Results tagged “physics”

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.

Physics vs Poetry

When I’m traveling I try to read the New Yorker — a transatlantic flight usually gets me through most of an issue. I was even more interested than usual when I picked up the issue at Heathrow and found the front-cover blurb, “Physics vs Poetry: New fiction by Ian McEwan”. McEwan is thought of as a “science-friendly” writer and has often populated his fiction with scientists and scientific ideas (usually doctors and medicine, as in Enduring Love and Saturday). His new story is called “The Use of Poetry”, but doesn’t quite manage to escape stereotyping his protagonist, the made-up physics Nobelist Michael Beard. McEwan’s Beard doesn’t really get poetry for its own sake; for him, “The Use of Poetry” is mostly for seducing his wife-to-be. At least McEwan is smart enough, and a good enough writer, that his stereotype isn’t quite so simple: his Beard is so smart that he can fake his way into smart opinions about Milton. He doesn’t really get it, it seems, but he can mouth the words at least as well as the supposed literary scholars (who, needless to say, neither try nor succeed at understanding his physics).

And — I’m not sure if this is to McEwan’s credit or otherwise — he stereotypes Beard’s counterpart, his future wife Maisie Farmer, studying English at Oxford when Beard is doing Physics, even more. After University, she becomes a hackneyed post-sixties feminist figure, attending “a group run by a collective Californian women…. Her consciousness was raised.”

McEwan, I think, prefers rationalists to literary types, but draws the divide too sharply. As Peter Coles has been talking about lately, that stereotypical distinction is just wrong. Most of my physicist friends love art, novels, poetry, music — and quite a few of them make it themselves, usually quite proudly if with varying degrees of emotional and aesthetic success.

What makes McEwan’s portrayal of Beard so unappealing is the backhandedness of the compliment behind it: yes, he’s smarter than everyone around him. But somehow even he doesn’t quite get the poetry, even if that’s almost a distinction that doesn’t make much of a difference.


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.

Science 2008

Out of the blue last weekend, I was invited to participate in a review of the year’s science stories on PressTV, which I subsequently learned was an Iranian-oriented news channel; according to my Teheran-raised grad student, “the Iranian government doesn’t have much control over them, so they are sort of free of sides”. Media whore that I am, I didn’t hesitate too long before accepting, and started to mull over the biggest science stories of the past year.

After a few moments reflection, I couldn’t come up with a very exciting list. The biggest pure-science story was the start of the Large Hadron Collider, but (even if it hadn’t broken!) we wouldn’t expect to see any results until next year or later. There was the launch of the Fermi Space telescope (née GLAST), giving the first map of the whole sky in gamma rays. There were the tantalizing hints from PAMELA of an excess in the cosmic-ray spectrum, potentially the signal of decaying Dark Matter, and certainly the prompt for some interesting intra-science controversies. There was the Nobel Prize for the uncovering of fundamental symmetries (and its own controversies), and the Gruber Prize in cosmology. There were new PhDs for three outstanding scientists, and another one that was a bit more newsworthy. Here in the UK, perhaps the biggest science story, still not completely played out, was the £80 million shortfall in the Science and Technology Facilities Council’s physics budget: results from the last few weeks seem like grants around the country have been cut severely.

Of all of these, only the LHC made the list from PressTV. Instead, we were presented with a list including using mobile phones for medical consultations and data-taking; Iran’s first rocket launch (which was inevitably tied to the country’s putative nuclear ambitions, but was more interesting in the context of scientific launches by China and India this year); and a throwaway article on homeopathy that the editors (frighteningly) didn’t originally realize was a spoof (but at least eventually discarded). Update: The show was shown on Christmas Day and is available now for streaming or downloading. Painful…

But really the biggest science story of the year was the biggest story of the year, period (full stop): the election of Barack Obama. He’s got Steve Chu, a Nobel-prize-winning physicist in the Cabinet as Energy Secretary and John Holdren, a PhD physicist and environmental expert from Harvard directing the White House Office of Science and Technology: with these appointments, along with biologists Jane Lubchenko heading NOAA, and Harold Varmus and Eric Lander co-chairing with Holdren the Council of Advisers on Science and Technology, it looks like science in general, and climate change in particular, will be taken seriously and taking center stage in the new administration. Of course there are still some details, such as the fate of NASA’s post-shuttle launch capabilities and in particular its scientifically-derided Mars program, which aren’t clear; you can weigh in via the NY Times here. Let’s hope it’s coupled to and not separated from (or, worse, at odds with) the economic policies needed to get the US — and the world — out of the credit crunch/recession/depression.

