Lambda-CDM theory - Woo or not?

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Are you aware that you are still showing the symptoms of a crank

Michael Mozina said:
Did anyone else notice how "dark energy" went from being just a placeholder term for human ignorance (we don't know the real cause) to becoming a "specific" hypothesis (Ben's word)?
...usual "deity" rant...
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Did anyone else notice that Michael Mozina is lying about what everyone in this thread has been saying?
There is no ignorance about the "real cause" of dark energy. Dark energy is by defintion the "real cause" of the effect. Or if you like:
Dark energy is a placeholder term for an area of human knowledge.
That knowledge is that the rate of expansion of the universe is measured to be expanding. This effect must have a cause. We measure several properties of the cause, e.g. that it emits no detectable light (is dark), is not very dense and seems to act like an energy. We call that cause dark energy. We have several candidates for the actual makeup of dark energy.
That we do not have complete knowledge is correct - that is not ignorance.
​
Did anyone else notice that Michael Mozina is still persisting in displaying to the world his crank symptoms? So we may as well officially expand this post from another thread
to include the previous point of Michael Mozina's ridiculous renaming delusion:
12. The delusion that changing the word that is used to describe something changes what is described.
Calling sometign a deity does not change anthing.
As Shakespeare said: A rose by any other name would smell as sweet.
A Godrose smells as sweet as a rose.
A Satanrose smells as sweet as a rose.
​
 
Reality Check said:
A Godrose smells as sweet as a rose.
A Satanrose smells as sweet as a rose.​
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And a concerted effort to diminish the validity of a well supported hypothesis by renaming it with some kind of made up baby-talk jargon smacks of desperate stupidity.
 
Dark Energy and Empirical Science VI

Michael Mozina said:
Did anyone else notice how "dark energy" went from being just a placeholder term for human ignorance (we don't know the real cause) to becoming a "specific" hypothesis (Ben's word)?
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Remarkable, isn't it? Maybe this is the first time that scientists have ever put forward an hypothesis to establish a cause for observed phenomena, where the cause was previously unknown. Maybe this moment before us is a turning point in human history. Maybe this is a landmark moment that will forever define a new direction for scientific thought, one of observation followed by hypothesis. Let us bask in the eternal light of this cherished moment of intellectual surprise and discovery.

OK, maybe not. Moving on, then ...

Michael Mozina said:
This dark energy concept sure seems like it's morphing itself into a very specific and very impotent 'dark energy' deity, one that epically fails to show up in the lab like any other deity that we could 'name'.
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Actually, sarcasm aside, it is morphing itself into a very specific and very important 'dark energy' scientific hypothesis, one that epically shows up in observations of the natural universe, unlike any other deity you can name. What is your beef with observations of the natural universe? Why do you think that observations of the natural universe are meaningless tripe?

Why don't you just admit that you hate science altogether, and let's get on with your real agenda of proving the existence of a mythical electric deity? We already know that you hate the word "empirical" so much that you had to invent a new meaning for the word, special and unto yourself (e.g., What is "Empirical" Science V, What is "Empirical" Science III, Delusional Science). We already know that you hate any controlled laboratory experiments that conflict with your precious electric deity (e.g., Magnetic Reconnection Redux XI, Magnetic Reconnection Redux X, Comments on Magnetic Reconnection III). We already know that you hate thermodynamics so much, you have to deny its very existence lest it conflict with your worship of the iron deity (e.g., No Iron "Surface" for the Sun, The Great Iron Layer, Iron Sun Surface Thermodynamically Impossible V). Come on, we know you hate science. So just admit it up front and we can move this discussion into the religion forums, where you belong. With you it's nothing but invisible electric deities and invisible iron deities anyway.
 
Michael Mozina said:
Let's try it this way: An "energy density" of "what" exactly? (real physics please).
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(We don't know yet. If we knew exactly what it was, we'd have said so already.)

Do you want to know what the hypotheses are for "real things" that have vacuum energy density? Vacuum fluctuations of orginary virtual particles (a well-known feature of particle physics, visible in the Casimir effect) are one example hypothesis. A cosmological constant (an allowable, underlying feature of the geometry of spacetime) is another example hypothesis. A field condensate, akin to the Higgs condensate---a standard feature of particle physics, expected to be visible at the LHC---is another example hypothesis. And so on.

"Hey", I can hear you repeating, "That's all stuff we've never seen empirically so it is just more religion-dogma-bunny-magic-words". It's stuff we haven't seen, indeed, which is why they are still HYPOTHESES rather than simple facts. But so was the Top Quark prior to 1995. So was the neutrino prior to 1956. You're allowed to hypothesize stuff you haven't actually seen, that is how hypotheses work.
 
