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

[Michael Mozina]

Actually, I'd be impressed with anyone who had been taught GR before 1917.

Perhaps you could quote Einstein using the term "dark energy"?

 

[sol invictus]

Perhaps you could quote Einstein using the term "dark energy"?

The simplest and best candidate for dark energy is a positive cosmological constant, Michael. So yes, dark energy has been part of GR essentially since its discovery.

Which is not a surprise if you know anything about the structure of the theory - a cosmological constant is the unique generally covariant term one can add that affects the theory at long distances (at least without invoking bizarre things like inverse powers of curvature invariants).

 

[Michael Mozina]

The simplest and best candidate for dark energy is a positive cosmological constant, Michael.

A "cosmological constant" isn't a physical explanation sol, it's an "observation". In no way does GR directly explain why "acceleration" is happening.

 

[ben m]

In no way does GR directly explain why "acceleration" is happening.

GR is just as capable of explaining "why" acceleration is happening as it is capable of explaining "why" a baseball accelerates downwards at 9.8 m/s/s. The former is simply the normal GR equation-of-motion of matter in the presence of a 10^-29 g/cc vacuum energy density. The latter is the normal GR equation-of-motion of matter in the presence of a 6x10^24 kg blob of matter.

GR doesn't explain why the Earth is there or why its mass-energy is 6x10^24 kg. GR does not tell you why the cosmological constant is there or why its energy density is 10^-29 g/cc.

Do you understand the difference?

 

[Michael Mozina]

GR is just as capable of explaining "why" acceleration is happening as it is capable of explaining "why" a baseball accelerates downwards at 9.8 m/s/s.

The acceleration isn't "downwards", so where does that leave you?

 

[Tubbythin]

The acceleration isn't "downwards", so where does that leave you?

 

[Skwinty]

The acceleration isn't "downwards", so where does that leave you?

Good grief
Charlie Brown!

 

[Reality Check]

I have provided them with paper after paper after paper after paper to make my point mathematically on many topics. They simply ignore the math too.

You are wrong and close to lying Michael Mozina.
You have presented some papers. You have not presented any understanding of the mathematics in them.

Why should any theory be judged based on my personal math skills, particularly when better sources are available? What difference does it make if I do them here on command?

The difference is that you are making unfounded assertions. If you cannot back them up then you are just wrong or deluded.

You probably never will either. No scientific theory should be judged based on the individual math skills of yours truly. I won't play that game with them. My personal math skill are absolutely irrelevant because I have already provided many mathematical references, and they completely and utterly ignore them.

No you have not. You have cited a few papers with mathematics in them.

I pointed out where Guth made an error in his equations, specifically by claiming a "vacuum" has "negative pressure".

That is definiitly a lie:

• You have never cited Guth's equations.
• You have never shown where there is an error in Guth's equations.
• Vacuum energy has negative pressure. That is nothing to do with Guth. That is a basic consequence of general relativity.

You need to checkout the magnetic reconnection thread. I've provided ample mathematical support for a "circuit" orientation to MHD theory and they simply ignore it.

Another lie.
You have never cited a paper or textbook that describes a "circuit" orientation to MHD theory.
You have cited a 1966 paper by Alfven and Carlquist about an electric circuit model for the energy on solar flares. Science has progressed in the last 40 years. We now know that solar flares cannot be described by the simplistic treatment of Alfven and Carlquist.
You have cited 4 other papers about solar flares.

Solar flares are not MHD theory.

In this case I simply have to admit I can't compete with metaphysics, and I have no faith in the interpretation or even much faith in the analysis of WMAP data. Here's one reason why:

http://arxiv.org/abs/1001.4643

You obviously have a lot more faith in the mainstreams position than I do.

That is an interesting mainstream preprint: Inconsistency between WMAP data and released map
The preprint is too new for any knowledgeable people to comment on it. It looks like a possible bug in the software used to convert calibrated differential time-ordered data (TOD) of the Wilkinson Microwave Anisotropy Probe (WMAP) mission to their cosmic microwave background (CMB) maps.

I wonder how this possible bug introduced errors that produced a power spectrum that can be fitted by the Lambda-CDM model ?

FYI MM: The data in the power spectrum often fitted to the Lambda-CDM model come from the WMAP (2006), Acbar (2004) Boomerang (2005), CBI (2004), and VSA (2004) instruments.

ETA
I just noticed Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters (Submitted on 26 Jan 2010).
This has an interesting comment: "A new map-making technique was adopted for the 7-year data which combines optimal noise handling with “asymmetric” data masking (Jarosik et al. 2010)".
Strangely this new map-making technique gives the same power spectra as the old one.

 

[ben m]

The acceleration isn't "downwards", so where does that leave you?

GR, the only known theory of gravity, predicts outward acceleration in some cases and inward acceleration in others. Do you think that I'm mis-stating these GR solutions? Do you think GR itself is wrong?

