Split Thread Michael Mozina's thread on Dark Matter, Inflation and Cosmology

Dark Energy is a Cosmological Constant

Tim Thompson said:
Dark energy is not any manifestation of classical electromagnetism, ...
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Michael Mozina said:
Dark energy isn't even "real" Tim. It can't "be" anything. Electromagnetism is real, and it has a real affect on real things, including the ability to accelerate plasma.
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Don't make us laugh too hard. Of course dark energy is "real", how could it not be "real"? We all know that the words "dark energy" are just the arbitrary name given to "that which causes the acceleration of the expansion of the universe", whatever "that" may be. So dark energy is real by definition, which is a pretty hard "real" to get around. Now, as I recall ...
Michael Mozina said:
Although I personally favor an acceleration "interpretation" of the available data just like the mainstream, ...
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So this Mozina fellow does agree with the interpretation of the data that the acceleration is real. And then he said ...
Michael Mozina said:
There's only one known force of nature that can generate a continuous acceleration of plasma, and that is the EM field.
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So this Mozina fellow says the acceleration is real, and he says the cause of the acceleration must be electromagnetism. Therefore, by definition, whether you like it or not, you do in fact think that "dark energy" is in fact electromagnetism. Now, I provided a little calculation to show that dark energy cannot be an electric field (post 677 in thread) and ben_m provided a little calculation to show what kind of magnetic field is required to push stars around (post 721 in thread). I don't recall seeing any equally quantitative & objective response from you, so I can only conclude that you now know as well as we do that the acceleration of the expansion of the universe cannot be a result of anything done by classical electromagnetic fields (but see my post 655 in thread which shows that quantum electrodynamic effects are being considered by some as a plausible candidate for "dark energy").

Tim Thompson said:
If you cannot provide a quantitative physical argument in opposition to the quantitative physical arguments already presented, then the discussion is over, isn't it?
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Michael Mozina said:
Likewise if you can't produce a physical empirical demonstration that "dark energy" isn't simply a figment of your overactive imagination, and an ad hoc gap filler of epic proportions, the discussion is over isn't it? When did "dark energy" ever cause even a single atom to "accelerate" in a lab Tim?
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Whether or not dark energy accelerates anything in a lab is not at all relevant to the question of its reality. We have been down this road before, and one of the many weaknesses you demonstrate, is the ability to redefine common words & concepts to suit your own arbitrary purpose, without bothering to mention it. For instance, you can look up the word "empirical" and see that it does not require a controlled laboratory experiment. You can also look up the word "science", and see that it too can get along without controlled laboratory experiments. Indeed, I am sure there are plenty of archaeologists and zoologists and astronomers (and others) out there who would be thrilled to hear that Michael Mozina has evicted them from the pantheon of "science" to some lesser state of mythologists.

There is a great deal of valid scientific evidence from which the valid scientific conclusion is drawn that the expansion of the universe has accelerated over cosmological time, and that the driving force for this acceleration is not one of the known classical forces, gravity or electromagnetism (I think we can all agree that the strong & weak nuclear forces with such microscopic effective range are out of the running). Therefore, the cause of the acceleration must be some other, previously unknown agent. The observational data are most consistent with a cosmological constant term in Einstein's equations. See, for instance, Riess, et al., 1998 & Perlmutter, et al., 1999 (these were the first papers to report observational evidence for an accelerated expansion); Wood-Vasey, et al., 2007 constrains the nature of dark energy, and Davis, et al., 2007 demonstrate the superiority of the cosmological constant over other exotic models of dark energy.

And an interesting recent abstract deserves attention (emphasis mine):

