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

Outstanding questions for Michael Mozina

We know by now that Michael Mozina is incapable of answering these questions. But he may shock us and the list is still an interesting summary of his mistakes and misunderstandings.
I added a couple more.


It would be nice if MM could point us to the answers to any of these if I have missed them.
  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
  8. What is the source for BBT models prior to 1990's predicted deceleration?
    First asked 2 February 2010
  9. Can you understand that dark energy is observational and not metaphysical?
    First asked 2 Februaray 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.
 
Tim Thompson said:
I suggest you seek out The Expanding Universe by Sir Arthur Eddington (Cambridge University Press, 1933; still in print). He has quite a bit to say about the cosmological constant (which he calls the cosmical constant). He considered it an absolute requirement for general relativity to be a complete theory and thought Einstein was wrong to abandon it; just look up cosmical constant in the index. The book is readable by a general audience. There is also a fair amount of discussion of the cosmological constant in Gravitation by Misner, Thorne & Wheeler (W.H. Freeman & Co., 1970; also still in print). Builds strong muscles just lifting its 1279 pages off the shelf and definitely not for a general audience. However, bits & pieces of the discussion might be accessible. Although Einstein never liked the cosmological or cosmical constant, it never went away.
Click to expand...

OK, thanks.
 
Michael Mozina said:
I think it's time you guys give us your "genesis" chapter that starts something like:
Click to expand...

I worry, MM, that talking about inflation again will distract you from the issues you have repeatedly brought up as the Big Problems With Cosmology:

a) You repeatedly insisted that "negative pressure" was nonsense, that gravity could only attract, that GR could never predict inflation, and so on. You now appear to agree that GR generates an acceleration-prediction from a positive-vacuum-energy source hypothesis.

b) You repeatedly insisted that EM cosmology had been ignored, and if EM forces were included we would see that dark energy was unnecessary. You now appear to agree that no actual "inclusion" of EM forces has ever been shown to work, and that each one we went into detail on was shown to fail.

Finish the arguments you start, Michael. You just spent a 1000-post thread on two lines of argument based entirely on ignorance. Please spend some time trying to absorb that before changing the subject, eh?

Lesson #1: your mental-picture version of an inconsistency-riddled mainstream cosmology is baloney. There are no minus-sign errors, simple mispredictions, etc. We shouldn't need a 1000-post thread to pound that into you. The next time you think Guth/Perlmutter/Einstein/etc. made an obvious howler of a math error, the burden is on you to identify the error.

Lesson #2: Everything in this thread has boiled down to "I really, really think the vacuum energy is zero and something else is causing acceleration." Yet you clogged a 1000-page thread with tangential accusations, including the assumption that everyone was wrong about everything. A thread about "we ought to assume lambda=0 until we have two independent lines of evidence" might have been interesting. This wasn't it; this was "the first ten things that pop into my head about lambda obviously beat 90 years of scholarship". That sucked.
 
ben m said:
The next time you think Guth/Perlmutter/Einstein/etc. made an obvious howler of a math error, the burden is on you to identify the error.
Click to expand...


Or the burden of proof could equally be if such mathematical models have actually been worthwhile, or caused more confusion than good, than actual direct errors.
 
Zeuzzz said:
Ignoring a certain paper that I posted are we then reality check?
Click to expand...
If you mean Timothy E. Eastman's opinions about current cosmology published in the Journal of Cosmology then yes I am ignoring this derail from Michael Mozina's opinions about dark matter, inflation and cosmology.

If you want to discuss it then create a new thread.
 
sol invictus said:
A couple of comments on this CC business.


  1. as far as I know the only source for Einstein having said that the CC was his biggest blunder is Gamow 40 years or so after the fact. So one might take that with a grain of salt.

  2. GR does not belong to Einstein. GR is a theory that exists independently of Einstein, Einstein's beliefs at various times, and Einstein's motivations at various times. In fact Einstein's beliefs and motivations are totally irrelevant to any discussion of the value of the CC.

  3. the CC is in fact unique in several ways:

    • Thought of as a geometrical term, it is the only modification of the Einstein-Hilbert action that is consistent with general covariance, effective at "long" (i.e. longer than the Planck length) distances, and that doesn't involve inverse powers of curvature and derivatives. In other words, by the standard logic of effective field theory, it must be included as a parameter and cannot simply be set to zero by fiat. Put another way, even if one sets it to zero in the classical action, it will re-appear at 1-loop due to quantum corrections. And if one sets it to zero in the 1-loop effective action, it re-appears at 2-loops. It's very hard to squash, and it's very hard to get it to be small enough, let alone zero (which is known as the "cosmological constant problem").

