Tag Archives: IoP

History of Physics at the IoP

This week saw a most enjoyable conference on the history of physics at the Institute of Physics in London. The IoP has had an active subgroup in the history of physics for many years, complete with its own newsletter, but this was the group’s first official workshop for a long while. It proved to be a most enjoyable and informative occasion, I hope it is the first of many to come.

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The Institute of Physics at Portland Place in London (made famous by writer Ian McEwan in the novel ‘Solar’, as the scene of a dramatic clash between a brilliant physicist of questionable integrity and a Professor of Science Studies)

There were plenty of talks on what might be called ‘classical history’, such as Maxwell, Kelvin and the Inverse Square law of Electrostatics (by Isobel Falconer of the University of St. Andrews) and Newton’s First Law – a History (by Paul Ranford of University College London), while the more socially-minded historian might have enjoyed talks such as Psychical and Optical Research; Between Lord Rayleigh’s Naturalism and Dualism (by Gregory Bridgman of the University of Cambridge) and The Paradigm Shift of Physics -Religion-Unbelief Relationship from the Renaissance to the 21st Century (by Elisabetta Canetta of St Mary’s University). Of particular interest to me were a number of excellent talks drawn from the history of 20th century physics, such as A Partial History of Cosmic Ray Research in the UK (by the leading cosmic ray physicist Alan Watson), The Origins and Development of Free-Electron Lasers in the UK (by Elaine Seddon of Daresbury Laboratory),  When Condensed Matter became King (by Joseph Martin of the University of Cambridge), and Symmetries: On Physical and Aesthetic Argument in the Development of Relativity (by Richard Staley of the University of Cambridge). The official conference programme can be viewed here.

My own talk, Interrogating the Legend of Einstein’s “Biggest Blunder”, was a brief synopsis of our recent paper on this topic, soon to appear in the journal Physics in Perspective. Essentially our finding is that, despite recent doubts about the story, the evidence suggests that Einstein certainly did come to view his introduction of the cosmological constant term to the field equations as a serious blunder and almost certainly did declare the term his “biggest blunder” on at least one occasion. Given his awareness of contemporaneous problems such as the age of the universe predicted by cosmologies without the term, this finding has some relevance to those of today’s cosmologists who seek to describe the recently-discovered acceleration in cosmic expansion without a cosmological constant. The slides for the talk can be found here.

I must admit I missed a trick at question time. Asked about other  examples of ‘fudge factors’ that were introduced and later regretted, I forgot the obvious one. In 1900, Max Planck suggested that energy transfer between oscillators somehow occurs in small packets or ‘quanta’ of energy in order to successfully predict the spectrum of radiation from a hot body. However, he saw this as a mathematical device and was not at all supportive of the more general postulate of the ‘light quantum’ when it was proposed by a young Einstein in 1905.  Indeed, Planck rejected the light quantum for many years.

All in all, a superb conference. It was also a pleasure to visit London once again. As always, I booked a cheap ‘ n’ cheerful hotel in the city centre, walkable to the conference. On my way to the meeting, I walked past Madame Tussauds, the Royal Academy of Music, and had breakfast at the tennis courts in Regent’s Park. What a city!

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Walking past the Royal Academy on my way to the conference

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Views of London over a quick dinner after the conference

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Filed under History and philosophy of science, Institute of Physics

Frontiers conference 2009

I spent last weekend at the Frontiers conference of the Irish branch of the Institute of Physics. This is a conference aimed at establishing links with secondary schools all over the country and bringing physics teachers up to date with the latest developments in physics and physics teaching. I attended Frontiers for the first time at University College Dublin last year and enjoyed it immensely (see September 2008 post). This year it was WIT’s turn to host the conference and I think it went very well, thanks to the superb organisational skills of Paul Nugent, David Keenahan, Alison Hackett and Eilish Mc Loughlin of the Institute of Physics and WIT physicist Gabriel Gallagher.