Analytical Considerations about the Cosmological Constant and Dark Energy
Aberu, de Assis & Dos Reis; International Journal of Modern Physics A, Volume 24, Issue 28-29, pp. 5427-5444 (2009).
Abstract: The accelerated expansion of the universe has now been confirmed by several independent observations including those of high redshift type Ia supernovae, and the cosmic microwave background combined with the large scale structure of the universe. Another way of presenting this kinematic property of the universe is to postulate the existence of a new and exotic entity, with negative pressure, the dark energy (DE). In spite of observationally well established, no single theoretical model provides an entirely compelling framework within which cosmic acceleration or DE can be understood. At present all existing observational data are in agreement with the simplest possibility that the cosmological constant be a candidate for DE. This case is internally self-consistent and noncontradictory. The extreme smallness of the cosmological constant expressed in either Planck, or even atomic units means only that its origin is not related to strong, electromagnetic, and weak interactions. Although in this case DE reduces to only a single fundamental constant we still have no derivation from any underlying quantum field theory for its small value. From the principles of quantum cosmologies, for example, it is possible to obtain the reason for an inverse-square law for the cosmological constant with no conflict with observations. Despite the fact that this general expression is well known, in this work we introduce families of analytical solutions for the scale factor different from the current literature. The knowledge of the scale factor behavior might shed some light on these questions mentioned above since the entire evolution of a homogeneous isotropic universe is contained in the scale factor. We use different parameters for these solutions and with these parameters we establish a connection with the equation of state for different DE scenarios.
​

So the current consensus, based on empirical scientific evidence is that the expansion of the universe is real, its acceleration is real, the cause of the acceleration is real, the cause of the acceleration is most likely a cosmological constant, and the cause of the acceleration (which is by definition "dark energy") is not strong, weak or electromagnetic in nature.

Now, Mr. Mozina endlessly declares that its all just some kind of "fudge factor" or "myth", but other than his own highly subjective opinion, Mr. Mozina has not come forth with a single atom of objective reason to reject all of the observational data, in favor of his own electro-mythical whatever that even he can't describe or explain. One gets the idea that the Mozina Motto is "damn the science, full speed ahead!".
 
Tim Thompson said:
Don't make us laugh too hard. Of course dark energy is "real", how could it not be "real"? We all know that the words "dark energy" are just the arbitrary name given to "that which causes the acceleration of the expansion of the universe", whatever "that" may be. So dark energy is real by definition, which is a pretty hard "real" to get around. Now, as I recall ...
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Again, I have to point out this isn't right. There are models that have acceleration that don't have dark energy. They are generally thought to have something at least as bad though.
As an example, http://arxiv.org/abs/0709.2044 details one such - the LTB models which do away with the Copernican Principle.

That said...
So this Mozina fellow says the acceleration is real, and he says the cause of the acceleration must be electromagnetism.
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I'm not aware of any that reproduce acceleration using EM or anything like it. It's always some gravitational effect, whether produced by dark energy, large scale inhomogeneity or a change in the physics of gravity.

I also agree it's nuts to expect to be able to measure dark energy in the laboratory. The amount of dark energy is a free parameter which we fit with astronomical observation. When we do so, we get a quantity that is about 10 milligrams for the total amount in the volume of the Earth. I don't know how you would ever be expected to measure that in a laboratory context against the mass of the Earth - the ratio is about 1 part in 10^30.

Just because it is not measurable in the laboratory (by any means I can think of) does not mean it is not real or not measurable elsewhere - in fact its the very measurements we can make outside the lab that show it can't be measured in the lab.
 
edd said:
Again, I have to point out this isn't right. There are models that have acceleration that don't have dark energy. They are generally thought to have something at least as bad though.
As an example, http://arxiv.org/abs/0709.2044 details one such - the LTB models which do away with the Copernican Principle.
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But doesn't acceleration inevitably involve energy? From your link: " a simple spatial variation in the Hubble rate can account for the distant supernova data in a dust universe without any dark energy." How does a "simple variation in the Hubble rate" happen without energy? BTW, I'm not a physicist.
 
Perpetual Student said:
But doesn't acceleration inevitably involve energy? From your link: " a simple spatial variation in the Hubble rate can account for the distant supernova data in a dust universe without any dark energy." How does a "simple variation in the Hubble rate" happen without energy? BTW, I'm not a physicist.
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Usually you build a cosmology by assuming we're nowhere special in the universe, and everywhere is much the same as everywhere else. You have, in other words, on sufficiently large scales a uniform density.

In a LTB model you put yourself at, or very close to, the centre of an enormous underdensity. This means the Hubble parameter is not the same everywhere, and evolves differently over time. It also means it's not the same for every observer.