 

[ben m]

That is an interesting mainstream preprint: Inconsistency between WMAP data and released map
The preprint is too new for any knowledgeable people to comment on it. It looks like a possible bug in the software used to convert calibrated differential time-ordered data (TOD) of the Wilkinson Microwave Anisotropy Probe (WMAP) mission to their cosmic microwave background (CMB) maps.

Actually, the same authors preprinted two earlier versions of their work, (see http://lanl.arxiv.org/abs/0905.0075 for one) and these versions did attract mainstream comments. The conclusion seems to be that Li and Liu are simply mistaken.


http://scienceblogs.com/catdynamics/2009/07/is_cosmology_about_to_become_b.php

 

[sol invictus]

A "cosmological constant" isn't a physical explanation sol, it's an "observation". In no way does GR directly explain why "acceleration" is happening.

OK, so apparently you now admit that dark energy has been in GR from the beginning.

Moving on to your new topic, can you give an example of something you consider a "physical explanation" from GR?

 

[sol invictus]

I pointed out where Guth made an error in his equations, specifically by claiming a "vacuum" has "negative pressure".

That is definiitly a lie:

• You have never cited Guth's equations.
• You have never shown where there is an error in Guth's equations.
• Vacuum energy has negative pressure. That is nothing to do with Guth. That is a basic consequence of general relativity.

Correct. And it wasn't Guth that first "claimed" that, it was Einstein. Not that it's much of a claim, since it follows immediately and trivially from both the definition of pressure in GR and from all other definitions of it.

 

[Michael Mozina]

Correct. And it wasn't Guth that first "claimed" that, it was Einstein. Not that it's much of a claim, since it follows immediately and trivially from both the definition of pressure in GR and from all other definitions of it.

Just because you *can* stuff a number into a math formula, doesn't mean you should, or that the number you came up with applies to the scenario in question.

The limit of pressure in a "vacuum" is not "negative infinity", it is *ZERO*. The problem is sol, there is no way for you get get a "negative pressure" from a vacuum.

It's not a "trivial" issue because without that magic negative pressure that Guth stuffed into his mythical vacuum, his mass object can't be 'sucked apart'.

 

[sol invictus]

Just because you *can* stuff a number into a math formula, doesn't mean you should, or that the number you came up with applies to the scenario in question.

That's true. Leaving inflation aside for a moment, the current standard model of cosmology contains a positive CC precisely because it fits the data better than anything else.

The limit of pressure in a "vacuum" is not "negative infinity", it is *ZERO*.

Actually, it appears experimentally that it is neither.

The problem is sol, there is no way for you get get a "negative pressure" from a vacuum.

Not only is there a way for me to get one, there was a way for Einstein.

It's not a "trivial" issue because without that magic negative pressure that GuthEinstein stuffed into his mythical vacuum, his mass object can't be 'sucked apart'.

Fixed that for you.

 

[Tubbythin]

Just because you *can* stuff a number into a math formula, doesn't mean you should, or that the number you came up with applies to the scenario in question.

Just because a number could be zero and that may give a more elegant solution doesn't mean you should assume it is zero especially when there is no evidence in favour of it being 0 and some evidence against it.

The limit of pressure in a "vacuum" is not "negative infinity", it is *ZERO*. The problem is sol, there is no way for you get get a "negative pressure" from a vacuum.

Yes there is. P=-dE/dV. Any system for which dE/dV gives a positive number has a negative pressure.

It's not a "trivial" issue because without that magic negative pressure that Guth stuffed into his mythical vacuum, his mass object can't be 'sucked apart'.

Its not magic.

 

[Michael Mozina]

GR, the only known theory of gravity, predicts outward acceleration in some cases and inward acceleration in others. Do you think that I'm mis-stating these GR solutions? Do you think GR itself is wrong?

I think it's "wrong" to change that 'zero' into something other than zero unless you *EXPLAIN* (via actual physics) what that number represents and it's empirical "cause".

 

[Michael Mozina]

Fixed that for you.

But of course the brand of GR that Einstein taught has a zero constant.

 

[Tubbythin]

I think it's "wrong" to change that 'zero' into something other than zero unless you *EXPLAIN* (via actual physics) what that number represents and it's empirical "cause".

Can you explain "G"? Or can you only measure it? Can you explain "m_e"? Or can you only measure it? Can you explain "hbar"? Or can you only measure it?

 

[Michael Mozina]

GR, the only known theory of gravity, predicts outward acceleration in some cases and inward acceleration in others.

Gravity will act to slow everything down over time with Einstein's zero constant definition of "gravity". When you stuff "dark energy" in there, you aren't describing "gravity" because "gravity" doesn't do repulsive tricks. Let's see you jump off the planet and speed away based with nothing but "gravity".

 

[Michael Mozina]

Can you explain "G"? Or can you only measure it? Can you explain "m_e"? Or can you only measure it? Can you explain "hbar"? Or can you only measure it?

Measuring something is only half the problem. Empirically *EXPLAINING* it is still the ultimate goal.