|
Post by speakertoanimals on Mar 29, 2011 16:53:24 GMT 1
Except they WOULDN'T be because the local illumination by hot stars (which illuminates whatever you are going to have making up your fog) is different!
We KNOW about the interstellar medium, for example. Ditto the interstellar radiation field, which is typically spectrum of surface of average star (about 10,000K) just DILUTED.
So, your FOG is already there, and as I predicted, we have what does get scattered back to us is average star temp, just diluted because it doesn't scatter that much (else we wouldn't be able to see anything through it!).
AsI keep saying, you can't get a blackbody spectrum at 2.7K using sources of illumination that are stars at thousands of kelvin.
Interstellar and intergalactic stuff isn't going to be at a uniform temp,. because energy input isn't uniform in our present-day very clumpy universe -- some bits of space have lots of stars, other bits don't. What gets scattered by anything in those regions reflects (pun intended) the illumination available locally, just as what colour you see in fog depends on the exact type of streetlights.
|
|
|
Post by speakertoanimals on Mar 29, 2011 18:59:20 GMT 1
Finally I found a few decent references: WHY the CMB can't be red-shifted starlight: www.astro.ucla.edu/~wright/stars_vs_cmb.htmlNote the point about it wouldn't give an EXACT blackbody spectrum. And this on the interstellar radiation field -- refers to a mistaken claim that Eddington 'predicted' the CMB. www.astro.ucla.edu/~wright/Eddington-T0.htmlNote what crops up again and again -- what DATA fits the blackbody spectrum and what doesn't. All that we know at present that would be anywhere NEAR as good a blackbody as would be needed to explain the exact CMB spectrum would be microblack holes, which would all have to be of JUST the right mass (hence temperature in terms of Hawking radiation). You can't fudge it up from scattering etc, because present sources of ilumination (ie stars) have spectra that are just too mussy, and the current universe is too clumpy anyway to produce such a uniform result. In note that apart from the exact SHAPE of the spectrum of the CMB, we also would have to come up with a process that also got the exact power part right as well! Because theoretical considerations of a blackbody give not just the SHAPE of the spectrum is related to the temperature, but also exactly how much power there is in any given frequency band. Not just the distribution of colours, if you like, but exactly how bright as well..................
|
|
|
Post by carnyx on Mar 29, 2011 22:53:28 GMT 1
@sta,
Oh dear, wrapped round the axle again!
Again you fail to READ what has been STATED. Fog is the analogy, and NOT THE SUBSTANTIVE POINT. I am not taking about illuminating interstellar dust with starlight, etc... I am talking about interstellar dust being at 2.7 degrees K.
Have another try.
|
|
|
Post by speakertoanimals on Mar 30, 2011 13:01:01 GMT 1
More BOLLOCKS! If I misunderstood, probablu because you have no idea what you actually mean, or are incapable of stating anything in a coherent fashion.
AsI said before, we KNOW about interstellar medium, and dust, and we KNOW what temperature it is at, and it isn't the steady 2.7K.
Hence your post reduces to, in effect, there is some MAGIC substance between the stars that MAGICALLY is able to remain at 2.7K even though the external environment, amount of illumination etc varies greatly. That this MAGIC pixie dust is then then spread out in JUST he right way to give the correct power per unit angle to match the blackbody spectrum not just in terms of shape, but power per unit waveband.
It's all totallly and utterly ridiculous, that should be clear to anyone. So, we have two possibilities, you're either know so little physics, and are so poor at physical reasoning, that you really believe this is a possible and reasonable attem;pted explanation, or you're just another wind-up merchant. Which are you?
|
|
|
Post by carnyx on Mar 30, 2011 15:22:15 GMT 1
@sta,
You clearly do not understand the first thing about the nature of fog ... and smoke ... and dust-storms, white-outs, sandstorms, etcetera ....which speaks of a lack of experience, and curiosity. The squillions of tiny particles that make up any kind of mist are of varying sizes and at varying temperatures and at varying densities.. and of varying materials! .... but when you have enough of them, you will see an entirely homogenous field, radiating at just the right wavelengths, etc.