    • Thought of as an energy density, the CC fits perfectly into Einstein's equations. Contrary to what ben said, the equation in PS's post above is completely general (those are Einstein's equations, with no special assumptions). That equation doesn't just apply to homogeneous and isotropic universes, it applies all the time. And T_\mu \nu includes the cosmological constant. The CC is a form of energy and pressure, and therefore it's an additive term that changes the diagonal elements of T. It can arise in many ways: from quantum vacuum energy as above, from a scalar field potential that's non-zero in a minimum, from a 4-form "electric" flux (don't go bananas MM, that's not a standard electromagnetic field energy, it's something much weirder involving significant new physics), or simply from a shift in the zero-point of potential energy.

  4. as ben has been emphasizing, GR is a theory of gravity, not a theory of energy and mass. GR tells us what the gravitational field is given the stress-energy that sources it, just as Maxwell's equations tell us the electromagnetic field given the charges and currents that source it. Maxwell's equations cannot tell us what the charges and currents are at some instant; they can only tell us what the fields will be if the charges and currents are something at that instant (and, coupled with some more equations, what everything will look like later or earlier).

    By exactly the same token, GR cannot tell us what the value of the CC is. All it can tell us is what the universe will do given its value. The CC is an input, a source; at least as far as physicists understand now it must be fixed by observation and experiment, and cannot be fixed by theory or set to zero.
Click to expand...

Very helpful. Thanks.
 
Zeuzzz said:
I very much doubt you'll get this. The people who have suffered explaining the process numerous times are now probably too embarressed to keep touting that nonsense so have given up.

I'll have a go though.

Nothing went bang.

Oh dear, the most basic princple of cause and effect broke down straight away.

Wouldn't it be crazy if a theory like that gained popularity eh? :)
Click to expand...
What a lot of gibberish.
 
Zeuzzz said:
You having trouble with the words? spelling? grammer? I can help.

If you having trouble with the meaning then you need to explain why.
Click to expand...

It seems to be a collection of sentences which bare little relation to one another.
 
sol invictus said:
Thought of as an energy density, the CC fits perfectly into Einstein's equations. Contrary to what ben said, the equation in PS's post above is completely general (those are Einstein's equations, with no special assumptions). That equation doesn't just apply to homogeneous and isotropic universes, it applies all the time. And T_\mu \nu includes the cosmological constant. The CC is a form of energy and pressure, and therefore it's an additive term that changes the diagonal elements of T. It can arise in many ways: from quantum vacuum energy as above, from a scalar field potential that's non-zero in a minimum, from a 4-form "electric" flux (don't go bananas MM, that's not a standard electromagnetic field energy, it's something much weirder involving significant new physics), or simply from a shift in the zero-point of potential energy.
Click to expand...

I'm going to admit confusion on this point. (It's actually something that's confused me for a while; hopefully someone here can help me.) Isn't the cosmological constant term a different term than the stress-energy tensor? If it was part of the ordinary energy/pressure density, then why would it need a separate term? And isn't it (in the context of GR, anyway) supposed to be constant over all space and time--i.e. intrinsic to the geometry of spacetime?

As I've said, my understanding of GR is pretty meager. Hopefully one of you can lead me in the right direction.
 
Zeuzzz said:
I very much doubt you'll get this. The people who have suffered explaining the process numerous times are now probably too embarressed to keep touting that nonsense so have given up.

I'll have a go though.

Nothing went bang.

Oh dear, the most basic princple of cause and effect broke down straight away.

Wouldn't it be crazy if a theory like that gained popularity eh? :)
Click to expand...
The last couple of posts looks like you want an actual response to this as a serious display of your knowledge of cosmology.

The response is that you are displaying an ignorance of the Big Bang theory that could only be gained by depending on unreliable science (news articles?).

BBT states nothing about the origin of the universe.

It states: Something went bang. Before that we know nothing and speculate a lot.

Wouldn't it be crazy if a theory like that gained credibility by the collection ofscientific evidence eh? :)
 
ben m said:
I worry, MM, that talking about inflation again will distract you from the issues you have repeatedly brought up as the Big Problems With Cosmology:
Click to expand...

I'm thinking you don't have the guts to even try such a thing. I think Zeuzzz has you pegged.

a) You repeatedly insisted that "negative pressure" was nonsense,
Click to expand...

Actually what I said is "negative pressure in a vacuum" is nonsense. Guth's magic vacuum is nonsense. That's what I said. I'm sure you could figure out a physical way to put 'negative pressure" on a surface in a physical/mechanical way, but no vacuum contains "negative pressure". That idea is nonsense and Guth used that nonsense to "pull" his mass thingy apart.

that gravity could only attract,
Click to expand...

Let's see you jump off the planet superman.

that GR could never predict inflation,
Click to expand...

GR could never "predict" inflation. You made that up all on your own.

and so on. You now appear to agree that GR generates an acceleration-prediction from a positive-vacuum-energy source hypothesis.
Click to expand...

