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In a very different way of translating scientific ideas into other forms and media, my friend, colleague and collaborator Lloyd Knox is back with a new series of short video documentaries under the auspices of his Spherical Cow Company. After a hiatus of a few months, they set themselves a challenge of producing three videos in three days.

The first video discusses the idea that the structure we see in the Universe today — galaxies, clusters of galaxies and the three-dimensional patterns that they form — was seeded by microscopic fluctuations traceable to the innate randomness of quantum mechanics, regions of slightly higher or lower density than average. These fluctuations were originally tiny both in size — much smaller than the scale of an atom, and in amplitude — the difference between the fluctuation and the average may have been only one part in a septillion (which is 1 followed by 24 zeros). A short early period of cosmological inflation caused the fluctuations to expand to macroscopic size, and 14 billion years of gravity caused them to grow, attracting more and more matter. But don’t take my word for it — go watch Lloyd’s video.

In the next two days, Lloyd moved the discussion closer to home. First, perhaps inspired by a sunny day in California, he talks about powering the sun, or more precisely, the initial spark to the sun’s burning provided by gravity as it was formed. Finally, on Friday, Lloyd talks about neutrinos, a by-product of the sun’s nuclear burning, which gives us a way of looking directly into the center of the sun — a very difficult way, since we can only detect a tiny fraction of all of the neutrinos streaming out towards us.

(The Company’s site also has an excellent discussion between Lloyd and one his readers about some of the subtle points of the Cosmic Microwave Background radiation that both Lloyd and I have spent much of our careers thinking about.)

One of my old friends from graduate school, and a colleague to the present day, Lloyd Knox — whom you may remember from such cosmology hits as the Dark Energy Song — has started an initiative to create “short documentary videos to demonstrate the explanatory power of simple physical models and to help us understand and aesthetically appreciate the natural world”. It’s called The Spherical Cow company — the name comes from the traditional physicists’ trick of idealizing and simplifying any problem he or she gets, sometimes out of all recognition — but usually, when done well, keeping enough of the salient features.

The first video does just that, giving a simple description of the formation of the Cosmic Microwave Background, in the form of a conversation between Lloyd and his son, Teddy — with interpolations for animations and narration. Even with those occasional animations, the whole thing is pleasingly low-fi, but well-explained and charming (especially so for me, as I know the protagonists). I look forward to the next videos in the series, and I’ll certainly be recommending them to students of all ages.

(Warning, scattershot blogging echo-chamber post follows.)

Last week I went to the Science Blogging Talkfest sponsored by the Biochemical Society and led by Alice Bell from Imperial’s excellent Science Communication program.

Partially because the event was mostly attended by science bloggers themselves, there was a bit of a preaching-to-the-converted sense to the proceedings. (I tried to engage in some good-natured tweaking, pointing out that probably the greatest influence of [supposedly] science blogging has been in absurdly dragged-out climategate saga, but I couldn’t get a rise out of the audience.) But it was heartening to see just how mainstream science blogging has become.

“Only” five years ago (scare-quotes denoting an eternity of internet-time), the academic-blogosphere chattered on about an anonymous article in the Chronicle of Higher Education which contended that bloggers were essentially unsuitable to be hired as faculty members, and a couple of years after that several of my colleagues felt the need to seriously restrict their blogging while searching for permanent positions. I was heartened to see that the question of whether blogging could actually hurt someone’s career seems to be less worrying. Although Petra Boynton said that one of her previous departments were less than enthusiastic about it, most of the panelists have found that, with an increased in impact and communication in general, blogging has taken its position as an effective way to engage with the public.

One of the more novel (to me) things going on at this meeting was the Twitter backchannel: the organizers projected a running stream of tweets marked with the #talkfest tag. It was a decent mix of jokes and apposite comments, especially including erstwhile MP Dr Evan Harris’ provocative comments about whether scientists should be forced to do public engagement at all. It’s certainly good that blogging and communication don’t hurt your career — but should they be requirements for scientific advancement? Not all scientists’ talents lie in that direction, and we shouldn’t expect them to. There was also a twitter discussion of the gender makeup of the panel, which was dishearteningly 1/6 female despite an audience of at least 50% women.