It's perfectly ordinary gravity working on perfectly ordinary matter - we've just contrived things and put the matter in the right place and ourselves in the right place to make it look like the universe is expanding and accelerating, when in fact it's only doing that for a certain subset of the stuff in the universe, and only when you look at it from where we are. You've basically just put a whole bunch of stuff just out of view and have it pulling on the matter we see accelerating away from us.

Finished that popcorn now Michael?
 
Perpetual Student said:
But doesn't acceleration inevitably involve energy? From your link: " a simple spatial variation in the Hubble rate can account for the distant supernova data in a dust universe without any dark energy." How does a "simple variation in the Hubble rate" happen without energy? BTW, I'm not a physicist.
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(very quick glance at paper). The model Edd links to is of an inhomogeneous Universe; it's expanding at one rate over here and at another rate over there---that's fine from a GR perspective, since the expansion rate is a "local" property of spacetime determined by initial conditions at some early point in the Big Bang. If the Big Bang had been inhomogenous, then the FRW equations we use to calculate its evolution don't apply, and so our ability to extrapolate redshifts and distances into "trajectories" would be wrong.

But this hypothesis can only look like the data IF the "inhomogeneity" is a bunch of spherical shells centered on Earth. It requires a sort of conspiracy theory in which the Earth is located at the one, unique place in the Hubble curve "accidentally" is isotropic in all directions and "accidentally" has the acceleration-like turnover.

ETA: edd understands it better and (as usual) explained it better. I want to emphasize, though, that the "underdensity" of the LTB model isn't just any random underdensity---those would not be too surprising---it has to be a perfectly spherical one to a precision of 10^-5, with the Earth located within 10^-5 of the center.
 
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Yeah, it's hideously contrived, which is why we generally go for the one-parameter addition of a cosmological constant instead. There are people checking into this sort of thing in more detail to build tests that can tell the two circumstances apart, but I've never met anyone that thinks it's very likely given how well lambda-CDM works.

But it does demonstrate that dark energy is not the only conceivable cause of acceleration.
 
edd said:
But it does demonstrate that dark energy is not the only conceivable cause of acceleration.
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... which is one of the ways a casual observer can tell that Dark Energy is a scientific hypothesis and not ... well, a cult or a dogma or whatever else MM thinks it is.

Also: the LTB paper is a nice example of a competently-presented alternative cosmology theory. It does not contain any epistemological rants against dark energy, dark matter, inflation, or magnetic reconnection. It presents a detailed quantitative theory which any physics-educated reader can compare, on their own, to any data. It does not avoid doing any math, nor argue that math is irrelevant or constructed or whatever. It straightforwardly reviews the strengths and weaknesses of the new hypothesis as well as the strengths and weaknesses of the standard dark-energy hypothesis.
 
Energy and the Accelerated Expansion

Perpetual Student said:
But doesn't acceleration inevitably involve energy?
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Actually, from the point of view of classical physics (quantum mechanics not allowed), not necessarily (as I have already pointed out elsewhere). One need only look at Einstein's equations to see that the "cosmological constant" is pure geometry. So, if the cosmological constant is the simplest explanation for the accelerating expansion, then it does not involve "energy" at all in any classical sense, but only the pure geometry of space. Hence, "dark energy" may have been an unfortunate choice of words for the name, since energy need not be involved.

Of course, once we try to establish a quantum field theory for the cosmological constant, like vacuum energy or some such thing, then we have energy back in then game as one might expect. It's just not there as an entity of classical physics. We can make the accelerated expansion due to classical energy by shying away from the cosmological constant and asserting an additional scalar field into the stress-energy tensor (i.e., "quintessence" theory; Wetterich, 2002; Chongchitnan & Efstathiou, 2007).

It's easy to get hung up on the words and miss the physics. "Dark energy" may not be any form of classical energy, just as "magnetic reconnection" may not be a literal physical description of what's happening. But in both cases there is a unique physical system behind the name that obeys the laws of physics just as rigorously as anything else. It's just that, at least in the case of dark energy, we are willing to set aside the momentary arrogance required to demand that we already know what all of the laws of physics really are and there is nothing left to discover in the universe. Some of the people who work these threads would do well to set that arrogance aside.
 
