Plasma Cosmology - Woo or not

[Reality Check]

Reference for this figure?

Wow - you are still ignorant of all of the evidence that ~4% of the universe is matter (the rest is dark matter and dark energy), Zeuzzz!
What is 99.999% times 4%?

As for a reference - use Google or your memory.

 

[Reality Check]

Ending your post with an uncited, without context quote from Jim Peebles is quite dumb, Zeuzzz.

FYI: The natural science of cosmology by P. J. E. Peebles, Keynote lecture at the seventh International Conference on Gravitation and Cosmology, Goa India, December 2011

The network of cosmological tests is tight enough now to show that the relativistic Big Bang cosmology is a good approximation to what happened as the universe expanded and cooled through light element production and evolved to the present. I explain why I reach this conclusion, comment on the varieties of philosophies informing searches for a still better cosmology, and offer an example for further study, the curious tendency of some classes of galaxies to behave as island universes.

 

[Zeuzzz]

Wow - you are still ignorant of all of the evidence that ~4% of the universe is matter (the rest is dark matter and dark energy), Zeuzzz!
What is 99.999% times 4%?

This comment is hilarious

Proof of dark mater and dark energy please.

Go.

 

[Reality Check]

This comment is hilarious

Proof of dark mater and dark energy please.

This comment is totally ignorant
There is no such thing as "proof" in science.
The ignorance is becoming even worse from you Zeuzzz. Dark matter and dark energy are observations that have been known about for decades and you still do not know about them !
Dark Matter.
Dark Energy.

 

[Zeuzzz]

Fail.

You linked to two pages full of nothing more than pipe dreams of what we simply have to assume exist due to extraneous extrapolation of gravitational theory from Earth bound in situ physical sciences applied to universal scales.

Try harder.

 

[Zeuzzz]

This time maybe link to better evidence than webpages that openly say themselves that the things you are touting as fact are 'hypothetical' and not detectable, in the very opening paragraphs.

 

[Reality Check]

Zeuzzz, Cite the experiments on stars in labs

You linked to two pages full of nothing more than pipe dreams of what we simply have to assume exist due to extraneous extrapolation of gravitational theory from Earth bound in situ physical sciences applied to universal scales.

Failure to show that ability to even read what is linked:
Dark Matter.
Dark Energy.
Dismissing actual sceince as "pipedreams" makes it look as you are indulging in pipedream fantasies of your own. Read the Wiki pages. Look up the scientific papers that are cited.
Better yet - try reading some literature on cosmology rather than relying on crackpot pc web sites (the "99.999% is plasma" delusion is a common bit of insanity on their sites).

Failure to understand that gravitational forces have been tested from tiny scales in labatories to cosmological scales.


Failure to understand that plasma physics experiments cannot be scaled to more than small scales.

Failure to understand the problems with your "must be tested labs" fantasy, e.g. you deny the existence of stars!
Zeuzzz, Cite the experiments on stars in labs

 

[Reality Check]

This time maybe link to better evidence than webpages that openly say themselves that the things you are touting as fact are 'hypothetical' and not detectable, in the very opening paragraphs.

This time try to understand some basic scientific terminology in "dark matter is a type of matter hypothesized to account for a large part of the total mass in the universe."
Dark matter is hypothesized because it has not been detected here on Earth. In fact it is possible that it will never be detected here on Earth.
This is not a problem in science. We can detect the effects of dark matter and this is striong evidence that dark matter exists.
There are other things that we have not detected directly, e.g. quarks, stellar black holes.
There are things we never expect to detect in labs, e.g. stars!

 

[Ziggurat]

Fail.

You linked to two pages full of nothing more than pipe dreams of what we simply have to assume exist due to extraneous extrapolation of gravitational theory from Earth bound in situ physical sciences applied to universal scales.

Try harder.

Fail.

You linked to two pages full of nothing more than pipe dreams of what we simply have to assume exist due to extraneous extrapolation of plasma theory from Earth bound in situ physical sciences applied to universal scales.

Try harder.

Of course, our gravitational experiments are actually not all earth-bound.