Michael Mozina said:
Did anyone else notice how "dark energy" went from being just a placeholder term for human ignorance (we don't know the real cause) to becoming a "specific" hypothesis (Ben's word)? This dark energy concept sure seems like it's morphing itself into a very specific and very impotent 'dark energy' deity, one that epically fails to show up in the lab like any other deity that we could 'name'.
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I don't get the problem. DE is actually a placeholder for a wide class of ideas to solve the acceleration problem (although it's getting a bit beyond solving just the one problem now). A cosmological constant is a specific hypothesis though, and a specific hypothesis is exactly what is desired as a specific hypothesis is generally the most predictive and most falsifiable. You make it sound like it's a bad thing when in fact it's the thing we want to work with most, because we don't even need a lab to get it to epically fail, in principle.

Unfortunately for your preconceptions though, even the simplest form of dark energy is yet to fail in even a non-epic manner.
 
sol invictus said:
Very crudely the amount of dark energy is just the amount of mass in the sphere times c^2, times a factor of 2 or 3 or so since dark energy wins. In other words the dark energy density is about twice or three times the average mass density times c^2.

To be more accurate you can put in by how much it wins (i.e. the magnitude of the observed acceleration). To be even more accurate you'll need GR, since dark energy gravitates differently than cold matter (due to its pressure).

I think that means the Newtonian procedure I suggested would be off by 2 (since it's actually density plus 3*pressure that matters, and that adds up to -2*density for dark energy).
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So is the 2 or 3 factor ( repeated below) just a fudge factor:
the amount of dark energy is just the amount of mass in the sphere times c^2, times a factor of 2 or 3 or so since dark energy wins.
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or is the justification based only on observations or is it due to the difference between GR and Newton?
 
Perpetual Student said:
So is the 2 or 3 factor ( repeated below) just a fudge factor:
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It's a fudge factor at the level of the analysis I suggested, which was just supposed to give you a sense of how the real calculation goes.

or is the justification based only on observations or is it due to the difference between GR and Newton?
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Both. GR tells you how dark energy (or more precisely, vacuum energy and/or cosmological constant) gravitates, observations tell you how much acceleration there is, and so the two together tell you how big the dark energy density is.

Newton alone doesn't really work for this, because dark energy is an intrinsically relativistic thing. It has a pressure that's comparable to its energy density, which is impossible for any non-relativistic form of energy. That's why you need the fudge factor when you try to use Newtonian gravity.
 
Michael Mozina said:
It is? Is this a new "property" that you "assigned" to it in an ad hoc manner, or can I expect you to demonstrate that "dark energy" has a zero charge in a lab anytime soon?
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Yes, I can do it right now.

(I turn on my digital multimeter, a Fluke 87, in autoranging DC mode. It operates for some time without shorting out.)

There, that's an direct observation. The hypothesis, which you just presented, "empty space is electrically charged", leads (via Maxwell's Equations) to the conclusion that the Universe is suffused by an infinitely-strong electric field. This is observationally not true, as I just demonstrated. Therefore empty space is not electrically charged. Next?

See, Michael, we're not making it up. People have spent the past 15 years trying every way they could think of to explain the cosmological data. The "dark energy" thing is NOT, as you seem to think, the first random thing that came to mind, which we stuck to out of laziness. It is, rather dramatically, the only thing left after uncounted alternative hypotheses failed.

How exactly did you rule out electrons, protons and other moving charged particles again? What if it's some ugly combo deal where neutrinos provide some of that moving "energy/mass" and moving charged particles provide the rest?
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(sigh) Neutrinos, electrons, protons, plasmas, and so on---no matter how many of them you put in, and in what combinations---always, always, always predict that the supernova distance-luminosity curve would bend down. The data shows that the distance-luminosity curve bends up. http://www.supernova.lbl.gov/PDFs/expansionhistoryphystoday.pdf

Sorry, Michael---once again, this stuff you're throwing out is all stuff that people thought of years ago. It's all been looked at. It doesn't work. Go back in time to 1975, suggest that the Universe is full of neutrinos, and maybe you'll be taken seriously for a few minutes before people realize you have no idea what you're talking about. It's not 1975, it's 2010. We've learned a thing or two about what neutrinos, electrons, and protons can and cannot do to the large-scale behavior of the Universe.

ETA: We've also explained it to YOU, personally, in great detail, over and over again, in simple posts and complex posts, in casual posts and citation-choked posts, in science language and in cretin language. Did you read any of that?
 
