Lambda-CDM theory - Woo or not?

[Michael Mozina]

We have, the Casimir effect.

What you have is a *force* of nature, that *pushes* two plates together, not a "negative pressure environment". I finally realized yesterday where this whole problem starts. Your side does *not* comprehend the difference between force and pressure. In the Casimir experiments, the chamber is *always* positively pressurized. Even a "vacuum" state is not quite a "zero" pressure, but has a positive number of atoms and pressure in the chamber due to the presence of these atoms. What you have is a *force* (a QM force) that *pushes* the two plates together *in spite of the pressure in the chamber*. The analogy of two magnets in a chamber is very similar. Yes, they will experience the force of magnetic attraction. No, there is no "negative pressure" between the two magnets.

Guth needs "negative pressure" out of a vacuum in order for his theory to fly, and it cannot fly because that is a physical impossibility. There could of course be a "force" of some kind that has some effect on the expansion, but it has nothing to do with "negative pressure in a vacuum".

 

[Ziggurat]

And do BECs (Bose-Einstein condensates) behave like (ordinary) fluids (i.e. diagonal stress tensor)?

Under "normal" conditions , superfluids should behave exactly like ordinary fluids in terms of the stress tensors. Where they stand out most obviously is when you have flow, since they're zero viscosity and quantized vorticity - that should remain the same even in a field, though the field might change critical values (flow, temperature, etc) at which the fluid will go normal. In a field, though, other funny things may happen (ie, Meisner effect in superconductors, which are basically superfluid electrons). And if you have a vortex lattice, I imagine that might be able to give the stress tensor different values for different directions, but I suspect you still wouldn't get off-diagonal terms.

But this is speculation on my part, so don't make a machine that depends on this being correct and will blow up and kill your lab assistant if I'm wrong. Unless you don't like your lab assistant. But in that case, I'd recommend building a machine that depends upon MM being right to not kill the poor sap.

 

[Ziggurat]

I finally realized yesterday where this whole problem starts. Your side does *not* comprehend the difference between force and pressure.

Still waiting for a response from you about the definition of pressure. You keep claiming that other people are confusing the two, but you haven't given us your definition. You've tried to change my definition into a form that is harder to work with (for reasons that still make no sense to me and which you haven't explained), but you haven't actually said whether or not you accept the definition I gave. So you can keep saying that we're confusing the two, but I've given a definition of pressure (and a completely standard one at that, and one which is distinct from force), and you haven't. I don't think I'm on the side that's confused about it.

 

[Michael Mozina]

Still waiting for a response from you about the definition of pressure. You keep claiming that other people are confusing the two, but you haven't given us your definition. You've tried to change my definition into a form that is harder to work with (for reasons that still make no sense to me and which you haven't explained),

I did explain it to you. My definition keeps you from trying to confuse pressure and force, whereas your definition easily allows for such confusion.

This confusion is obvious in the Casimir example where there is *positive pressure* in the chamber, and also a QM force that pushes the plates together. It is analogous to a magnetic field that attracts two magnets in a positive pressure environment.

Guth's theory *requires* a "negative pressure" from a "vacuum". That is a physical impossibility. The notion of an external force might be fine, but the notion of a "negative pressure in a vacuum", is not.

 

[Michael Mozina]

But in that case, I'd recommend building a machine that depends upon MM being right to not kill the poor sap.

Er, I'd suggest better equipment and stress management classes personally.

 

[Ziggurat]

I did explain it to you. My definition keeps you from trying to confuse pressure and force, whereas your definition easily allows for such confusion.

It does nothing of the sort. They're exactly the same if you use relativistic mass, except yours is harder to use (nobody calculates relativistic mass for a gas at room temperature, for example). And if you use invariant mass, then yours is simply wrong. And considering that the units on my equation are units of pressure, I have no idea why you think it can possibly be confused for force.

