I have the unfortunate duty of using this blog to announce the death a couple of weeks ago of Professor Leon B Lucy, who had been a Visiting Professor working here at Imperial College from 1998.
Leon got his PhD in the early 1960s at the University of Manchester, and after postdoctoral positions in Europe and the US, worked at Columbia University and the European Southern Observatory over the years, before coming to Imperial. He made significant contributions to the study of the evolution of stars, understanding in particular how they lose mass over the course of their evolution, and how very close binary stars interact and evolve inside their common envelope of hot gas.
Perhaps most importantly, early in his career Leon realised how useful computers could be in astrophysics. He made two major methodological contributions to astrophysical simulations. First, he realised that by simulating randomised trajectories of single particles, he could take into account more physical processes that occur inside stars. This is now called “Monte Carlo Radiative Transfer” (scientists often use the term “Monte Carlo” — after the European gambling capital — for techniques using random numbers). He also invented the technique now called smoothed-particle hydrodynamics which models gases and fluids as aggregates of pseudo-particles, now applied to models of stars, galaxies, and the large scale structure of the Universe, as well as many uses outside of astrophysics.
Leon’s other major numerical contributions comprise advanced techniques for interpreting the complicated astronomical data we get from our telescopes. In this realm, he was most famous for developing the methods, now known as Lucy-Richardson deconvolution, that were used for correcting the distorted images from the Hubble Space Telescope, before NASA was able to send a team of astronauts to install correcting lenses in the early 1990s.
For all of this work Leon was awarded the Gold Medal of the Royal Astronomical Society in 2000. Since then, Leon kept working on data analysis and stellar astrophysics — even during his illness, he asked me to help organise the submission and editing of what turned out to be his final papers, on extracting information on binary-star orbits and (a subject dear to my heart) the statistics of testing scientific models.
Until the end of last year, Leon was a regular presence here at Imperial, always ready to contribute an occasionally curmudgeonly but always insightful comment on the science (and sociology) of nearly any topic in astrophysics. We hope that we will be able to appropriately memorialise his life and work here at Imperial and elsewhere. He is survived by his wife and daughter. He will be missed.
Cosmology fans in and around London: Please come here my colleague Jean–Philippe Uzan, visiting us from Paris, who will talk about “ Harmony in the Universe: between science and music” this coming Thursday, 25 October 2012 in the Huxley Building here at Imperial College. It’s free, but please contact us at email@example.com if you’re going to come.
Urban Sputnik, our collaboration with Vanessa Harden and Dominic Southgate of Gammaroot Design is currently on display at Imperial College in the main entrance of the Norman Foster-designed business school, located on Exhibition Road in London, just up the street from the Science Museum, the V&A Museum and the Natural History Museum. I’ve discussed the pieces that will be on display before, and if you’re anywhere near South Kensington in London over the next few days, please come and see them.
If that piques your interest, you can hear more from us directly: on Tuesday evening, November 8, we’ll be hosting a short presentation — with drinks and snacks — talking about the creation of the pieces and the science behind them.
I’ve just finished another term, in fact the heaviest teaching load I’ve ever had at once: a twenty-six hour lecture course, three hours a week as one of several computer lab “demonstrators”, and another four hours or so per week in first-year student tutorials.
For those from outside of the Imperial system: our tutorials are small group meetings during which we go over a selection of the problem sheets handed out during the week in the lecture courses; here, like most of the UK, these are not explicitly marked, but instead the students get the solutions a week or so after they are handed out. The tutorial session is one of the few chances for any sort of discussion or feedback.
The tutorials can be fun and even challenging (but I’m glad I get to see the answers before the students). It is heartening to see the students trying — sometimes struggling — to really understand the problems. However, the fourth hour in a week going over the same problems can get repetitive; there aren’t that many different questions the students ask.
On the other hand, lab demonstrating doesn’t offer much intellectual at all. I have mostly supervised computer labs, which involves standing around while the students work their way through a “script”, writing programs and (we hope) learning about programming. I admit that I don’t think this is a particularly efficient use of my time: although considerable overall high-level organization is needed, the labs themselves could be (and indeed are, partially) monitored by graduate students. Unfortunately, they don’t get more than beer money for their trouble — and postdocs don’t get paid at all.