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Reality Check said:
Did anyone else notice that Michael Mozina is lying about what everyone in this thread has been saying?
There is no ignorance about the "real cause" of dark energy. Dark energy is by defintion the "real cause" of the effect. Or if you like:
Dark energy is a placeholder term for an area of human knowledge.
That knowledge is that the rate of expansion of the universe is measured to be expanding. This effect must have a cause. We measure several properties of the cause, e.g. that it emits no detectable light (is dark), is not very dense and seems to act like an energy. We call that cause dark energy.​
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With all due respect, RC, I think you're trying to concede MM some point of the language; you're getting it wrong and confusing the issue. Dark energy isn't a placeholder term for anything, except insofar as there are multiple underlying physics ideas, and any one of them might turn out to generate the actual vacuum-energy-density that we call dark energy. If we find out that the observed redshift pattern is due to the "cosmic void" business, then no, we won't apply the words "dark energy" to that. If we find out that all galaxies have a big string tied to them and God is tugging on them, we won't apply the words "dark energy to that.

It's not a placeholder at all. It only describes things that go into the source term of the Einstein equation in the form of a scalar quantity times the metric tensor. That's not literally everything we don't know about the cosmology, it's that one thing---the magnitude and maybe the time dependence of that scalar.​
 
ben m said:
With all due respect, RC, I think you're trying to concede MM some point of the language; you're getting it wrong and confusing the issue. Dark energy isn't a placeholder term for anything, except insofar as there are multiple underlying physics ideas, and any one of them might turn out to generate the actual vacuum-energy-density that we call dark energy. If we find out that the observed redshift pattern is due to the "cosmic void" business, then no, we won't apply the words "dark energy" to that. If we find out that all galaxies have a big string tied to them and God is tugging on them, we won't apply the words "dark energy to that.

It's not a placeholder at all. It only describes things that go into the source term of the Einstein equation in the form of a scalar quantity times the metric tensor. That's not literally everything we don't know about the cosmology, it's that one thing---the magnitude and maybe the time dependence of that scalar.
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I agree that "placeholder term" is way too simplistic and general for what dark energy is. But given the problems that MM has with understanding anything complex, I have tried to keep things simple -probably too simple.
 
Tim Thompson said:
Remarkable, isn't it? Maybe this is the first time that scientists have ever put forward an hypothesis to establish a cause for observed phenomena, where the cause was previously unknown. Maybe this moment before us is a turning point in human history. Maybe this is a landmark moment that will forever define a new direction for scientific thought, one of observation followed by hypothesis. Let us bask in the eternal light of this cherished moment of intellectual surprise and discovery.

OK, maybe not.
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Yes, that is how science usually works. To be fair, Michael Mozina is unfamiliar with that paradigm.

Michael Mozina said:
Did anyone else notice how "dark energy" went from being just a placeholder term for human ignorance (we don't know the real cause) to becoming a "specific" hypothesis (Ben's word)?
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You're over-generalizing. No one has suggested that "dark energy" is a placeholder that refers to all human ignorance or to every specific instance of human ignorance. In particular, no one has suggested that "dark energy" is an alias for Homer SimpsonWP, Michael Mozina, or W.D.Clinger.

Where we have agreed with you is that dark energyWP is a placeholder that stands for any cause that behaves like vacuum energyWP or Einstein's cosmological constantWP. (In case you've forgotten, that's the notion of dark energy that's named within the title of this thread.)
 
Reality Check said:
Let's try it this way: Are you ignorant of what the term energy density means? (real physics please).
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Probably. He doesn't know what pressure is. We went around in circles for pages and pages once, trying to get him to define pressure, and he couldn't do it.
 
Ziggurat said:
Well, yes. If it had charge, it wouldn't be dark. Do you know why, Michael? Can you figure it out?
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Birkeland figured it out for me over 100 years ago. You still can't figure out what causes the acceleration of solar wind, so we can easily demonstrate the flaws in your logic based on your own claims.

You don't know the "real empirical" cause of acceleration of solar wind, so we begin by labeling this "unknown acceleration", "dark energy". Dark energy is able to generate this acceleration pattern, so now all we have to do is find out which force(s) of nature might do that and we can figure out how "dark energy" manifests itself right here inside our own solar system. Once we figure that out we'll know exactly how "dark energy" works "out there somewhere".

Sound fair? It is your "methodology"' after all, right?

Now we look back 100 years in time and we notice that Kristian Birkeland came up with an empirical "prediction" about "flying electric ions' of all sorts coming from the sun. How did he accomplish this feat? He used the EM field, and specifically "electricity".