Hello? I'm the one that pointed out the solar mechanics that blew away any notion that we needed "negative pressure" to get "acceleration' of matter.

b) You repeatedly insisted that EM cosmology had been ignored,
Click to expand...

Yep. You've ignored Birkeland's work for almost 100 years now. Bruce for about 60 and Alfven for about 50 years. You're still in hard core denial about the "circuit" approach to MHD theory.

and if EM forces were included we would see that dark energy was unnecessary.
Click to expand...

The EM field is the only known force of nature that "naturally" accelerates matter on a daily basis, even inside our solar system. If there is a "likely cause" of massive acceleration, the EM field is the obvious first option to fully explore. You folks haven't scratched the surface yet, because you can't even recognize a "solar discharge' when you see one in multimillion dollar satellite images.

You now appear to agree that no actual "inclusion" of EM forces has ever been shown to work, and that each one we went into detail on was shown to fail.
Click to expand...

No, I'm simply admitting that *I personally* haven't figured out a way to do it *yet*, but my personal ignorance in the moment is no crystal ball about the future. The EM field is still the most likely culprit and I personally haven't stopped trying to figure out a way to explain the observational evidence with an EM field. I'm sure other people are thinking about the very same issue. I have confidence that someone will figure it out, if not me personally.

Finish the arguments you start, Michael. You just spent a 1000-post thread on two lines of argument based entirely on ignorance. Please spend some time trying to absorb that before changing the subject, eh?
Click to expand...

Nobody is changing the subject. I simply want to see you put together a cohesive argument from start to finish and see how "unified" your beliefs actualy are when it comes right down to it.

Lesson #1: your mental-picture version of an inconsistency-riddled mainstream cosmology is baloney.
Click to expand...

So set me straight and put together a consistent, logical, rational creation event from start to to finish, what started it, what happened in what order,etc.

There are no minus-sign errors, simple mispredictions, etc.
Click to expand...

Guth's minus sign for "pressure" in a "vacuum" was certainly an error of epic proportions in the final analysis. The lowest possible energy state for a vacuum is zero, not negative infinity. That's a serious physical and mathematical error. Period.

Lesson #2: Everything in this thread has boiled down to "I really, really think the vacuum energy is zero and something else is causing acceleration."
Click to expand...

Correction. It has boiled down to the physical reality that the lowest possible "pressure" state for a "vacuum" is zero. It's actually higher than zero because we can't remove all the kinetic energy from any vacuum, even if would could remove every single atom. Nature's "vacuums" are universally positive pressure environments, with neutrinos, photon and matter everywhere.

Yet you clogged a 1000-page thread with tangential accusations, including the assumption that everyone was wrong about everything.
Click to expand...

Oh boloney. You're the one's claiming WIKI is wrong about every topic under the sun. I'm just picking on your three invisible friends, not the entire scientific community.

A thread about "we ought to assume lambda=0 until we have two independent lines of evidence" might have been interesting. This wasn't it; this was "the first ten things that pop into my head about lambda obviously beat 90 years of scholarship". That sucked.
Click to expand...

What "sucked" IMO was the chorus of "liar liar pants on fire" when I simply tried to point out that Einsteins use of the constant was not designed (by him) to create anything other than a static universe. What sucks is that you folks won't even put a up a cohesive "genesis story" for fear of having it picked apart, line by line, concept by concept.
 
MM:

As I have followed this debate about the CC and dark energy, a question has occurred to me. Some people here have accused you of not understanding the mathematics of GR, perhaps unfairly -- I don't know you and I don't have any way to evaluate that kind of comment. So, I was wondering just how familiar are you with the following equation?

[latex] R_\mu_\nu - \dfrac{1}{2}g_\mu_\nu R + g_\mu_\nu\Lambda= \dfrac{8\pi G}{c^4}T_\mu_\nu [/latex]

Do you understand the nature of the various elements? Are you able to explain the mathematical meaning of [latex]R_\mu_\nu[/latex], the Ricci curvature tensor, for example?

I am not asking this to disparage your knowledge but would like to know so I can better understand your state of knowledge and basis for the discussion here.
 
Michael Mozina said:
Actually what I said is "negative pressure in a vacuum" is nonsense.
Click to expand...

Yet you also said that the "CC in the EFE gives acceleration, matter in GR gives deceleration" is correct, and you apparently agreed with all of the signs in a gas-vs-Casimir comparison. In both cases, whatever else is going on, the vacuum has the opposite dU/dV of an ordinary gas. Ordinary gases have positive pressure. Vacuum energy has the opposite.

You're not disagreeing with any of the science any more, you're just complaining about the terminology.

GR could never "predict" inflation. You made that up all on your own.
Click to expand...

