Thursday, August 30, 2012

The largest patterns in the Universe

In addition to the developing series of posts on probability and statistical inference, I also want to write another series discussing the patterns in the distribution of galaxies, clusters of galaxies and dark matter in the Universe: how we reconstruct these patterns from observation, and how we can use this information to learn about the very distant past back near the time of the Big Bang some 14 billion years ago. This is what much of my day-to-day research is about, so I can claim more expertise on this subject than on some of the others I post about.

I'll try to keep the majority of the discussion at a level suitable for readers with an interest in cosmology, but no detailed technical knowledge of it, though I hope to include enough information to interest more expert readers as well. However, rather than constructing a systematic development of ideas from first principles I'm afraid I will flit about like a butterfly, alighting on topics that are of particular interest to me at the moment! Questions and feedback are welcome via the comments box.

Today's post is about the homogeneity of the distribution: the absence of pattern.

Wednesday, August 22, 2012

The disgrace of Niall Ferguson

(The content of this post is somewhat beyond the usual remit of this blog.)

A month or so ago, a friend drew my attention to the 2012 BBC Reith Lectures given by Niall Ferguson, a Harvard professor of economic history. This is a particularly prestigious lecture series on BBC Radio 4. Past lecturers have included many famous names, from Bertrand Russell in 1948 to Aung San Suu Kyi in 2011; I would recommend several previous lectures. But on listening to Ferguson, I was so annoyed by the combination of factual errors, non sequiturs, deliberate misrepresentations and schoolboyish debating tactics I heard that I almost composed a long diatribe for this blog to point them all out. In the end I refrained, partly for the sake of my blood pressure.

Now, however, Ferguson is back in the news, for an execrable cover story in Newsweek attacking Barack Obama's economic policy that contains many of the same tactics he employed in his Reith lectures, and I can no longer pass up the opportunity to comment. Luckily the Newsweek story has stirred up such justifiable disdain everywhere that I will be able to outsource much of the detailed commentary and merely provide you with a round-up of the reasons why you should never believe a word Ferguson says or writes.

Monday, August 13, 2012


I just wanted to make a couple of quick points about the system of leaving comments on this blog. I've been away on holiday for a couple of weeks (I tried to arrange some posts in advance so you wouldn't notice) and on my return I notice that this blog has been flooded with comments that Blogger has picked up in its (rather good) spam filter. These comments are all of a similar style — effusive in their general praise for my blog, but reluctant to specify any details, and always advertising some other website as well. Now it may be that I have a particularly enthusiastic fan who writes in broken English, but more likely the spam filter is doing its job very well. Therefore I won't reinstate those comments.

However, I noticed that the spam filter also picked up a few genuine comments as well (since reproduced here). Generally speaking I don't check the spam filter so such comments could remain lost forever. So if you are a real person trying to leave a comment on a post but you don't see it appear, you should try to (a) make sure your comment addresses the content of the post and not simply some vague generalities, (b) avoid gratuitous plugs for irrelevant websites, and (c) not suspiciously post and delete too many comments in too short a time. In case your insightful contribution is still lost to the æther, explain the problem on here and I will try to reinstate your comment.

Saturday, August 11, 2012

The Shining Mountain

At this sort of time every year I find my thoughts turning to the mountains, and today for no particular reason I wanted to write a little about a particular favourite of mine. There are a few peaks around that are sometimes claimed to be the most beautiful, inspiring or aesthetically pleasing in some way — the Matterhorn and Ama Dablam are ones that are mentioned very often — but for me, nothing quite matches up to Changabang in the Garhwal Himalaya.

Instead of attempting to describe the mountain myself, let me quote from the description in a book called Scottish Himalayan Expedition, written by the mountaineer and author W. H. Murray in 1950. By all accounts, Murray was a wonderful man with a deep love of mountains, and an ability to express that love in the written word that I've never found with any other writer. This little paragraph itself is one of the main reasons that Changabang features at the top of my personal list of favourite mountains:
The nearest of the great peaks, Rishi Kot, turned to us an edge like a cutlass but black as gun-metal, whereas Changabang, its neighbour, by day the most like a vast eye-tooth fang, both in shape and colour — for its rock was a milk-white granite — Changabang in the moonlight shone tenderly as though veiled in bridal lace; at ten miles' distance seemingly as fragile as an icicle; a product of earth and sky rare and fantastic, and of liveliness unparalleled, so that unawares one's pulse leapt and the heart gave thanks — that this mountain should be as it is.
Murray's description of the entire expedition sitting out in the freezing night air, wordlessly eating their dinner while staring transfixed at this glorious summit above them, has stayed with me ever since I first read it as a teenager. In fact the entire book is excellent; if you can find it anywhere, you should read it.