You guys have all these various "magnetic reconnection" theories to tinker around with, but each and every one of them is simply a theory about the way the EM field manifests itself in the solar system.

Unless both you and Birkeland are incorrect, the EM field *MUST* be responsible for that "unknown acceleration" and our term "dark energy" is now understood to be directly related to the EM field.

Now why in the world do I need to to look anywhere other than the EM field to explain acceleration of plasma outside of the solar system?
 
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Michael Mozina said:
Unless both you and Birkeland are incorrect, the EM field *MUST* be responsible for that "unknown acceleration" and our term "dark energy" is now understood to be directly related to the EM field.
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Kristian Birkeland never proposed any such mechanism for the accelerated expansion of the Universe. He never even gave the idea a second thought. Are you lying again, or are you just ignorant?

Oh, and speaking of all that lying you do to support your religious attachment to your crackpot notions, do you figure to stop that, or can we just expect you to continue?
 
Michael Mozina said:
Now why in the world do I need to to look anywhere other than the EM field to explain acceleration of plasma outside of the solar system?
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I wonder how many times you've posed that question on this forum - and had it answered?

I would say at least 10, and probably more like 20.
 
edd said:
I don't get the problem. DE is actually a placeholder for a wide class of ideas to solve the acceleration problem (although it's getting a bit beyond solving just the one problem now).
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Please read my last post to Zig and you can see why that "we don't really know" concept opens the door for all of you to eventually become "EU promoters" one fine day in the future edd. :)

A cosmological constant is a specific hypothesis though, and a specific hypothesis is exactly what is desired as a specific hypothesis is generally the most predictive and most falsifiable.
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A cosmological constant isn't a "thing", it's a number in a math formula. Unless and until you understand the "physical cause" of that "constant", you really haven't figured out anything. You know the constant but you don't know the 'cause".

You make it sound like it's a bad thing when in fact it's the thing we want to work with most, because we don't even need a lab to get it to epically fail, in principle.
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Hmmm. Well, maybe. You might actually falsify some "general ideas" that way, but that's about it. You can't "prove" that "dark energy" is the cause of acceleration however by pointing at the sky. Unless you can demonstrate that "dark energy" is somehow empirically related to acceleration of plasma/objects (like the EM field in the lab), you really just have a "religion', one that epically fails to have any effect here on Earth.

Unfortunately for your preconceptions though, even the simplest form of dark energy is yet to fail in even a non-epic manner.
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IMO you folks have deluded yourselves into believing that a new force of nature is required to explain an acceleration process you simply do not understand. You can't even be sure you won't all one day end up in the EM field camp anyway. About all you really know is that "acceleration happens", and you can't figure it out yet.

Dark energy is no more the cause of acceleration than invisible potato energy. There is no cause/effect connection between dark energy and acceleration any more than there is a an empirical link between God energy and the same observation.

I do find it fascinating that you are all straddling both sides of this fence so 'dark energy" cannot be "falsified". Ben's concept "might' be falsified in some way because it is more specific. *All* concepts of "dark energy" cannot be ruled out anymore than all concept of God energy could be ruled out. What you've done is shifted the burden of proof by *insisting* that the term can be generic and also specific. By doing that, it becomes impossible falsify all connections between that observation of acceleration and what you're calling "Dark energy". In GM's mind, the dark energy *must* exist, simply by definition. The "dark energy" is the "cause" of the "acceleration", there is "acceleration" and therefore 'dark energy" will always exist (only in his head however).

What you've done here is you've created a nice 'religion' that cannot ever actually be "falsified" because it's too generic. That applies not only to your "Dark energy" concepts, but also to inflation, dark matter, etc. All of these terms of so vague as to be 'unfalsifiable" because because they all ultimately represent generic labels that define our human ignorance.
 
Michael Mozina said:
Birkeland figured it out for me over 100 years ago.
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No he didn't.

You still can't figure out what causes the acceleration of solar wind, so we can easily demonstrate the flaws in your logic based on your own claims.
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Sorry, but this makes no sense.

You don't know the "real empirical" cause of acceleration of solar wind, so we begin by labeling this "unknown acceleration", "dark energy".
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No, you do. There's no "we" here. And you can call it whatever you want to, though choosing a name that's already being used for something else is... what's the word? Stupid.

Sound fair? It is your "methodology"' after all, right?
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Nope. You need to start with a model. You don't have a model. Go get yourself a model.

But you won't, because a model would require equations and numbers, and you can't do that. You're math-phobic. Or maybe even math-allergic.

