Lambda-CDM theory - Woo or not?

[Michael Mozina]

Indeed, there may be.

When such an idea is proposed, and it passes the usual (empirical) tests (as well as the ones about internal consistency, of course), then we will all be in a position to answer this question (and many others). Until that day ...

What *empirical* tests? You mean those point at the sky and add math exercises? Those are "simple observations". There is not "test" of inflation in a point at the sky exercise. Even when it fails your 'tests'. you ignore them, as in the case of "Dark flows", or you modify the properties of Nereid the inflation deity.

I'm not sure which idea you are referring to, but Mathew Edwards' one, per that link, fails many tests (e.g. it is clearly inconsistent with QED,

How so?

I must say I'm somewhat surprised you'd even suggest this one, MM; after all, it certainly fails whatever the "controlled experiment" test is that you have been insisting on.

So what? At least his theory *might* be actually "testable" whereas the inflation deity evidently doesn't exist anymore. Ari's theory also has some hope of being physically tested. Inflation is a pure act of faith on the part of the believer without any hope of ever "testing" anything.

You know, a funny thing happened in the last 100 years ... or rather, several funny things ...

Those parts of Birkeland's work that withstood the tests of hundreds of empiricists who came after him were modified, adopted, and became part of mainstream space science, geophysics, etc.

Ya, only "grudgingly" and "reluctantly" and 50 years after his death. What part of his work doesn't stand up to empirical scrutiny? It was all done in a lab to begin with.

Those parts which failed such tests have been dropped (e.g. his ideas on planetary rings*.

Ok, I'll bite, how did his ideas "fail" in any way? How about his solar wind concepts? You folks can't explain something Birkeland actually simulated in a lab. What's your problem explaining high speed solar wind? Jets? Coronal loops?

And yes, sometimes it does take several decades for an idea to be tested sufficiently well that it can be accepted, modified, or left to gather dust

So I'll have to be dead before you finally accept Birkeland's explanation of say solar wind, or coronal loop discharges, or jets, or anything related to solar physics? No thanks. I already know his ideas work empirically.

But I'm still trying to understand what you mean by "PC/EU theories" (PS was merely quoting you), or "EU theory", or "EU/PC theory", or ...

What is so difficult to understand about applying GR theory and MHD theory to objects in space?

I have still not seen you take one single step toward demonstrating your inflation deity in concrete empirical ways. When can I expect to see a demonstration of theory, or is the inflation deity incapable of "predicting" anything useful in a controlled scientific experiment? If not, it's no better than numerology.

 

[Tubbythin]

Do you have comprehension problem or just a weird desire to twist my words? I said *gravity* shows up in empirical experiments and I therefore don't care which math formulas you use to describe it, be it Newton's equations, Einstein's Equations, or some QM theory on gravity. I can tell that gravity exists in nature. That's what I said.

We can all comprehend what you're saying. It just doesn't make the slightest bit of sense.
You previously said:

I accept GR as taught by Einstein.

And then you reject the notion of spacetime expansion/contraction. Which is rejecting GR, not accepting it.

 

[Perpetual Student]

It's in proportion. Think of it like this - you shoot two equal projectiles out in opposite directions in empty space and observe their trajectory. The force of gravitational attraction of one on the other is proportional to its mass, and as long as they are slowing down (i.e. accelerating towards each other) at the right rate, you know that's the only force acting. But instead, you observe that the projectiles have started to accelerate away from each other. That means there is another force acting on them which is larger than the force of attraction. Since the force of attraction on one was proportional to the mass of the other projectile, if this new force is coming from gravity, its source must be a mass that's larger (but not much larger, since the acceleration isn't very big). I've ignored the 1/distance square here, but since both dark energy and the mass in the universe are more or less equally spread around that actually doesn't affect this.

See the point? If there was zero acceleration, it would mean the average density of dark energy was about the same as matter. Since the acceleration is positive, it means it's greater than matter.