Tim Thompson said:
Actually, from the point of view of classical physics (quantum mechanics not allowed), not necessarily (as I have already pointed out elsewhere). One need only look at Einstein's equations to see that the "cosmological constant" is pure geometry. So, if the cosmological constant is the simplest explanation for the accelerating expansion, then it does not involve "energy" at all in any classical sense, but only the pure geometry of space. Hence, "dark energy" may have been an unfortunate choice of words for the name, since energy need not be involved.

Of course, once we try to establish a quantum field theory for the cosmological constant, like vacuum energy or some such thing, then we have energy back in then game as one might expect. It's just not there as an entity of classical physics.
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That's not correct. The cosmological constant appears in the Einstein-Hilbert Lagrange density as, well, a constant. If you carry out the integral it you get the 4-volume of spacetime times that constant. In other words including the CC is equivalent to including a constant energy density (note that what I've said has nothing to do with quantum mechanics, it's purely classical field theory).

In non-gravitational physics such an energy density wouldn't have any effect (since it's only energy differences that matter, and so a universal additive constant doesn't do anything), but gravity turns out to act on all forms of energy, even constants, and so the CC affects the geometry and can drive acceleration. Without such a term there is no way to achieve an accelerated expansion, because all ordinary forms of matter and energy act to decelerate it.
 
Michael Mozina said:
So how's a layman supposed to comprehend this stuff, when "experts" like Tim and Sol can't even agree? FYI, Sol is correct. :)

:popcorn1
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Actually Tim and Sol are both correct. The cosmological constant is a funny wee beasty.

The Einstein field equations are usually quoted as:

3f50fd206f2fe543a6a8a3e687cf74c3.png


In this form the cosmological constant appears with the Ricci curvature tensor and the scalar curvature. It is thus part of the geometry of spacetime (as per Tim Thompson's post).

But it is just as valid to subtract the cosmological constant term from both sides of the equation. In that form the CC appears with the stress-energy tensor. It is thus part of the stress-energy that is being considered as the source of the gravitational field (as per sol invictus's post).

What Tim and others have been pointing out in recent posts is that the CC is not the only candidate for dark energy. It is however the candidate that requires the least departure from known physics.
 
Reality Check said:
Actually Tim and Sol are both correct. The cosmological constant is a funny wee beasty.

The Einstein field equations are usually quoted as:

[qimg]http://upload.wikimedia.org/math/3/f/5/3f50fd206f2fe543a6a8a3e687cf74c3.png[/qimg]

In this form the cosmological constant appears with the Ricci curvature tensor and the scalar curvature. It is thus part of the geometry of spacetime (as per Tim Thompson's post).
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You can't change the interpretation of a term by subtracting it from both sides of an equation. If you want to know whether it corresponds to an energy density or not, look at the action principle from which that equation comes. The CC appears as an additive term (with no derivatives) in the Einstein-Hilbert Lagrangian; therefore it's an energy density. It has units of energy/volume. It can arise due to quantum vacuum energy, or due to a constant piece in a classical scalar potential energy function, or in several other ways, but it's always an energy density.

Granted, energy in general relativity is a very subtle topic (actually energy is always a surprisingly subtle thing). But in this case I don't think there's much ambiguity.
 
sol invictus said:
You can't change the interpretation of a term by subtracting it from both sides of an equation. If you want to know whether it corresponds to an energy density or not, look at the action principle from which that equation comes. The CC appears as an additive term (with no derivatives) in the Einstein-Hilbert Lagrangian; therefore it's an energy density. It has units of energy/volume. It can arise due to quantum vacuum energy, or due to a constant piece in a classical scalar potential energy function, or in several other ways, but it's always an energy density.

Granted, energy in general relativity is a very subtle topic (actually energy is always a surprisingly subtle thing). But in this case I don't think there's much ambiguity.
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My impression was that the inclusion of an additive term in a Lagrangian implicitly defines that additive term as an energy density. But it seems that I am wrong.

It is many, many years since I did my GR courses but I recently viewed Leonard Susskind's lectures on GR via YouTube. He did seem to imply that the CC was a geometrical term when it appeared on one side of the EFE and an energy term on the other side but he may have been simplifying things for the students.