You guys have all these various "magnetic reconnection" theories to tinker around with, but each and every one of them is simply a theory about the way the EM field manifests itself in the solar system.

Unless both you and Birkeland are incorrect, the EM field *MUST* be responsible for that "unknown acceleration" and our term "dark energy" is now understood to be directly related to the EM field.
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It's not our "dark energy", it's your "dark energy". The cosmological dark energy model cannot produce solar winds, because unlike what you believe in, it's actually constrained by observation and theory, and makes specific and limited predictions. The fact that your conception of EM fields can do anything is a pretty damned good indicator that your conception of EM fields is wrong.

Now why in the world do I need to to look anywhere other than the EM field to explain acceleration of plasma outside of the solar system?
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Because plasmas shield EM fields but they don't shield gravity? Duh.
 
sol invictus said:
I wonder how many times you've posed that question on this forum - and had it answered?

I would say at least 10, and probably more like 20.
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I'm still trying to figure out how you know that this acceleration is related to Gauss's Law of gravity or electricity. Care to elaborate on how you ruled out one in favor of the other?
 
Ziggurat said:
No he didn't.
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Of course he did. He physically made the plasma move Zig. Acceleration of plasma is a direct "prediction" that came from his experiments. If you can't figure out acceleration, he sure could.

No, you do. There's no "we" here. And you can call it whatever you want to, though choosing a name that's already being used for something else is... what's the word? Stupid.
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FYI, that's my beef with your "dark energy" label. You don't know the real "cause", so you claim the 'cause'' is "dark energy. It's circular feedback loop.

Nope. You need to start with a model. You don't have a model. Go get yourself a model.
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Birkland created a *WORKING MODEL* in the lab, as well as a mathematical model. It's all in his book Zig.

It's not our "dark energy", it's your "dark energy". The cosmological dark energy model cannot produce solar winds, because unlike what you believe in, it's actually constrained by observation and theory, and makes specific and limited predictions.
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So at first you had no idea what the actual "cause" might be, but now you've created a theory so specific and so impotent in the lab that it entirely unfalsifiable because it's entirely impotent outside of your mythology. It has no influence on anything we might experiment with. It's a "Dark energy of the gaps" argument in the final analysis because you cant' demonstrate a lick of it, and you can't show that your deity is real. All you can show is a pattern of acceleration and no cause/effect link to your dark deity.

The fact that your conception of EM fields can do anything is a pretty damned good indicator that your conception of EM fields is wrong.
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I didn't say they could do anything, I said they are the "cause" of "acceleration" of plasma. You cannot show your mythical entity even exists, let alone that it "accelerates" anything.

Because plasmas shield EM fields but they don't shield gravity? Duh.
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Huh? Care to connect a few more dots?
 
sol invictus said:
Newton alone doesn't really work for this, because dark energy is an intrinsically relativistic thing. It has a pressure that's comparable to its energy density, which is impossible for any non-relativistic form of energy. That's why you need the fudge factor when you try to use Newtonian gravity.
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Aren't photons (the carrier particles of the EM field) intrinsically relativistic things?
 
Michael Mozina said:
Now we look back 100 years in time and we notice that Kristian Birkeland came up with an empirical "prediction" about "flying electric ions' of all sorts coming from the sun. How did he accomplish this feat? He used the EM field, and specifically "electricity".

Unless both you and Birkeland are incorrect, the EM field *MUST* be responsible for that "unknown acceleration" and our term "dark energy" is now understood to be directly related to the EM field.
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:eye-poppi
This is the most nonsensical thing you've said yet, Michael, and that's saying something. You've made jaw-dropping mistakes of science knowledge, but this is a complete and utter failure of rationality.

"Alfred Wegener used plate tectonics to make correct predictions. Einstein used GR to make correct predictions. Tom Appelquist used GIM (quark flavor) theory to make correct predictions. Steve Weinberg used electroweak theory to make correct predictions. THEREFORE the unknown acceleration MUST be caused by plate tectonics, GR, quark flavors, and electroweak theory." It's utter baloney.

(That's *leaving aside* the many things that Birkeland got wrong.)

You're wrong, Michael. The reason we say that EM theory does not explain the acceleration is that EM theory does not explain the acceleration. We have equations which completely describe what EM theory can do. We have data for the acceleration. The one does not work like the other.
 
Michael Mozina said:
Aren't photons (the carrier particles of the EM field) intrinsically relativistic things?
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For anyone capable of sentience, yes, photons are intrinsically relativistic, which means that Newton's theory of gravity cannot properly describe their gravitational effects (or the effects of gravity on them, like gravitational lensing).