Yes. That was easy, thanks. DE counteracts the effects of both visible matter and dark matter, which is why it appeared to be so out of proportion to me (I was not taking DM into account).

 

[Perpetual Student]

It's also a central part to what Einstein called GR. Hell, it's in basically every GR textbook out there, including the ones written before dark matter, dark energy, and inflation were even thought of. You are the only one who thinks expansion of space itself isn't an intrinsic part of GR.

I'm still not clear on this. Einstein developed GR before there was any knowledge of cosmological expansion (except for Lemaître, who was universally ignored). He introduced "lambda" to counteract the effects of gravity, which would otherwise cause the universe to contract. If GR included expansion (as a "central part" -- as you say), why did he not declare to the world that "space is expanding! Here it is -- in my GR theory!"? It would appear that he was happy to have lambda counteract gravity and leave it at that. This has the appearance of a little revisionist history.

 

[Reality Check]

I'm still not clear on this. Einstein developed GR before there was any knowledge of cosmological expansion (except for Lemaître, who was universally ignored). He introduced "lambda" to counteract the effects of gravity, which would otherwise cause the universe to contract. If GR included expansion (as a "central part" -- as you say), why did he not declare to the world that "space is expanding! here it is -- in my GR theory! ? It would appear that he was happy to have lambda counteract gravity and leave it at that. This has the appearance of a little revisionist history.

My impression is that Einstein introduced lambda (the cosmological constant) in order to allow for a static universe solution to his field equations, in addition to the contracting and expanding solutions. He could have announced to the world that "space is contracting, static or expanding! here it is - in my GR theory!" but that would not have surprised anyone.

 

[ben m]

I'm still not clear on this. Einstein developed GR before there was any knowledge of cosmological expansion (except for Lemaître, who was universally ignored). He introduced "lambda" to counteract the effects of gravity, which would otherwise cause the universe to contract. If GR included expansion (as a "central part" -- as you say), why did he not declare to the world that "space is expanding! here it is -- in my GR theory! ? It would appear that he was happy to have lambda counteract gravity and leave it at that. This has the appearance of a little revisionist history.

Einstein had two reasons to put in the cosmological constant in:

• (a) because he knew that there was nothing contradictory about it---it doesn't violate conservation of energy, it's correctly Lorentz invariant, etc.---- AND because
• (b) he thought that it matched observations, which at the time were very limited.

Later, due to Hubble et. al., the observations swung dramatically towards an expanding Universe, (b) was obviously invalidated, and the most sensible explanation at the time seemed to set the constant to zero. Later again, when we finally measured not just the present-day expansion rate but its entire progression, we again modified our judgement of (b). But there was never disagreement about (a). Einstein knew that Lambda != 0 was a valid way for space to behave. So did Hubble, Zwicky, etc. So did Guth, Linde, Steinhardt. So did Riess and Perlmutter. So do I. Is it zero or nonzero? is a question for the data to answer, not a logical point to argue about like bad wannabe-Aristotles. The available data have changed over the century, hence the disagreement over (b) and over the exact value. In disagreeing with (a), MM is disagreeing with Einstein and pretty much everyone else.

 

[Perpetual Student]

One more in a seemingly endless series of questions about DE:

Does quantum theory provide for the existence of DE particles? If so, might they ever be detected -- produced on earth?

 

[sol invictus]

I'm still not clear on this. Einstein developed GR before there was any knowledge of cosmological expansion (except for Lemaître, who was universally ignored). He introduced "lambda" to counteract the effects of gravity, which would otherwise cause the universe to contract. If GR included expansion (as a "central part" -- as you say), why did he not declare to the world that "space is expanding! Here it is -- in my GR theory!"? It would appear that he was happy to have lambda counteract gravity and leave it at that. This has the appearance of a little revisionist history.