The best part of undergraduate teaching for me, though, is lecturing. When it goes well, it can be a remarkably effective way of communicating. Of course, it doesn’t always go well. Sometimes I’m not as well-prepared as I would like, or sometimes I don’t even understand the material as well as I need to. Sometimes the students don’t have the background that I thought they did. And sometimes the material is just hard, too hard to really get the first time through. Even problem sheets and studying for exams isn’t always enough: I certainly admit that I didn’t really understand much of the material that I now use every day until I was in graduate school, applying it in the course of my research. And some stuff I didn’t understand until I had to teach it (which implies that there is plenty of physics that I still don’t understand, so still much more to learn).
This term’s Cosmology course felt pretty good: after three years not only do I understand the material, but also I understand something about how to explain it to not-yet-expert upper-level physics students. The downside of this is that my explanations get a bit longer every year, so it gets harder and harder to squeeze in the most exciting material which inevitably has to come at the end, building on the foundation of the rest of the course.
This year, the Physics Department has an artist-in-residence, Geraldine Cox. Among her many other cool projects, she has been lurking in the back of our lecture theatres, sketching furiously. Many thanks to her for these pictures of me at the blackboard, in one of my favorite striped shirts:
(The graph on the upper left is labeled “Do we live in a special time?” — We seem to live at a time labeled by the vertical line, just as the Universe is transitioning from being mostly made of “matter” — the middle of the three plateaus in the graph — to mostly something very like Einstein’s cosmological constant, or the so-called “Dark Energy” — the rightmost plateau, which may go on infinitely far to the right. So we might have expected to find ourselves near a plateau rather than a one of the few times in between. This is an anthropic argument, and must be treated with care.)
As always, I welcome feedback, anonymous or otherwise, from any of my students on this course or any other. (When I asked for some comments a few weeks into the term, the most amusing came from the student who praised my voice and asked if I was a singer — which doesn’t jibe with the other, less positive, comments on my American accent….)
Finally, today was one of the high points of post-graduate teaching: one of my students, Jude Bowyer, passed his PhD viva with his thesis, Local Methods for the Cosmic Microwave Background. Well done to the soon-to-be Dr. Bowyer!
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.
I’ve just finished teaching my eleven-week winter-term Cosmology course at Imperial. Like all lecturing, it was exhilerating, and exhausting. And like usual, I am somewhat embarrassed to say that I think I understand the subject better than when I started out. (I hope that the students can say some of the same things. Comments from them welcome, either way.)
It’s my second year, and I think I am slowly getting the hang of it. It’s hard to fit all of the interesting and up-to-date research in cosmology into 26 lectures, starting from scratch. This time I spent a little more time in the early lectures trying to give a heuristic explanation of some of the more advanced background topics, like the interpretation of the metric in Einstein’s General Relativity, and the physics behind the transition of the Universe from and ionized plasma to a neutral gas.
In a way, much of this was prelude to some of the most most exciting research in modern cosmology, the growth of large-scale structure from its first seeds into the pattern of galaxies we observe in the Universe today. Explaining this requires a lot of background: early-Universe thermodynamics and why the Universe started out hot, dense, and dominated by radiation; enough relativity to motivate how structure grows differently on large and small scales; and the generation of the initial conditions for structure, or at least our best current idea, inflation, which takes initial quantum randomness and blows it up to the size of the observable Universe (and solves quite a few other problems besides). All of this, and the background required even to get to these topics, barely fit into those 26 lectures (and I admit I was a little rushed toward the end…). And it was even harder to compress them down into four hours of postgraduate lectures.
Alongside this, I decided that none of the available textbooks had quite the right point of view for my discussion, at least not at the undergraduate level I was aiming for (and there are some very good textbooks out there, including Andrew Liddle, An Introduction to Modern Cosmology; Michael Rowan-Robinson, Cosmology; and Peter Schneider, Extragalactic Astronomy and Cosmology: An Introduction). So I also wrote a hundred or so pages of notes (which are available from my Imperial website, if you’re interested in a crash course).
I’m often puzzled by exactly what students want from the 26 hours of lectures themselves. Many, it seems to me, would prefer to merely transcribe my board notes without having to pay close attention to what I am actually saying; perhaps note-taking is not a skill that students perfect at school nowadays. I hope at least that those written notes make it a bit easier to both listen and think during the lectures. (Again, constructive criticism is more than welcome.)
This week I’ll be giving a review (just half an hour!) of cosmology at the IOP’s High-Energy and Astroparticle Physics 2010 meeting. And then I get to indulge in some of my hobbies, like doing scientific research.