ETA:
I got that impression from his addition of the CC to EFE about 14 minutes into lecture 10. Starting from EFE without the CC term:
  • We expect/hope that energy and momentum will be conserved on the right hand side of the EFE, i.e. the covariant derivative of the stress-tenergy tensor will be zero.
  • This means that the covariant derivative of the left hand side will also be zero, i.e. the covariant derivative of the Einstein tensor will be zero ("covariant conservation").
  • You can add a constant times the metric to the left hand side and still have covariant conservation.
Since he was talking about geometry at that point I thought that the CC term (on the left hand side of the EFE) was a geometrical term. However from then on CC is refereed to as a energy density.
 
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Keep in mind PS that the original "prediction" (say 25 years ago) of "big bang" theories in general was that the expansion process was slowing down over time. The ad hoc insertion of "dark energy" 15 years ago was a direct result of the observation of apparent acceleration. That acceleration process was *NOT* a prediction of earlier BB theories, in fact it's exactly the opposite of earlier predictions. "Dark energy" was specifically and intentionally stuffed in there about 15 years ago or so to "explain" that observation of acceleration. That observed acceleration of the physical universe absolutely requires additional "energy". As Sol points out, all gravitational forces act to 'slow down' the expansion process. Whatever speeds it up must absolutely add energy to the system.
 
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Michael Mozina said:
Keep in mind PS that the original "prediction" (say 25 years ago) of "big bang" theories in general was that the expansion process was slowing down over time. The ad hoc insertion of "dark energy" 15 years ago was a direct result of the observation of apparent acceleration. That acceleration process was *NOT* a prediction of earlier BB theories, in fact it's exactly the opposite of earlier predictions. "Dark energy" was specifically and intentionally stuffed in there about 15 years ago or so to "explain" that observation of acceleration. That observed acceleration of the physical universe absolutely requires additional "energy". As Sol points out, all gravitational forces act to 'slow down' the expansion process. Whatever speeds it up must absolutely add energy to the system.
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First asked 29 January 2010
MM,
Can you give a citation for your assertion that BBT 25 years ago only predicted that the expansion process was slowing down over time?

This may be a case of your ignorance of science yet again.
  1. BBT has always predicteded that the expansion process was either slowing down, speeding up or constant. Generally people went with the constant expansion option.
  2. Dark energy is an observation not a theory. The theories are about the composition of dark energy, e.g. the cosmological constant.
  3. As sol invictus and oithers have pointed out dark energy is not the gravitational force. The effects of dark energy are the same as a repulsive gravitational force but a cosmological constant results in a force law that varies as r not 1/r^2.
  4. We are talking about the universe. There is no energy to be added to the system.
 
Michael Mozina said:
Keep in mind PS that the original "prediction" (say 25 years ago) of "big bang" theories in general was that the expansion process was slowing down over time.
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So what? Those theories have been shown to be incorrect. The "original Big Bang theory", if by that you mean "the EFE with lambda=0", does not agree with cosmology data.

Are you ever going to comment on the fact that electromagnetic forces cannot be contributing to this or any other large-scale acceleration?
 
Michael Mozina said:
Keep in mind PS that the original "prediction" (say 25 years ago) of "big bang" theories in general was that the expansion process was slowing down over time. The ad hoc insertion of "dark energy" 15 years ago was a direct result of the observation of apparent acceleration.
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There's a name for that process. It's "science".

That acceleration process was *NOT* a prediction of earlier BB theories, in fact it's exactly the opposite of earlier predictions.
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No, not really. First of all there isn't really such a thing as "BB theory". The only theory is general relativity, but that just tells you the dynamics, not what the universe is composed of or whether it has a CC. All of that has to be fit using data. The current data, which are much more precise and plentiful than the data 25 years ago, show that a small positive CC fits well.

It's very much like using Newtonian gravity and mechanics to describe the solar system. You have to make observations, use your observation to fit some parameters (like positions and velocities of planets), and then test your model against more observations. If it doesn't fit, it might be because there's another body that's hard to see that is perturbing the others.