So why think-up even more far-fetched Mcguffins to claim a 'complete' understanding of the CBR,. Is it in order to have a dogma to preach?
What is known about CBR is not much.. and it can never be fully understood ... and correlations with other conjectures are no substitute for the actualité.
That you have such a low tolerance of any hint of departure from your current dogma, makes you an easy play.
As was the round earth, flying, radio communication, etcetera, ad infinitum.
|
|
|
Post by speakertoanimals on Mar 30, 2011 18:28:06 GMT 1
No you don't. A link I supplied earlier already explained WHY when you mix black body spectra with DIFFERENT temperatures, what you don't get out at the end is another blackbody spectrum. SO stop with the patently false claims.............. www.astro.ucla.edu/~wright/stars_vs_cmb.html No, I just hate people that prefer to argue from a position of ignorance of the observed facts, and with little regard to any form of logic. All so you can spout this nonsensical 'science is dogma' crap. You are really very, very unoriginal, quite boring frankly. Bye-bye little pixie dust fan...............
|
|
|
Post by carnyx on Mar 30, 2011 22:44:39 GMT 1
@sta
Re your link. What has the fog analogy got to do with stars? Where do you get the idea that small particles at 2.7deg K or so, could emit the same spectrum as stars?
|
|
|
Post by speakertoanimals on Mar 31, 2011 12:33:18 GMT 1
1) WHY is all the fog at the same temp? Illumination varies localy hence any actual ordinary dust etc will have a temperature that varies with position. And ditto density, since the universe now is clumpy. Hence how, from varying temperature and varying density of any ordinary 'dust' or 'fog' do you claim to get the extreme uniformity we see in the CMB?
2) THe point was that adding spectra from various sources at different temps doen't 'even out' to a blackbody -- the example was just using different temp layers of stars, same holds for your mythical varying temp pixie dust.
|
|
|
Post by carnyx on Mar 31, 2011 17:03:42 GMT 1
@sta, The CBR is claimed to emanate from beyond the furthest resolvable emitting object, which has a redshift of circa 10. So, the CBR must have a redshift of greater than 10 but we cannot know any more that that. Patrtly, becase it has no structure .. no spectral components. However, light emitting from objects who are so far away that their image cannot be resolved, can still be detected. In other words the light from say a sodium streetlight will still detectable even if the lamp itself is not resolved as an image, say through diffusion and the inability of the optics to bring it into focus. But the characteristic spectral lines, the stucture, will still be detectable! So, within the diffuse background radiation we should see evidence of patches of spectral absorbtion and emission lines from objects that our telescopes can't quite resolve yet ... but we don't see these lines! And we know that even at stupendous redshift values that would bring even gamma rays down into the visible, we will still see spectral lines! Where are they? So, we know we have a continuum of stellar objects stretching out beyond the current redshift of 10, which we cannot resolve, but somehow beyond them we CAN detect the stuff that gives us the structureless CBR. This is clearly dodgy and rather, we ought to be looking for other sources of blackbody radiation. And, matter at an averaqe of 2.7 deg K seems to be a good candidate. How about those free hydrogen atoms we are told about, at about 1 atom per cubic metre, warmed somehow by the energy coming off photons that are passing by and slowly losing energy? .. or a similar kind of explanation? ( PS I came across this interesting piece just now, which desribes just such a scenario. And Marchesarosa ought to be interested in it, too, as it deals with science's peer-review process.) www.aoi.com.au/scientific/SciCMBR/
|
|
|
Post by speakertoanimals on Mar 31, 2011 21:20:36 GMT 1
Except it isn't that simple. Theoretical predictions of the spectral distortions of the CMB due to various hydrogen absorption processes are out there (2004). But there are also other things that have happened to the CMB, and have been detected, such as the Sunyaev-Zeldovich Effect (CMB photons scatter off electrons).
