Assyrian
Basically pulling an Obama (Thanks Calminian!)
Don't get me wrong, the bible doesn't say God created everything perfect. It is however a very common Creationist belief, one AnswersInHovind seem to share, that crops up very regularly as part of their no death before the fall argument. What I was showing is how creationist arguments contradict each other. AiH's response is was the instability of the galaxies does not matter if they only needed to be around for a few thousand years of young earth, but this leaves out another creationist idea that Adam and Eve and all the animals and plants were supposed to live forever in Eden, they were not created for a just few thousand years.
Seems to be arguing Dark Matter and Modified Gravity are debating the evidence of the bullet cluster, therefore science hasn't got a clue, therefore creationism is right. Doesn't actually follow.On the issue of "dark matter" i have to go with Dr. Hartnett on that one:
Has ‘dark matter’ really been proven?
Clarifying the clamour of claims from colliding clusters
by John Hartnett
8 September 2006
Recently, a paper claimed that direct empirical proof of the existence of ‘dark matter’ has been finally found.1 This has been dutifully repeated in the more popular media. 2 It is claimed that this demolishes the criticisms of ‘dark matter sceptics’ (myself among them) who claim that the whole dark matter scenario is the result of incorrect physics being applied to the dynamics of astronomical bodies.
What was found?
Source: NASA / CXC / CIA / STSci / Magellan / Univ. of Ariz. / ESO.
Clowe, Bradac and co-authors claimed that the Bullet cluster (1E0657-558) at a redshift of 0.296 is a unique merger of two clusters, and that new analysis just accepted for publication in Astrophysical Journal Letters has ‘…enable[d] a direct detection of dark matter,…’
This topic has been in the news and on several websites over the past few days. The arguments all hinge on Clowe, Bradac et al.’s interpretation of the gravitational lensing evidence. That is, whether the correct physics has been applied to these visible arcs seen in and around galaxies in the two Bullet sub-clusters. The usual interpretation is that it is gravitational lensing,3 and a reconstruction allows one to correctly locate the dark matter.4
Is it really dark matter?
They claim ‘direct proof’. That seems to be stretching things a bit, to put it mildly, given the many assumptions and interpretations necessarily involved (see this explanation of some of the logic of proof in general). In this case they were out to disprove some alternate gravity theories that purport to explain the anomalies which cause others to postulate ‘dark matter’. Those theories made predictions, and according to the analysis being discussed here, the researchers have found data that contradicts those theories. However, a recent paper claims that this is mistaken, namely that at least one of those same theories can explain the ‘lensing’ that is observed in this cluster.5
Even if we were to grant them the disproof, though, it is not a proof nevertheless. Let’s be clear here: “dark matter” is not an explanation for what we see; it’s an admission that no one has an explanation. Perhaps a more accurate headline would have been, ‘Scientists have proved that they haven’t got a clue what the universe is made of’, rather than, ‘Dark matter revealed’.6 Because it isn’t revealed. But if you give a name to an admission of gross ignorance—‘dark matter’, ‘dark energy’—then you may eventually believe you have explained something!
The main problem I see hinges on where the x-ray-emitting gas is. The shock heating from the collision of the clusters might well bias the mass calculations for the normal matter. The determination of the mass from x-ray emission is linked to the assumption of hydrostatic equilibrium,7 and the equation used to calculate the location of the mass is the collisionless Boltzmann equation. But by the authors’ own admission, the system is not in equilibrium. Also, they claim one cluster passed through another,8 so the x-ray gases are heated to hundreds of millions of degrees, hardly collisionless. That is why it was named the Bullet cluster. There is a clear picture9 of the x-ray emission shaped like a bow shock wave. The article says:
‘The cluster is also known as the bullet cluster, because it contains a spectacular bullet-shaped cloud of hundred-million-degree gas. The X-ray image shows the bullet shape is due to a wind produced by the high-speed collision of a smaller cluster with a larger one.’… if you give a name to an admission of gross ignorance—
‘dark matter’, ‘dark energy’—then you may eventually believe you have explained something!
They argue that the separate methods (gravitational lensing, and x-ray emissions) allow the authors to separate where the normal matter is from where the dark matter is. But still, many assumptions have been applied which may be wrong. So I suggest that the location of the mass is still in question.
Claims of ‘direct proof’ of dark matter have been made before, and have fizzled.10 Considering that we live in a part of the galaxy that is meant to be dominated with the stuff and is allegedly six or seven times more concentrated than normal matter, i.e. all around us, what is it? Some claim it comprises heavy neutrinos. If standard neutrinos, there would need to be about 10 billion times the amount of the normal matter made from protons and neutrons. Hence the need to look for a massive neutrino. But there are supposed to only be about 20 particles per cubic centimetre! It seems more than prudent to adopt a ‘wait and see’ approach on this alleged ‘proof’.
Another question that might be asked is: if gravitational lensing is correct in the Bullet cluster, why don’t we see it in the CMB?11 After all, cosmic microwave radiation is supposed to come from the background of all the galaxies (supposedly containing putative dark matter) in the visible universe and therefore should be lensed by foreground galaxies—but it isn’t.
I believe we need to apply Occam’s razor.12 We should be wary of claiming the existence of anything where ad hoc assumptions are introduced to the norm, resulting in a complex system of more components than are really necessary. I suggest that dark matter, dark energy, inflation, etc are such items, ones on which history will ultimately pass unfavourable judgement.
Dark matter—vital for big bang believers
But why all the fuss? A lot has to do with ‘big bang belief’. It seems that dark matter is necessary to prop-up the failing paradigm of the Friedmann cosmologies commonly believed by many to describe not only the structure but also the true (‘big bang’beginning of the universe. The many well-qualified critics of the big bang have rightly lambasted dark matter and dark energy as ‘hypothetical entities’ or ‘fudge factors’ (see Secular scientists blast the big bang, which cites An Open Letter to the Scientific Community published in New Scientist). However, to get the theory to work, a universe comprising 22% dark matter is an absolute must. Therefore it has become now an all-out battle to prove that the dark matter sceptics (like me), who dispute the existence of the stuff, are wrong.
Has ‘dark matter’ really been proven?
What Carmeli [the alternative to dark matter given further down the creation.com article] has done is produce another explanation, alongside dark matter and modified gravity, trying to reconcile the mass of galaxies with their rotational velocities. This is a new kid on the block in Cosmology and it will be interesting to see if it gains acceptance as other cosmologist work with the idea and try to apply it to different areas, or look for flaws. The relevance to this discussion is that if Carmeli is right it explains the rotation of galaxies and contradicts AiH's argument that galaxies would have fallen apart if the universe was old.
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