So once again: how do you define pressure? Screw how you'd change my definition, and forget negative pressure for a moment. Just consider a gas at positive pressure. How do you define the pressure it's at? I've given my definition: what's yours? I know it's not what you gave me earlier - nobody uses relativity to define something as everyday as pressure. If you can't write an equation for it, then explain it in words.

 

[Michael Mozina]

For example, it seems, in the MM view, that everyone who has studied this general topic cannot be agnostic as it were, they must take a stance one way or the other.

This is an utterly false statement by the way.

As it relates to Lambda-CDM theory, I simply "lack belief" in the idea. You could interpret this statement as "strong" atheism, or "weak atheism".

The difference between us is that while you may lack belief in EU theory, you persecute that specific theory to the point of not allowing it to be discussed openly and fully on websites where you moderate. On the other hand, you do allow for other "mainstream" beliefs to be discussed without any time limits. Whereas I don't mind you discussing Lambda-CDM theory or other solar theories openly in the classroom and on the internet, you do not afford me the same courtesy. It is you that are not acting as an agnostic, but rather as a "true believer" who is intent on protecting the status quo at all costs, including but not limited to virtual execution of all persistent heresy.

 

[derekmcd]

And this would be another great example of "false advertising". GR theory is a theory about the *attractive* curvature of gravity. BBT is dependent upon inflation and dark energy, neither of which are technically even related to GR, they are just stuffed into a GR formula. If there was truth in advertising, you wouldn't be able to get away with claiming that the underpinning of BBT is GR. It's not.

You claim to understand General Relativity and attempt to critique subsequent models and theories that are based on GR. Then you present a description of GR as quoted:

"GR theory is a theory about the *attractive* curvature of gravity. "

Attractive curvature of gravity???

Michael, the reason folks have a hard time taking anything you say seriously is due to descriptions like this. If you understood GR, you might realize how horribly wrong your description is. GR has nothing to do with attraction nor does it describe a "curvature of gravity".

I don't believe any of the ten terms in the EFE's address an attractive force. There is no curvature of gravity. Curvature is a geometrical description of Newtonian gravity... curvature IS gravity.

It is painfully clear that you don't understand the things you wish to critique. This makes your critiques irrelevant.

Same with your description of the Casimir effect. The evacuated chambers they use have nothing to do with the quantum vacuum flucuations they are measuring. The laboratory vacuum is for the simple purpose of minimizing discrepancies in the actual experiment.

 

[DeiRenDopa]

We may consider the latter to be something like the universality of QED, and there are certainly lots and lots and lots of tests done (and, no doubt many more that could be done) that show the wide ranging and deep consistency associated with an assumption of universality of QED ... but in some sense this is no different than saying that the true theoretical underpinning of the BBT is GR.

And this would be another great example of "false advertising". GR theory is a theory about the *attractive* curvature of gravity. BBT is dependent upon inflation and dark energy, neither of which are technically even related to GR, they are just stuffed into a GR formula. If there was truth in advertising, you wouldn't be able to get away with claiming that the underpinning of BBT is GR. It's not.

Well, let's following the trail of breadcrumbs to see how we got here, shall we?

Way back when, Skwinty wrote (extract):

If the interpreted cause of redshift was incorrect or Hubble made some mistakes in his empirical measurements.

The reason I ask is:

The expansion of space, which is the predominant interpretation of cosmological redshift, is the foundation of the BBT, specifically when running time in reverse.

Or, am I misunderstanding the issue?

To which I replied (extract):

You are, in one respect.

The CMB, the primordial abundance of light nuclides, and large-scale structure are just as much "foundation of the BBT" as the Hubble relationship. And, as si has noted, the one thing which ties this all together is GR.

The true theoretical underpinning of the BBT is GR.

And that is the reason why, when all is said and done, that what "many are trying to prove" is nothing other than a falsification of GR (or a dramatic revision of it).

Once you grasp this you can easily see why PC (as defined by Lerner, for example) is the very definition of scientific woo.

