The cosmological principle is the idea that, ‘viewed on a sufficiently large scale, the properties of the Universe are the same for all observers.’ In general, this seems to hold true – but Brian Thomas’ most recent article, Massive Quasar Cluster Refutes Core Cosmology Principle, is in reference to an apparently contradictory observation.
The homogeneity aspect of the principle places a limit on the size of structures in the universe, though exactly what value this limit has is not universally agreed upon. But according to a recent paper, A structure in the early Universe at z ∼ 1.3 that exceeds the homogeneity scale of the R-W concordance cosmology (open access), the newly-discovered “Huge Large Quasar Group” (Huge-LQG) is significantly larger than even the largest calculated value would allow. The Huge-LQG beats the previous record holder for ‘largest known structure in the universe,’ the Sloan Great Wall, several times over. Even when broken down into two separate groups of quasars, which could conceivably be the case, the main group is still too large. The paper discusses the implications of this result, but does warn:
Of course, history and, most recently, the work of Park et al. (2012) indicate that one should certainly be cautious on the question of homogeneity and the cosmological principle. The SGW [Sloan Great Wall] (Gott et al. 2005) – and before it, the [CfA2] Great Wall (Geller & Huchra 1989) – was seen as a challenge to the standard cosmology and yet Park et al. (2012) show that, in the ‘Horizon Run 2’ concordance simulation of box-side 10 Gpc, comparable and even larger features can arise, although they are of course rare. Nevertheless, the Huge-LQG presented here is much larger, and it is adjacent to the CCLQG [a second LQG], which is itself very large, so the challenges still persist.
We thus shouldn’t be too hasty to dismiss the cosmological principle on this basis, but no explanation of that type presently available can be used to explain the feature.
Where does Thomas come in though? Creationists do not like the cosmological principle, which is actually rather odd. Couldn’t God have created a homogeneous universe, and then picked this small part to do his business? There’s no reason why not, and that wouldn’t be a problem at least for this part of the principle. Instead, though, after claiming that the cosmological principle is not supported by the evidence, he says:
A competing perspective, called the Anthropic Principle, assumes that unique places can exist within the universe. Specifically, it suggests that the earth was uniquely designed for human survival and enjoyment. Whereas the Cosmological Principle has not found supporting evidence, the stunningly improbable collection of earth’s life-friendly parameters does support the Anthropic Principle.
Brian is specifically referring to the strong anthropic principle, which is really the idea that the universe must include intelligent life – hence the ‘design.’ (The weak principle, on the other hand, holds that the universe appears to suit us only because, if it didn’t, we wouldn’t be here to complain about it.) Brian is treating the situation like a zero-sum game between the cosmological and anthropic principle – claiming that one’s loss is automatically the other’s gain. This is not so – the anthropic principle would not demand large structures of which we are not a part, though it does not forbid them, meaning that the Huge-LQG is not a prediction of that model. And, as the paper says, there are other models that do not involve homogeneity. Despite this, Brian concludes:
Without the Cosmological Principle, there is no Big Bang. In the process, this news adds confirmation to the Bible-friendly Anthropic Principle.
Naturally, neither statement is true. Put away that champagne, guys.
The lack of posting here lately hasn’t been entirely my fault. There was no DpSU for Wednesday at all – I think we changed over from 2012 news to 2013 news this week, and that was the casualty. Meanwhile the That’s a Fact video scheduled for the 12th never materialised, and the site hasn’t been updated to reflect this. We shall see what comes of that.