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

[Michael Mozina]

It seems from the papers you posted that your position is that the apparent recession of galaxies is due to actual movement through space as opposed to metric expansion, the expansion being the standard explanation. It would have saved time for you to have actually stated this.

My apologies. I guess I just assumed you knew like everyone else.

 

[Reality Check]

For those that may be interested:
Here is an interesting blog entry of the process that one astronomer went through before they were convinced that the evidence was strong enough for dark energy:
What it took to get me to believe... in Dark Energy

If his response to the 1998 Type 1a supernovae data is typical then it is likely that the existence of dark energy took many years so be acceptd in general.

 

[Reality Check]

It seems from the papers you posted that your position is that the apparent recession of galaxies is due to actual movement through space as opposed to metric expansion, the expansion being the standard explanation. It would have saved time for you to have actually stated this.

My apologies. I guess I just assumed you knew like everyone else.

I thought that were problems with treating the apparent recession of galaxies as due to actual movement through space.
The ones that I can think of are:

• That means that the Earth (or a point close to the Earth) is the center of the universe. That is a bit of a medieval concept. There is no evidence that the Earth, Solar System, Milky Way or even Local Group are special places.
• Run time backwards. At some point in the past all ~100 billion galaxies in the universe are within a small volume. That looks like a black hole to me. No known explosion could extract the galaxies from the singularity and even if one could then they could not pass outside of the event horizon. So we must still be in that black hole. Where are all the effects that we can expect from this?
• Where does the CMB come from?

 

[Perpetual Student]

For those that may be interested:
Here is an interesting blog entry of the process that one astronomer went through before they were convinced that the evidence was strong enough for dark energy:
What it took to get me to believe... in Dark Energy

If his response to the 1998 Type 1a supernovae data is typical then it is likely that the existence of dark energy took many years so be acceptd in general.

Thanks.

 

[Xephyr]

I wish I could live an additional 300 years just to see how cosmology and science in general has advanced... what has become science 'fact' and what ends up getting tossed into the hypothesis garbage bin.

Put me on that cryonic freezer list, thank you very much.

 

[Perpetual Student]

Question for the physicists:

If the acceleration of cosmic expansion in not a form of energy but instead,

"if the cause is found to be, for instance, a cosmological constant, then it is not "energy" at all, at least in classical general relativity, but rather simply an artifact of the geometry of space."__Tim Thompson

would that not violate the law of conservation of energy since the overall energy of the universe would be increasing?

 

[Tim Thompson]

Cosmological Conservation of Energy

... would that not violate the law of conservation of energy ...

This time I will quote a passage from the book Cosmology: The Science of the Universe by Edward Harrison, Cambridge University Press 2000 (2nd edition):

The conservation of energy principle serves us well in all sciences except cosmology. In bound systems that do not expand with the universe (because they are dense compared with the average density of the universe), we can trace the cascade and interplay of energy in its multitudinous forms and claim it is conserved. But in the universe as a whole it is not conserved. The total energy decreases in an expanding universe and increases in a contracting universe. Where does energy go in an expansing universe? And where does it come from in a contracting universe? The answer is nowhere, because in the cosmos, energy is not conserved
Edward Harrison, "Cosmology: The Science of the Universe", page 349.
​

The energy in an expanding universe decreases (not increases) because of the loss of energy to redshifting photons. I think the key to the lack of universal conservation of energy is really the difficulty in defining "energy" for the universe as a whole. We usually associate energy with time (as in, for instance, the energy form of Heisenberg's uncertainty principle, delta-E*delta-T ~ h). But time is not Newtonian, so there is no one "time" that can be assigned to the universe.

Now, Macleod, 2005 disagrees with this notion and restores cosmological conservation of energy by projecting cosmological observations onto flat space-time and applying the rules of special relativity. I don't personally know enough to say if Macleod is right. So at least it is evidently controversial whether or not the conservation of energy principle is globally valid for the universe taken as a whole (no local experiment will violate the conservation of energy principle even in Harrison's case).

And in passing I see Maxson, 2009 who seems to argue that the expansion of the universe is a consequence of conservation of energy, though I have not read the paper, just the abstract.

