emitted by a black body at 2.7K. Red shift comes into it if one considers the observed expansion of the universe, which we get from red shifts that can be calculated by emissions lines from atoms. Applying that presumed expansion to the CMBR, one gets the result that it would have come from a hot plasma condensing at a certain temperature, in smaller universe. Which is a clean and simple explanation for it. 

 

You are right that there are no emission lines of atoms in the CMBR itself which one can assign and show to be redshifted by a certain amount. (If there were, it would not be black body radiation.) But how would one explain black body radiation, coming equally from every point in the sky, and corresponding to a temperature less than 3 degrees above absolute zero, as due to some matter creation process? What process would that be and why would it produce this ultra-cold radiation?  How could it be "proof" of anything like that?  

 

Re depth, every way we look there is radiation, there is no way as far as I can see of determining if it is uniformly distributed in the direction we look. For example the anisotropy shown in the Cobe/Planck results viewed from a different galaxy might allow particular hot spots in the CBR to be pinpointed at a particular distance in the direction we are looking in space. If two satellites were separated by a large distance then a depth measurement might be attainable. As I understand it, this is not the case, so there is no way of determining depth, unless maybe a single satellite has a very large orbit, and takes shots from different view points.

 

The CBR has no spike so no red shift can be reliably associated with it, unlike galaxies. Galaxies exhibit red and blue shift, so allowing speeds to be calculated, the luminosity of the stars allow distance calculations. Applying the BB theory and then ascribing a red shift to the CBR, and claiming this as proof of the BB, strikes me as a being a little bit dodgy. 

 

There are other theories that might explain black body. Black Body radiation is not unlike theoretical Hawking Radiation from a 4 dimensional Black Hole. I think it was Popolawski that theorizes we live in a 5 dimensional universe inside a black hole, would a five dimensional black hole not also have something like Hawking radiation?  

 

Perhaps the theoretical big bang lasting fractions of a second violating the known laws of physics, might be overstretching the maths a bit, and not testable. I have an open mind on the subject. For instance would space and the CBR not look exactly the same, if localized inflationary stages, produced particles continuously for a few  billion years. We know particles can spontaneously appear out of a vacuum, is this not similar to particle creation in the Big Bang, just a bit slower. If virtual particles are separated, they become more like real particles the longer they exist. An inflation of space between a pair of virtual particles with the correct properties MIGHT produce real particles, which MIGHT give of random amounts of radiation as they become stable particles. Not unlike Hawking radiation perhaps, which will never be detectable with all the other radiation around a black hole!     



#73 exchemist

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Posted 18 May 2019 - 08:51 AM

Re depth, every way we look there is radiation, there is no way as far as I can see of determining if it is uniformly distributed in the direction we look. For example the anisotropy shown in the Cobe/Planck results viewed from a different galaxy might allow particular hot spots in the CBR to be pinpointed at a particular distance in the direction we are looking in space. If two satellites were separated by a large distance then a depth measurement might be attainable. As I understand it, this is not the case, so there is no way of determining depth, unless maybe a single satellite has a very large orbit, and takes shots from different view points.

 

The CBR has no spike so no red shift can be reliably associated with it, unlike galaxies. Galaxies exhibit red and blue shift, so allowing speeds to be calculated, the luminosity of the stars allow distance calculations. Applying the BB theory and then ascribing a red shift to the CBR, and claiming this as proof of the BB, strikes me as a being a little bit dodgy. 

 

There are other theories that might explain black body. Black Body radiation is not unlike theoretical Hawking Radiation from a 4 dimensional Black Hole. I think it was Popolawski that theorizes we live in a 5 dimensional universe inside a black hole, would a five dimensional black hole not also have something like Hawking radiation?  

 

Perhaps the theoretical big bang lasting fractions of a second violating the known laws of physics, might be overstretching the maths a bit, and not testable. I have an open mind on the subject. For instance would space and the CBR not look exactly the same, if localized inflationary stages, produced particles continuously for a few  billion years. We know particles can spontaneously appear out of a vacuum, is this not similar to particle creation in the Big Bang, just a bit slower. If virtual particles are separated, they become more like real particles the longer they exist. An inflation of space between a pair of virtual particles with the correct properties MIGHT produce real particles, which MIGHT give of random amounts of radiation as they become stable particles. Not unlike Hawking radiation perhaps, which will never be detectable with all the other radiation around a black hole!     