If the CMB DIDN'T have extra evidence there in the fluctuations about perfect blackbody, same temp in every direction, we wouldn't have so many people working on it! It is precisely because it DOES contain information about the early universe that we can't see any other way that there is a reason to keep looking. But before you look, you have to be able to estimate whether the predicted effect is going to be big enough to see with current instruments, and also WHERE you should look in terms of frequency. Ongoing work.
|
|
|
Post by speakertoanimals on Mar 31, 2011 21:42:58 GMT 1
I followed the link -- it's nonsense! Except the observed hubble shufts (due to expansion) fit with what we see as the CMB temp now and what we think was the physical process going on when the CMB originated. The same model fits BOTH observations, that is kind of the whole point. Who said anything about a tight WAVELENGTH, he must mean temperature, surely. Except we have a perfectly good reason what temperature and what excatly was going on when the CMB originated, when the universe became transparent................ Other howlers: Except a black body spectrum refers to a perfect EMITTER and thermal radiation, as well as a black body as a perfect ABSORBER. Basic stuff here! Black body radiation is a far from abstract concept, in that we can build a set-up to generate cavity radiation, for example, and observe the spectrum. Old-style physicsts knew this when they worrried about precisely the fact that classical physics COULDN'T predict the MEASURED spectrum of such radiation.......... Just because we don't have any perfect abosorbers lying about, doesn't mean that the concept of blackbody EMISSION isn't totally relevant. Ah, I think this is the old claim that Eddingtons temp predicted based on AVERAGE amount of starlight and the CMB are the same thing! They aren't: www.astro.ucla.edu/~wright/Eddington-T0.html3.18 ISN'T 2.7 In summary: is almost total crap from start to finish.
|
|
|
Post by carnyx on Mar 31, 2011 21:53:53 GMT 1
Exactly. And so, by no means cut and dried.
Theories such as Big-bang that rest upon these provisional foundations should also be treated as speculative, and not treated as Gospel
|
|
|
Post by speakertoanimals on Apr 1, 2011 2:06:47 GMT 1
O god, you've just resorted to the ole creationist argument that evolution is only a THEORY.....................
AND scientific theory is only ever as good as the evidence that supports it, and is ALWAYS subject to change if new data appears. In that cosmology is just the same as ANY OTHER science, despite your daft claims it isn't proper science.
Speculative is a very different thing from your witterings, which seem to consist mostly of almost total ignorance of the actual data that supports the big bang, and that excludes the various alternative hypotheses (such as the universe isn't expanding, CMB could be some foggy effect etc.). You seem to think that whatever the evidence to date actually IS, ANY hypothesis is as good as any other, even those that have FAILED. Its the creationsists and teach the controversy all over again................
Intelligent design, magic pixie dust, both equal duds when it comes to actual science.............................
A bit like yourself.
|
|
|
Post by carnyx on Apr 1, 2011 9:38:56 GMT 1
Re CBR.. all you see is the emanation from a Lambertian fog at 2.7 deg K. That's all you know. And how far away is it? Can you ever know? Is there an apparent big gap in distance between it, and the furthest resolvable objects? Will you have to wait for Astronomers (aka proper scientists) to build better telescopes to try to close that gap?
In the meantime why resort to proclaiming as a matter of faith, unprovable crazy speculations that life is receding at ever faster speeds, and all we can ever see is the smile of the Cheshire Cat? Why not admit that the evidence today will allow of a number of potential explanations? Why screech like a religious zealot, STA? .. unless cosmology is a matter of belief.
CBR? It's Turtles all the way! But Cosmology is just modern astrological speculation. It is NOT a science.
(PS re that link., I suppose you thought I had taken it seriously .. that I believed in it ...and needed to be protected from heretical influences ... )
|
|
|
Post by marchesarosa on Apr 1, 2011 10:44:10 GMT 1
Why do zealots like STA always bring up remarks about "creationism" when anyone questions their pet hypothesis?
Surely there is more than one possible explanation of what scientists (think they) see in the universe?
I think the constant refs to "creationism" come from a very defensive mind. It is intended as a slur. It does not represent a enquiring mind. It represents ideology and too much vested interest in ones own particular viewpoint.
The alternative to the Big Bang hypothesis is not "creationism", STA, it is merely "something else".
|
|