I spent a few hours last week with a bunch of science fiction writers, giving them a tutorial on modern cosmology as part of the (first) “Physics for Fiction” workshop organized by my Imperial Astrophysics Colleague Dave Clements. The participants were some very big names in modern Science Fiction, and some hot up-and-coming writers, including Stephen Baxter, Pat Cadogan, Jaine Fenn, Paul McAuley, Hannu Rajaniemi and Alastair Reynolds. There are some photos, including a couple of me in full-on lecturing mode, by photos by Simon Bradshaw on Flickr.
Science fiction writers are a tough crowd: many of them are technically literate (there were a few science PhDs among them) but it’s also clear that, for their writing at least, they don’t just want to know the facts, they want to know what’s cool, and what can be relevant on a human scale, and how they can pass that along to their readers. If it can be vaguely realistic, all the better. So there was perhaps more interest in planets and quantum cryptography than in the origin of the Universe (although that’s a subject that some of our participants who dabble in the grandest “space opera” could sometimes touch on.
But this afternoon I took a few hours off and attended the Imperial College postgraduate degree ceremony. In and amongst the several hundred students received their degrees were all three of my first students (I celebrated their successful PhD vivas here, here and here). There were a couple of short speeches, and a few honorary degrees awarded (the morning ceremony gave one to F1 head and infamous labour donor Bernie Ecclestone), but most of the time was taken up by the students marching up one at a time and shaking the hand of an Imperial luminary. In addition to my students, their were a few other astrophysics PhDs awarded, including to Dr Brian May, who got (by far) the biggest cheer of the day. Me, I got the rare honor of sitting on the stage of the Royal Albert Hall, in my academic regalia (American PhDs robes are heavier than those from the UK, for reasons that escape me, not ideal for a couple of hours under stage lights — and it now appears that my hood wasn’t even the proper maroon and black combo that my Chicago degree apparently calls for).
I admit I was inordinately proud of my students, in my meagre supervisory role as Doktorvater (to use the excellent Germanic term for supervisor): they’ve all done fantastic theses, important science, and most importantly by the end I was able to just get out of the way while they did the hard work. Congratulations again to each of them.
If I’ve got any longtime readers, they may recall that I spent a week paired with Anne Snelgrove MP in the UK Parliament a couple of years ago, as part of a program connecting scienctists with Members of Parliament (described here and here). This week, Anne kept up her side of the bargain and visited us here at Imperial; our press office has done a better job describing it than I could do.
Right now, I am in Paris, attending a meeting of the Planck Surveyor Satellite High Frequency Instrument Core Team, doing my meager bit planning for what we’ll actually do once the data starts flowing in a year or so. Also, enjoying as much French wine and food as I can manage in about 48 hours.
Congratulations to Dr Brian May, PhD, for successfully defending his PhD thesis, “Radial Velocities in the Zodiacal Dust Cloud”. At the time of his defense, I was up in Durham, lecturing to the mostly younger incoming class of STFC-supported UK grad students. Best of luck to them, too, and let’s hope they can finish before their funding runs out in three or four years and so won’t have to make do with a less interesting career like Brian’s.
Combining as it does my vocation with my avocation, it’s impossible to resist an easy post about our favorite rock-star PhD student, especially when he’s made the Guardian’s Leader (aka Editorial) page and the front of the BBC News site (complete with a spiffy pic of the rock star with our new head of group). Less than three nervous weeks for Brian to prepare for his PhD viva! Of course, I should point out that, like parents and their kids, we love all of our students equally, even the ones who haven’t made platinum records, written West End musicals and books on astrophysics, and inspired Wayne’s World.
It was an intense, exhilarating and ultimately frustrating three-and-a-half week adventure —and I fear that it didn’t go very well. It’s tough material, probably the first stuff that these second-year students have seen in their undergraduate career that’s really brand new to them. And, of course, this was my first time teaching it so our combined inexperience didn’t exactly presage a “positive learning outcome”.
What did I learn, then?
- Precision counts: I made my fair share of mistakes, mostly just typos, but those are easy for me to correct or even ignore, much harder for the 180 other people in the room who don’t already understand the material.
- Organization counts: actually, my lectures were highly structured, but I don’t think that always came through as I spoke. Explicit (numbered sections, bullet points, real sentences) is better than implicit.
- Preparation counts: In principle all of us lecturers know what the student have already learned, but just because something has been on on a syllabus doesn’t mean they really understand. Particularly with math, I think we often expect a level of facility that comes with years and years of practice doing integrals, solving equations, getting used to unfamiliar notation, that the students don’t yet have. (Needless to say, we’re usually convinced that things were better when we were in their place, but I’m not always so sure, as we look back with our rose-tinted shades.)