 

[schrodingasdawg]

Conservation of energy comes from the laws of physics not being explicitly time dependent. More specifically, if the Lagrangian of a system doesn't explicitly depend on time, then energy is conserved. If cosmological laws are explicitly time-dependent (that is to say, if given the laws of cosmology in some form, replacing t with t+dt would produce a change in the action) then energy wouldn't necessarily be conserved.

I don't know the Lagrangian or action for GR off the top of my head, but I'd imagine metrics can be constructed that cause the Lagrangian to be explicitly time-dependent.

 

[Michael Mozina]

I'd certainly not criticise someone for claiming that recession of galaxies is due to movement through space.

Likewise an "acceleration through space" is simply a different way of describing the same accelerating expansion process.

 

[Michael Mozina]

Classical Maxwellian electromagnetism can be ruled out at once by the simple observation that the expansion treats charged particles (i.e., plasma) and neutral material in identical fashion. I don't know how to get classical electromagnetic fields to couple to neutral matter with the same strength as they couple to electrically charged matter, and I am unaware of anyone else professing an ability to describe this.

You've heard of the term "dusty plasma" haven't you? How much of a given galaxy is in the form of a "neutral" material in your opinion that isn't otherwise generating a magnetic field like a neutron star or "black hole"? (Please refrain from trying to claim that "dark matter" is "neutral")

 

[edd]

Energy conservation in GR is in this FAQ:
http://math.ucr.edu/home/baez/physics/Relativity/GR/energy_gr.html

 

[ben m]

You've heard of the term "dusty plasma" haven't you? How much of a given galaxy is in the form of a "neutral" material in your opinion that isn't otherwise generating a magnetic field like a neutron star or "black hole"? (Please refrain from trying to claim that "dark matter" is "neutral")

The answer is irrelevant to mainstream cosmology. The only long-range, well-organized force on plasma, gas, dust, planets, stars, and black holes (and dark matter) is gravity. Electromagnetism, like the strong and weak force, adds lots of interesting short-range details. Gravity exerts exactly the same acceleration on charged objects and uncharged objects, magnetized objects and unmagnetized objects, etc. Electromagnetism does not. That's why the solar corona manages to accelerate electrons and protons (high q/m) but not, e.g., Mercury and Venus (low q/m).

In other words, I don't learn that DM is neutral by studying, e.g., its orbits around the galaxy or its attraction to large-scale structures. That's all gravitational physics which works just the same way on (hypothetical) charged dark matter as on (hypothetical) neutral dark matter. I learn that DM is neutral by looking for the short-range interactions characteristic of charged particles---shock acceleration, photon emission, photon absorbtion, bound states---and finding them absent.

You, meanwhile, are the one with a theory under which things with wildly different charge-to-mass ratios (protons with q/m = 10^5 C/g, dust with q/m = 10^-10 C/g, stars with 10^-34 C/g) are all meant to wind up feeling the same acceleration in an electromagnetic field. As you'd have had to account for if you ever used an electromagnetic field equation ...

 

[DeiRenDopa]

The answer is irrelevant to mainstream cosmology. The only long-range, well-organized force on plasma, gas, dust, planets, stars, and black holes (and dark matter) is gravity. Electromagnetism, like the strong and weak force, adds lots of interesting short-range details. Gravity exerts exactly the same acceleration on charged objects and uncharged objects, magnetized objects and unmagnetized objects, etc. Electromagnetism does not. That's why the solar corona manages to accelerate electrons and protons (high q/m) but not, e.g., Mercury and Venus (low q/m).

In other words, I don't learn that DM is neutral by studying, e.g., its orbits around the galaxy or its attraction to large-scale structures. That's all gravitational physics which works just the same way on (hypothetical) charged dark matter as on (hypothetical) neutral dark matter. I learn that DM is neutral by looking for the short-range interactions characteristic of charged particles---shock acceleration, photon emission, photon absorbtion, bound states---and finding them absent.

You, meanwhile, are the one with a theory under which things with wildly different charge-to-mass ratios (protons with q/m = 10^5 C/g, dust with q/m = 10^-10 C/g, stars with 10^-34 C/g) are all meant to wind up feeling the same acceleration in an electromagnetic field. As you'd have had to account for if you ever used an electromagnetic field equation ...

This thread has fallen down to page 2 ... we can't have that!

