Cosmological Red Shift

Schneibster:

Perhaps we are splitting hairs between us? My reading of the Big Bang description from a fraction of a second after the some speculated "Beginning from nothing, there was the extreme (Alan Guth hypothesis?) "Inflation" phase which saw the universe suddenly expand, and only non-massed energy permeated that space-time; and that phase was actually postulated to be only a very tiny size compared to the subsequent expanded size during the less-extreme "Expansion" phase claimed to be continuing to this day. So your above assertions do not gel with my understandings from reading the theory. I am confused on that now, let alone the rest. Can you please help un-confuse me by pointing out where my understanding is not consistent with what I read in the Big Bang theory?

I am trying to be clear on my understandings regarding equal validity of frames claims. I can see where in SR that would be so because the transforms are easily made between SR frames. However, in the GR theory I have read, no two frames in a gravitational well are requally valid because their "transforms" have to be done with direct regard to their position and orientation in the gravity well.

I have no problem with the SR frames angle and arguments in its domain of applicability; but I do have a problem with the same angle and arguments being attempted as "explanations" in GR domain of applicability when discussing cosmologically expanding "curvature" of space-time itself, which has no SR frames involved except in the usual way when calculating normal Doppler type motional SR frames as such separate from the cosmological frames of totally non-equal GR type. Have I explained what I see as the salient difference between your SR type based perspective and my GR type perspective of what is actually active in cosmological redshift 'frame' considerations? And why conflating the two types in discussion trying to separate the respective component contributions from relative SR Doppler and locally-determined GR Cosmological "curvature" effects on measured total redshift'?

I have put your word "perceived" in bold in order to direct your attention to what may be crux of a misunderstanding between us because appear to have missed my point made earlier about that very perceived frequency aspect. If you read back you will see where I was at pains to explain that the that intrinsic property may be perceived as altered but only because of the local interaction parameters involving relative speeds between the receiver and the photon during absorption. So I already understand what you have explained regarding "perceive" values" due to relative SR Doppler effects. But I also explained that the photon itself s not actually altered in frequency (wavelength) during that absorption process, since its wave peaks and troughs are not altered during absorption in a receiver whose cycling frequency is such that absorption can take place. Only if the photon is reflected will the photon have its outgoing frequency (wavelength) determined by the collision and scattering energies involved, and exchanged, between photon and scattering object. I hope I have clarified this to your satisfaction so you can adjust your future explanations to take into account this distinction I made already regarding my understandings of intrinsic (eg, at emission and in free flight) and extrinsic (eg, perceived at absorption) wavelength (frequency) properties of the photon?

Thanks again for all your hard work and detailed discussion of the aspects which have been of interest to me on this topic, Schneibster. I can only hope to assuage my guilt, at so monopolizing your time and talent for my selfish needs, by pretending to myself that our detailed discussion has been of some benefit to you as it has been (a lot) to me. Thank you.

 

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paddoboy:

Please edit your post to quote me not The God. Thanks.

I referred to Planck and WMAP, not Bicep2.

The required mutual understanding and agreement sought between me and Schneibster is about the isotropy (or not) of the cosmological space-time expansion. Only once we settle on an agreed basis for that issue (one way or the other) can we then discuss the CMB maps and error margins and variations which may affect what we perceive and put into our CMB maps.

I am not cynical about anything. I am skeptical according to the scientific method until the discussion is settled one way or the other with learned members here; which list does not include you by any stretch of the imagination or generosity; as again being confirmed by your continuing incessant intrusions, based on your own need to have a say on anything and everything even when you are patently not competent to participate at the level of scientific discussion between me and the learned members here.

Again I beseech you, paddoboy, to keep out of my discussions and don't address me again. You have nothing except personal asides and vacuous and un-comprehended and un-argued links to clutter these pages so one easily may miss important posts due to your spreading the important posts thin by interspersing them with your utterly banal posts. Please stop and leave me alone. Thanks.

 

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Too late for that now, but apologies...

You said..."recent trouble with assumptions about what local as well as deep distant space dust and other complicating factors " which was what caused the anomalous readings with BICEP2, and compared with WMAP and Planck in which that problem was not evident. The two lots of data from both those probes are exlemplary. An example of cynicism I suggest.

Schneibers excellent understandings are generally accepted by mainstream: That's the only agreement that really matters.
If he isn't answering you, perhaps there's a reason: He did mention about people he puts on ignore.

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My opinion is your posts are all very cynical and you ignore any reputable advice and answers you have been given:
I know my own competence and I don't pretend or see the need to put on an act. And your opinion on my competence does not matter one iota, since your own lack of credentials are evident. BTW, I'm not the first person to have commented on the confusing nature of your posts.