I'm not an expert on Einstein's thought process, but I'm pretty certain he didn't realize at first that GR implied the universe must always expand or contract. That wasn't his primary concern - he was trying to find a relativistic version of Newton's law of gravity, and he discovered GR (which is basically the unique possibility). His first and primary task was to demonstrate that GR correctly reproduced Newton in the non-relativistic limit, and to extract the first post-Newtonian corrections (like gravitational lensing, and possibly the precession of the perihelion of Mercury). It was a few years later that he concentrated on cosmology, and I presume it was then that he realized one needed a CC to have any chance of finding a static solution.

One of the incredibly beautiful things about GR is how unique it is. It is essentially impossible to modify - the only possible modification that's consistent with basic principles and has any effect at all on large distances scales is to add a CC. The modern view of physics is that one should include all terms that are consistent with the symmetries of the problem, and the CC is the only such term for GR. So from the modern point of view, there should be a CC, and the issue is (as ben m says) to use the data to fix its value.

One more in a seemingly endless series of questions about DE:

Does quantum theory provide for the existence of DE particles? If so, might they ever be detected -- produced on earth?

There are theories of DE in which that might happen, yes. But they are more complicated than necessary - the simplest possibility is a pure CC, which does not have any dynamics (i.e. there are no particles associated with it).

 

[derekmcd]

Hi Michael,

First, let me state I have no desire to debate you on the majority of the subject matter here. We've been down that road elsewhere.

However, I did respond to your request for a critique of Ari's paper on another forum. However, it's seems the focus of your attention is elswhere... namely, here.

I'm having difficulty posting and have already lost two attempts. I'm just going to retype my replies to you from the other forum:

I started reading through Brynjolfsson's paper:

[there was a link to Ari's paper here, and I now realize that is why I couldn't post my previous attempts. His paper are easily found on Arxiv.]

I made it to page 4 of 95.

His critique of the Pound-Rebka experiment is flawed. His application of quantum transition does not apply to the photon changing wavelength. Quantum transition has everything to do with the quantum state of the electron bound to an atom and whether it can absorb or emit a photon. Considering his paper is the application of quantum mechanics to General Relativity and thus requiring a modification to relativity, he might try to understand what he is applying and to where it is applied.

Also on page 4, I don't understand how he can normalize the Poynting vector when he is concerned with the field of a single photon.

Maybe it's my ignorance, but it appears to me the two of his beginning premises are flawed. It's no wonder you don't see any in depth critiques of his papers. If the flaws are as obvious to a layman like myself, I can completely understand those who work in the field not giving his papers the time of day. Clearly, I will admit that my pointing out these two flaws may be misguided. However, until someone clarifies them for me... they are flaws.

You did respond to the above and I went on to elaborate with:

The photon exists as a wave function, but when it is detected (as per the Pound Rebka experiment) the wave function collapses. The wave function is a state of probablilities. While Brynjollfson's (referred to as "Ari" from here on out... I have his last name memorized, but it's still a pain to type), reference to the ability to predict what the photon will do within that short of a distance may be correct, it doesn't apply to the aforementioned experiment. There is no prediction. It is actual, real time, data.

The Pound-Rebka experiment used an atom to emit a photon. If that photon's energy is different, an identical atom will not absorb it. This is what the experiment tells us. The photon's energy was not the same. If it was the same, said atom should have absorbed it.

Now, if you applied the wave function probabilities to predict if the energy of the photon would change, you would realize the prediction is not possible. However, this is irrelevant. The Pound-Rebka experiment is not based on quantum mechanical predictions.

When an atom jumps from an energetic state to a lower energetic state, it emits a photon. The time required to make the jump is where the probability laws are pertinent.

Gravitational redshift is not a jump from one energetic state to another. There is no transition. Ari's critique of the Pound-Rebka experiment is fundamentally flawed. The very premise of his paper.

There must be a reason why such public papers have not been accepted for publication. It can't be political and/or a conspiracy. If Ari's papers had merit, the institution that rejected them run the risk of ruining their credibility. I just don't see that happening. If these papers had merit in their presentation of such a profound paradigm shift, physicists would be flocking to them like flies on... well, you know. However, they are not.