Then, upon reflection, I added this, in a later post:

Upon reflection, I think this is only partly right ...

In terms of volume of data, the overwhelming source of observations used to test cosmological models/concepts/etc is the detection of photons (or, if you prefer, electromagnetic radiation).

The detections ('observations') are analysed within a framework that includes two vital assumptions: some form of a Copernican principle (crudely, we are not in a special place in the universe), and that photons are photons are photons. The two are not independent, but are also not identical (I think).

We may consider the latter to be something like the universality of QED, and there are certainly lots and lots and lots of tests done (and, no doubt many more that could be done) that show the wide ranging and deep consistency associated with an assumption of universality of QED ... but in some sense this is no different than saying that the true theoretical underpinning of the BBT is GR.

One implication that I got to thinking: to what extent are contemporary cosmological models (concepts, ideas) bolstered by observations other than those which are detection of photons?

At first, I couldn't think of any, but then I came up with quite a few; here's an interim list (in shorthand):

* Olbers' paradox in neutrinos (the Sun is the only observed extraterrestrial source of neutrinos - within selected energy bands and neutrino types/flavours - therefore ...)

* the cosmic ray energy spectrum and composition (this not only corroborates much of the photon-detection based observations, but also very likely sets some interesting, and possibly quite strong, constraints on QED beyond the solar system)

* the UHECR anisotropies (so far only the first Auger results, and so still rather tentative, but potentially very powerful)

* the elemental and isotopic composition of interstellar dust grains (may not say much about cosmology, but does provide independent support for some aspects of photon-based observations)

* something about the (so far) null detections from various gravitational wave radiation detectors (I'm not sure what these would mean if you set aside all photon-based observations as potentially subject to massive, subtle, etc systematics).

Maybe I should start a new thread on this ...

So ...

... within the context of what Skwinty wrote, my comments are just fine.

However, when you dig deeper you find cosmological models with (some kind of) inflation and lambda have greater explanatory and predictive power than those without them ... but they are still pretty darn good models.

OTOH, take away GR and the cosmological models are close to useless (in terms of being able to account for existing observations and make predictions about what will be found when new ones come in).

Take away QED, and there are, effectively, no observations to explain.

Now I don't expect that will make it any clearer to you, MM (for reasons that have been discussed at some length), but perhaps it might to some other readers.

 

[Michael Mozina]

You claim to understand General Relativity and attempt to critique subsequent models and theories that are based on GR. Then you present a description of GR as quoted:

"GR theory is a theory about the *attractive* curvature of gravity. "

Attractive curvature of gravity???

Michael, the reason folks have a hard time taking anything you say seriously is due to descriptions like this.

It's hard to take you seriously when you nitpick my words and ignore the whole point entirely. Gravity has the effect of *attraction* between two bodies of mass. Lambda-CDM theory has "gravity" doing *repulsive* tricks.

Same with your description of the Casimir effect. The evacuated chambers they use have nothing to do with the quantum vacuum flucuations they are measuring. The laboratory vacuum is for the simple purpose of minimizing discrepancies in the actual experiment.

All that is true Derek. Yesterday I finally realized the problem. Your side has not acknowledged and will not acknowledge the difference between pressure and force. Like the two magnetic analogy, a "force" at the level of QM is pushing the plates together or causing acceleration between the magnets, and yet there is always "positive pressure" in the chamber at all times.

Guth's theory requires 'negative pressure' from a "vacuum". That is a physical impossibility. There could be some other force of nature involved in this expansion process, but it cannot possibly be related to "negative pressure in a vacuum".

 

[DeiRenDopa]

I think it's accurate to say that for MM a serious component of cosmology has to do with (personal) beliefs, in a manner similar to religious or political beliefs.

Er, no. I simply note the difference between a "faith based" religion and empirical science. Inflation is a "faith based" belief system.