Gemini telescope: back for the UK

In an unexpectedly rational decision, STFC (UK astronomy’s funding council, if you haven’t been paying attention) and the board of the Gemini telescope, have come to some sort of agreement to reinstate UK observing time for the time being, with the further statement from Gemini that “The Board asks that the Chair and Designated Members, including the UK, meet face-to-face at the earliest opportunity to further discussion of possible continued UK involvement in Gemini.” (Via Andy Lawrence.)

UK Gemini telescope bid rejected

Many others have been doing their best to disseminate information on the UK Physics funding crisis (especially Sheffield Prof Paul Crowther) but it’s probably worth pointing out the latest repercussion (which has already been picked up by the BBC): despite a bid to remain involved at a reduced level, it looks like the UK will be forced to completely withdraw from the Gemini telescope consortium. This is particularly dangerous for astronomers here, as Gemini-North was the only large telescope (about 8 meters in diameter) in the Northern Hemisphere to which the UK had access. Now, half the sky will be inaccessible, at least at the highest sensitivities and with the most advanced instruments. (Realistically, this will likely force us to collaborate with European, Asian and American colleagues, and probably to give up leadership roles in these projects.)

Meanwhile, committees are meeting, the government is holding hearings, and we scientists are being quietly advised that, essentially, you attract more flies with honey than vinegar, so we’d better not start pondering the thought that, perish forbid, anyone had actually made a mistake getting to this increasingly difficult position. Let’s hope that whatever is going on behind the scenes is better than what we’re seeing out front.

UK Physics on the chopping block

Today we heard that the (bizarrely agglomerated) UK Department for Innovation, Universities and Skills will be significantly cutting the physics budget that comes through the Science and Technology Facilities Council (STFC). STFC was formed earlier this year out of PPARC (Particle Physics and Astrophysics) and the CCLRC (which ran big facilities like the Rutherford Appleton Lab). When it was formed, we were told this would enable better science. But it seems we may have been sold a bill of goods: the science program is being saddled with what is, essentially, CCLRC’s debt, in the form of an £80 million shortfall that will fall disproportionately on academic research. And therefore, of course, on physics departments and, inevitably, physics education.

The Delivery Plan has just been announced, but of course the spin is all on the overall increase to funding, not these cuts. Happily (and a little surprisingly) the BBC highlighted the impact on physics in its usual stroppy manner.

Andy Lawrence has been following the news of the impending cuts over the last few weeks. Chris Lintott and Stuart have some more details. The headline cuts seem to be: withdrawal from the International Linear Collider (particle physicists’ next big instrument after the LHC at CERN), cessation of all support for ground-based solar-terrestrial physics facilities (i.e., telescopes and instruments that investigate the sun and its impact on the earth from the ground), and “revisiting the on-going level of investment” in gravitational wave detection, dark matter detection, the Clover CMB experiment and the UKIRT telescope. The UK will pull out of the Isaac Newton Group of telescopes.

Most important for me, so-called post-launch support for existing space missions (such as the Planck Surveyor CMB Mission, although it was never explicitly mentioned in the plan) will be cut by around 30%. This is a very cynical ploy: we will undoubtedly be so excited by the data from missions like Planck that we will donate our time, gratis, just to make sure that it gets analyzed.

There do appear to have been some small victories. Rather than a full termination as mooted last week, STFC plans “to withdraw from future investment in the twin 8-metre Gemini telescopes and we will work with our international partners to retain access to Gemini North.” So at least UK astronomers will have access to a world-class telescope in the Northern hemisphere. Most importantly, “Science Minister Ian Pearson said [on the BBC] funding arrangements would be reviewed,” — which we hope means actual compromises are possible — although of course he “did not promise extra money.”

On a day in which Nancy Pelosi became the first female Speaker of the US House of Representatives, the Guardian reminds us that there are still plenty of jobs that discriminate between the sexes, including “Physics professors: There is a grand total of 515 physics professors in the UK, and a mere 25 of them are women.” There are plenty of female of grad students, quite a few postdoctoral fellows, some junior faculty members, and almost none in the most senior positions. This isn’t just the delayed effect of old habits being worked through the system — females still leave the profession from all levels in disproportionate numbers. So much for our enlightened ways.

The Guardian also reported on recent statements from the new Science Minister, Malcolm Wicks, that the UK is reconsidering its unwillingness to support human space exploration. They specifically say that “The tide is turning: the Royal Astronomical Society published a report last year, by three independent scientists, which highlighted the scientific case for Britain to send people into space.” However, they don’t emphasize that the RAS “has not yet taken a formal position on UK involvement” and that most RAS members (the ones I know, at least — this is anecdotal evidence) are opposed to extensive investment in putting humans into space. Although most of us are romantic enough not to oppose it completely.