Acceleration, not inflation. We'll get to inflation later. Anyway: we just spent five pages establishing that The EFE is the GR prediction for motion in response to sources. If the source is vacuum energy, GR predicts acceleration. Did you forget?

Hello? I'm the one that pointed out the solar mechanics that blew away any notion that we needed "negative pressure" to get "acceleration' of matter.
Click to expand...

... then you agreed that you had no idea how to "get" acceleration of massive objects. You said that you "bet" someone would figure something out in the future.

Yep. You've ignored Birkeland's work for almost 100 years now. Bruce for about 60 and Alfven for about 50 years. You're still in hard core denial about the "circuit" approach to MHD theory.
Click to expand...

... the circuit MHD theory that neither you nor anyone else has actually used in quantitative cosmology? In a quantitative cosmology discussion, yes, I ignore it.

The EM field is the only known force of nature that "naturally" accelerates matter on a daily basis, even inside our solar system.
Click to expand...

Yes, it does a very good job of obeying Maxwell's Equations and making forces which obey Newton's Law. That's all it does, and that's how I know it doesn't work on astronomical scales.

The EM field is still the most likely culprit and I personally haven't stopped trying to figure out a way to explain the observational evidence with an EM field.
Click to expand...

Then why was the a = q/m E calculation such a surprise to you in this very thread?

Guth's minus sign for "pressure" in a "vacuum" was certainly an error of epic proportions in the final analysis. The lowest possible energy state for a vacuum is zero, not negative infinity. That's a serious physical and mathematical error. Period.
Click to expand...

For the 100th time: negative pressure arises from positive energy, but positive dU/dV. Repeat after me: the cosmological constant has positive energy density and negative pressure. the cosmological constant has positive energy density and negative pressure. the cosmological constant has positive energy density and negative pressure. Do we need another 1000 posts to get that through to you?
 
Michael Mozina said:
The EM field is the only known force of nature that "naturally" accelerates matter on a daily basis, even inside our solar system.
Click to expand...

News Flash!... I'd like to report my discovery that I am currently accelerating around the sun in an elliptical orbit and, contrary to MM's assertion, the EM fields surrounding me have very little to do with it.

... now back to the 8th lather, rinse, repeat cycle.
 
So let's go through again:

  • MM has absolutely no idea what "negative pressure" even refers to. He seems to think it's invalid because by definition it requires negative energy. I now have no idea what he has learned, failed to learn, or is deliberately ignoring from the past 1000 posts. Trying again:
    • Theoretically speaking, there is no question that "negative pressure" is what you expect from positive vacuum energy. MM's statements to the contrary are flat misunderstanding.
    • GR-wise, there is no question that a negative pressure term gives outward acceleration. MM's statements to the contrary are flat misunderstanding.
    • In observations, 100% of available data are perfectly consistent with the hypothesis of a vacuum energy density of +10^-27 g/cc. MM's statements to the contrary are flat misunderstanding.
    • Several major pieces of data are inconsistent with the midcentury hypothesis of a vacuum energy density of zero. MM does not seem to dispute this.
 
Michael Mozina said:
Hello? I'm the one that pointed out the solar mechanics that blew away any notion that we needed "negative pressure" to get "acceleration' of matter.
Click to expand...


Actually you've never demonstrated that you have the qualifications to speak knowledgeably on the issue of solar mechanics, and often demonstrated that you don't. You've also shown without a doubt that you don't understand the concept of negative pressure as it's being discussed in this thread.
 
ben m said:
MM has absolutely no idea what "negative pressure" even refers to. He seems to think it's invalid because by definition it requires negative energy. I now have no idea what he has learned, failed to learn, or is deliberately ignoring from the past 1000 posts.
Click to expand...

My current speculative hypothesis: Michael has no understanding of calculus and, as such, doesn't realise that dU/dV can be negative without either U or V being negative.
 
Zeuzzz said:
I
Nothing went bang.
Click to expand...

Still the same straw, how wonderful of you. Explained many times and you still revert to lies, deception and straw.

Nothing went bang is correct becuase that is NOT the thery.

"The universe appears to be expanding."
"We can not say what existed prior to the BBE or is outside the universe."

Those are the theroy.

Not your usual lies and mis-characterizations.
 
Zeuzzz said:
You having trouble with the words? spelling? grammer? I can help.

If you having trouble with the meaning then you need to explain why.
Click to expand...

I will make it easy for you:

You are full of ****. You are deluded, pretend a lot and haven't a clue. For years you have misrepresented every time you tried to present manistream science.

You can't handle the real math or science, three years ago you were still quoting pop science arcticles that had been debunked by COBE.

When asked to do the work and provide the evidence you resorted to pouting and gradstand arm waving.

You still haven't retracted your agnosticism of the nuclear fusion in stars.

Now you present some sort of philosophy and pretend that it is meaningful.
 