Murray and his companions would have been looking at Changabang from the south-west, its most spectacular profile. Here's a photograph of it from the same angle, taken by Doug Scott in 1974:

Bonington, Haston, Hankinson and Scott admiring Changabang, 1974. Photo by Doug Scott.

The ridge on the right drops down to Shipton's Col, named after the great mountaineer and explorer who first crossed it while mapping the Nanda Devi Sanctuary in 1936. (Shipton's connection with the name of this blog was explained here.) This photo is from the expedition by a team of British and Indian climbers who made the first ascent of Changabang in 1974, by the south-east face. I recently found Doug Scott's original report of the climb in the Alpine Journal online here. It contains several other beautiful black-and-white photographs of Changabang and the surrounding peaks. Here's yet another photograph with a slightly different view:

The most beautiful mountain in the world
Dougal Haston in front of the West Wall. Photo by Doug Scott.

Towering above the climber, Dougal Haston — who, you'll notice, is carefully rehydrating himself in the medically recommended manner — is the famous West Wall of Changabang, with the left skyline dropping down to the Bagini Pass (apparently that's not the real Bagini Pass; see the correction in the comments below). Despite appearances, the West Wall is actually mostly too steep for any great quantities of snow to remain on it; its colour in the photo is due, as Murray noted, to the whiteness of the granite.

The West Wall played an important role in mountaineering history: in 1976, a two-man British team — Peter Boardman and Joe Tasker — made a dramatic and revolutionary ascent of it using 'big wall' techniques that no one had previously thought were possible in the high Himalaya. It took them 25 days. Part of their training for the route in England involved spending nights hanging in hammocks inside industrial meat freezers. Boardman's book about the ascent, The Shining Mountain, is one of the all-time classics of mountaineering literature — again, if you get your hands on it, read it. In some ways Boardman was not a dissimilar writer to Murray, his passion and the simple poetry of his language shining through (please excuse the pun) on every page. After their disappearance on Everest in 1982, the Boardman-Tasker prize has been awarded every year for outstanding mountain literature.

Viewed from the north, Changabang is in some ways less impressive, as at 6864 metres high it is somewhat lower than its immediate neighbour Kalanka (6931 m). This is what it looks like from the Bagini glacier:

Changabang and Kalanka north faces
Kalanka (L) and Changabang (R) from the north, the Bagini Pass on the right (not quite, see the comments below!). Photo: unknown.

Less impressive in some ways maybe, but from a mountaineer's perspective the grandeur of that sweeping vertical north face is awe-inspiring. Frank Smythe described it as "a peak that falls from crest to glacier in a wall that might have been sliced in a single cut of a knife." That north face was first climbed — Alpine-style, no less! — by Andy Cave and Brendan Murphy in 1997, though Murphy sadly died in an avalanche on the descent. In a neat symmetry, Andy Cave won the Boardman-Tasker award in 2005.

For the time being, I believe the northern perspective of Changabang is the only one available to mountaineers, since the Nanda Devi Sanctuary remains closed to expeditions (Though I may be wrong on this: it is possible that partial access to the Sanctuary has recently been allowed again, and it is also possible that Changabang can be seen from the southwest from some location outside the Sanctuary).

At some point in the future, I have promised myself a visit to Changabang. Not to climb it, which would be beyond my capabilities, but merely to see it for myself, from the Bagini glacier if the Sanctuary remains closed. Until then, I must content myself with other people's photographs, and Murray's words.

Saturday, August 4, 2012

Why don't more scientists enter politics?

This is a question posed by Shaun over at The Trenches of Discovery, in a piece I would urge you to read. He argues that scientists are not shy of expressing opinions on matters of political interest, and scientists are well-qualified (some would say better qualified than most) to offer opinions on, and to frame, policies on matters of great importance to society. So why are they under-represented in politics?

I found this a bit of a thought-provoking question. As readers will have noticed, this particular science blog is not backward in expressing political opinions, so some sort of considered response appears to be in order. If you click through to Shaun's post you can see some of my immediate reactions in the comments; however, while I am happy to shoot from the hip over at his blog, I will try to express myself more coherently and thoughtfully on my own.