Lambda-CDM theory - Woo or not?

[Perpetual Student]

We have all been here, done that when Michael Mozina demonstrates yet again (and again and again) his persistent inability to learn .
For example (w.r.t. inflation)

And we all thought nothing could be denser than osmium.

 

[Michael Mozina]

sol invictus

So, I've been trying to get a feel for this proceedure.
Since we need to calculate the mass of the dark energy in the sphere:

Except you don't know that there is *ANY* "dark energy" inside the sphere! For all you know all the mass/energy/cause of curvature you're looking for exists *OUTSIDE* that sphere! That's the whole problem in a nutshell. You're looking for something inside the sphere that may not even *BE* in the sphere.

 

[edd]

Except you don't know that there is *ANY* "dark energy" inside the sphere! For all you know all the mass/energy/cause of curvature you're looking for exists *OUTSIDE* that sphere! That's the whole problem in a nutshell. You're looking for something inside the sphere that may not even *BE* in the sphere.

What part of

By "Gauss' law", only the mass and dark energy inside the sphere defined by that radius and origin can affect the motion of the test cluster.

did you not understand?

(I mean that more honestly than it comes across. There's some subtleties about what sol said that weren't very explicit perhaps?)

 

[Tim Thompson]

Dark Energy and Empirical Science IV

All you actually know is that you're utterly and completely clueless as to the actual cause of the acceleration.

Wrong again. What I actually have said on numerous occasions is that I don't know what dark energy really is. However, one should more carefully note that "don't know" and "clueless" are not at all synonymous. We have lots of clues, and I have pointed them out before (Dark Energy and Empirical Science II and in particular Empirical Evidence for Dark Energy). But you have chosen to ignore all of the clues, fearful no doubt that your unreasonable doctrine of faith might be challenged. The only person creating a religion around here is you, but your religion is failing against the withering glare of reason.

You don't know it involves (internal) energy.

To which I have already responded, and you have already ignored ...

You should show us the controlled laboratory experiment which supports your assertion that the universe is exposed to influences from outside the universe. If you can't do that, then by your own standard of "empirical", your claim is not empirical, and is as you would say, a figment of your imagination.

You don't know if that energy is actually "dark" either.

Things that one cannot see are usually referred to as "dark". Things that one does not know are usually referred to as "dark". Your language skills suffer in the withering glare of 5 year olds, who have all figured out what "dark" means, but like many 5 year olds, you are still afraid of it.

Your alleged "properties" are purely arbitrary as far as you know.

They are not at all arbitrary. They are in fact tightly constrained by observation. I have already presented you with observations to examine (Empirical Evidence for Dark Energy), but fearful of observations that might challenge your faith, you have chosen to ignore them. Indeed, the non-arbitrary constraints of observation have made it clear that by far the most likely explanation is the cosmological constant term in Einstein's equations (see Dark Energy and Empirical Science II and the cosmological constant links therein). That certainly counts as a "clue". The only person being arbitrary around here is you, because you arbitrarily choose to ignore & reject anything and everything that might challenge your unreasonable religious doctrine of faith.

Bottom line: There is no religion at work from our end, only from yours. You, Michael Mozina are the one & only person engaged in the defence of a a religious argument, while the rest of us are engaged in empirical science. And I might add that you are failing badly while we are remarkably successful. Neither is there any hint of arbitrariness at work from our end, only from yours. You, Michael Mozina are purely arbitrary in your choice to always ignore anything and everything that conflicts with your subjective & unreasonable religious doctrine of faith. Indeed, you have yet to present anything even remotely resembling empirical science in this "debate", and don't fool yourself into thinking that it has gone unnoticed.

 

[ben m]

Except you don't know that there is *ANY* "dark energy" inside the sphere! For all you know all the mass/energy/cause of curvature you're looking for exists *OUTSIDE* that sphere! That's the whole problem in a nutshell. You're looking for something inside the sphere that may not even *BE* in the sphere.