BB radiation, from all over the sky, at <3K? Come on! You're just waving your hands. You have no mechanism to propose that would give that outcome. 

 

Nobody claims the CMBR is "proof" of anything. Nothing ever is, where a scientific theory is concerned. But, given the observed expansion of the universe, as seen by the cosmological red shift, the CMBR at <3K does exactly fit the idea of a plasma universe at an earlier stage. So for now at least, that explanation of it wins. 

 

It seems to me that so-called dark matter and the placeholder known as "dark energy" are the real mysteries. If anything is going to come along and overturn current cosmology it will probably come from them.


Edited by exchemist, 18 May 2019 - 08:52 AM.


#74 Flummoxed

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Posted 18 May 2019 - 09:34 AM


 

 

Nobody claims the CMBR is "proof" of anything. Nothing ever is, where a scientific theory is concerned. But, given the observed expansion of the universe, as seen by the cosmological red shift, the CMBR at <3K does exactly fit the idea of a plasma universe at an earlier stage. So for now at least, that explanation of it wins. 

 

It seems to me that so-called dark matter and the placeholder known as "dark energy" are the real mysteries. If anything is going to come along and overturn current cosmology it will probably come from them.

 

Yes they do, The CBR is claimed as proof of the Big Bang. The CBR measurements is what swung the argument to the BB away from the Steady State expanding universe.

 

Galaxies are mostly red shifted, giving concrete evidence for galaxies moving away from us, and possible expansion of space, driving the movement. Conversely by the same argument, some are blue shifted which in a few billion years time, when all the red shifted galaxies have disappeared over the visible horizon, might lead someone to believe the universe is contracting.

 

There appears to be no way separating a CBR measurement at the edge of the visible universe from a CBR measurement taken locally. The CBR measurements appear not to have a distance associated with them. For example the CBR at the edge of the visible universe could be significantly less than 2.75K whilst that measured locally is measured at 2.75K, how are the signals separated? 

 

How are measurements of the CBR made indicating what distance the measurement is made at, allowing a red shift to be ascribed to those CBR measurements at that distance. ?? 



#75 Flummoxed

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Posted 18 May 2019 - 09:50 AM

BB radiation, from all over the sky, at <3K? Come on! You're just waving your hands. You have no mechanism to propose that would give that outcome. 

 

 

 

Big Bang can be called hand waving, it was rescued via the appended inflationary stage, of Guth and later Linde when it was realized the CBR was not as smooth as predicted by Guth. A Hot Big Bang and particle creation is theory, and not testable in the lab.

 

Particles do appear out of the vacuum slowly, and is testable in the lab. If a method of particle creation is testable it is plausible, is it not ?. 



#76 Dubbelosix

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Posted 18 May 2019 - 09:53 AM

I'll be sticking up for exchemist at the moment, since there is no proof concerning CMBR, it is called an evidence. Albeit, many consider it a strong evidence, but to call it a proof is too strong a terminology.



#77 Flummoxed

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Posted 18 May 2019 - 09:55 AM

This was funny! :lol:

 

We both posted a reply almost simultaneously!

 

You wouldn't happen to know how depth is applied to the CBR measurements, allowing red shift to be applied, and incontrovertible proof of the Hot Big Bang ? 


Edited by Flummoxed, 18 May 2019 - 09:55 AM.


#78 exchemist

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Posted 18 May 2019 - 09:58 AM

Yes they do, The CBR is claimed as proof of the Big Bang. The CBR measurements is what swung the argument to the BB away from the Steady State expanding universe.

 

Galaxies are mostly red shifted, giving concrete evidence for galaxies moving away from us, and possible expansion of space, driving the movement. Conversely by the same argument, some are blue shifted which in a few billion years time, when all the red shifted galaxies have disappeared over the visible horizon, might lead someone to believe the universe is contracting.

 

There appears to be no way separating a CBR measurement at the edge of the visible universe from a CBR measurement taken locally. The CBR measurements appear not to have a distance associated with them. For example the CBR at the edge of the visible universe could be significantly less than 2.75K whilst that measured locally is measured at 2.75K, how are the signals separated? 