"Dark energy" was specifically and intentionally stuffed in there about 15 years ago or so to "explain" that observation of acceleration.
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Again, that's called "science".

That observed acceleration of the physical universe absolutely requires additional "energy". As Sol points out, all gravitational forces act to 'slow down' the expansion process. Whatever speeds it up must absolutely add energy to the system.
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Gravitational forces due to ordinary matter and radiation act to slow down the expansion. By the way, that includes all forms of classical electromagnetic energy.

Gravitational forces due to dark energy or a positive CC act to speed it up.
 
sol invictus said:
Without such a term there is no way to achieve an accelerated expansion, because all ordinary forms of matter and energy act to decelerate it.
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I think it should be noted that your statement is true only in a closed system. For instance, a greater concentration of matter beyond our visible sliver of the universe might act to accelerate matter. Likewise other forces of nature might work as well, they just need to be acting from the outside.
 
Michael Mozina said:
I think it should be noted that your statement is true only in a closed system. For instance, a greater concentration of matter beyond our visible sliver of the universe might act to accelerate matter. Likewise other forces of nature might work as well, they just need to be acting from the outside.
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The starting point for modern cosmology is the assumption that the earth is not in an especially unusual place in the universe. That assumption plus our observations imply that the universe is close to homogeneous and isotropic on large scales (the scales on which the overall expansion is dominant). And in fact that's all that's necessary for my statement to hold - the system doesn't need to be "closed", it just needs to be homogeneous and isotropic.

You are correct that there are alternatives to dark energy, like that the earth is very near the center of a spherically symmetric (isotropic) but not homogeneous matter distribution. At least to me, that model is far less palatable than simply including a CC, which one expects to be present anyway based both on classical GR and quantum mechanics. But until the spherical model can be tested with data that's just an opinion.
 
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ben m said:
So what? Those theories have been shown to be incorrect. The "original Big Bang theory", if by that you mean "the EFE with lambda=0", does not agree with cosmology data.
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So essentially the answer to PS's questions is: "Yes, acceleration requires extra energy".

Are you ever going to comment on the fact that electromagnetic forces cannot be contributing to this or any other large-scale acceleration?
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Why should I? You've made no serious to understand my beliefs related to externally driven acceleration, so what's the point?
 
Michael Mozina said:
I think it should be noted that your statement is true only in a closed system. For instance, a greater concentration of matter beyond our visible sliver of the universe might act to accelerate matter. Likewise other forces of nature might work as well, they just need to be acting from the outside.
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At last you get something right :D !

The "greater concentration of matter beyond our visible sliver of the universe" is the LTB model that was mentioned yesterday by edd and others.

Only gravity works in this model - other known forces of nature such as EM do not work. Remember that on cosmological scales the universe is neutral so there is nothing for EM forces to act on. You might get around this by making the EM forces really, really big so that they can influence electrons and ions. But then the EM forces become really, really easy to detect.
 
I have a question for you sol....

I recall handing you a paper on replacing "dark energy" with an EM field, and I recall you finding a flaw it in. Did you ever consider "fixing" that flaw, or was it somehow (physically) beyond repair? If so, can you recall *WHY* it's beyond repair?
 
Reality Check said:
At last you get something right :D !

The "greater concentration of matter beyond our visible sliver of the universe" is the LTB model that was mentioned yesterday by edd and others.

Only gravity works in this model - other known forces of nature such as EM do not work. Remember that on cosmological scales the universe is neutral so there is nothing for EM forces to act on. You might get around this by making the EM forces really, really big so that they can influence electrons and ions. But then the EM forces become really, really easy to detect.
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Hell, you can't "detect" them when they heat the solar atmosphere to tens of millions of degrees and generate million mile per hour solar wind! When it comes to electrical currents in space you're willfully blind.
 
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Michael Mozina said:
I have a question for you sol....

I recall handing you a paper on replacing "dark energy" with an EM field, and I recall you finding a flaw it in. Did you ever consider "fixing" that flaw, or was it somehow (physically) beyond repair? If so, can you recall *WHY* it's beyond repair?
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It can't be fixed. There's a very simple and general reason why EM fields cannot provide acceleration. it's the same reason that ordinary matter cannot either. Acceleration requires negative pressure - in fact it requires a pressure that's sufficiently negative that it counterbalances the associated energy density (you need p<(-1/3)\rho). But it's trivial to prove that EM energy doesn't satisfy that condition (and cannot under any circumstances). The things that can give you acceleration are more exotic than that. The classic example is positive vacuum energy from quantum fluctuations, but there are others.