 

[Zeuzzz]

We can detect the effects of dark matter and this is striong evidence that dark matter exists.

Evidence needed.

And yes I've read the links in your signature, and the literature they are based on, and no they are not evidence of dark matter.

 

[Reality Check]

Evidence needed.

Dark Matter.
Dark Energy.

And yes I've read the links in your signature, and the literature they are based on, and no they are not evidence of dark matter.

And no, you are lying because if you had read the links or the papers they refer to you would know that the observations are evidence of dark matter.

ETA:
Let us hope that you are not going to repeat your ignorance of Clowe that Tim Thompson corrected on 22nd August 2012 or extend it to the other observations of dark matter:
On the matter of Clowe, et al., 2006
Clowe, Douglas; et al. (2006). "A Direct Empirical Proof of the Existence of Dark Matter". The Astrophysical Journal Letters 648 (2): L109–L113. arXiv:astro-ph/0608407. Bibcode 2006ApJ...648L.109C. doi:10.1086/508162.

 

[Zeuzzz]

Clowe, Douglas; et al. (2006). "A Direct Empirical Proof of the Existence of Dark Matter". The Astrophysical Journal Letters 648 (2): L109–L113. arXiv:astro-ph/0608407. Bibcode 2006ApJ...648L.109C. doi:10.1086/508162.

That post from Tim was a good post. But I feel he is still dodging the elephant in the room. You can use literature in astronomy to imply many different things in the context of which theory you are viewing it through. But we are still dealing with things we can observe to infer things we can't.

Claiming the things we can't observe as empirically proven is getting things totally backwards.

In fact the bullet cluster seems to be a special event, such high velocity merging systems are very rare for system like this where the infall velocities of clusters surroundings are more than 3000 kms^–1 at about 2V_r200 (If V_r200 is the virial radius, it gives the distribution of realistic initial velocities of sub-clusters before they collide, and the velocity distributions can be worked out).

By comparing the in fall velocity distributions with the initial velocities used by the non-cosmological hydrodynamical simulations the initial velocity of 3000 km s^–1 at about 2V_r200 is needed to satisfy the required shock velocity, X ray mass peak data and X-ray brightness and structure. Such a high infall velocity in the ΛCDM model, and the corresponding probability of finding 3000km s^–1 (http://adsabs.harvard.edu/abs/2008MNRAS.389..967M) is around the 1x10^-10 value. The very existence of the Bullet cluster data is not proof of dark matter or LCDM, in fact the data is against the predictions of LCDM until much lower in-fall velocities for 2V_r200 are observed.

 

[Reality Check]

That post from Tim was a good post. But I feel he is still dodging the elephant in the room.

Your feelings are wrong. He stated what any person who knows anything about science will state.
When we observe galaxy closers colliding, see that their ICM is split into 2 components then their ICM has 2 components.
If one ICM component does not emit light and gravitates then that is dark matter.

Claiming the things we can't observe as empirically proven is getting things totally backwards.

And that is where you really go wrong - we have observed dark matter.
The ignorance of claiming that only things that emit light can be observed should be obvious to you.

In fact the bullet cluster seems to be a special event,

Wrong

• NASA Finds Direct Proof of Dark Matter
• another observation
• and Abell 520

You really need to learn to read:
Simulating the Bullet Cluster

We present high resolution N-body/smoothed particle hydrodynamics (SPH) simulations of the interacting cluster 1E0657-56. The main and the subcluster are modelled using extended cuspy Λcold dark matter (ΛCDM) dark matter haloes and isothermal β-profiles for the collisional component. The hot gas is initially in hydrostatic equilibrium inside the global potential of the clusters. We investigate the X-ray morphology and derive the most likely impact parameters, mass ratios and initial relative velocities. We find that the observed displacement between the X-ray peaks and the associated mass distribution, the morphology of the bow shock, the surface brightness and projected temperature profiles across the shock discontinuity can be well reproduced by offset 6:1 encounters where the subcluster has initial velocity (in the rest frame of the main cluster) 2.3 times the virial velocity of the main cluster dark matter halo. A model with the same mass ratio and lower velocity (1.5 times the main cluster virial velocity) matches quite well most of the observations. However, it does not reproduce the relative surface brightness between the bullet and the main cluster. Dynamical friction strongly affects the kinematics of the subcluster so that the low-velocity bullet is actually bound to the main system at the end of the simulation. We find that a relatively high concentration (c = 6) of the main cluster dark matter halo is necessary in order to prevent the disruption of the associated X-ray peak. For a selected subsample of runs we perform a detailed three-dimensional analysis following the past, present and future evolution of the interacting systems. In particular, we investigate the kinematics of the gas and dark matter components as well as the changes in the density profiles and the motion of the system in the LX-T diagram.