LWRRc

For example, it seems, in the MM view, that everyone who has studied this general topic cannot be agnostic as it were, they must take a stance one way or the other.

If you weren't over there at BAUT holding regular witch trials, insisting on *not* discussing EU ideas, and insisting that only your *religion* has merit, then maybe your statements would not ring nearly as hollow as they do. Since you folks go out of your way to burn all your heretics at the stake and virtually execute the most vocal critics, your feign of agnosticism" is utterly absurd. You're a "believer" to the point of participating in (in your case overseeing) the virtual execution of all dissent. The Lambda-religion is not full of agnostics, it's full of hard core followers that attack any and all dissenters, and who refuse to allow other belief systems to even be discussed openly and fairly. Every competing theory has to be judged based on your own preferred standards and observations. Even though you personally don't believe in inflation, somehow any competing theory has to be "just as good" as your theories in ways that you personally decide, "or else". You impose 30 days time limits on all topic *except your own religion*.

My goodness, where did this come from?!?

IIRC, si posted a succinct response to something like this that you wrote earlier, didn't he?

In any case, how you arrived at the conclusion that the BAUT forum has any impact on how cosmology is actually done, I do not know.

Whatever happened to publishing papers in relevant peer-reviewed journals?

If you want to get increased acceptance of any particular theory or model, in cosmology, shouldn't you be writing papers and submitting them to ApJ for publication (for example)?

Make no mistake about it, Lambda theory is a "religion". It's core tenets are based on "faith", not on empirical science. It's followers do not allow for, nor condone dissent. If you get out of line, you get virtually executed on the internet, and we can only assume it's worse in person when your job and livelihood are on the line .

Huh?

You're here, in the JREF Forum, attacking contemporary cosmological models, aren't you? And promoting "EU/PC theory", aren't you? And didn't Z write a great many posts, here in this section of the JREF Forum, on similar topics?

Don't those two sets of facts show - empirically - that your claims are wrong?

 

[Michael Mozina]

However, when you dig deeper you find cosmological models with (some kind of) inflation and lambda have greater explanatory and predictive power than those without them ... but they are still pretty darn good models.

First of all, such theories have no "predictive" value. Guth "postidicted" the so called "properties" of inflation so he could post-fit the observation in question. Calling it "predictive" is silly because nothing new was "predicted".

Birkelands empirical experiments about aurora "predicted" high speed solar wind. They "predicted' high energy discharges in the solar atmosphere. They 'predicted' a whole host of things that "surprised" Birkeland during his experimentation process with *real* forces of nature, in *real* experiments.

Guth simply 'made up' inflation and postdicted the whole thing to fit, right down to solving his "missing monopole problem". Nothing new was actually "predicted" based on physical experimentation.

OTOH, take away GR and the cosmological models are close to useless (in terms of being able to account for existing observations and make predictions about what will be found when new ones come in).

So maybe you'll have to include MHD theory and look *beyond simply gravity* for a solution?

Take away QED, and there are, effectively, no observations to explain.

I don't expect you to understand me any better, but QED in terms of a mathematical proof based on a *known force of nature* is just fine by me. When you start trying to apply this logic to elves and pixies however, it's not actually QED anymore.

 

[Michael Mozina]

You're here, in the JREF Forum, attacking contemporary cosmological models, aren't you? And promoting "EU/PC theory", aren't you? And didn't Z write a great many posts, here in this section of the JREF Forum, on similar topics?

Don't those two sets of facts show - empirically - that your claims are wrong?

What this demonstrates is that fortunately there *are* places of integrity on the internet where free speech can still be heard. The fact that many astronomy forums, particularly those on which you moderate do not enjoy this level of free speech demonstrates the dark side of your religion. I have no need to virtually silence you even while I openly criticize Lambda theory, whereas you have been involved in virtually executing me on more than one occasion. Talk about hypocrisy.