When science blogging started out as its own sub-genre in the middle of the decade, no one was quite sure what it would be for. Would it be used within science as an online lab notebook, or as a substitute or adjunct to papers? That doesn’t seem to have panned out — even in the post-’net open world, the structure of science encourages secrecy, at least until the work can be packaged into what are still more or less old-fashioned papers in what are still more or less old-fashioned journals (albeit with the important twist of pre-publication posting on the arXiv in many fields). Within collaborations, however, wikis, rather than blogs, have become ubiquitous as an easy way to communicate amongst scientists who are already expert — the easy ability to add small chunks of information is exactly what is needed. (Within the Planck Satellite collaboration, we actually use a wiki as a sort of blog — we keep a reverse-chronological list of “posts” discussing our latest results.)

Instead, blogs seem to be used almost exclusively as a window into the life, methods and results of scientists, directed at a knowledgeable but lay public. Indeed, it was suggested at the talkfest that someone could make a very useful living textbook from the scattered blog posts on a given subject. I’m not so sure — one of the advantages of a proper textbook is a single voice and, more prosaically, a single notation starting from scratch— but it’s probably worth trying if someone’s got the wherewithal to do the bit-work involved.

It was especially nice to meet several of my fellow Imperial College bloggers, including biophysicist Stephen Curry (whose own post on the Talkfest also has a list of other reactions to it), whom I was somewhat embarrassed to discover actually works in the same building as I do. As always at these sorts of events, much of the amusement was during the inevitable pub visit afterwards and especially the pre-panel milling about — thanks to the organizers for the excellent combination of cupcakes and beer.

My colleagues and I spend what is probably an inordinate amount of time complaining about the occasional lapses of the basic skills of our students, their inability to take notes, their obsession with marks and what’s going to be on the exams. Because, like everyone else, we like to complain.

But pretty often I get the chance to see them at their best. In the Physics department at Imperial, we interview students who are on the boundaries between final “degree classifications”, the British system of awarding degrees as First Class, 2.1, 2.2, etc. Last week, I was on the panel for this year’s cohort. And it was a pleasure to sit in front of a few of our students and watch them, in real time, thinking like physicists. Of course this means making the occasional mistake, but it also means that delicious “aha!” moment when they figure something out and (this is the best part) they know that they have, whether it’s finding a sign error in their derivation of the motion of a pendulum, or a thought experiment explaining why Einstein’s relativity makes sense.

For the interviews, I was paired with one of our external examiners, UCL particle physicist and fellow-blogger Jon Butterworth. On the same day as our interview, the Guardian published Simon Jenkins’ latest in a series of risible anti-science screeds, and Jon decided to take him to task neither with reasoned argumentation nor with a counter-polemic, but with parody. As with many great ideas on the internet, this one got picked up and built upon, so that the Guardian, to its credit, eventually gave Jon his own space to reply. Jenkins likely thinks we’re producing too many scientists (Imperial only trains scientists, doctors, and engineers, after all!) but I hope that Jon was pleased with the ones he saw.

So my congratulations to this year’s graduating students, and the best of luck to them whatever they go on to do. Pace Jenkins, the world needs more well-trained scientists like them, not fewer.

A couple of my friends have got into a bit of a spat on the internet. Megan McArdle, a writer for the Atlantic Monthly, wrote “The Freeloaders”, arguing that file sharing, as practiced by today’s 20-something young adults, is destroying the music industry.

Marc Weidenbaum, who writes the wonderful disquiet blog, first first answered in prose. Marc argues, mostly correctly I think, that Megan’s argument conflates the major-label recording industry with the music industry as a whole. Despite the illegality (and let’s not be coy about it, there is plenty of theft involved), the more general ethos of free culture has spawned plenty of great art that flourishes outside of the stranglehold of that same recording industry.

He then realized a better rejoinder would be in the great tradition of answer records: he invited some musicians to comment, musically, on the article (and its accompanying illustration): the result is Despite The Downturn, freely available (free as in beer and as in freedom), mostly electronica, an amazing turnaround of just a couple of days from thought to expression. So at least something good has come out of this disagreement.

(See below for an update.)

In one of the more bizarre meta-experiments that have come out of the latter-day social web, Trieste astrophysicist Paolo Salucci is trying to use Facebook to spread some astrophysics, not to the public, but within the astronomical community.

Specifically, he’s trying to “eliminate the deep-routed [sic] wrong misconception [sic] of Flat Rotation Curves of Spiral Galaxies”. A little scientific background: rotation curves are simply a measurement of how fast the stars are moving around the center of their host galaxies (plotted as a function of distance from the center to make a curve). If gravity is responsible for the motion of the stars, we can use the curve to determine the amount of mass in the galaxy. And when we do this, we find that there appears to be much more mass than the luminous matter — the stars — is responsible for. This is one of the strongest pieces of evidence for dark matter.