Sorry, as I have told you, you don't own these threads: You post here and anyone can reply.
If for some reason you do not like my replies or style, I would ask myself, am I actually hitting a home run with regards to your reasons etc.
just saying.
ps: If you like put me on ignore, but my choice is to refute any nonsense to the best of my ability and any other peculiarities with regards to intentions etc.
You should know that by now.

 

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It appears you have no confidence in me.

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Sad.
I did ask you are series of questions way back in post 93, just to determine where you were coming from/
I hope you don't mind me repeating them......
[1]Do you believe we see cosmological redshift?
[2]Do you accept the universe/spacetime is expanding?
[3]Do you accept standard accepted cosmology?
[4]Do you have problems with GR?

The crux of the matter of this thread is of course cosmological redshift does happen...spacetime/Universe is expanding...GR is still overwhelmingly supported along with those two scenarios.
The god as I have shown in post 94 does not accept cosmological redshift, so as an extension he also denies spacetime/universal expansion as well as GR [among a host of other overwhelmingly supported mainstream theories].
These are the same methodological arguments that YEC's and other God botherers are continually trying to raise to find fault with 21st century mainstream cosmology.
They also fail.

 

All attributions at post 199 to be contributed to expletive deleted.
Apologies for any confusion...Off goes my head, on goes a pumpkin.
Oddly enough though there views are similar.

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True you can assign any point in the frame's grid as the origin and if coordinates are used, you must assign some point as the origin; but in some cases all you need to know is that the frame is inertial. For example Compton scattering.

For compton scattering, I could put the origin at the location of particle scattering the incoming photon, or where the photon was a minute earlier, or at the center of the earth, or time square, NYC. or as usually done in the case of Compton scattering, not set any point as the origin as no coordinate values are used.

Just two conservation laws are used. None of these origin choices makes it a different frame - they only change the values of the coordinates, of say the scattering particle before the photon scatters off it.

 

Pl refer to the highlighted part, everything else is ok...

A master frame is fixed at origin (0,0,0)....now we have one more frame A whose origin is at (1,1,1), now we have one more frame B at (2,2,2)...all other aspects of A and B are same with respect to master frame. Now if you are saying that A and B are not two frames, I cannot believe that...you must be making a different point here. Please note that origin is an integral part and if all other aspects are same, it will change only the coordinate...but nonetheless frames with diffrenet origins will be different only.

 

Who has confidence in your Physics ? Please name one poster and get him vouch for that.

I will answer your questions..

1. No we do not see cosmological redshifts. We see the spectrum on specifically designed instruments and we observe the shift there ? It is not like that train siren which you could hear. The redshift could push the wavelength in invisible range.

2. Well the observation says that the universe is expanding. I do not know what you mean by spacetime expanding...and I am sure even you do not know what it means.

3. Stupid question.

4. I do not have problems with GR, I have problems with some of the absurd solutions/predictions of GR. and the absurdities are Black Holes, Worm Holes, Time Travel, spacetime warping and twisting and what not.

 

And could you tell us why anyone would even wish to "come out of SR?" Other than for explaining something like quantum entanglement or the nature of time, obviously.

SR is a description of a dual reality, just like the real thing actually is. Without the duality of observers, inertia (ANY kind) does not exist, nor do inertial reference frames. Without SR, there is no physics, bound energy, Newton's third law, or geometry. G-d loves geometry almost as much as he / she / it hates inconsistency. Nature kills and the scientific method works only for the sake of eliminating inconsistency. This is what happens when the only means of correcting any errors is to erase the mistake and all of the previous mistakes that led to proposing an inconsistent solution to a problem. In the short term, evolution could care less about whether the solution is complete or optimal or not.

Adjust your respective philosophies accordingly, because this is not something that is ever likely to change.

 

Could you clarify this. Are you saying the big bang happened after the universe was billions of light years in size?

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Interesting...

 

If you're referring to BICEP2, that's one out of how many?

So now they're all wrong?

That's not skepticism.

The CMB is isotropic to 0.002%. That's two parts in 100,000. That's what the CMB should look like. According to theory. And confirmed by Planck.