 

[edd]

It's hard to take you seriously when you nitpick my words and ignore the whole point entirely. Gravity has the effect of *attraction* between two bodies of mass. Lambda-CDM theory has "gravity" doing *repulsive* tricks.

That misses half of what GR has to say - especially in the context of systems containing something like dark energy. You're quite literally ignoring sources of gravity if you believe it's just about masses attracting.

You might have difficulty believing the evidence for negative pressures, but the gravitational effect of them should they exist and should GR be true is quite straightforward to determine.

 

[Ziggurat]

You might have difficulty believing the evidence for negative pressures,

He's got difficulty believing that even in the case of liquids at negative pressure, where the experiments are easy to perform and the data trivial to interpret. In fact, I think he probably has some rather confused notion about what pressure means, and what it means for it to be negative at all.

 

[edd]

He's got difficulty believing that even in the case of liquids at negative pressure, where the experiments are easy to perform and the data trivial to interpret. In fact, I think he probably has some rather confused notion about what pressure means, and what it means for it to be negative at all.

Yes, well if he has difficulty believing some straightforward stuff there's only so much one can do.

 

[Tubbythin]

First of all, such theories have no "predictive" value. Guth "postidicted" the so called "properties" of inflation so he could post-fit the observation in question. Calling it "predictive" is silly because nothing new was "predicted".

You seem to have no comprehension of how science is done...
Observation is made that needs explaining.
Devise/construct a theory that explains these effects.
Make predictions with this theory.
Test these predictions by experiment or observation to see whether they match reality.

This is exactly what has happened with inflation.

 

[Tubbythin]

What this demonstrates is that fortunately there *are* places of integrity on the internet where free speech can still be heard. The fact that many astronomy forums, particularly those on which you moderate do not enjoy this level of free speech demonstrates the dark side of your religion. I have no need to virtually silence you even while I openly criticize Lambda theory, whereas you have been involved in virtually executing me on more than one occasion. Talk about hypocrisy.

My ironometer is about to blow. Michael Mozina, the man behind the bare faced lie:

Lambda-CDM theory is just the opposite. It begins with a prophetic premise. "The universe was created on such and such a date......

wants to discuss integrity? Fantastic

 

[Tubbythin]

What you have is a *force* of nature, that *pushes* two plates together, not a "negative pressure environment". I finally realized yesterday where this whole problem starts. Your side does *not* comprehend the difference between force and pressure.

Hmm. I think pretty much everybody would disagree with you there. I think pretty much everybody would agree the problem is mostly that you don't seem to understand virtually anything about physics at all.

 

[Michael Mozina]

That misses half of what GR has to say - especially in the context of systems containing something like dark energy.

Even if we assume that something is driving an acceleration process, why would you believe that automatically has something to do with "gravity"?

You might have difficulty believing the evidence for negative pressures, but the gravitational effect of them should they exist and should GR be true is quite straightforward to determine.

Despite claims to the contrary, there has been no evidence presented of "negative pressure". The Casimir effect is taking place in a "positive pressure" chamber. What we observe is "force" from the level of QM "pushing" the plates together in a positive pressure environment.

The fluid in a chamber scenario was an interesting analogy, but in that case there was no "negative pressure", just "external force" being applied to the bonds of the liquid until they break. Since a vacuum is not a liquid it's also an inapplicable analogy.

A "negative pressure" in a "vacuum" is physically impossible. It might "work out" on paper in a math formula mind you, but if we try to recreate such a thing in the real world, we run out of atoms and particles in the vacuum chamber but then how do we get to "negative pressure"?

Guth's theory specifically requires something that is physically impossible. While an external "force" might be a reasonable possibility, the expansion process cannot possibly be related to "negative pressure" in a "vacuum". That is not a physical possibility. A *perfect* (one we could never create) vacuum would simply have no kinetic energy in the form of atoms or QM. The pressure can never become "negative", only "positive" with an asymptote at zero pressure as we achieve zero particles (atoms/subatomic) in the chamber.