 

How are measurements of the CBR made indicating what distance the measurement is made at, allowing a red shift to be ascribed to those CBR measurements at that distance. ?? 

Citation please? I will be very surprised if the word "proof" appears in any scientific description of the findings or their significance. 

 

 

It is meaningless to talk of a CMBR signal "from" anywhere. It is all around. That is the point.



#79 exchemist

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Posted 18 May 2019 - 10:00 AM

Big Bang can be called hand waving, it was rescued via the appended inflationary stage, of Guth and later Linde when it was realized the CBR was not as smooth as predicted by Guth. A Hot Big Bang and particle creation is theory, and not testable in the lab.

 

Particles do appear out of the vacuum slowly, and is testable in the lab. If a method of particle creation is testable it is plausible, is it not ?. 

And how does that account for black body radiation, at <3K,  all over sky?



#80 OceanBreeze

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Posted 18 May 2019 - 10:18 AM

This was funny! :lol:

 

We both posted a reply almost simultaneously!

 

 

It isn’t funny at all, you and Flummoxed are both wrong!

 

Exchemist is right – there is no concept of “proof” in physics, and in fact, the word does not appear anywhere in your reference.

 

Not even the part you highlighted in Red, which only states: “The results confirmed the Big Bang theory of the origin of the universe”

 

The word “confirmed” means to strengthen; in this case, it strengthens the Big Bang Theory; it does not prove it. It is still a theory!

 

And your strawman argument about NASA being nobody, which Exchemist did not imply in any way, is transparently disingenuious.

 

The object of discussion here is to exchange ideas with the hope that everyone comes out of the discussion with maybe a bit more knowledge than they had before going in.

 

Your idea seems to be that you must “win” an argument by making unfounded assertions, using bold red font, to focus attention, but almost all of what you have posted In this thread, as well as several others, is flat out wrong.

 

Try listening to what the other person is saying and reading for comprehension, rather than simply looking for arguing points that seem to support your pre-conceived notions, and you will get a lot more benefit out of this forum.



#81 Flummoxed

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Posted 18 May 2019 - 10:23 AM

Citation please? I will be very surprised if the word "proof" appears in any scientific description of the findings or their significance. 

 

 

It is meaningless to talk of a CMBR signal "from" anywhere. It is all around. That is the point.

 

https://wmap.gsfc.na..._tests_cmb.html

 

That is the point, it is anisotropic so how can slight fluctuations in one direction be ascribed uniform properties at the edge of the visible universe, allowing a red shift to be applied. It could be a completely different temperature in the distance masked by a hotter temperature locally. 

 

Edit CMBR was one of the nails in the coffin of Steady state theory https://en.wikipedia...ady-state_model It was predicted to be originally 5K. 

 

If the CMBR is at a uniform temperature in all directions. Galaxies could be moving through space rather than space expanding.  


Edited by Flummoxed, 18 May 2019 - 10:37 AM.


#82 Flummoxed

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Posted 18 May 2019 - 10:39 AM

there is no concept of “proof” in physics

 

Ive read that before  :shocked:



#83 OceanBreeze

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Posted 18 May 2019 - 10:51 AM

Ive read that before  :shocked:

 

Apparently it didn't "stick".

 

Why did you write: "The CBR is claimed as proof of the Big Bang"?



#84 exchemist

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Posted 18 May 2019 - 11:09 AM

Stop talking about things that you don't understand and go to learn from the primary sources of CMB or CBR relevance, instead.

Maybe you'll learn WHY hundred of millions of USD were invested on this fundamental research in the last 30 years.

 

This link is one where you can start to learn a little bit about CMB, instead of going around spreading nonsenses.

Be humble and admit that you are sustaining your assertions without any validation from primary sources. Here is one:

 

COBE - NASA Science Mission Directorate (and this is what I call a primary source)

 

https://science.nasa.gov/missions/cobe

 

COBE
 
 
 

The purpose of the Cosmic Background Explorer (COBE) mission was to take precise measurements of the diffuse radiation between

1 micrometer and 1 cm over the whole celestial sphere. The following quantities were measured: (1) the spectrum of the 3 K radiation

over the range 100 micrometers to 1 cm; (2) the anisotropy of this radiation from 3 to 10 mm; and, (3) the spectrum and angular

distribution of diffuse infrared background radiation at wavelengths from 1 to 300 micrometers.