Zueuus you are sooo full of ****:

Your article presents the same BOGUS strawmen as suaul, but since you just spam and run, you are not aware that every point in it has already been addressed in the threda.

Well done sir! You are full of **** as usual.

Geoffrey Burbidge, eminent physicist and professor emeritus of the University of California San Diego, is one of many highly respected cosmologists who have questioned the validity of the big bang model and has pointed out many of its shortcomings: "there have been very few real predictions;" for example, "while the black body nature of the radiation was predicted by the big bang theory, the numerical value of the temperature was not, and cannot be" (Burbidge, 2006, p. 5).

Further, some scientists have taken umbrage at the willingness of BB modelers to embrace ad hoc assumptions as a means of patching over gaps in the "standard model" such as the inability to explain why most of the universe appears to be missing. For example, as critiqued by Burbidge (2006) BB theorists have resorted to hypothesizing the existence of invisible "dark matter" and "dark energy" to account for the 95% of mass-energy that is "missing," given BB assumptions. These assumptions, however, are then used to support yet other BB related theories such as current "scenarios" proposed for galaxy formation, which in turn "rests on this belief that this missing mass is real, because only if [cold, dark matter] exists in large measure is it possible to simulate galaxy formation at all" (Burbidge, 2006, p. 6).

The prevailing focus on assimilation and confirmation can also become problematic when transitions are made to even stronger claims. Clowe et al. (2006) for example, claim to have found "proof" of "dark matter," based on their interpretation of data from a galaxy collision. The Clowe et al. paper features some impressive technical arguments and then fails to consider a number of important and very critical caveats. In particular, the argument assumes that normal matter is fully accounted for by an inventory of visible stars and hot plasmas. However, it has been reported that non-visible interstellar gas, lower-energy plasmas and brown dwarfs, in combination, likely exceed luminous stars in the estimated mass of the nearby portion of our galaxy (e.g., Fuchs, Jahreiss, and Flynn, 2006). As summed up by philosopher of science James Hall, "Our hypotheses may get support or they may go down in flames, but they never, ever get proved" (Hall, 2005).

The same can be said of interpretations of the so-called Cosmic Microwave Background radiation (CMB). Because of its cool temperature, the BB modelers claim the CMB is conclusive evidence of cooling after a very hot beginning. However, the CMB could be due to a number of causes, including the burning of hydrogen.
Click to expand...

:ld:
 
Dark Matter: Direct Detection?

Michael Mozina said:
http://arxiv.org/abs/1002.0504
FYI, they found some more of that "missing mass" in our own galaxy, and oh ya, it's "baryonic material" we just never identified until now, not some new and exotic type of mass. Get used to that scenario. It's happens a lot and it's going to keep happening.
Click to expand...
Mozina posted this thinking that the discovery of these ultra faint dwarf galaxies and star clusters provides good evidence that dark matter is entirely baryonic. But, as I showed in Dark Matter and Ultra Faint Dwarf Galaxies, back on page 30 (a post to which Mozina never responded), in fact the discovery of new ultra faint dwarfs solves a major problem with dark matter cosmology, and so tends to confirm rather than falsify the theory of non-baryonic dark matter.

I have already shown elsewhere that the astronomical evidence in favor of the non-baryonic dark matter hypothesis is significant (e.g., Galaxy Rotation & Dark Matter, Dark Matter II, Dark Matter and Science). Is there now also evidence from ground based experiments?

The DAMA project (including DAMA/NaI and DAMA/LIBRA) has produced results that are consistent with the laboratory detection of elusive non-baryonic dark matter particles. These results are reported in two recent papers:
  1. First results from DAMA/LIBRA and the combined results with DAMA/NaI;
    Barnabei, et al., The European Physical Journal C 56: 333, August 2008
  2. New results from DAMA/LIBRA
    Bernabei, et al., Feb 2010; presented at the Int. Conf. Beyond the Standard Models of Particle Physics, Cosmology and Astrophysics (BEYOND 2010), 1-6 February 2010, Cape Town, South Africa.

Drukier, et al., 1986 and Freese, et al, 1988 predict an annual periodicity in dark matter particle detection for Earth based experiments, independent from particular models of particle properties, simply due to the motion of Earth. Of course, since the year is a rather natural periodicity to see on Earth based experiments, one must be careful to avoid confusing our own seasons with dark matter. Nevertheless, this can be done, by identifying a set of simultaneous criteria which must be met, in order to be certain that the signal detected is the signal desired.

