Category Archives: Uncategorized

Robert Boyle summer school

I spent last weekend at a most enjoyable summer school in honour of Robert Boyle, the Waterford-born Anglo Irish aristocrat who became a major figure in the English scientific revolution. Boyle was extremely well-known in his day for his scientific discoveries, his role in the Royal Society and his discussions on the usefulness of the new scientific method (if he is less well-known today, it may be because his contributions were later eclipsed by the groundbreaking advances of his contemporary, the genius Isaac Newton).

250px-Robert_Boyle_0001

The Irish-born scientist and aristocrat Robert Boyle

IMG_0636

Lismore Castle, the birthplace of Robert Boyle

The summer school took place from Thursday 4th to Sunday 7th of July in the Heritage Centre in Lismore, the beautiful town that is the home of Lismore Castle where Boyle was born.  The talks covered a wide range of topics, from the history and philosophy of the scientific revolution to Boyle’s own life and were of huge interest to anyone with an interest in history, science or indeed the history of science.  It was the sort of conference I like best – a small number of inter-disciplinary talks aimed at curious academics and the public alike, with lots of time for questions and long breaks for discussion. Other highlights were an open-air barbecue in Lismore Castle on Friday evening, a re-enactment in costume of some famous Boyle experiments and a tour around the famous Lismore Castle Gardens.

IMG_0626

Song and dance in the grounds of Lismore Castle

The festival proper started with a lecture on Thursday evening by Jim Malone, the Robert Boyle professor of medical physics at Trinity College Dublin:  ‘Robert Boyle: Getting to Know the Man from Lismore’. This was a general overview of Ireland’s most famous scientist, from Boyle’s early years in Ireland to his travels in Europe in 1639-45, from the rise of the Royal Society in England to Boyle’s prolific work at Oxford in the period 1655-1668. It was a very appropriate introduction to Boyle’s great contributions to science, medicine, philosophy and theology and there were also many biographical details I hadn’t heard before, not least the astonishing number of awards and honours he turned down – clearly not a scientist motivated by fame or fortune. You can find more on Jim and his lecture on the conference website here.

IMG_0623

On Friday morning, Dr Anna-Marie Roos of the University of Lincoln laid out the historical context of Boyle’s work in more detail in her lecture ‘Robert Boyle and Early Modern English Science’. Starting with the work of Sir Francis Bacon, she described the emergence of a new questioning of the wisdom of the ancient Greeks, a new philosophy propagated by the invisible college. She then went on to describe Boyle’s experimentation in the context of complementary investigations by colleagues such as Hooke, Wren and Halley. This talk established a detailed social context for Boyle’s investigations very carefully without in any way detracting from the great work he did. You can find more on Anna-Marie and her lecture on the conference website here.

IMG_0625

In the afternoon, Dr Bill Eaton of Georgia Southern University gave the talk ”Boyle in Ireland; Medicine and the Mechanical Philosophy’ where he made a very interesting point on Boyle’s philosophy of science. It turns out that although Boyle spent very little time in Ireland, he did some work on dissection of animal and human cadavers with William Petty in the period 1652 to 1654 in Ireland, experiments that played a very important part in the development of his philosophy of science. Thus, while we associate Boyle’s  scientific work with his later years at Oxford, it is likely that his earlier studies in anatomy in Ireland probably played an important role in in his development as a scientist, particularly in his belief in experimentation to judge the rightness or wrongness of a hypothesis. More on Bill and his lecture here.

IMG_0626

Song and dance at the castle barbecue

I had a sore head after the open-air barbecue at Lismore Castle on Saturday morning, but not so sore that I didn’t enjoy the superb lecture ‘For the Glory of God and For the Relief of Man’s Estate’ by Dr Allan Chapman of the University of Oxford. In many ways, this was the perfect sequel to Anna Marie’s earlier talk on historical context (see above), I never tire of Allan’s unique coupling of a huge breadth of historical knowledge with an ability to communicate key historical points in clear, simple language. To pick one important theme, Professor Chapman was at pains to trace the rise of the new philosophy to a number of earlier advances in the 15th and 16th century; from geography (the voyages to the Americas proved Aristotle wrong on many counts) to anatomy (animal dissections showed the ancients to be equally wrong on the innards of living species), from herbal medicine (tried and tested herbal remedies were far superior to ‘cures’ from ancient books) to the discovery of the invisible force of magnetism. It set Boyle’s investigations in a yet wider context and I was particularly struck by Allan’s insight that to Boyle and his colleagues, new instruments such as the microscope were very much the equivalent of new ships for the previous century’s explorers. Another great theme was Allan’s careful analysis of Boyle’s motivation, that each experiment was driven by his dual passion of investigating God’s creation and relieving the suffering of man. Allan analysed the latter in detail, explaining how Boyle and his contemporaries expected the new investigations to help combat the ever-present threat of famine. You can find more on Allan and his lecture on the conference website here.