Photons have a pressure equal to +1/3 their energy density (in units where c=1). According to general relativity, it is rho+3p (energy density + 3*pressure) that determines the acceleration of the expansion rate of the universe. If rho+3p>0, as it is for photons, it means the acceleration is negative (the expansion of the universe slows with time). Therefore, photons (or EM fields) cannot be responsible for the observed acceleration.

A cosmological constant or vacuum energy has a pressure equal to minus its energy density. Therefore rho+3p=-2 rho<0 as long as rho>0 (which is called a positive cosmological constant or vacuum energy), and hence resulting acceleration is positive.

In general, any form of energy with p<-rho/3 will cause acceleration. However observations have ruled out any form of energy with p>-.9 rho or so as the primary driver for the acceleration. That leaves very little room for anything other than a cosmological constant (with p=-rho).
 
sol invictus said:
Photons have a pressure equal to +1/3 their energy density (in units where c=1). According to general relativity, it is rho+3p (energy density + 3*pressure) that determines the acceleration of the expansion rate of the universe. If rho+3p>0, as it is for photons, it means the acceleration is negative (the expansion of the universe slows with time). Therefore, photons (or EM fields) cannot be responsible for the observed acceleration.
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Michael, I want to repeat this once again. What Sol is saying is basically the same thing I said below:

ben m said:
(sigh) Neutrinos, electrons, protons, plasmas, and so on---no matter how many of them you put in, and in what combinations---always, always, always predict that the supernova distance-luminosity curve would bend down. The data shows that the distance-luminosity curve bends up. http://www.supernova.lbl.gov/PDFs/expansionhistoryphystoday.pdf
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Stop saying "plasma effects did it". No they didn't. Stop saying "photons did it". No they didn't. Stop saying "EM fields did it". No they didn't. It doesn't work. The phenomena you keep proposing to fill empty space have the opposite effect to what is observed. Are you listening? Please reply.
 
sol invictus said:
For anyone capable of sentience, yes, photons are intrinsically relativistic, which means that Newton's theory of gravity cannot properly describe their gravitational effects (or the effects of gravity on them, like gravitational lensing).

Photons have a pressure equal to +1/3 their energy density (in units where c=1). According to general relativity, it is rho+3p (energy density + 3*pressure) that determines the acceleration of the expansion rate of the universe. If rho+3p>0, as it is for photons, it means the acceleration is negative (the expansion of the universe slows with time). Therefore, photons (or EM fields) cannot be responsible for the observed acceleration.
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That argument entirely depends on whether the acceleration is *internally driven* or *externally* (to this physical universe) driven. An attraction of matter on this side of a void to something on the other side of a void might lead to acceleration over time as the objects of attraction move closer together.

Then again we'd have to give up this idea that all matter and energy was ever lumped together.
 
Michael Mozina said:
Of course he did. He physically made the plasma move Zig.
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Using a device intended to simulate the earth.

Acceleration of plasma is a direct "prediction" that came from his experiments. If you can't figure out acceleration, he sure could.
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Actually, he couldn't. His numbers (such as they are) were wildly wrong. Quite excusable given the limited information he had to work with, but it was still just plain wrong.

FYI, that's my beef with your "dark energy" label. You don't know the real "cause", so you claim the 'cause'' is "dark energy. It's circular feedback loop.
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No, Michael. It's a hypothesis.

Birkland created a *WORKING MODEL* in the lab
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... of the earth.

as well as a mathematical model.
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Not of stellar winds he didn't.

So at first you had no idea what the actual "cause" might be, but now you've created a theory so specific and so impotent in the lab that it entirely unfalsifiable
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But it's not unfalsifiable. You keep claiming it is, but that's simply not true. This belief of yours is simply another in a seemingly endless stream of things you just don't understand.

I didn't say they could do anything
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And yet, you remain perpetually ignorant about what they cannot do.

Huh? Care to connect a few more dots?
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Wow. You really missed the boat on that one. And no, I don't think I'll bother. Repeated attempts to educate you have met with consistent failure. You have chosen ignorance, and have received accordingly.

For example, you still can't define pressure.
 