Look, Michael. Dark energy is a hypothesis in which there's something in the sphere. This is a good hypothesis for various reasons that escape you. We don't know whether or not it is true---it's a HYPOTHESIS, remember?

"There's something outside the sphere instead" would be a different hypothesis. OK, I'll play along---do you want us to consider this hypothesis, as an alternative to the dark energy hypothesis? We have---Edd just did. Edd's short post effectively takes the hypothesis you just proposed and applies the known laws of GR to it. Your hypothesis---"the universe is accelerating towards something outside the horizon" just failed. Now we can throw it away.

Do you have any other alternatives to the (still-unproven, remember) hypothesis that there's an energy density of 10^-29 g/cm^3 associated with empty space, popularly called "dark energy"?

 

[edd]

We have---Edd just did.

Credit to sol, whose post above I quoted.

 

[sol invictus]

sol invictus

So, I've been trying to get a feel for this proceedure.
Since we need to calculate the mass of the dark energy in the sphere:
Would one intergate the rate of acceleration with respect to the radius then multiply that by the total mass of the sphere, then subtract the gravitational potential energy in the sphere, then finally divide this result by c² to get the mass of the dark energy in the sphere?

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).

 

[Michael Mozina]

That's pretty much what numerous people here have been trying to tell you.

The problem Mr. Spock is that we could just as rightly point at that solar wind acceleration you cannot explain and call that "dark energy" too. Are you cool with that? I mean if it's nothing more that a placeholder term for human ignorance, and "dark energy" is a known cause of unknown causes of acceleration.....

 

[ben m]

The problem Mr. Spock is that we could just as rightly point at that solar wind acceleration you cannot explain and call that "dark energy" too. Are you cool with that? I mean if it's nothing more that a placeholder term for human ignorance, and "dark energy" is a known cause of unknown causes of acceleration.....

No, Michael, dark energy is the hypothesis that empty space has an energy density of 10^-29 g/cm^3. Go ahead and play your game---you're invited to plug dark energy into GR and ask the resulting equations "does this explain the solar wind". The answer, you will find, is NO. Therefore dark energy is not a hypothesis relevant to "something we don't know about the solar wind".

Does empty space has an energy density of 10^-29 g/cm^3 sound like a placeholder for dark matter? No. For gamma ray bursts? No. For the solar wind? No. For the Permian-Triassic extinction? No. For the meaning of Linear A? No. For the cosmic void hypothesis? No. It's a specific hypothesis that may or may not be the true explanation of cosmic acceleration.

Let me try it your way. Cosmic acceleration is caused by an iron surface. The solar wind is caused by an iron surface. The Permian-Triassic Extinction was caused by an iron surface. Galactic rotation curves are caused by an iron surface. High-temperature superconductivity is caused by an iron surface. The strange-quark content of the proton is unusual because of the iron surface. Check it out, I'm a lone voice speaking truth to power about the "Sun has an iron surface" hypothesis/dogma/religion/etc.

 

[Ziggurat]

The problem Mr. Spock is that we could just as rightly point at that solar wind acceleration you cannot explain and call that "dark energy" too.

Once again... a rose by any other name. The label isn't important, Michael. The model is. There's a model which we name "dark energy". It may or may not be correct, but it's still a scientific model. Your "dark energy" solar wind acceleration? Not a model, not scientific. Maybe someone could develop such a model, but they haven't, and you haven't. And if anyone ever did, they wouldn't call it "dark energy" because that name is already taken by a model that has nothing to do with solar wind acceleration. It would be like naming a newly discovered lizard species "cat".

I mean if it's nothing more that a placeholder term for human ignorance

But it isn't.

 

[Michael Mozina]

What part of
"By "Gauss' law", only the mass and dark energy inside the sphere defined by that radius and origin can affect the motion of the test cluster. "
did you not understand?