I’ve just finished my lectures for the course in Fourier Series and Fourier Transforms that I’ve been teaching.

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.)
Still, I did some things right. The students may disagree, but I think I actually did a reasonable job at explaining the material in a way that isn’t just copying from the books. Perhaps that’s why my lecture notes seem to be more popular than the lectures themselves. And at least my loud Yankee voice carries to the back of the room.

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!)

Majorana in superposition

This morning I found what is undoubtedly one of the weirdest papers ever to appear on the arXiv, “Ettore Majorana: quantum mechanics of destiny”, by O. B. Zaslavskii. On the one hand, it’s a short retelling of the life of Ettore Majorana, a major figure in the development of mid-20th-Century particle physics. On the other, it’s a weird structural/semiotic analysis of Majorana’s life in the context of his work on quantum mechanics. That is, not an analysis of his work, but an analysis of his life as if it were a quantum-mechanical system!

Majorana is remembered nowadays for his work on the fundamental properties of particles, in particular neutrinos and the equations that can describe them. If neutrinos are their own antiparticles, they are called Majorana neutrinos (otherwise they are Dirac neutrinos, after the British physicist who wrote down another possible set of equations that describe particles like electrons which are different from their antiparticles). But he is also known for having disappeared in the late 1930s under so-called “mysterious circumstances”.

The paper makes the claim that Majorana’s disappearance was an example of his applying the logic of quantum mechanics to his own life (and death) — superposition, probability, uncertainty. If artists live their lives as works of art, why shouldn’t scientists live theirs as if they embodied their scientific ideas? Or at least, why can’t the historian use quantum mechanics as an interpretive structure for understanding the past? (Like, say, Freudian and Marxist literary criticism, or, more recently, the application of Darwinian evolution to literary theory — although “it would be pointless and, indeed, comical to base literary criticism on quantum mechanics, string theory, or general relativity” according to this article on Darwinian criticism.)

Well, I am all for breaking down the barriers between the two cultures

Marx: Science and Paradox

It is … paradox that the earth moves round the sun, and that water consists of two highly inflammable gases. Scientific truth is always paradox, if judged by everyday experience, which catches only the delusive nature of things.

—Karl Marx, Das Kapital, quoted by Francis Wheen in The Guardian.

Or that objects in motion tend to stay in motion: It took an extraordinary leap of imagination, to traverse the nearly two millennia from Aristotle, who thought otherwise, to Newton, who realized this, despite no one ever having, say, thrown a ball that didn’t stop moving (it took another couple of centuries before we could do that — launch a satellite into orbit, that is).

Once you accept these supposed paradoxes, does that help you understand that the universe might have had a beginning, and no end, starting from hot and dense 15 billion years ago? Or that proto-apes may have begat proto-humans?

I spent the early part of the week in Sheffield at the first meeting of the Institute of Physics Astroparticle Physics Group. There were talks on the search for the Dark Matter, gravitational waves, neutrino astrophysics, gamma-ray astrophsyics, and, of course, cosmology. All of this sometimes goes by the name “non-accelerator particle physics”: trying to learn about the basic constituents of the Universe in way other than smashing particles against one another at high speeds in a particle accelerator. Aside from the excellent science, we had the conference dinner at the Kelham Island Museum, which had some great machines from Sheffield’s industrial past (the UK’s equivalent of Pittsburgh).

(An aside: I’ll go along with Clifford’s observations that the UK is woefully, frighteningly, ridiculously expensive. It cost me £120 to get between London and Sheffield.)

Another distraction from the science was a discussion of the recent announcement that the UK government wants to reorganize the funding of both particle physics and astrophysics, especially as they relate to so-called “large facilities”, such as big telescopes and the aforementioned particle accelerators. The heads of the current Particle Physics and Astrophysics Research Council (PPARC) and the Central Laboratory of the Research Councils (CCLRC) got together last week to respond to the government and endorse the possible changes, and to nudge them in some specific directions. The worry, however, is that the progeny of these two councils would embody the worst of both worlds: big, unweildy, badly managed, and driven more by industrial applications than science. Indeed, the Royal Astronomical Society has produced its own response to the government, and reacted somewhat warily to the PPARC/CCLRC paper: science must remain at the forefront, not the facilities.

The RAS is now headed by Michael Rowan-Robinson, my colleague at Imperial. Another Imperial colleague, Professor Sir John Pendry, has been in the news recently for his part in developing “metamaterials” with weird properties such as the ability to bend light around them, making them appear invisible (but invisibility to radar — stealth technology —is more likely to be developed before one that could make someone invisible in visible light).


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?