Let me explain what that means. It means the redshift of the CMB is isotropic to two parts in 100,000. Over the entire sky. That's a far better measure of expansion than we're ever going to get from galaxy redshifts. Not only that but the amount of anisotropy, that same two parts in 100,000, is just the right amount to make the galaxies we see, in theory. Those fluctuations account for the formation of the filaments of dark matter, and their attraction of normal matter, and the formation of galaxies, in about the number and distribution we see. It's an important confirmation of matter dynamics in the early universe, and of our theories of galaxy formation not long thereafter. I don't see anybody beating down the doors and saying ΛCDM is wrong, and they would be; it would be the news of the decade in astrophysics and cosmology.

No, SRT frames are GRT frames; they're just GRT frames with zero curvature, which is a pretty good approximation of most of the universe, which is far from galaxies and fairly flat on the scale of inter-galactic-cluster distances. Galaxy clusters take up only a very small amount of the universe. Most of it is just empty space with not much in it. Matter is very sparse which is obvious if you consider that it's only about 30% of all the mass/energy (about 5% visible matter and 25% dark matter), whereas dark energy (i.e. space) is about 70%. And matter is, of course, by E=mc², very much denser than energy.

So there's not much gravity out there to warp spacetime enough to account for redshift, nor even a sizeable fraction of it.

Done. See the previous comment: there's not much gravity out there to warp spacetime enough to account for redshift, nor even a sizeable fraction of it.

No, they are not cause and effect. There isn't enough matter in the universe to account for even a very small fraction of the galactic redshifts. This is a swing and a miss. Now you're arguing with the umpire about whether it was a swing or not and he's about to throw you out of the game.

The problems aren't "very real." They're based on a misunderstanding of the amount of matter in the universe, and its distribution. You're way out of line.

As far as Billy T's thought experiment, it fails to describe on the basis I already explained quite a few posts back.

 

Yes. It grew to a very large size during inflation when there was nothing in it but the inflaton; then the inflaton underwent vacuum decay and dumped all its energy into the empty spacetime, creating the Big Bang everywhere in the nascent universe. This is standard mainstream ΛCDM, the Standard Model of cosmology, by definition the mainstream.

Good question!

 

Interesting answer.

 

That is not at all my understanding of the big bang. My understanding is that inflation occurred very shortly after the big bang occurred and at the end of the inflation period the universe was still relatively tiny.

Could you cite a source that discusses what you are refering to?

 

Sure.

First comes a quantum fluctuation in whatever "pre-space" existed prior to the beginning of our universe. We know nothing about this "pre-space" and very little about the quantum fluctuation except that it had to have a large cosmological constant in order to drive inflation. As a result of this large cosmological constant, spacetime expanded very, very fast; tens of orders of magnitude (an order of magnitude is 10x) at minimum faster than it is expanding now, and probably a lot more than that. The universe expanded from a single quantum fluctuation to at least billions of light years, and probably far more than that, in 10^-42 seconds. There was still nothing in it but the large cosmological constant, which Guth named the "inflaton."

After 10^-42 seconds, the inflaton underwent vacuum decay, because a large cosmological constant is inherently unstable. The cosmological constant fell to a much smaller value, and the difference was dumped into the nascent universe as ordinary energy; this was the beginning of the Big Bang. All of this space, billions of light years wide, was filled with a plasma constituted of every elementary particle in approximate equilibrium (that means there were the same number of photons, neutrinos, quarks, electrons, dark matter particles, etc., etc., plus all their antiparticles in it) at a staggeringly enormous temperature. Space continued to expand due to the smaller, but still significant, cosmological constant, and as it did the plasma continued to fill all of space but cooled (as all plasmas do when they expand, by the Ideal Gas Law, q.v.). As it cooled, it successively passed below the temperature thresholds beyond which each different particle fell out of equilibrium with the plasma and all but a tiny fraction of the particles and antiparticles annihilated turning them back into energy and slightly reheating the plasma. Eventually all the matter particles and massive energy particles had fallen out, and then things started to get complicated. The very small anisotropies we see today in the CMB indicate that there were small density fluctuations, and as gravity took over due to the mass that had fallen out of equilibrium acting against the cosmological constant, the expansion slowed, and the density fluctuations grew by accretion due to their gravity. Going further is probably off-topic for this thread and even going this far is probably a bit off-topic.

Now, note that by the time the Big Bang started the universe was already (again, for emphasis, at least) billions of light years wide and totally filled with plasma at an enormous temperature, so hot that all the particles were in equilibrium, so hot that even the color force that prevents us seeing bare quarks was overcome, so hot that even the baryons couldn't exist as formed particles because the quarks wouldn't stick together.

So that's ΛCDM as it is formulated today, stopping just on the threshold of the creation of the first baryons, and I want to emphasize (I have said it in another post not long ago) that this is the Standard Model of cosmology, the definition of mainstream cosmology today, accepted by all but a tiny fraction of cosmologists and astrophysicists.