I did not understand how any of you decided which law to use, gravity or electricity. How did you decide what "dark energy" interacts with?

 

[ben m]

I did not understand how any of you decided which law to use, gravity or electricity. How did you decide what "dark energy" interacts with?

Let's try this again: dark energy is the hypothesis---the specific hypothesis---that there's an energy density.

General Relativity says, very specifically, that all forms of energy need to be added up to correctly represent its source term. Dark energy therefore goes right in there.

(There's no way around it unless GR is wrong. If you hypothesize that GR is wrong, that's a different hypothesis; that is not the dark energy hypothesis.)

Electromagnetism says that all forms of electric charge go into its source term. What's the electric charge of dark energy? Zero. So the E&M source term is the same whether the dark energy is there or not. See?

(Do you want to write down a hypothesis where empty space is electrically charged? Go ahead; that would be a new hypothesis, and a different hypothesis than the dark-energy hypothesis. It's also already well-known to be wrong---so don't bother.)

 

[Michael Mozina]

Electromagnetism says that all forms of electric charge go into its source term. What's the electric charge of dark energy? Zero.

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? This is the kind of stuff that makes me cringe. You guys are literally 'making up' this stuff as you go and none of it can be "demonstrated" in a lab. It all has to be "taken on faith".

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?

 

[GeeMack]

I did not understand [...]

Well that is pretty much the foundation of your arguments from ignorance, isn't it, Michael?

 

[Michael Mozina]

Let's try this again: dark energy is the hypothesis---the specific hypothesis---that there's an energy density.

Let's try it this way: An "energy density" of "what" exactly? (real physics please).

 

[Michael Mozina]

Well that is pretty much the foundation of your arguments from ignorance, isn't it, Michael?

No, that is the foundation of your 'dark stuff of the gaps' arguments, it's foundation of your 'religion' and your 'faith in the unseen'.

 

[Michael Mozina]

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'.

 

[Ziggurat]

It is?

Well, yes. If it had charge, it wouldn't be dark. Do you know why, Michael? Can you figure it out?

How exactly did you rule out electrons, protons and other moving charged particles again?

Because you can see those with light.

What if it's some ugly combo deal where neutrinos provide some of that moving "energy/mass"

Mass doesn't provide the observed behavior under GR. It doesn't fit the observations. If it did, people would just crank up the density on dark matter, but it doesn't.

and moving charged particles

... aren't dark.

 

[Reality Check]

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?

Michael Mozina: Your memory is certainly short and getting worse.
The thread that you started (Michael Mozina's thread on Dark Matter, Inflation and Cosmology) anwered the EM part months ago, e.g.

• dark energy is not classical electromagnetism VI
  12th February 2010

And one of the many, many questions that you have been incapable of answering:

• Why and how do you get an EM field to cause the observed acceleration of the expansion of the universe?
  12 January 2010

The physics is simple. Dark energy is the cause of an acceleration in the rate of expansion of the universe. Electrons, protons and other moving charged particles and neutrinos all contribute to the energy/stress tensor of GR. They all create more spacetime curvature, i.e. slow down the rate of the expansion of the universe. Slow down is the opposite of accelerate !

 

[GeeMack]

No, that is the foundation of your 'dark stuff of the gaps' arguments, it's foundation of your 'religion' and your 'faith in the unseen'.

I don't have a religion. Your continuous claim that I do is a lie. I did ask you several posts ago if you could have the decency to stop lying. I take it the answer is, "No?"

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'.

Oh it shows up in a lab alrighty. Any time someone has done an experiment and determined that the Universe is expanding at an accelerated rate, it is accepted that there is a cause for that effect. You know, cause and effect, that science stuff you keep wrongly suggesting isn't involved in the dark energy hypothesis? The name for that cause, and not given arbitrarily as you've wrongly suggested, the name is dark energy. You've been told probably a hundred times or more and you're still not getting it. Imagine that.