Feedback is, of course, welcome.
p.s. On a more amusing note (purposely buried down here, free of links), it looks like Imperial Astrophysics is going to be getting a very special new (-ish) graduate student soon.
Today I started teaching my first real lecture course (as pointed out in the comments, the link is only accessible within the Imperal network).
I am teaching the second-year physics students mathematical techniques of Fourier Series and Fourier Transforms — this is the theorem that you can represent any function as a sum of so-called sinusoidal waves. That bit I think I explained all right. But then we had to start getting down into the mathematical details. Unfortunately, I think I lost them somewhere trying to make the analogy between vectors (i.e., arrows in space) and functions; you can describe a vector by giving its value in three perpendicular directions (x, y, z, for example), just like you can describe a function f(t) by giving its value at each value of t. A full set of these directions (x, y, z in the case of spatial vectors, or the individual values of t for the function) is called a basis. But we can rotate our vector to describe it any basis that is convenient.
The idea behind Fourier Series is that there is a specific basis made of sine and cosine waves — and expanding our function in this basis lets us understand things like sound and light in terms of frequency: light as a mixture of colors or sound as a mixture of pitches. For many problems in physics, these mixtures (with the somewhat more technical name of “linear superpositions”) are described by very simple formulae. Indeed, in addition to his laws of motion, Isaac Newton is famous for the first description of light this way (although he didn’t have the mathematical technology that Joseph Fourier would only develop in the 19th Century).
Indeed, there are some mathematical formulae behind all of this — not too complicated technically, but I’m not sure I was able to get the concepts behind them through to the students. It’s hard to calibrate to exactly what the students already know (which may not be the same as what they’ve already seen in their coursework!). Also, I worry that I may have drowned them in a sea of notation without actually explaining what I meant in quite enough words.
(In the unlikely event that any of Imperial’s second-year students are reading this, feel free to leave an anonymous comment and let me know what you thought!)
- Last week I participated in a collaboration between the Dana Centre (the adult wing of the Science Museum) and some artists, entitled “Big Ideas.”
- Imperial College is to be leaving the University of London.
- Fantastic late-night Dinner last weekend, with (among many others!) Kosso, Rachel, Imp, Deirdre, Sophie, Barry, guest of honor Robert Scoble, and, amazingly, subsidized food and, yes, really, I'm not making this up, free champagne from Microsoft. The latter was captured by Ian, including a picture in which I look very louche indeed. I also seem to have volunteered to do a podcast with Gia for her work with the new movie, Sunshine, and finally repaid my free-wine debt to Jason and Nick from Stormhoek vineyards by explaining all of cosmology to them in about half an hour (lubricated by wine, of course).
Next week, I need to account for my time down to about 15 minutes, as part of Imperial’s TOAST (The Original Academic Staff Time) Survey. This will let the College figure out exactly how we (collectively and anonymously, or so we’re told) spend our time. Which, I presume, lets them figure out how to best get money from the government, and allocate it internally. Last time, one of my colleagues included his bathroom visits, but I think they are trying to avoid such fine-grained reporting this round.
Maybe I’ll post my results.
Also, we’ve got a new dress code “in the light of security concerns raised by the terrorist incidents which had occurred over the Summer”: ID Cards must be visible at all times (sort of a test run for the government?); and “Clothing that obscures an individual’s face is not allowed on any of the College’s campuses” -- no hoodies, no veils.
Regular readers may have noted a slackening of my posting pace over the last couple of weeks. For the first time in life, I'm earning my keep doing what most people think a "University Lecturer" (a.k.a. "College Professor" in the US) gets paid to do: teaching (in fact, most of our professional stature and advancement is based upon research, but that's another story).
So far I've taught a few sessions of our first-year ("freshman") Seminars in Communication and Teamwork -- it's a joy to see these exciting and excited students thinking, speaking and working together. Next week I dive into one of the unique -- and somewhat daunting! -- aspects of the UK University system: tutorials, just me with three or four students.
So, if any of the students I'm teaching see this, I'd love to hear from you -- leave a comment if you're willing to do it in public, otherwise send an email.
p.s. I haven't been able to bring myself to watch Supernova, the BBC's new sitcom revolving around the life of (wait for it) an astronomer... Has anyone out there seen it?