Michael Mozina said:
That argument entirely depends on whether the acceleration is *internally driven* or *externally* (to this physical universe) driven. An attraction of matter on this side of a void to something on the other side of a void might lead to acceleration over time as the objects of attraction move closer together.
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a) "externally driven" sure doesn't sound like "the universe is plasma and plasma exerts forces so plasma did it", which you were presenting a post or two ago.

b) "That argument depends on ..." So what? That's how hypotheses work. We have presented a hypothesis under which the acceleration is caused by (yes, "internal") vacuum energy. If the hypothesis is false, then the hypothesis is false.

c) "an attraction to something ... might lead to ..." Aha, so you're hypothesizing that space has feature X (and that you don't know whether actually exists---OMG unempirical bunnies) and you want to say that that might explain the data. This is called an "alternative hypothesis". Do you want to talk about this alternative hypothesis? We can do that. That is not what you've been doing; you've been ignoring the word "hypothesis" and complaining that the mainstream hypothesis is a woo dogma religion that's not even worthy of being named.

Do you want to stop arguing that the dark energy hypothesis is obviously wrong, and stop arguing that EM forces obviously explain everything, and start asking whether some sort of cosmic void hypothesis is a good alternative hypothesis? Go right ahead.
 
Michael Mozina said:
That argument entirely depends on whether the acceleration is *internally driven* or *externally* (to this physical universe) driven.
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You are correct that what I wrote assumed that the energy and pressure in question are distributed approximately homogeneously and isotropically in the universe (or at least inside one Hubble volume of the universe). That assumption is consistent with all cosmological observations, but there is still room for an isotropic but inhomogeneous universe (i.e. a configuration with the earth at a special symmetric point in the center). That hypothesis is disfavored for reasons that should be obvious, and in any case is possible to test.

An attraction of matter on this side of a void to something on the other side of a void might lead to acceleration over time as the objects of attraction move closer together.
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Yes, but it would also lead to a direction dependence. No such dependence has been observed.

Then again we'd have to give up this idea that all matter and energy was ever lumped together.
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Actually no, we wouldn't. But in any case, see Ben's reply.
 
ben m said:
a) "externally driven" sure doesn't sound like "the universe is plasma and plasma exerts forces so plasma did it", which you were presenting a post or two ago.
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I think you've just had a hard time visualizing the idea correctly from my perspective.

b) "That argument depends on ..." So what? That's how hypotheses work. We have presented a hypothesis under which the acceleration is caused by (yes, "internal") vacuum energy. If the hypothesis is false, then the hypothesis is false.
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Well, the fact you can't create "negative pressure" in a "vacuum" really should be your first clue Ben. That's certainly how I see things anyway. You're looking for a physical impossibility by expecting to find an 'energy" that is unlike any other form of energy known to exist in nature.

c) "an attraction to something ... might lead to ..." Aha, so you're hypothesizing that space has feature X (and that you don't know whether actually exists---OMG unempirical bunnies) and you want to say that that might explain the data.
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But Ben, I'm not proposing any *NEW* forces of nature! I'm simply rearranging *KNOWN* forms of matter and energy and looking for empirical solutions to existing problems. You're simply 'making up" a new kind of energy that has to have a "negative pressure" unlike an EM field, unlike any known form of energy.

How then can your fantastic sounding "hypothesis" (if you can call it that) possibly be considered more likely than the one I just suggested? You're fixated on finding your invisible negative pressure bunny that you haven't even bothered to fully explore other options IMO.
 
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Michael Mozina said:
How then can you "hypothesis" (if you can call it that) possibly be considered more likely than the one I just suggested?
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Maybe because, "Go read Birkeland," or, "I'm so stupid I can't understand what you're saying so it must be something else," aren't hypotheses at all?
:dl:​
 
Michael Mozina said:
I think you've just had a hard time visualizing the idea correctly from my perspective.
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Your perspective is one of ignorance.

Well, the fact you can't create "negative pressure" in a "vacuum" really should be your first clue Ben. That's certainly how I see things anyway.
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Of course you do. But you don't even know what pressure is, so your opinions on what sorts of pressure are possible are quite irrelevant.
 
Reality Check said:
I agree that "placeholder term" is way too simplistic and general for what dark energy is. But given the problems that MM has with understanding anything complex, I have tried to keep things simple -probably too simple.
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FYI, your concept was never all that 'complex', just too "general" and self serving. It's also based on a circular feedback loop:

Acceleration is observed. You don't understand it. You created a name to describe your ignorance (mythical dark energy). You give this imagined energy all sorts of "imagined" properties (negative pressure, darkness, zero charge,etc). You create a scenario where it cannot ever even be physically "tested" by a human being, now or ever. You made the term so vague that even if your "main" set of claims is falsified, it cannot ever undermine your "faith" in your new invisible magical energy. There's always room to recreate a ton of new presumed "properties" when you never have to demonstrate any of it in a lab. That's all you're doing RC.