Why is that???

Maybe they are just flawed.

 

[DeiRenDopa]

[...]

One more in a seemingly endless series of questions about DE:

Does quantum theory provide for the existence of DE particles? If so, might they ever be detected -- produced on earth?

There are theories of DE in which that might happen, yes. But they are more complicated than necessary - the simplest possibility is a pure CC, which does not have any dynamics (i.e. there are no particles associated with it).

And, as of today, the best observations, from independent teams, and several quite different phenomena/effects*, are consistent with just this pure CC (a.k.a. lambda), although the constraints are mild (or weak).

The WMAP5 paper (preprint actually) that I provided a link to earlier is perhaps the best summary; here's the entry in ADS.

Here are some relevant word-bites (from the abstract):

We obtain tight, simultaneous limits on the (constant) equation of state of dark energy and the spatial curvature of the universe: –0.14 < 1 + w < 0.12(95%CL) and ...

We test a time-dependent w with a present value constrained as –0.33 < 1 + w 0 < 0.21 (95% CL).

One curiosity, that reflects modern publication trends, is that the paper itself has a 'publication date' of '02/2009' ... yet ADS already lists a whopping 825 citations to it!

* CMB, SNe Ia, and BAO

 

[DeiRenDopa]

Is MHDEnzo part of "EU theory"?

Or maybe I should ask, is MHDEnzo the best present-day realisation of "EU theory"?

Hot off the astro-ph press:

Cosmological AMR MHD with Enzo

David C. Collins, Hao Xu, Michael L. Norman, Hui Li, Shengtai Li

(Submitted on 16 Feb 2009 (v1), last revised 16 Feb 2009 (this version, v2))

In this work, we present MHDEnzo, the extension of the cosmological code Enzo to include the effects magnetic fields through the ideal MHD approximation. We use a higher order Godunov Riemann solver for the computation of interface fluxes. We use two constrained transport methods to compute the electric field from those interface fluxes, which simultaneously advances the induction equation and maintains the divergence of the magnetic field. A third order divergence free reconstruction technique is used to interpolate the magnetic fields in the block structured AMR framework already extant in Enzo. This reconstruction also preserves the divergence of the magnetic field to machine precision. We use operator splitting to include gravity and cosmological expansion. We then present a series of cosmological and non cosmological tests problems to demonstrate the quality of solution resulting from this combination of solvers.

Based on what y'all have read of MM's posts, both here and in the two other, related, threads, how well would you say MHDEnzo meets his criteria for "EU/PC theory"?

 

[Michael Mozina]

My impression is that Einstein introduced lambda (the cosmological constant) in order to allow for a static universe solution to his field equations, in addition to the contracting and expanding solutions. He could have announced to the world that "space is contracting, static or expanding! here it is - in my GR theory!" but that would not have surprised anyone.

This was the closest thing to a full and honest answer that you got. There's a bit more to the story however and one point that needs to be clarified. The problem for Einstein at the time is that objects in motion tend to stay in motion, and through Einstein's tenure, any sort of "expansion" would have been objects in motion oriented. It would have been very easy for Einstein to explain a "contracting" universe, one that was being pulled together by the curvature of gravity. It would have been equally easy for Einstein to explain an "expanding" universe where objects in motion stay in motion, and their inertia is great enough to keep them expanding forever, in spite the slight tug of gravity. What GR didn't "explain" very well was the idea of a "static" and stable universe, and that was the "mainstream" theory of the day. GR really didn't fit very well with a static universe that was completely dominated by gravity, so he added a "lamba", which was actually only a constant. That constant he added could have represented any known force of nature, including weak persistent EM fields for all he knew at the time. All he was trying to do is explain how a universe came to be stable over time.

At *no time* however did Einstein try to make the constant he added do any superluminal expansion tricks.