Question for long-time posters (and lurkers): can you recall any examples of MM making a *quantitative* case (argument, point, narrative)?

As in a *consistent* quantitative point, with numbers which correspond to observed (or estimated) values of physical quantities (as defined in standard physics textbooks)^?

And what about maths ... any examples of the application of any math (even arithmetic!) - in a consistent, coherent way - to an event, observation, phenomenon, etc in physics or astronomy?

^ not just quoting one (e.g. "million mile an hour solar wind")

 

[Tubbythin]

This thread has fallen down to page 2 ... we can't have that!

Question for long-time posters (and lurkers): can you recall any examples of MM making a *quantitative* case (argument, point, narrative)?

As in a *consistent* quantitative point, with numbers which correspond to observed (or estimated) values of physical quantities (as defined in standard physics textbooks)^?

And what about maths ... any examples of the application of any math (even arithmetic!) - in a consistent, coherent way - to an event, observation, phenomenon, etc in physics or astronomy?

^ not just quoting one (e.g. "million mile an hour solar wind")

I don't remember any such examples... other than him telling us how many orders of magnitude stronger the EM force is than gravity.

 

[GeeMack]

This thread has fallen down to page 2 ... we can't have that!

Question for long-time posters (and lurkers): can you recall any examples of MM making a *quantitative* case (argument, point, narrative)?

In tens of thousands of postings in discussions scattered all around the Internet, nope, never.

As in a *consistent* quantitative point, with numbers which correspond to observed (or estimated) values of physical quantities (as defined in standard physics textbooks)^?

Nope.

And what about maths ... any examples of the application of any math (even arithmetic!) - in a consistent, coherent way - to an event, observation, phenomenon, etc in physics or astronomy?

Nope.

^ not just quoting one (e.g. "million mile an hour solar wind")

Hasn't happened. I've read literally thousands of his posts and can't recall a single time when he demonstrated even the most rudimentary math skills, not pertinent to any of the discussions anyway. Seems he has never ventured into quantitative-land and expressed any of his crackpot notions in actual numbers of any sort. And when asked to support his wacky conjectures quantitatively, he bitches and moans about how he did that once a long time ago so he should never have to do it again. Something like, "I won't bark math on command," if I recall. And I predict his response to these posts will be to badmouth us for insulting him, when pointing out that no quantitative support has ever been provided is not an insult, it's a fact. And it's highly germane to the discussion. I also predict more complaints reflecting his general disdain for math.

 

[Pythonic]

Question for long-time posters (and lurkers): can you recall any examples of MM making a *quantitative* case (argument, point, narrative)?

No. But in fairness to MM, the main thrust of his point is not to put forth a new explanation, but a skeptical view of the "quantitative only" (?) explanation of dark matter. So, what would he model exactly?

Where MM falls short is not providing a quantitative *refutation* of the existing model. That is, stating quantitatively where the current model fails.

 

[Tim Thompson]

Dark energy is not classical electromagnetism

You've heard of the term "dusty plasma" haven't you?

I have. Dust accounts for about 1% of the mass of the interstellar medium (ISM) in the Milky Way, and the total mass of the ISM is about 10% of the stellar mass, which therefore constitutes about 90% of the baryonic mass of the Galaxy. Furthermore, elliptical galaxies don't have any dust at all.

How much of a given galaxy is in the form of a "neutral" material in your opinion that isn't otherwise generating a magnetic field like a neutron star or "black hole"?

The ISM is, by mass, approximately 85% neutral (Galaxies in the Universe by Sparke & Gallagher, Cambridge University Press, 2007 (2nd edition), table 2.4 page 101). The neutral matter is strongly concentrated in the plane of the Galaxy, so the vast bulk of the gaseous material by volume is ionized.

(Please refrain from trying to claim that "dark matter" is "neutral")

Why should I refrain from doing the incredibly obvious? If "dark matter" were electrically charged it would be "bright matter" and we would see it easily.

Now, consider the quote from me that Mozina was responding to:

Classical Maxwellian electromagnetism can be ruled out at once by the simple observation that the expansion treats charged particles (i.e., plasma) and neutral material in identical fashion. I don't know how to get classical electromagnetic fields to couple to neutral matter with the same strength as they couple to electrically charged matter, and I am unaware of anyone else professing an ability to describe this.