Professor Chapman’s discussion of Boyle’s concern for the relief of man’s estate set the stage nicely for a more contemporary talk, ‘Plants for the 21st Century’, by Professor Liam Dolan of Oxford University. This was yet another tour-de-force: starting with some astonishing diagrams of plants by Boyle’s contemprary Robert Hooke, Liam went on to describe groundbreaking research in botany today, not least the use of modern genetics to meet the challenge of feeding the world’s growing population in the face of climate change. This was an overview of current attempts to modify plant genes in order to improve the resistance of crucial crops to disaster, for example the synthesis of a new strain of rice that can survive widespread and frequent flooding in Bangladesh. Similar efforts are ongoing to synthesis crops that can survive prolonged drought, a likely consequence of climate change in other parts of the world. It was a superb introduction to the fraught topic of genetic modification and it fitted very well with Boyle’s concern for the  ‘relief of man’s estate’. You can find more on Liam and his lecture here.

All in all, a superb conference in a beautiful setting. There were several other great talks, not least a discussion of Boyle’s contemporary Valentine Greatrakes  by Dr Peter Elmer and a superb talk on ageing and dementia by Professor Ian Roberston. Ireland is home to a great many excellent summer schools on literary figures and traditional musicians, but none on scientists; I suspect this festival will become be a major event in the Irish summer calender in a few years.

P.S. I should say this was the second annual Boyle summer school organised by the CALMAST science outreach group at WIT and by the Lismore Heritage Centre. It was sponsored by Science Foundation Ireland, the Royal Society of Chemistry, the Institute of Chemisty in Ireland, the Institute of Physics in Ireland, the Robert Boyle Foundation,  i-scan, Abbott, Lismore Castle Arts and the Lismore House Hotel.

2 Comments

Filed under History and philosophy of science, Science and society, Uncategorized

A quantum conference at Castletown House

I spent most of the bank holiday weekend at a conference in beautiful Castletown House in County Kildare. Castletown House is well-known as a venue for classical music concerts but I had never been there for a conference before!

castletownhomelargeimage2

Castletown House in Co. Kildare

The conference was Irish Quantum Foundations, this year’s meeting of the Irish Quantum Field Group. Organised by Eoin O’Colgain of the University of Oviedo in conjunction with theoretical physicists at the Dublin Institute for Advanced Studies, the National University of Ireland, Maynooth and Trinity College Dublin, it was most enjoyable.  Of course,  I’m not a quantum theorist (or any other sort of theorist) but as well as many talks on quantum field theory and string theory, there were seminars on recent advances in experimental particle physics and cosmology. You can find the programme and abstracts here – highlights for me were  a seminar on the recent results from the Planck satellite by Steven Gratton of Cambridge University and a talk on recent studies of the internal structure of the proton at LHCb by Ronan McNulty of University College Dublin.

The conference also featured a public science lecture on the Higgs boson by Peter Higgs of Edinburgh University. Yes, the man himself! Peter’s visit to Ireland received quite  bit of media attention and his lecture certainly didn’t disappoint. About 400 young people turned up in Maynooth University late on Friday afternoon to hear him describe how his work in quantum theory led him postulate the existence of the Higgs boson in 1964. Younger colleagues from Edinburgh then described the successful search for the Higgs at the Large Hadron Collider and how the discovery fits into modern physics. It was a very enjoyable outreach event and I think the point, that what once seemed an abstruse piece of theoretical physics went on to become a major lynchpin of modern physics , was well-made. A nice touch was that Professor Higgs was introduced by Dr Brian Dolan, a quantum theorist at Maynooth who informed the assembled students and visitors that he had studied under Higgs as a student at at Edinburgh!

British physicist Peter Higgs (R) congra

Peter Higgs being congratulated by Dr Fabiola Gianotti of the ATLAS experiment at CERN , on the day of the announcement of the discovery of a Higgs-like particle at the LHC

The last talk of the conference was a memorial lecture in honour of my father, Lochlainn O’Raifeartaigh. The lecture was given by Professor Nathan Seiberg of the Institute of Advanced Studies at Princeton, a very appropriate choice – Nathan is a world-renowned figure in quantum field theory and string theory, particularly for his work in supersymmetry. This work is closely related to that of Lochlainn, in fact several of my father’s last papers were on the Seiberg-Witten model. Nathan gave a superb overview of some new advances in supersymmetry, carefully drawing out the connections between his own work and that of Lochlainn in many instances. Dad always said that he thought his work on supersymmetry breaking was probably his best and it’s good to know that scientific work can live on, just as music and literature do.