Look at all that dark matter , Zeuzzz !

The very existence of the Bullet cluster data is not proof of dark matter or LCDM, in fact the data is against the predictions of LCDM until much lower in-fall velocities for 2Vr200 are observed.

It is the distribution of mass in the Bullet custer that is the direct empirical "proof" of drak matter.
P.S. A semantic agreement that we have is that the authors should not have the word proof in the title of their paper - it should be something like "Direct Empirical Evidence of the Existence of Dark Matter to add to The Existing Strong Evidence of Dark Matter".

The likelihood of finding the Bullet cluster is 100% because we have found it!
It is a rare situation, e.g. if we went looking for another such system the likelihood is ~10^-7 according to the paper's introduction. So there around 10 more bullet culsters that may be out there (100 billion galaxies, ~1000 per cluster for ease of arithmetic).
Your 10^-10 figure does not seem to appear in the paper.

 

[Zeuzzz]

Your 10^-10 figure does not seem to appear in the paper.

It doesn't appear in there, because I calculated it myself, using more up to date data than Clowe et al used, from the reference I supplied.

http://adsabs.harvard.edu/abs/2008MNRAS.389..967M
Simulating the Bullet Cluster
Mastropietro, Chiara; Burkert, Andreas

 

[Reality Check]

It doesn't appear in there, because I calculated it myself, using more up to date data than Clowe et al used, from the reference I supplied.

So how did you get from the 10^-7 quoted in the paper or the computer simulation results in the paper to the 10^-10?

Not that it matters because we still have the fact that the Bullet Custer (and other clusters) exists and give strong empirical evidence the dark matter exists. I am just interested in how you get a factor of 1000 difference from actual astronomers doing the math.

 

[Tim Thompson]

Calculating probabilities

It doesn't appear in there, because I calculated it myself, ...

Please show your calculation.

 

[Tubbythin]

That post from Tim was a good post. But I feel he is still dodging the elephant in the room. You can use literature in astronomy to imply many different things in the context of which theory you are viewing it through. But we are still dealing with things we can observe to infer things we can't.

Claiming the things we can't observe as empirically proven is getting things totally backwards.

Define "observe".

 

[Zeuzzz]

Please show your calculation.

Well taking P_V as the pairwise velocity the change in ΔPv = the velocity of the main cluster minus the velocity of the satelite, and if the only force acting is gravitational then this will be proportional to M^1/2.

So

P_v²(x in) = P_v²(x out) + (2GM_main)/(V_r200) [(V_r200/v_in) - (V_r200/v_out)]

So the probability density for a gaussian distribution [p(logP_V] is [1 / 2 pi σ_v²] exp [-(logP_V - v)² / 2σ_v²]

So if (ν, σ_ν ) are (3.02, 0.07) and (3.13, 0.06) with a couple of cursory assumptions
P(>3000) = 3.3×10⁻¹¹ and 3.6×10⁻⁹ at z = 0 and 0.5, respectively.

Which is why I gave the mid figure of 1.0^-10 above, which is roughly in the middle of the two values.

Show your working. I feel like i'm back at uni

 

[Zeuzzz]

Define "observe".

Something we can detect via radiation from the EM spectrum which contains data.

 

[Tubbythin]

Something we can detect via radiation from the EM spectrum which contains data.

Must the radiation be emitted by the object itself? Or can it be secondary radiation? What about a lack of radiation? Can we observe something through the lack of radiation coming from, say, some part of the sky?