Salucci has a fairly specific axe to grind: the evidence is often caricatured as “flat rotation curves”. However, when considered in detail, the rotation curves are not completely flat, but do indeed seem to rise and (in the rare cases we can measure far enough out from the center) fall. More specifically, galaxy rotation curves do appear to take a very simple form, each of them being one of a very limited family of possibilities. This is much less variation than might have been naively surmised, but does seem to be borne out by massive numerical simulations of the Universe (including dark matter) as well as the observations.

Nonetheless, I think Salucci misses the point (or perhaps I miss his): indeed we do say “galaxies have flat rotation curves” but this meme (let’s not call it a “wrong misconception”) isn’t about the detailed shape of the rotation curves — rather, it is shorthand for “galaxies are dominated by dark matter”. Yes, we probably should be more precise in our language, but I don’t think we are spreading quite as gross a misconception as Salucci (who works directly in this field and so is admittedly more attuned to it than I) worries.

Of course the real interest in this experiment may just be the attempt to use a consumer social network to foster real discussion (or right thinking) within a specialized and technical community. Sarah Kendrew has an excellent dissection of the methodological side of Salucci’s attempt: can we actually measure how big a problem this “wrong misconception” is? How quickly should we expect Facebook to solve this problem? Would this be a good or a bad thing, outside of the usual professional channels of peer-review and conferences? I completely agree with Sarah that this experiment per se may not teach us much, but that the broader presence of professional astronomers, and scientists more generally, in the world of the web has already begun to prove itself useful as a tool for communication to the public and within the professional community.

Update: I had a very nice telephone discussion with Paolo Salucci today. I just want to re-emphasize the point that he is, indeed, right about the facts of the case: rotation curves are not flat (hence the name of the group), and moreover (and more subtly, which is the rub) it is exactly the rising and falling shape of these curves that makes the standard cosmological explanation of dark matter more compelling (and a just plain better fit to the data) than, say, alternative gravity theories such as MOND and its more theoretically coherent variants like TeVeS.

I was sitting in the lecture theatre of the Royal Institution at the Science Online London meeting (of which I hope to write more later, but you can retroactively follow the day’s tweets or just search for the day’s tags) when I realized I had missed the fifth anniversary of this blog this past July. So: thanks for your attention for over 400 posts on cosmology, astrophysics, Bayesian probability and probably too much politics and religion.

Today is also a much more important date: the 400th anniversary of Galileo’s telescope. Even Google is celebrating.

Right now, I’m at a meeting in Cambridge discussing Primordial Gravitational Waves — ripples in space and time that have been propagating since the first instants after the big bang. Despite my training as a theoretical physicist, I’m here to discuss the current state of the art of experiments measuring those waves using the polarization of the cosmic microwave background, which probes the effect of those gravitational waves on the constituents of the Universe about 400,000 years after the big bang. Better go finish writing my talk.

Thanks to The Telegraph’s digital chief, Ian Douglas, for his pointer to me as one of “Five Great Physics Blogs”. Despite its usually, erm, detestable politics, The Telegraph has usually had excellent science and technology coverage, and I’m happy to be picked in such good company: the four other blogs are Peter Coles’ In the Dark, Seed Magazine’s group ScienceBlogs, the anonymous Female Science Professor, and The Physics ArXiv Blog which discusses the latest physics preprints from the ArXiv.

A quick pointer to Initiative for Cosmology (iCosmo). The website brings together a bunch of useful calculations for physical cosmology — relatively simple quantities like the relationship between redshift and distance, and also more complicated ones like the power spectrum of density perturbations (which tells us the distribution of galaxies on the largest scales in the Universe) and quantities derived from that like the distortions in the shapes of galaxies due to gravitational lensing, when the path of light from galaxies is perturbed by intervening mass in the Universe. Combined with good documentation and tutorials (and downloadable source), it makes a good companion to sites such as LAMBDA’s CMB toolbox, which provides similar services targeted specifically at Cosmic Microwave Background science. iCosmo looks like it will be useful for researchers in the field as well as students, so thanks and congratulations to its creators (I’d like to point directly at the page listing them, but that doesn’t seem to be possible… instead, there’s a discussion forum at CosmoCoffee.).

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