The error in that paper was something really elementary, I forgot what exactly. Something like including a gauge mode (with a wrong sign kinetic term) in the energy.
 
Michael Mozina said:
So essentially the answer to PS's questions is: "Yes, acceleration requires extra energy".
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Yes essentially the answer to PS's question is: "Yes, acceleration requires extra energy" in the LBT model. That extra energy is the gravitational potential energy of the extra matter outside of the visible universe.

Michael Mozina said:
Why should I? You've made no serious to understand my beliefs related to externally driven acceleration, so what's the point?
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As far as I can see, you have never presented an externally driven acceleration belief until today and that seems to be driven by the mention of the LBT model.
I could be wrong - please provide a link to the post where you state that your cosmological EM fields are generated outside of the visible universe.
 
Michael Mozina said:
Hell, you can't "detect" them when they heat the solar atmosphere to tens of millions of degrees and generate million mile per hour solar wind! When it comes to electrical currents in space you're willfully blind.
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Hell, we can and do detect them when they (EM forces) heat the solar atmosphere to tens of millions of degrees and generate million mile per hour solar wind! When it comes to science you're willfully blind :eye-poppi

I hope that you are not idiotic enough to think that stellar physics has any application to cosmology. The word stellar should give you a clue.
 
Michael Mozina said:
The solar wind is not operating on negative pressure, and the sun accelerates material all day every day. I don't follow your logic.
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Actually you just cannot read your own posts
sol invictus is talking about the dark energy that you mention in your post not the solar wind.

sol invictus said:
Originally Posted by Michael Mozina
I have a question for you sol....

I recall handing you a paper on replacing "dark energy" with an EM field, and I recall you finding a flaw it in. Did you ever consider "fixing" that flaw, or was it somehow (physically) beyond repair? If so, can you recall *WHY* it's beyond repair?
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It can't be fixed. There's a very simple and general reason why EM fields cannot provide acceleration. it's the same reason that ordinary matter cannot either. Acceleration requires negative pressure - in fact it requires a pressure that's sufficiently negative that it counterbalances the associated energy density (you need p<(-1/3)\rho). But it's trivial to prove that EM energy doesn't satisfy that condition (and cannot under any circumstances). The things that can give you acceleration are more exotic than that. The classic example is positive vacuum energy from quantum fluctuations, but there are others.

The error in that paper was something really elementary, I forgot what exactly. Something like including a gauge mode (with a wrong sign kinetic term) in the energy.
Click to expand...
 
Reality Check said:
I hope that you are not idiotic enough to think that stellar physics has any application to cosmology. The word stellar should give you a clue.
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Er, it's a "working example" of continuous acceleration of matter. If we aren't going to look to nature to find working examples, what are we doing, playing "make believe"?
 
Michael Mozina said:
The solar wind is not operating on negative pressure, and the sun accelerates material all day every day. I don't follow your logic.
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Again, isotropic but not homogeneous distributions can cause an outward acceleration that could explain what we see, if the earth were at the center and the distribution had the right characteristics.

But if the solar wind was distributed throughout space homogeneously and isotropically (as we expect everything in the universe to be on large scales) it wouldn't cause acceleration (any more than the gas in a room causes things floating in it to accelerate in some particular direction).
 