At question time, I asked Nathan about his thoughts on the lack of evidence for supersymmetry at the LHC so far (a lack of evidence that is leading some commentators to declare supersymmerty dead in the water). Like so many theorists, he had a very general overview:

“Even if supersymmetry is not realized in the energy range explored by the LHC, it is still and will always be important.  The impact of supersymmetry on theoretical physics and on mathematics has already been huge and it will continue to be essential…there are many parallels with other theoretical ideas that did not solve the problems they were designed to solve but turned out to be crucial in other contexts.”

Of course this is true – gauge theory in particular is full of examples of  advances that seemed to run into a wall, and were later found to be extremely important in other contexts. (Yang-Mills theory is a good example).

All in all, a superb conference – photos will be available on the conference website soon.

Update

I had a very nice conversation with Peter Higgs on Friday about Lochlainn, he remembered him well and was very complimentary about his work. He also pointed out that Irish students, physicists and engineers were losing out by Ireland’s non-membership of CERN, a point he also made on national TV (see link here, the interview is 20 mins in). I got my photo taken with Peter, but it came out looking like Jackson Pollock painting!

Hi Res Cormac Higgs

6 Comments

Filed under Uncategorized

Ireland loses a great physicist

There are sad tidings in Ireland this week with the news that Professor Alex Montwill, Ireland’s best-known particle physicist, has died. Alex was an outstanding  physicist in the field of experimental particle physics and the best teacher I ever had, inspiring generations of physics students with his legendary undergraduate lectures on the physics of the elementary particles and the puzzles of the quantum world. If I can pass on even a morsel of his great knowledge to my own students, my career will have been worthwhile.

7bbb810ae7a09aaf553d3210.L._V192199472_SX200_

Professor Alex Montwill of the UCD particle physics group

The biography below is reproduced from the Institute of Physics

Professor Emeritus of Experimental Physics at UCD, Alex Montwill was one of the first Irish scientists to work at CERN in the late 1950’s. From about that time onwards he was head of the Fundamental Particle research group at UCD which later became members of the European Nuclear Emulsion Collaboration. The collaboration carried out extensive studies in hypernuclear physics and subsequently made the first observation of the creation and decay of a particle containing a charmed quark. Apart from over 40 years’ teaching at UCD,  Alex lectured at City College New York and at the University of Minnesota, Minneapolis. He presented some 150 Science slots on RTE1 radio in 1980’s and 1990’s. He is co-author with Ann Breslin of the book entitled ‘Let there be light’ which was published in 2008 by Imperial College Press. Alex’s hobbies were bridge and chess in both of which he represented Ireland in international competition.

I would like to add: Alex and Ann published a second book ‘ The quantum adventure’ just this year. It’s a fantastic read for anyone with an interest in quantum physics. Also, Alex chose the title ‘The laboratory of the mind‘ for his radio show, a title that gives you a feel for his deep interest in the philosophy of physics, an interest he passed on to generations of students. On a personal note, he knew my father well as a physicist and must have got a shock when I came along and was  a very ordinary student! Yet both Alex and Ann were  extremely supportive of my work in communicating the ideas of physics from the beginning.

Image.ashx Image2.ashx

As well as the countless students he inspired to take up physics as a career, Alex’s legacy can also be seen in today’s thriving particle physics group at UCD. This group, led by Professor Ronan Mc Nulty, is heavily involved in experiments at the LHCb detector at the Large Hadron Collider; these experiments probe the asymmetry between matter and antimatter, a puzzle of fundamental importance in particle physics.

Finally,  a most interesting ‘life-in-physics’ interview with Alex recorded by Dr Tony Scott on behalf of the IoP is available at:
http://www.iopireland.org/resources/audio/page_50891.html

Ar dheis Dé go raibh a anam

2 Comments

Filed under Uncategorized

Planck and the inflationary universe

Last week saw the first release of new measurements of the cosmic microwave background by the Planck satellite . There have been many articles and blogposts on the results (see last post), all noting that the data fit well to the standard ‘ΛCDM’ model of a universe containing dark energy (69.2 +- .019 %), dark matter (25.8 ± 0.4%) and ordinary matter (4.82 ± 0.05%). Other results are a slightly revised value of the Hubble constant (67.3 +- 1.2 km/s/MPC) and a revised estimate of the period of expansion (13.8 billion years), aka ‘a new age for the universe’. However, there has been relatively little discussion of the implications of the Planck data for the theory of inflation.

