Archive for conformal cyclic cosmology

Hawking Points in the CMB Sky?

Posted in Astrohype, Bad Statistics, The Universe and Stuff with tags , on October 30, 2018 by telescoper

As I wait in Cardiff Airport for a flight back to civilization, I thought I’d briefly mention a paper that appeared on the arXiv this summer. The abstract of this paper (by Daniel An, Krzysztof A. Meissner and Roger Penrose) reads as follows:

This paper presents powerful observational evidence of anomalous individual points in the very early universe that appear to be sources of vast amounts of energy, revealed as specific signals found in the CMB sky. Though seemingly problematic for cosmic inflation, the existence of such anomalous points is an implication of conformal cyclic cosmology (CCC), as what could be the Hawking points of the theory, these being the effects of the final Hawking evaporation of supermassive black holes in the aeon prior to ours. Although of extremely low temperature at emission, in CCC this radiation is enormously concentrated by the conformal compression of the entire future of the black hole, resulting in a single point at the crossover into our current aeon, with the emission of vast numbers of particles, whose effects we appear to be seeing as the observed anomalous points. Remarkably, the B-mode location found by BICEP 2 is at one of these anomalous points.

The presence of Roger Penrose in the author list of this paper is no doubt a factor that contributed to the substantial amount of hype surrounding it, but although he is the originator of the Conformal Cyclic Cosmology I suspect he didn’t have anything to do with the data analysis presented in the paper as, great mathematician though he is, data analysis is not his forte.

I have to admit that I am very skeptical of the claims made in this paper – as I was in the previous case of claims of a evidence in favour of the Penrose model. In that case the analysis was flawed because it did not properly calculate the probability of the claimed anomalies in the standard model of cosmology. Moreover, the addition of a reference to BICEP2 at the end of the abstract doesn’t strengthen the case. The detection claimed by BICEP2 was (a) in polarization not in temperature and (b) is now known to be consistent with galactic foregrounds.

I will, however, hold my tongue on these claims, at least for the time being. I have an MSc student at Maynooth who is going to try to reproduce the analysis (which is not trivial, as the description in the paper is extremely vague). Watch this space.


Shooting at the Cosmic Circles

Posted in Astrohype, Bad Statistics, The Universe and Stuff with tags , , , , on May 11, 2011 by telescoper

Another brief update post of something that whizzed past while I was away and thought I’d mention now that I’m back.

Remember the (now infamous) paper by Gurzadyan and Penrose about evidence for the Conformal Cyclic Cosmology that I blogged about last year?

The original analysis was comprehensively dissected and refuted by a number of papers within a few days of its appearance – see here, here and here – only for Gurzadyan and Penrose to dig an even bigger hole for themselves with a nonsensical reply.

Undaunted, the dynamic duo of Gurzadyan and Penrose have produced yet another paper on the same subject which came out just as I was heading off on my hols.

There has subsequently been another riposte, by Eriksen and Wehus, although I suspect most cosmologists ceased to care about this whole story some time ago. Although it’s a pretty easy target, the Eriksen-Wehus reply does another comprehensive demolition job. The phrase “shooting fish in a barrel” sprang to my mind, but from facebook I learned that the equivalent idiomatic expression in Italian is sparare sulla Croce Rossa (i.e. shooting on the Red Cross). Perhaps we can add a brand new phrase for “taking aim at an easy target” – shooting at the cosmic circles!

I was struck, however, by the closing sentences of the abstract of Eriksen-Wehus reply:

Still, while this story is of little physical interest, it may have some important implications in terms of scienctific sociology: Looking back at the background papers leading up to the present series by Gurzadyan and Penrose, in particular one introducing the Kolmogorov statistic, we believe one can find evidence that a community based and open access referee process may be more efficient at rejecting incorrect results and claims than a traditional journal based approach.

I wholeheartedly agree. I’ve blogged already to the effect that academic journals are a waste of time and money and we’d be much better off with open access and vigorous internet scrutiny. It may be that this episode has just given us a glimpse of the future of scientific publishing.