90% of the baryonic mass of a spiral galaxy is stars. While stars are electrical neutral for all practical purposes, we expect a star of solar mass to carry a net electrical charge of about +77 Coulombs because lighter electrons are more easily expelled from the sun. So the sun builds a net charge until it is in equilibrium (Neslusan, 2001)

So, let us consider F = ma = QE where m is mass, a is acceleration, Q is electric charge and E is electric field. We know the mass of the sun, 1.9891x10³⁰ kg. We also know that any systematic cosmological electric field as large as 1 v/m would make itself obvious (induced electric fields in the solar wind are milli-Volts per meter), so I will use that as an upper limit on any cosmological electric field. So the acceleration is just QE/m which is 77/1.9891x10³⁰ = 3.87x10^-29 m/sec². Not much of an acceleration. Let's give it 14 billion years (4.4x10¹⁷ sec) and see what happens. 3.87x10^-29 m/sec² x 4.4x10¹⁷ sec = 1.7x10^-11 m/sec. That's far short of the thousands of kilometers per second that are typical cosmological redshift equivalent relative velocities.

So, let us ask what kind of field strength is required to accelerate a star like the sun to a speed of 1000 km/sec, given 4.4x10¹⁷ sec to pull it off. That's v = at or v/t = a or 10⁶ m/sec / 4.4x10¹⁷ sec = 2.27x10^-12 m/sec². OK, now E = ma/Q or E = (1.9891x10³⁰ kg x 2.27x10^-12 m/sec²) / 77 C = 5.86x10¹⁶ V/m. I think we can all agree that a cosmological electric field on the order of 10¹⁶ Volts per meter would be rather more than simply "obvious".

Something has to push the stars of a galaxy up to a few thousand km/sec recession velocity, at least. The numbers we see above certainly appear to me to rule out classical electromagnetic fields as the physical basis for dark energy.

 

[ben m]

MM has been repeated presented with, and repeatedly ignored, the "sun's charge to mass ratio is different than proton's" argument.

I think his mistake is in thinking that the Sun is ionized, so it's all charged, so that's what counts. MM, is that right? This view forgets that protons have the opposite charge from electrons; in the presence of any electromagnetic field, either E or B, they feel forces in the opposite directions. If the Sun's protons are feeling a 10^20N force to the left, then its electrons are feeling a 10^20 N force to the right for a net force of zero. (Except, as Tim points out, for the force on the slight excess charge (under 100C) which has been again repeatedly cited and ignored.)

The vectory-ness of the EM forces is one of the many things MM would have discovered if he had been curious about how an EM-forces-causing-dark-accelerations model would actually work.

 

[DeiRenDopa]

Question for long-time posters (and lurkers): can you recall any examples of MM making a *quantitative* case (argument, point, narrative)?

No. But in fairness to MM, the main thrust of his point is not to put forth a new explanation, but a skeptical view of the "quantitative only" (?) explanation of dark matter. So, what would he model exactly?

Indeed.

Perhaps I was too terse.

By writing "case (argument, point, narrative)", my intended meaning was not only any new (against-the-mainstream, alternative, fringe, ...) case (etc), but also any consistent, quantitative critique of any theory/model/hypothesis/idea (whether as well-established as QED, or as far out as Thornhill's Electric Star idea, or anything in between).

Where MM falls short is not providing a quantitative *refutation* of the existing model. That is, stating quantitatively where the current model fails.

Yep ... but I think it's important to always include the second part ("*consistent*") ... it's incredibly easy to "stat[e] quantitatively where the current model fails"^; whether any such statements have a consistent basis is a whole different kettle of sardines ...

^ e.g. estimated primordial abundance of ⁷Li

 

[Michael Mozina]

No. But in fairness to MM, the main thrust of his point is not to put forth a new explanation, but a skeptical view of the "quantitative only" (?) explanation of dark matter. So, what would he model exactly?

Indeed.

Where MM falls short is not providing a quantitative *refutation* of the existing model. That is, stating quantitatively where the current model fails.

If we quantitatively come up with a number of say how many invisible elves can fit on the head of a pin, how does one refute that number "quantitatively"?

Dark energy doesn't move a single atom in an empirical experiment, so how do we know how much of it is required to move/accelerate a whole universe? How do I refute the number they come up with?