I also need to correct a misapprehension on your part. Confusion is raised by a very small piece of terminology that is often overlooked by laymen reading popular science books about cosmology: this is the distinction between "universe" and "visible universe." Further confusion is raised by a failure in such popular science books to differentiate between the inflationary epoch and the Big Bang proper. It's often said in popular science books that "the universe" was the size of a pea "in" the Big Bang; what is actually meant is that the visible universe we can see today was the size of a pea, and even that's not quite correct. It actually was the size of a pea fairly early in the inflation epoch, not during the Big Bang; and at that point no matter or energy except the inflaton existed in it. By the time the Big Bang started, the space that would become the visible universe was billions of light years wide. Today that has expanded to at minimum (and yet again I stress, at minimum) 100 billion light years, 50 billion light years in every direction from Earth, and most likely far larger than that.

This is incorrect. All frames are equally valid; frames in a gravity field (or undergoing acceleration) are not equivalent to unaccelerated frames. This is because they are approximately flat, whereas accelerated frames are curved. Using GRT, coordinates can still be transformed between such frames; but one must use GRT, because SRT and classical physics have no math to describe curved frames of reference. Under GRT one transforms the coordinates from a frame with nonzero curvature to a frame with zero curvature.

No, because you are making a distinction when there is no physical difference. SRT frames are GRT frames; they are the limit case of GRT where curvature is zero. GRT subsumes SRT, it does not replace it.

And also because there isn't sufficient gravity in most of the universe (particularly in space far from any galaxy) to account for more than a vanishingly small fraction of observed galactic redshifts. Nor redshift of the CMB. I emphasize, by far. Orders of magnitude. It's like confusing a pea with the Earth.

All incorrect. By "perceived" I mean, "measured within some frame." And I never said photons (or waves) were altered by absorption. Or for that matter emission. Other than being emitted and absorbed, which turns them from and to other forms of energy.

Oh, I'm having fun. No stress.

 

Most references on the Internet focus on the traditional Big Bang theory, not the inflationary theory; as a result they fail to properly describe inflation and place it in the wrong context, and at the wrong point in the timeline. For a modern, up-to-date view of ΛCDM which places inflation at its proper point in the timeline, see Susskind(2005) The Cosmic Landscape: String Theory and the Illusion of Intelligent Design. I can look up the exact page numbers for you if you like but you'll have to wait until I have time to find the book and find the information.

A very obvious problem with placing inflation after the Big Bang is that there is no explanation for it. Placing it before solves this problem by accounting for the inflaton in terms we understand, as a large cosmological constant. It also solves the problem of the origin of the energy in the Big Bang, by accounting for it as the energy dumped into the universe from the vacuum decay of the inflaton. Furthermore, it accounts for the inflaton itself as cosmological constant, an inherent feature of the vacuum. And finally, it accounts for the origin of the universe from a vacuum fluctuation; the cosmological constant, in this view, is a random parameter of such vacuum fluctuations, and our universe started with a large cosmological constant and inflated.

You should see Tryon(1973) "Is the Universe a Vacuum Fluctuation?" from Nature, and further works along the same line by Guth, Vilenkin, and Linde. Susskind in the reference above refers to their papers on this subject and personal discussions with Vilenkin and Linde. I will see if he gives the names of papers in Susskind(2005) when I get around to digging the book up and gathering references from it.

 

It seems that you are describing a 'new and improved' big bang if you will, that does not have a wide acceptance. What you are calling the traditional big bang is not just an internet focus, it is in fact what is currently being taught at universities. I agree that there are clearly some problems with the current Big Bang Theory and there are several avenues of investigation which may be able to answer these questions.

I think you are not accurately reperesenting the idea of inflation before the big bang as the mainstream theory. It is actually one of the possible mainstream alternatives that may or may not pan out in the long run.

 

Been at least 6 or 7 years since I read Leonard Susskind's The Cosmic Landscape: String Theory and the Illusion of Intelligent Design...
It contained/contains quite a few assumptions and predictions...if I remember correctly...
I must inquire, Schneibster, have any of those assumptions/predictions since been falsified?

Also, I am inclined to agree somewhat with origin as to whether it is indeed seen by any majority of either working Cosmologists or Academia as THE Mainstream Theory...

...or one of the leading Mainstream Alternative* theories...

*perhaps somewhat of an Oxymoron...

 

Easily the overall best cosmology discussion here since I joined. I can't think of anything that wasn't addressed.