This has been done and the predicted annual signal has been reported. Bernabei, et al., 2000 report the detection of this annual signal at a 4-sigma confidence level, using data from the DAMA/NaI experiment, cycles 1-4 combined. Bernabei, et al., 2008, Bernabei, et al., 2009 & Bernabei, et al., 2010 report continued detection of the same cycle with the DAMA/LIBRA experiment which is an extension of the DAMA/NaI experiment. The new data are sufficient to support the detection at the 8.2-sigma confidence level, a much more robust result than had been reported earlier. Finkbeiner, Lin & Weiner, 2009 discuss the significance of the DAMA/LIBRA results. In particular, we note that other experiments, using different methods, do not detect this signal, and an explanation is required. Is the DAMA/LIBRA signal wrong? Or maybe the DAMA/LIBRA signal can be used to constrain dark matter particle properties. There are papers which address this issue (e.g., Feldstein, et al., 2009; Angle, et al., 2009; Ahmed, et al., 2009; Foot, 2008). Bernabei, et al., 2009 and Bernarbei, et al., 2008 describe the apparatus & technical details of carrying on the DAMA/LIBRA search for dark matter.

These papers and the many citations thereto should provide quite a sufficient field of exploration. For now, suffice to say that there are Earth based experiments at work looking towards direct detection of non-baryonic dark matter particles, to go along with extensive astronomical & astrophysical evidence. Against this robust package of observational & experimental data, along with a robust package of theoretical & practical physics (e.g, general relativity, classical mechanics, thermodynamics & electromagnetism), the best Mozina can do is rattle on about "metaphysical entities", without the offer of even a tiny sliver of anything recognizable as real science or real physics. It's time to face the music: The Mozina argument against the existence of non-baryonic dark matter is dead.

Note that I make no claim the non-baryonic dark matter must exist. But I do make the explicit claim that the data are consistent with the existence of non-baryonic dark matter, in the context of a completely valid exercise of science. There are of course numerous groups studying the obvious alternative of modified gravity. But it is the consensus of the community that the dark matter hypothesis is the simpler solution to the original "missing mass" problem. If the implications of the DAMA/LIBRA experiment stand up, it will add strong support to the non-baryonic dark matter hypothesis over the modified gravity hypothesis.
 
Tim Thompson said:
OK. You tell us: What is the physical reality of the cosmological constant? What is it really?
Click to expand...

It could be many things. I don't profess to have an "explanation". How about you tell me why you think it has anything to do with "dark energy"?

I'm still waiting for the "Genesis" chapter here before I can actually comment. I want to hear what your mass thingy was made of, was it "charged" in any way? What was it's physical size? Was anything "outside" the mass object? Where does the "vacuum" concept play into anything? Where does dark energy and inflation fit into this mythical legend?

So far you've all been extremely coy when it comes to laying out a real "theory", complete with details about size, charge, vacuum pressures, the relevance of inflation theory, etc. I don't even know if you all share the same "beliefs' about these things in until I hear some details.
 
ben m said:
So let's go through again:

MM has absolutely no idea what "negative pressure" even refers to.
Click to expand...

Not when you're applying it to a "vacuum" I do not. Come now Ben, stop being so coy. How large was your mass object before "inflation"? Where as inflation, inside or outside of the mass thingy? Was it charged in some way that might produce a "negative pressure" on the outside surface of the object? What exactly do you mean by "negative pressure" and how and where does it factor into anything? Be specific and lay out your genesis chapter.
 
ben m said:
Yet you also said that the "CC in the EFE gives acceleration, matter in GR gives deceleration" is correct, and you apparently agreed with all of the signs in a gas-vs-Casimir comparison. In both cases, whatever else is going on, the vacuum has the opposite dU/dV of an ordinary gas. Ordinary gases have positive pressure. Vacuum energy has the opposite.
Click to expand...

The only "vacuum energy" that might put "negative pressure" on a full spherical surface would be the EM field if your surface was charged in some way. More mass (like a spherical mass covering) on the "outside" of your mass thing might also produce "negative pressure" on the surface of the entire sphere. A "vacuum" can only ever contain "positive pressure" however, so by itself, it can never "suck" Guth's mass thingy apart. In a non charged scenario, all the 'pressure' form the QM fields would push *INTO* not away from the surface of his mass body.
 
I'm going to kick back now and go grab a beer and watch the game. Since I'm not betting on today's game, I going to hope the Saints win. Go Saints. :)
 
Michael Mozina said:
Not when you're applying it to a "vacuum" I do not. Come now Ben, stop being so coy. How large was your mass object before "inflation"? Where as inflation, inside or outside of the mass thingy? Was it charged in some way that might produce a "negative pressure" on the outside surface of the object? What exactly do you mean by "negative pressure" and how and where does it factor into anything? Be specific and lay out your genesis chapter.
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When we apply it to a vacuum then it produces negative pressure.