 

Science Highlights:
  • COBE revolutionized our understanding of the early cosmos.
  • It precisely measured and mapped the oldest light in the universe -- the cosmic microwave background.
  • The cosmic microwave background spectrum was measured with a precision of 0.005%.
  • The results confirmed the Big Bang theory of the origin of the universe.
  • The very precise measurements helped eliminate a great many theories about the Big Bang.
  • The mission ushered cosmologists into a new era of precision measurements, paving the way for deeper exploration of the microwave background by NASA's WMAP mission and ESA's Planck mission.

 

Do you understand now? Still persisting about "Nobody claims the CMBR is "proof" of anything"?.

 

Do you dare to call NASA nobody?

 

Will you ever learn?

And where does the word proof appear, please, in your source?

 

I reiterate: there can be no proof of any theory of science. Ever. This has been part of basic philosophy of science ever since Popper made his well-known observation that a scientific theory can only be disproved. In science, all theories are provisional. The only absolute facts are the observations - and even these are on occasion called into question by other workers in the field.


Edited by exchemist, 18 May 2019 - 11:15 AM.


#85 exchemist

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Posted 18 May 2019 - 11:51 AM

The first and middle phrases are quite strong: wrong and flat out wrong, specially for a Forum Moderator.

 

And telling to me that I use "unfounded assertions" is quite insulting, specially when I provide links from academia or institutions

which are first rank sites.

 

Also, you accusse me of using "straw man" arguments but you use "ad hominem" arguments instead.

 

I know the subject of this thread, in which I'm the OP. I'm also very well formed in electromagnetism and thermodynamics,

either on the theoretical or practical side. So, I don't make unfounded assertions NEVER!

 

And the highlighting of text by different means is the way I do things. Here, there or everywhere.

 

I started by saying that I disagree with the use of the Stefan-Planck theories in cosmology, because I dissagree

that the Universe behaves as a black body. Plain and simple. Such theories were developed for perfect black

bodies and, particularly with Wien-Planck, for perfect black body cavities with molecular or hertzian oscillators

into the walls, absorpting and emitting radiation under thermal equilibrium. I stand with my original position.

 

Later, this thread drifted towards the shape and size of the universe, where is now located the CBR leftover of the BB

and how the COBE, WMAP and PLANCK missions produced data to be analyzed and, also, how this data was analyzed

afterwards here on Earth.

 

I'd like to know why do you assert that I'm blatantly wrong in what I posted here. Which are your arguments, either on the

physics side, the mathematical side or the logical side.

 

And, if you can answer me: Which is your background to discuss this subject? Did you study in deep the theory of thermal

radiation or the history that goes from Kirchoff (1859) to Planck (1900)? Because I did, and I wrote a long paper about it,

which I posted in my blog. Just the pure theory of black body radiation till 1900, Nothing more, but nothing less.

 

And this knowledge is not pre-conceived notions, as you called. It's pure and absolute science, very well stablished.

 

And, finally, regarding your understanding that "there is no proof in physics", it really blew my head off!

 

I can't believe that any person can think that way. Then, all the history of proofs behind BB theory at the PTR institute

is pure BS? I don't know who taught you that, but this is what I call something "flat out wrong".

 

And, please, don't lecture me how to behave. I'm too old and civilized to receive recomendations about my way of doing things.

There are no proven theories in physics. There can of course be mathematical theorems used in the models of physics that can be proved. But the theories themselves? No.

 

This should be obvious if you can calm down and think about it for a moment. The history of science is littered with examples of theories that seemed "true" and then along came a new class of observation that showed they were either wrong or did not work in all cases. So clearly those theories cannot have been "proved", can they? And who, today, would be so confident as to say that none of our current theories will ever be showed wrong or incomplete? If only some of them, which ones?

 

No, the essence of the scientific enterprise is that it is always work in progress and its findings are provisional, at least in principle. Because we do not know the future and what we might find one day.      


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