When Hubble's observations of redshift over distance was discovered, the idea of an "expanding" universe caught on. At that point Einstein realized that GR was a perfectly elegant formula *without* any constants (no Lambda's) so he *TOOK THEM OUT AGAIN ALTOGETHER*. Arp's observations had not been swept under the rug yet, and nobody was sure how fast anything might be *moving*, and the assumption of the time was still "movement of objects", not "lambda space expansion". He took out Lambda entirely and reportedly called it his "greatest blunder". GR had no constants as Einstein taught it, and I am fine with GR theory without constants.

The mainstream however is attempting to "explain" superluminal expansion now with Einstein's blunder theory. Worse yet, they continue to call it "GR" and claim GR is consistent with this idea. In the business world, that is called "false advertising". Claiming superluminal expansion of "space" is compatible with GR is absurd if you're talking about Einstein's brand of GR. The "new and improved" Lambda-GR does superluminal expansion tricks for breakfast, but of course it's not the GR Einstein taught, the one with out any 'constants".

 

[DeiRenDopa]

Hi Michael,

First, let me state I have no desire to debate you on the majority of the subject matter here. We've been down that road elsewhere.

However, I did respond to your request for a critique of Ari's paper on another forum. However, it's seems the focus of your attention is elswhere... namely, here.

I'm having difficulty posting and have already lost two attempts. I'm just going to retype my replies to you from the other forum:



You did respond to the above and I went on to elaborate with:



There must be a reason why such public papers have not been accepted for publication. It can't be political and/or a conspiracy. If Ari's papers had merit, the institution that rejected them run the risk of ruining their credibility. I just don't see that happening. If these papers had merit in their presentation of such a profound paradigm shift, physicists would be flocking to them like flies on... well, you know. However, they are not.

Why is that???

Maybe they are just flawed.

Welcome to JREF Forum, derekmcd!

By now I think you've realised why you can't post links ... you need to get to 15 posts before the board's software allows you to.

That being said, may I enquire as to what other forum MM has been active on? The 'google coordinates' will suffice (google is the friend of many folk here).

You may have already noticed that I, for one, have found quite a few sets of (astronomical) observations that are inconsistent with AB's papers (collectively), which MM agreed to have a go at explaining (within AB's 'plasma redshift' model), but hasn't yet done so.

 

[Perpetual Student]

There are theories of DE in which that might happen, yes. But they are more complicated than necessary - the simplest possibility is a pure CC, which does not have any dynamics (i.e. there are no particles associated with it).

Well, that's another curve ball for the layman. Am I now to believe that 73% of the mass of the universe is not subject to quantum theory?

 

[Michael Mozina]

Hi Michael,

Hi Derek! Welcome. I'm glad you came over.

There must be a reason why such public papers have not been accepted for publication. It can't be political and/or a conspiracy.

Ah to be young and naive again...... Have you ever studied Arp and his objections to "Hubble's law"? I assure you it *can* be highly political, particularly when one starts futzing with the redshift interpretations. The Lambda model has become dogma at this point in time, and getting something like that published in the APJ is never going to happen.

If Ari's papers had merit, the institution that rejected them run the risk of ruining their credibility. I just don't see that happening.

So how come you believe that it cannot ever be a political sort of rejection, or a rejection based on "fear" rather than merit?

If these papers had merit in their presentation of such a profound paradigm shift, physicists would be flocking to them like flies on... well, you know. However, they are not.

Why is that???

Why didn't they "flock" to Birkeland's explanation of aurora, or his solar discharge ideas? He could *simulate* solar wind acceleration, and he could certainly explain it. I have no idea why the mainstream has become so dogma oriented, particularly over the past 25+ years or so. It wasn't always like that. Inflation and DE are relative newcomers in fact.

Maybe they are just flawed.