The rest of your post is dumb so I will respond in a similiar vein
Come now Michael Mozina, stop being so coy. How large was your EM field before inflation? Where as inflation, inside or outside of the EM field thingy? Was it charged in some way that might produce a negative pressure on the outside surface of the object? What exactly do you mean by positive pressure and how and where does it factor into anything? Be specific and lay out your genesis chapter
​
From your gibberish I can extract one coherent question, "What exactly do you mean by negative pressure".
The answer is exactly what is in all of the physics textbooks that you have never read.
The answer is exactly what all the posters have been telling you for many years, over many forums, in many threads and many posts.

The answer is exactly what you have not been able to comprehend for many years, over many forums, in many threads and many posts.
  • When pressure is defined as dF/dA then negative pressure is the result when there is an attractive force on a surface.
    This happens in the Casimir effect.
  • When the more general defintion of pressure = -dE/dV is used then negative pressure is any time that dE/dV is positive.
    This happens for a positive value of the cosmological constant (and in the Casimir effect!).
 
Michael Mozina said:
Not when you're applying it to a "vacuum" I do not.
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Which sign, then, did I get wrong in the calculation of dU/dV in a positive-energy-density vacuum?

(ETA: I and Sol and RC and TT and Einstein and Lemaitre and Zeldovich and Witten and Perlmutter and Guth and ... )
(ETA2: Do you, in fact, understand that for any function f(x), the derivative df/dx can be either positive or negative, independent of whether f(x) is positive or negative?)
 
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Michael Mozina said:
In a non charged scenario, all the 'pressure' form the QM fields would push *INTO* not away from the surface of his mass body.
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Except that we're not looking at kinetic pressure pushing on things. For the 11th time: we're looking at an energy density, and energy densities cause gravitational curvature. The vacuum energy density is positive, remember? The resulting curvature (according to 1915 GR, remember?) causes outward acceleration, remember? Positive vacuum energy (a hypothesis) causes (according to GR) outward acceleration, remember? That's what matters.

The reason you're unable to picture this based on "sucking" and "pushing" is that this has nothing to do with it.

The only reason we use the word pressure is that this behaves the same way as negative pressure in any actual equation dealing with the energetics of pressure. We do not call it "pressure" for the sake of your mental picture of a gas-like substance filling the vacuum, because this picture is nonsense.
 
As for Michael's "coy" comment: the mainstream theory is laid out explicitly in any mainstream astro textbook whatsoever---Peebles, Weinberg, Peacock, Dodelson, Wald, Misner-Thorne-Wheeler, etc. It's laid out in half of the links we've posted, like Sean Carroll's "living reviews" article. NASA spends literally millions of dollars developing educational materials about exactly this theory. There are probably ten thousand papers on the topic, both in broad overviews and in any detail you could possibly want to look into, in the refereed literature.

"Coy" my foot. The words you're looking for are "La la la la I can't hear anything."
 
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Dark Energy is a Cosmological Constant III

Michael Mozina said:
It could be many things. I don't profess to have an "explanation". How about you tell me why you think it has anything to do with "dark energy"?
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Analytical Considerations About the Cosmological Constant and Dark Energy
Abreu, de Assis & Dos Reis; International Journal of Modern Physics A 24(28-29): 5427-5444 (2009)
Abstract (emphasis mine):
"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."

There are of course many papers one can reference which present the detailed analysis which support the claim made in the above abstract , that "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" (e.g., Serra, et al., 2009; Kowalski, et al., 2008; Frieman, Turner & Huterer, 2008; Guzzo, et al., 2008; Wood-Vasey, et al., 2007; Davis, et al., 2007; Astier, 2006 & etc., including the original papers Riess, et al., 1998 & Perlmutter, et al., 1999).

Carroll, Press & Turner, 1992 offer a complete review of the cosmological constant in a paper published well before the discovery of the accelerated expansion of the universe in 1998. It was only after this discovery that cosmologists perceived the need for dark energy and realized that it came most simply in the form of a cosmological constant. Peebles & Ratra, 2003 and Carroll, 2001 offer complete reviews of the cosmological constant in papers published after it had become associated with the new concept of dark energy.

Keep an eye on my real point here. There are other possible explanations for dark energy including modified gravity, a scalar field in the stress-energy tensor, or even a time variable cosmological scalar field instead of a cosmological constant. The current state of observational data cannot rule out any of these possibilities. I am only insisting that the identification of the cosmological constant is both consistent with the observational data and the simplest (i.e., least complicated) source of dark energy, given the current state of observation.

Michael Mozina said:
I'm still waiting for the "Genesis" chapter here before I can actually comment. I want to hear what your mass thingy was made of, was it "charged" in any way? What was it's physical size? Was anything "outside" the mass object? Where does the "vacuum" concept play into anything? Where does dark energy and inflation fit into this mythical legend?
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I have no idea what you are talking about. What is "mass thingy" supposed to mean? And why are any of these questions supposed to be relevant at all? We need only interpret observed cosmological redshifts as an indication that the universe is expanding, and the acceleration of that expansion becomes an observed phenomenon. dark energy is simply a kinematic explanation for the observed phenomenon. I fail to see why anything you have said here nas anything to do with that.

