Archive for UCL

The Tim Hunt Debacle

Posted in Politics, Science Politics with tags , , , on June 14, 2015 by telescoper

After a whole day off yesterday to recover from an exceptionally busy week I’m back in the office on a Sunday to sort out a few things before leaving tomorrow on a short trip to the Midlands, of which more, perhaps, anon.

In a way I’m quite glad I have been so busy over the last few days, with Exam Boards and the like. Had I had time I might have been tempted to write a post at some point about the Tim Hunt affair which broke on Tuesday. As it turns out, everything moved so quickly that anything I wrote would have been overtaken by events. In any case I didn’t feel that I had much to add to the excellent response written by the Head of the Department of Physics & Astronomy, Prof. Claudia Eberlein, in the Huffington Post on Thursday.  However, now I have a little bit of time I thought I would add a few comments.

I hope it goes without saying that I thought Tim Hunt’s comments about female scientists, made in public at an event in South Korea, were outrageous and indefensible.  My heart sank when I found out what he’d said. I might have believed his story that they were intended to be humorous had it not been for an awful non-apology on Radio 4, which effectively made that line of defence untenable. Nobel Prize winning biochemist he may be, but Tim Hunt clearly has a lot to learn about how to interact with people. When we find ourselves in a hole, most of us have the sense to stop digging.

I know my opinion here differs from that of some of my friends and colleagues, but I also think University College London did the right thing in asking him to resign. I’ve heard it argued that it over the top for him to lose his job over his remarks. But that’s not what happened. In fact, Tim Hunt is in his seventies and has been effectively retired for many years; his position at UCL was honorary (i.e. unpaid). I don’t think the severance of his relationship with UCL can be construed as an excessive punishment. In today’s Observer there’s a piece in which Tim Hunt claims he has been “hung out to dry” . I have to admit that I find his attempt to portray himself as victim to be as nauseating as his earlier apology.  I think UCL were fully justified in severing their relationship with Tim Hunt. This is not an issue of freedom of speech. Tim Hunt had every right to express his opinions. Those opinions are, however, completely incompatible with the values of the institution with which he was associated and his statement of them harmful to the reputation if UCL. He simply had to go.

On the other hand, there’s a lot about this story that troubles me greatly. Although some of the social media reaction to Tim Hunt’s comments was incisively humorous, some was unpleasant and some downright nasty. Worse, the Twitterstorm that raged last week also unleashed the gutter press, chiefly the Daily Mail, whose hacks tried to drag Prof. Mary Collins (Hunt’s wife) into the story. That was unpleasant, even by the standards of the Daily Mail. Mary Collins’ private life has nothing to do with her husband’s failings.

Anyway, I hope that a line will now be drawn under this episode. Tim Hunt should now be left alone to enjoy his retirement. As someone once said of someone else “I’ve nothing against his family, but I’m glad he will be spending more time with them”.

Nobody should be deluded that the departure of one high-profile academic will solve anything.  Tim Hunt was one senior academic stupid enough make offensive comments in public. There are countless others in positions of power and influence who hold very similar opinions but only express them behind closed doors, or under the cover of anonymity. Indeed, I know a number of senior academics who put on a public show of being in favour of equality and diversity but in private have acted deliberately to undermine the careers of, usually junior, female scientists. The culprits aren’t always men, either..

P.S. In the interest of full disclosure I should point that I have never met Tim Hunt so do not know what his views really are. Neither do I have any connection with University College London.

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Why the Universe is (probably) not rotating

Posted in Cosmic Anomalies, The Universe and Stuff with tags , , , , , on October 1, 2013 by telescoper

Just a quick post to point you towards a nice blog post by Jason McEwen entitled Is the Universe rotating? It’s a general rule that if  an article has a question for a title then the answer to that question is probably “no”, and “probably no” is indeed the answer in this case.

The item relates to a paper by McEwen et al whose abstract is given here:

We perform a definitive analysis of Bianchi VII_h cosmologies with WMAP observations of the cosmic microwave background (CMB) temperature anisotropies. Bayesian analysis techniques are developed to study anisotropic cosmologies using full-sky and partial-sky, masked CMB temperature data. We apply these techniques to analyse the full-sky internal linear combination (ILC) map and a partial-sky, masked W-band map of WMAP 9-year observations. In addition to the physically motivated Bianchi VII_h model, we examine phenomenological models considered in previous studies, in which the Bianchi VII_h parameters are decoupled from the standard cosmological parameters. In the two phenomenological models considered, Bayes factors of 1.7 and 1.1 units of log-evidence favouring a Bianchi component are found in full-sky ILC data. The corresponding best-fit Bianchi maps recovered are similar for both phenomenological models and are very close to those found in previous studies using earlier WMAP data releases. However, no evidence for a phenomenological Bianchi component is found in the partial-sky W-band data. In the physical Bianchi VII_h model we find no evidence for a Bianchi component: WMAP data thus do not favour Bianchi VII_h cosmologies over the standard Lambda Cold Dark Matter (LCDM) cosmology. It is not possible to discount Bianchi VII_h cosmologies in favour of LCDM completely, but we are able to constrain the vorticity of physical Bianchi VII_h cosmologies at $(\omega/H)_0 < 8.6 \times 10^{-10}$ with 95% confidence.

For non-experts the Bianchi cosmologies are based on exact solutions of Einstein’s equations for general relativity which obey the condition that they are spatially homogeneous but not necessarily isotropic. If you find that concept hard to understand, imagine a universe which looks the same everywhere but which is pervaded by a uniform magnetic field: that would be homogeneous (because every place is identical) but anisotropic (because there is a preferred direction – along the magnetic field lines). Another example of would be s a universe which is, for reasons known only to itself, rotating; the preferred direction here is the axis of rotation. The complete classification of all Bianchi space-times is discussed here. I also mentioned them and showed some pictures on this blog here.

As Jason’s post explains, observations of the cosmic microwave background by the Wilkinson Microwave Anisotropy Probe (WMAP) suggest  that there is something a little bit fishy about it: it seems to be have an anomalous large-scale asymmetry not expected in the standard cosmology. These suggestions seem to be confirmed by Planck, though the type of analysis done for WMAP has not yet been performed for Planck. The paper mentioned above investigates whether the WMAP asymmetry could be accounted for by one particular Bianchi cosmology, i.e. Bianchi VII_h. This is quite a complicated model which has negative spatial curvature, rotation (vorticity) and shear; formally speaking, it is the most general Bianchi model of any type that includes the standard Friedmann cosmology as a special case.

The question whether such a complicated model actually provides a better fit to the data than the much simpler standard model is one naturally answered by Bayesian techniques that trade off the increased complexity of a more sophisticated model  against the improvement in goodness-of-fit achieved by having more free parameters.  Using this approach McEwen et al. showed that, in simple  terms, while a slight improvement in fit is indeed gained by adding a Bianchi VII_h component to the model,  the penalty paid in terms of increased complexity means that the alternative model is not significantly more probable than the simple one. Ockham’s Razor strikes again! Although this argument does not definitively exclude the possibility that the Universe is rotating, it does put limits on how much rotation there can be. It also excludes one possible explanation of the  peculiar pattern  of the temperature fluctuations seen by WMAP.

So what does cause the anomalous behaviour of the cosmic microwave background?

I have no idea.