Outstanding questions for Michael Mozina

  1. Do you understand that there is an upper limit on the baryonic mass of 6%?
    First asked 7 January 2010
    Note that baryonic mass includes all the things you have mentioned, e.g. rocks, planets, electron, ions, plasma, black holes, etc.
  2. Do you know that Alfven-Klein cosmology is invalid?
    First asked 8 January 2010
  3. What is wrong with the measurement of negative pressure in Casimir experiments?
    First asked 9 January 2010
  4. Why and how do you get an EM field to cause the observed acceleration of the expansion of the universe?
    First asked 12 January 2010
  5. Why do Casimir experiments not measure a replusive force and so positive pressure?
    First asked 14 January 2010
  6. What are your sources for the observation of massive Birkeland currents in the galaxy?
    First asked 14 January 2010
  7. What are your sources for evidence of relativistic jets linking many galaxies?
    First asked 14 January 2010
Some of Michael Mozina's debating tactics that reveal the depths that he has to descend to because he has no science to backup his claims:
Answered questions:
  1. Can you give a citation to "Birkeland's very first rough calculation..."
    Birkeland made a rough calculation on page 721 of his 1908 book of the average density of matter that is not in stars.
    That calculation was correct at the time given the knowledge of the universe. The calculation is wrong now since we know more about the universe.
  2. A couple of really simple physics questions for Michael Mozina on pressure.
    Is seems that MM cannot answer these simple questions on pressure other than regurgitating his usual Casimir effect is "relative pressure" from atoms. So I answered it for him in as simple a manner as possible. He still cannot understand it.
P.S.
 
Michael Mozina said:
Er, it's a "working example" of continuous acceleration of matter. If we aren't going to look to nature to find working examples, what are we doing, playing "make believe"?
Click to expand...
The orbit of the Earth is also a working example of continuous acceleration of matter.
Why are you ignoring it?

ETA
If you are persisting in your cosmological EM fields = dark energy idea then it is you who is playing "make believe".
 
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sol invictus said:
Again, isotropic but not homogeneous distributions can cause an outward acceleration that could explain what we see, if the earth were at the center and the distribution had the right characteristics.
Click to expand...

I don't think it necessarily has to be at the center of the distribution, it simply has to be somewhere in the acceleration stage.

Solar wind particles do continue to drift further and further apart from their solar wind neighbors (particles that left the surface at roughly the same time) over time. Some particles might have a similar trajectory, but over some long period of time, any deviation in trajectories leads to a ever growing distance between particles. As long as the acceleration process is constant, even particle ahead of us are moving faster and away from us, and particles that left later are moving slower and getting further apart. Everything visible would still have a redshift from our vantage point.
 
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Michael Mozina said:
Hell, you can't "detect" them when they heat the solar atmosphere to tens of millions of degrees and generate million mile per hour solar wind! When it comes to electrical currents in space you're willfully blind.
Click to expand...


So all the professional physicists on Earth are willfully ignorant.
 
Michael Mozina said:
Why should I? You've made no serious to understand my beliefs related to externally driven acceleration, so what's the point?
Click to expand...

Not only do I understand your beliefs, I took your beliefs and used Maxwell's Equations and Newton's Laws to evaluate them, something you are unable to do yourself. My conclusion was that you believe in a hypothesis which disagree with the data.
 
Michael Mozina said:
Everything visible would still have a redshift from our vantage point.
Click to expand...

You are incorrect. Even in your oversimplified model of the Solar Wind---one where its radial velocity is accelerating, as would be the case for a Coulomb's Law driven electrostatic force---any observer co-moving with the wind will see a different expansion along the axis that points to the Sun, versus in the plane perpendicular to that axis. This observer will see non-isotropic expansion AND non-isotropic acceleration of that expansion.

Do you need me to do the math for you? Last time I did the math showing that you were wrong, you ignored it.
 
Michael Mozina said:
As long as the acceleration process is constant, even particle ahead of us are moving faster and away from us, and particles that left later are moving slower and getting further apart.
Click to expand...

My last post states that you don't seem to understand the directions of force and acceleration vectors. The earlier posts whose math you are ignoring all argued that you don't understand the magnitudes of electromagnetic forces either.

To reiterate: the stars/galaxies that we observe "accelerating" away from us would be doing so, if your model were correct, under an acceleration of order 10^-11 m/s/s. Please tell me which electromagnetic force law you think can accelerate a star at 10^-11 m/s/s.

(Don't get this confused with the acceleration of solar wind protons. It is very easy to state an EM force law which will accelerate a proton to 10^6 m/s as in the solar wind---one microvolt per meter would be plenty, if you want to use Coulomb's Law. The calculation for stars is DIFFERENT because the charge to mass ratio is different.)
 
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