As we saw in previous posts, the theory of cosmic inflation suggests that the universe underwent an extremely rapid, gigantic expansion in the first fractions of an instant, expanding in volume by a factor of about 1078  in the time interval 10−36 to 10−32 of the first second. Such numbers seem crazy in comparison with the relatively sedate expansion of space observed today (Hubble constant above), but inflation gives a very neat solution to several different problems associated with the big bang model; a lack of magnetic monopoles in the universe, the smoothness of the cosmic microwave background, and the fact that the geometry of space appears to be flat. Best of all, it can be shown that inflation provides a natural explanation for the tiny perturbations in the microwave background that gave rise to today’s galaxies (it is thought that quantum fluctuations in the infant universe were amplified by inflation to become the seeds of today’s galactic structures).

inflation1

Inflation posits an extremely rapid expansion of space in the first fractions of a second

Inflation has become an extremely successful paradigm in big bang cosmology, and today there are few non-inflationary explanations for the geometry of the universe or the formation of structure. But what exactly was the mechanism of inflation? There are over a hundred distinct models; although the WMAP satellite gave results that are consistent with the general idea, the data did not allow one to discriminate between the different models of inflation. So how about Planck?

The first result is that Planck gives a measurement of Ωk = -0.0005 +- .07 for the curvature of space. This indicates a universe that is very close indeed to flatness. This result confirms and extends  many complementary measurements of the geometry of the universe and strengthens the case for inflation (essentially, inflation predicts that the universe expanded so quickly that any large-scale curvature was quickly smoothed out, just as a balloon blown up to gigantic proportions will appear flat to an observer). Explaining a spatial curvature that is exactly flat without inflation is extremely difficult as it requires a very special balance between the competing forces of expansion and gravity, so this is an important triumph for inflation.

A second profound result from Planck is that the ‘power’ spectrum of the perturbations in the microwave background has a ‘spectral index’ of 0.96 +-.009. This value, close to 1 but slightly less, is exactly consistent with almost all models of inflation. Best of all, the Planck data allow allow us to separate out two spectral parameters that could not be disentangled before (ns and r, see here). The upshot is that the new data render some inflationary models very improbable, while others remain possible but with new constraints.

planckfig1

Inflationary models (lines and circles) vs the Planck data; points within dark blue and grey shading represent confidence intervals of 95% and 68% respectively

In particular, many complicated inflationary models such as power-law, double-field, and hybrid-model inflation are now effectively ruled out. (These results are backed by a lack of detection of non-Gaussianity in the CMB spectrum). Instead, the simplest ‘slow-roll single field’ type models are firmly in the frame of possibility (yellow and orange lines for example) . Intriguingly, it seems a Higgs-type field is also a possibility if it is strongly coupled to gravity.

figure6

Slow-roll inflation; a slowly decaying potential is required for inflation to end in a manner consistent with the observable universe

All in all, a spectacular vindication for inflation, a theory that was once considered far too contrived to be true. You can find more on this in the official summary of the Planck results here  (p36) or the specific Planck paper ‘Constraints on Inflation’ here.  This is how science progresses; painstaking analysis of models gives predictions that can be compared to emerging data. Many possible scenarios are ruled out, while others remain possible. Overall, it is important not to lose sight of the main result i.e. that the extraordinary phenomenon of cosmic inflation is almost certainly right and the simplest models are looking most likely! (Note that there is a misprint in the summary paper: the text on page 36 should refer to fig 26, not 23 – you saw it here first).

The next step is that more detailed observations by Planck may be able to detect a phenomenon known as B-mode polarization in the microwave background; if so, this could allow us to narrow the inflationary candidates down further, not to mention provide us with the first observation of gravitational waves.

Planck and the cyclic universe

One intriguing alternative to inflation is the ekpyrotic cyclic universe. In this model, the big bang is the result of a collision of two branes in a cyclic universe. Such models can reproduce all the characteristics of a standard big bang universe in a natural way, without the extra premise of inflation and its special initial conditions. As a bonus, the postulate of a big bang in the context of a cyclic universe is very attractive because it sidesteps difficult philosophical questions such as ‘when did the laws of physics become the laws of physics?’ or ‘when did spacetime become spacetime?’