The weekend started with a dinner for the conference speakers and organisers in the Tower Hotel on the Friday night. It’s always great to catch up with other physicists in an informal setting and the occasion didn’t disappoint. In particular, I was amazed to discover that well-known science communicator and Northern Ireland Space Office director Robert Hill and I share a colourful past: many years ago Robert used to play 1st trumpet with the National Youth Orchestra of Ireland while I scraped away in the 1st violins!

Saturday morning kicked off with a series of three lectures: you can see the conference program here.

First up to the podium was Prof David Hughes, a highly distinguished astronomer and science communicator from the University of Sheffield, with a talk entitled ‘Telescopes: their history, development and future’. This was a masterly presentation on the evolution of the telescope over the centuries and its effect on science. The seminar covered the whole gamut – from Galileo’s use of a primitive telescope to observe the moons of Jupiter and the phases of Venus, and its impact on the geocentric model of the solar system, to Hubble’s use of the 100-inch Hooker telescope on Mt Wilson to establish the existence of distant galaxies and the subsequent discovery of the expanding universe (the first plank of evidence for the Big Bang model). I really liked the way the speaker emphasised the impact of each technological step in the development of the telescope: from refracting lenses to reflecting pyrex mirrors, from simple drawing to photographic images, from cumbersome mechanical mountings to computer-controlled giants, from simple photography to the modern CCD camera. (Interesting stat: for the last four centuries, the physical size of telescopes has doubled every 50 years). This was a masterclass in science communication and the audience was enthralled.

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David Hughes with an image of the Hooker telescope in the background

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It’s astonishing how astronomy still revolutionizes cosmology from time to time: throughout David’s talk I kept thinking of the recent measurements of distant supernovae that led to the discovery of a universe expansion that is currently acclerating (see post on dark energy here). Interestingly, David was quite cautious about this result in discussion, pointing out that it depends critically on our understanding of Type 1 supernovae – it’s just possible that the effect arises from a lack of understanding of these stars, although there is some coobborating evidence of dark energy from recent measurements of the cosmic microwave background.

In the second talk of the day, Eoin Gill of the WIT science communication group CALMAST gave a talk on ‘The life and legacy of Robert Boyle’. It’s often forgotten just how important the work of this Irish scientist was, from his theory of ‘corpuscules’ to his famous work on gases. Eoin gave a great talk on Boyle, giving an overview of his life and times and the impact of his scientific discoveries. As regards the former, many were surprised to hear that the Irish have a mixed view of one their most famous scientists because of his family background. Robert Boyle was able to indulge his passion for science due to vast wealth inherited from his father, the Earl of Boyle: unfortunately the latter was a notorious Englishman who made his fortune by stealing land from the Irish and redistributing it to English nobility!

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Robert Boyle (aka Eoin Gill) in action

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The high points of the talk were the simple but effective demonstrations. Taking his cue from the famous demonstrations employed by Boyle himself at Royal Society lectures, Eoin showed several neat demonstrations of the vacuum that could be done in the classroom – snuffing out candles in a sealed container attached to a simple pump, the elimination of noise from a bell in the same container, the impossibility of pulling apart spheres separated by a vacuum and many others.

The third talk of the morning was my own presentation on ‘Walton, the LHC and the Higgs boson’. This was a 40-min overview of the forthcoming experiments at the Large Hadron Collider at CERN and their importance in the study of the elementary particles, along with a few words on the role of the Waterford-born scientist Ernest Walton in the evolution of accelerator physics.

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Ronan McNulty of University College Dublin gave an excellent short talk on his group’s involvement in the LHCb experiment at last year’s conference, so this was an attempt at a more general overview of experimental particle physics. Part one dealt with the how, what and why of the LHC: how particles are created and detected, the relevence of such experiments for particle physics and cosmology and a few specifics on the proton beams and the detectors. (I also tried to emphasise the fact that relativistic effects such as mass-energy equivalence, time dilation and length contraction are routinely measured in particle experiments as I feel this point is often forgotten). The second part consisted of a whirlwind introduction to the Standard Model, from the discovery of quarks to electroweak unification. In the 3rd part, I sketched the role of the Higgs boson in the model and the difficulties of detection. I touched on the possiblity of physics beyond the standard model at the LHC (supersymmetric particles and the implication for grand unified theories) before finishing up with a few words on cosmology – the search for dark matter particles and the study of matter/antimatter decay in the LHCb experiment.