GM and you seem to "imagine" that dark energy *MUST* exist simply because you personally can't explain acceleration you observe with known forces of nature. You imagine that 'dark energy" *must* exist, just because acceleration exists. There is no correlation between the observation of acceleration and "dark energy' except in your head. It's entirely impotent in the lab!
 
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Ziggurat said:
Your perspective is one of ignorance.
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Like the term "dark energy" isn't a perspective of pure ignorance?

Of course you do. But you don't even know what pressure is, so your opinions on what sorts of pressure are possible are quite irrelevant.
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I know for a fact that not one of you can produce any form of energy that has that -rho component that sol described. You'll dance around that flaw no doubt but it's the 700 pound gorilla in the room. Your theory is based on a physical impossibility. None of you can even tell me what you' would add to or subtract from a "perfect" vacuum (no kinetic energy of any sort) to create a "negative" pressure. You seem to imagine that particle kinetic energy and pressure are somehow unrelated in that "vacuum".
 
Michael Mozina said:
How then can your fantastic sounding "hypothesis" (if you can call it that) possibly be considered more likely than the one I just suggested? You're fixated on finding your invisible negative pressure bunny that you haven't even bothered to fully explore other options IMO.
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Easy.

1) The one you just suggested is already known to be wrong---i.e. not to agree with the data. It's already ruled out.

2) Everything else you've suggested has also been wrong---i.e. not to agree with the data.

(Any hypothesis, even a surprising one, is better than one which is already ruled out.)

3) All of your "objections" to the dark energy hypothesis have been a mix of (a) blunt ignorance of scientific method or (b) refusal to think about the hypothesis using the actual tools of modern physics (GR, quantum mechanics, field theory).

The dark energy hypothesis is a perfectly reasonable extension of quantum field theory. When you plug its energy into ordinary GR, you find it accounts perfectly for the observations, using only one free parameter.
 
Michael Mozina said:
None of you can even tell me what you' would add to or subtract from a "perfect" vacuum (no kinetic energy of any sort) to create a "negative" pressure. You seem to imagine that particle kinetic energy and pressure are somehow unrelated in that "vacuum".
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Finally! Yes, particle kinetic energy and pressure ARE unrelated in this aspect of the vacuum. This is not a negative particle pressure. The dark energy can not be a bath of fast-moving particles.

It's a constant energy density. In GR, where what you care about is E and dE/dV, a constant energy density has the same GR properties as a negative pressure. A gas-like, photon-like, or plasma-like energy density has the same GR properties as a positive pressure. Dark energy is not gas-like at all.
 
Michael Mozina said:
I know for a fact that not one of you can produce any form of energy that has that -rho component that sol described. You'll dance around that flaw no doubt but it's the 700 pound gorilla in the room. Your theory is based on a physical impossibility.
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You used to think negative pressures were impossible under any circumstance. What you "know for a fact" is not, in fact, a fact at all.

None of you can even tell me what you' would add to or subtract from a "perfect" vacuum (no kinetic energy of any sort) to create a "negative" pressure. You seem to imagine that particle kinetic energy and pressure are somehow unrelated in that "vacuum".
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A perfect encapsulation of your ignorance. You still don't even know what pressure is. Let me give you a hint: particle kinetic energy doesn't define pressure. Not in a vacuum, not in a plasma, not in a gas, not in a liquid, not in a solid, not ever.
 
Ziggurat said:
You used to think negative pressures were impossible under any circumstance. What you "know for a fact" is not, in fact, a fact at all.
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Which other "natural" form of energy has that -rho component to it Zig? I think you're purposefully avoiding my point. What were you intending to add or subtract from that pure vacuum state (no kinetic energy) to achieve a "negative pressure"?

A perfect encapsulation of your ignorance. You still don't even know what pressure is.
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Oh, the irony.

Let me give you a hint: particle kinetic energy doesn't define pressure. Not in a vacuum, not in a plasma, not in a gas, not in a liquid, not in a solid, not ever.
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Then what does (physically speaking) define pressure in vacuum Zig?
 
Michael Mozina said:
I know for a fact that not one of you can produce any form of energy that has that -rho component that sol described.
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a) "... because I blustered my way through the Casimir Effect threads".

b) Remember HYPOTHESIS, Michael? The dark energy hypothesis is indeed positing something that has not been confirmed to exist. If we already had detected dark energy directly---for example, in a lab experiment---then it wouldn't be a hypothesis. The fact that we have not detected it is not an argument against it---that's what makes it (still) a hypothesis. HYPOTHESIS.
 
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