Well, if so, there should be actual line number and equation oriented objections cited so that I can respond to *specific* criticisms. Evidently DRD has provided a few criticisms but at first glance they didn't look specific, as in citing a line number or equation. I will have a look at them this weekend however and see if any of them have merit.

FYI, here's another paper on redshift that does not require superluminal expansion.

http://redshift.vif.com/JournalFiles/V14NO3PDF/V14N3EDW.pdf

There are many possible ways to "interpret" the redshift phenomenon purely from a mathematical point of view. Why pick one and call it "superior"?

 

[Michael Mozina]

Well, that's another curve ball for the layman. Am I now to believe that 73% of the mass of the universe is not subject to quantum theory?

Now now, don't peak under the hood! That's not fair! Now you went and opened up another fine can of worms......

 

[Michael Mozina]

Or maybe I should ask, is MHDEnzo the best present-day realisation of "EU theory"?

Hot off the astro-ph press:

Based on what y'all have read of MM's posts, both here and in the two other, related, threads, how well would you say MHDEnzo meets his criteria for "EU/PC theory"?

Beats me. I'd have to understand the Enzo 'extensions' to MHD theory I suppose. If he has them doing superluminal expansion tricks, forget it. If not, well, it might loosely fit under the umbrella of EU/PC theory, but then so does 'magnetic reconnection' theory and magnetic fields never actually disconnect or reconnect, so it's a pretty wide umbrella.

 

[DeiRenDopa]

What Chief Acolyte Anthony has to say about Birkeland and the solar wind

The terrela model was really rather simple. He [Birkeland] placed a sphere containing an electromagnet inside a large vacuum chamber, which represented the space around the Earth and its magnetic field. He then shot clouds of electrons towards this simulated Earth to produce light phenomena that looked like aurora. (We now know that the solar wind also consists of positive ions, as well as negative electrons.)

[...]

While the actual process is somewhat more complicated than he envisioned [...], his results were surprisingly good.

(bold added; source*)

Considering the author, this somewhat tarnishes the glow emanating from MM's keyboard, on the subject of Birkeland and the correspondence between his work and the (present day) observable universe, doesn't it?

The author is also somewhat more circumspect than MM in regard to the transcendent explanatory power of "Birkeland currents"; "Table I" is titled "Phenomena in which Birkeland currents are thought to play a role" (bold added).

The author quotes Birkeland:

The magnetic globe was then made the cathode in the vacuum-box, and experiments were carried out under these conditions for many years. It was in this way that there appeared experimental analogies to various cosmic phenomena, such as zodiacal light, Saturn's rings, sun spots, and spiral nebulae.

(bold added)

For all the praise MM heaps on Birkeland as an empiricist, it is curious that both MM and Birkeland (apparently) missed a curious inconsistency between the "experimental analogy" and the (even then known) reality of Saturn's rings ... the former is self-luminous, the latter merely reflects light.

* and a special thanks to IT, for his superb collection of links.

 

[DeiRenDopa]

Beats me. I'd have to understand the Enzo 'extensions' to MHD theory I suppose. If he has them doing superluminal expansion tricks, forget it. If not, well, it might loosely fit under the umbrella of EU/PC theory, but then so does 'magnetic reconnection' theory and magnetic fields never actually disconnect or reconnect, so it's a pretty wide umbrella.

Well, the preprint is freely, and easily, available, so you can find out quickly enough ...

... it might be interesting to learn how you answer your own questions, once you've actually read the preprint ...

 

[Perpetual Student]

FYI, here's another paper on redshift that does not require superluminal expansion.

http://redshift.vif.com/JournalFiles/V14NO3PDF/V14N3EDW.pdf

It's amazing that there are so many "alternate" theories and theorists out there! I have been reading about this stuff for years and never heard of these people. Why haven't their theories gained any traction anywhere in the world -- China or India, for example -- where there might be some motivation to show-up mainstream western scientists? It's hard for me to fathom that there could be such a powerful global barrier to accepting these theories if they had any merit.