You can find the slides from the talk here and a video will be available on the conference website next week. My only regret is that the conference had been running 15 minutes late all morning so there was no time for questions  – the best part of any talk. Also,  I never got time to show Kate McAlpine’s LHC rap, it would have gone down a bomb!

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After lunch, Robert Hill , the director of the Northern Ireland Space Office, gave a workshop on useful astronomy software and website resources for teachers. As the former science communicator for the Armagh Planetarium and founder of the Astrogazers Ireland Schools Network, Robert knows a thing or two about getting young people interested in astronomy and science and this was a highly useful workshop, fnishing with a great 3-D show on the universe. I won’t give more details, but examples of the sort of invaluable web resources he gave are

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The Hubble Site

The Faulkes Telescope Project

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Finally, there was a workshop on making videos for educational proposes by Jonathan Sanderson. Jonathan is a highly experienced producer of TV science shows (he has produced series on science for the BBC, ITV and RTE) and he gave us an overview of the SciCast project: this is a nationwide effort in the UK to get students to discover the wonder of science by making short films of simple scientific demonstrations. Jonathan had some great tips on how to get the students to work in teams for the production of such films and then showed us some classic examples from the existing SciCast collection. So far, there are more than three hundred films in the SciCast collection, you can view the collection here!

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A masterclass in science film directing

All in all, it was a great conference, with plenty of items of interest for any science educator. There were also plenty of useful freebies such as astronomy posters, polarising sheets, SPIN science magazine, flash memory sticks and a DVD on the universe produced by the ESA. Professional photos of the event and videos of the talks will be available on the conference website in a few days.

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Filed under Particle physics, Public lectures, Teaching

LHCb, UCD physics and the last symmetry

This weekend I was back at my Alma Mater, the UCD school of physics, for a conference for physics teachers organised by the Institute of Physics.

I arrived late and sneaked into the back row of Theatre E of the UCD science block, just as I used to all those years ago. Such a strange feeling to be back in that same seat in that same lecture hall (one difference is that the grounds of the college are beautiful now). The feeling increased when I was joined by two of my former professors, the best teachers I ever had; Alex Montwill (who taught courses in formal quantum theory and high energy physics) and Ann Breslin (special relativity and experimental high-energy physics). Alex was Ireland’s foremost experimental particle physicist for many years, but is probably best remembered for a well-known series of public lectures on modern physics on national radio.

There were some very nice talks, including one on the discovery of The Antikythera Mechanism by Mike Edmunds of Cardiff University and one on the work of the UCD high-energy astrophysics group by John Quinn. However, I was mainly there to hear Ronan McNulty, the leader of the new experimental particle physics group at UCD (UCD has always been strong in fundamental areas of physics such as astrophysics and particle physics). Ronan’s group has been involved with the DØ experiment at the Tevatron, the L3 experiment at LEP and now with the LHCb detector at the LHC (they got some nice attention recently when they were one of the few groups able to report some preliminary measurements from the September switch-on). The work of the group is very important not just because of its fundamental nature, but because it is the only group in the Republic of Ireland that has an official involvement with the LHC (thanks to our non-membership of CERN, see post below). I’m sure Alex and Ann are very proud to see this large and very successful experimental particle physics group at UCD as they themselves had a successful particle physics group at UCD many years ago, measuring particle tracks in emulsions sent over from CERN (I did my final-year project with their research group, estimating the mass of the muon from pion decay tracks).