Michael Mozina said:
So far you've all been extremely coy when it comes to laying out a real "theory", complete with details about size, charge, vacuum pressures, the relevance of inflation theory, etc. I don't even know if you all share the same "beliefs' about these things in until I hear some details.
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What "theory" are you talking about? So far we have all been far less "coy" that you have. You would not even admit to having any idea what the cosmological constant is supposed to be, despite insisting that you think it is absolutely necessary for general relativity to be a complete theory. If anybody is being "coy" around here it is definitely you, the man who never has produced a quantitative explanation of anything, and can't even produce qualitative explanations without running afoul of the laws of physics big time.
 
What known type of "energy" possesses "negative pressure"?

Why is "negative pressure" necessary for expansion of matter if the sun manages to do it everyday with known forces of nature?
 
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Michael Mozina said:
What known type of "energy" possesses "negative pressure"?

Why is "negative pressure" necessary for expansion of matter if the sun manages to do it everyday with known forces of nature?
Click to expand...


So what you're saying is that after over a thousand posts in this thread you still don't understand the concept of negative pressure. Got it.
 
schrodingasdawg said:
I'm going to admit confusion on this point. (It's actually something that's confused me for a while; hopefully someone here can help me.) Isn't the cosmological constant term a different term than the stress-energy tensor?
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It's part of it. Or to be a little more precise, one can consistently regard it as part of it.

If it was part of the ordinary energy/pressure density, then why would it need a separate term?
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It doesn't.

I can elaborate on that if you tell me what types of terms you're wondering about (in the action? in the stress tensor itself? in Einstein's equations?).

And isn't it (in the context of GR, anyway) supposed to be constant over all space and time--i.e. intrinsic to the geometry of spacetime?
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It's supposed to be constant over all space and time, yes. In the stress tensor, that means that its pressure is minus its energy.

Whether you think that means it's "intrinsic to the geometry of spacetime" is more or less up to you. Quantum vacuum energies have those features, but the magnitude and sign of the resulting cosmological constant depends on the spectrum of fields as well as the background geometry. To me, that doesn't sound very intrinsic.
 
Michael Mozina said:
What known type of "energy" possesses "negative pressure"?
Click to expand...

You have a 1000-post thread explaining why "negative pressure" is the normal and expected behavior of vacuum energy. Before we repeat it again, why don't you summarize what you think the mainstream view is?

Why is "negative pressure" necessary for expansion of matter if the sun manages to do it everyday with known forces of nature?
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Because those forces do not act strongly over long distances or on charge-neutral objects. (ETA: as you know from the previous 10 times you've made exactly the same claim.) (ETA2: and gravity IS a known force of nature. Dark energy is not a new force, it's an energy density, and all energy densities pull on spacetime in a straightforward way. As you know from the previous 10 etc etc.)
 
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GeeMack said:
Michael Mozina said:
What known type of "energy" possesses "negative pressure"?

Why is "negative pressure" necessary for expansion of matter if the sun manages to do it everyday with known forces of nature?
Click to expand...
So what you're saying is that after over a thousand posts in this thread you still don't understand the concept of negative pressure. Got it.
Click to expand...
MMs' cognitive disconnect is much, much deeper than that.

You see, tens of thousands of posts, by MM, make it abundantly clear that he has no grasp of what "quantitative" means, with respect to physics.

For example, gravity is "a known force of nature" because, in MM's view, a plasma ball purchased from Tesco falls when you let it go. Now MM seems to accept that gravity, as a known force of nature, can also produce apparently non-falling behaviour, like the plasma ball rising to the surface if submerged in a bath of water (or mercury), or can slingshot a spacecraft around Jupiter and out of the solar system ... but he does not understand why these things happen (beyond some intellect-lite word salad).

As a result, when it comes to seemingly counter-intuitive things like negative pressure or the cosmological constant as dark energy, he rejects them blindly.

But! There needs to be an intellectual figleaf for this irrational, emotional response, some sort of narrative that papers over the disturbing contradictions bubbling just beneath the surface.

And what is that security blanket? "Empirical tests", as in "done in a lab, here on Earth". That this prop is riddled with internal inconsistencies is not a problem for MM, because they can be transformed away by waving the 'qualitative' wand over them (no lab experiment has shown that two atoms attract each other gravitationally? no worries! two atoms, 10^23 atoms, they're all just atoms!).

Unless and until MM owns up to his outright rejection of two the key elements of modern physics - its quantitative nature, and its requirement for internal consistency - 1000-page threads will continue to grow like weeds in your garden.
 
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