Ronan gave a superb talk, ranging from a basic introducton to particle physics up to the search for asymmetry in matter/antimatter decay and their contribution to the VELO detector of the LHCb experiment – all within the paltry 20 minutes he was allotted on the program. You can find the slides from the talk here. At question time, I asked him his view of the likelihood of seeing supersymmetry at the LHC: like many experimentalists, he seemed pretty sceptical, pointing out that there has been absolutely no hint of supersymmetric particles up until now.

At lunchtime, we all had a great chat, ranging from supersymmetry to ‘progressive’ ideas in university administration, to Ireland’s continued non-membership of CERN. It’s always great to catch up with the people who taught you and to hear their perspective on things as an adult. I particularly enjoy talking to Alex and Ann as they are among the very few people who understand Lochlainn’s work in gauge symmetry and the impact it had at the time. Re CERN, it seems negotiations on the issue are continuing…

In other news, although they are now officially retired, Alex and Ann have just written a book (real academics don’t do retirement): Let there be lightis due to be published by Imperial next month. I got a sneak preview and it looks superb, as you might expect of the culmination of a lifetime’s reflection on physics by two highly respected physicists. The book is pitched at a level somewhere between undergraduate and the layman and is an introduction to pretty much all of modern physics from the perspective of the study of the nature of light – from optics to wave theory, from wave/particle duality to light quanta, from electromagnetism and light to special relativity, etc. The book will be officially launched at UCD next month, so I’ll discuss it in detail then.

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Postscript

Supersymmetry has been in my mind all day today, sparked by a comment Ronan made yesterday. He mentioned that as he understands it, one of the reasons mathematicians are keen on SUSY is that it’s the last remaining symmetry under the Poincare symmetry group. I think that’s right and in fact I once heard Julius Wess comment that he sometimes wished he had used the term ‘ultimate gauge symmetry’ in the original paper (he made the comment at a Memorial Syposium two years ago). Sadly, Julius, one of the last of the supersymmetry pioneers, passed away himself last year.

Julis Wess of the Wess-Zumino model of supersymmetry.

All day I’ve been thinking thatThe Last Symmetry would be a great title for a popular book on particle physics, if supersymmetric particles do turn up – possibly a better title than The Story of Atoms . Either way, I didn’t do too much work on my imaginary book over the summer, must get back to it. On the subject of language, I also wonder about the term super-matter…I’ve never heard the term but it’s a nice word and immediately hints at an analogy with antimatter (if SUSY does exist, it must involve a broken symmetry, just like matter/antimatter decay).

As to whether SUSY really exists, a philosophical point has also been on my mind – as far as I know, there is no path to a unified field theory of the interactions without some sort of symmetry betweenfermions (leptons and quarks, the constituents of matter) and bosons (the force carriers). In the 1960s, the unification program ran into a formidable mathematical wall with the emergence of a series of no-go theorems (McGlynn, O’Raifeartaigh, Coleman and Mandula) that showed that the strong interaction could not be incorporated into a single scheme with the other interactions using the methods that had been so successful in electro-weak theory. Mathematicians were hugely relieved when SUSY, a radical new symmetry between the two most fundamental classes of particles, suggested a possible way around the problem and even hinted at the inclusion of gravity. Without some form of SUSY, it’s not clear whether unification can happen, and without unification, the picture of a single ‘superforce’ in the early universe condensing out into the fundamental interactions we see today can’t happen – a major blow for cosmology as well as for particle physics. So I like to think that either we will see SUSY sometime, or if we don’t, we haven’t got our predictions right because we simply haven’t developed the right model of supersymmetry breaking yet…

Also, there is one famous mathematical clue. When theoreticians plot the magnitude of the coupling constants of the three strongest fundamental interactions as a function of energy, they converge – but not to a single point. That is, unless SUSY is included in the calculation – in which case they converge very nicely. Hmm…

PPS: . Last week was the hundreth anniversary of Minkowski space-time. I completely forgot about this, but Stefan and Bee have a great post on it on Backreaction

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Filed under Institute of Physics