During his presentation at Cambridge last week (see last post), Professor Paul Shellard mentioned that the new Planck data render many cyclic models, including the ekpyrotic universe, a lot less likely. At question time, I asked him what aspect of the new data disfavours the cyclic theories; it seems the lack of non-Gaussianities in the CMB spectrum rules out the conversion mechanism required by most cyclic models. However, Paul also suggested that the cyclic theorists would no doubt overcome this temporary setback by tweaking their models! I haven’t found much on this in the Planck papers so more on this later…

2 Comments

Filed under Uncategorized

Ancient light at Cambridge University

I stayed on in Cambridge today in order to catch a series of seminars on the exciting new measurements of primordial light from the early universe – the  PLANCK satellite measurements of the cosmic microwave background. The Institute of Astronomy here hosted talks by three PLANCK team leaders all associated with Cambridge: Professor George Efstathiou, Director of the Kavli Institute of Cosmology (seen on tv worldwide yesterday), Dr Anthony Challoner of the Department of Applied Maths and Physics, and Professor Paul Shellard, Director of the Centre for Theoretical Cosmology at Cambridge. This was not an occasion to be missed and it didn’t disappoint. (See here for an introduction to the cosmic background radiation and its importance in big bang cosmology).

735681main_pia16873-43_946-710

Map of the cosmic microwave background as measured by the PLANCK  satellite (2013). Image from ESA

There were three separate talks; Professor Efstathiou gave a general overview of the results, Anthony Challoner presented a talk on PLANCK mapping of dark matter by gravitational lensing, and Paul Shellard discussed the implications of the new results for physics beyond the standard cosmological model.

Professor Efstathiou started by explaining why the new measurements were of much greater sensitivity than those of the previous satellite WMAP. One reason is that PLANCK has detectors at both low and high frequencies; the latter (at over 100 GHz) is particularly useful for overcoming problem of  galactic emissions. (A great deal of this kind of work is about subtracting out a large foreground signal comprising emissions from the universe over billions of years). A consistent theme of George’s talk was that the new measurements are sufficiently precise to stand alone, rather than relying on complementary data from astrophysics. For example, a slight tension between the PLANCK measurements of dark energy (below) and data from recent supernova observations may indicate that the latter have larger uncertainties than previously estimated.

735692main_pia16874-43_946-710

A comparison of the resolution of images of the background radiation captured by the COBE satellite (1992), the WMAP satellite (2002) and the PLANCK satellite (2013). Photo from ESA.

I won’t try and summarize the full talk but the main results (in case you haven’t been reading the news) are:

1. The new data are in close agreement with the standard ΛCDM inflationary big bang model; the data fit extremely well to the standard 6 -parameter model  (no evidence of new parameters), although the results suggest some slight adjustments to the following parameters:

2. A revised value for the Hubble constant Ho (the expansion parameter): 67.3 +- 1.2 km/s/MPC, at the lower end of previous estimates

3. A new constraint on the curvature parameter: Ωk = -0.0005 +- .07 (zero to you and me)

4. A revised estimate of the dark energy contribution: 69.2 ± 1.0%

5. A revised estimate for the dark matter content of the universe:  25.8 ± 0.4%

6. A revised estimate for the ordinary matter content of the universe:  4.82 ± 0.05%

7. A revised ‘age’ estimate for the universe of 13.8 billion years

7. A ‘spectral index’ of 0.96, closely in agreement with simple models of inflation

This last result is one of the most important; as it says in the conclusions of the paperConstraints on Inflation’ (paper XXII of the PLANCK results) , “The simplest inflationary models have passed an exacting test with the Planck data”.

The results are published as a series of 18 papers on the ArXiv, and you can find the summary paper here . Two important anomalies previously seen in the WMAP data remain; an asymmetry between the ‘northern’ and ‘southern’ hemispheres, and the famous cold spot

Hubble_constant

                           New estimate of the Hubble constant (Planck collaboration, ESA)

Power_Spectrum_Blah-600x472

 The power spectrum of the cosmic microwave background (PLANCK collaboration, ESA)

George finished by emphasizing a number of caveats; something of a mismatch at low multipoles, the problem of degeneracy (see below) and the lack of a clear signal of B-mode polarization; he is hopeful that the latter may be forthcoming next year.

Anthony Challoner then gave a talk on ‘Full-sky Mapping of Dark Matter with PLANCK’, a description of the mapping of dark matter by PLANCK using the technique of gravitational lensing. The point here is that one cannot get everything from the ‘power’ spectrum above because of the problem of degeneracy; aspects of the  spectrum can be reproduced with different values of H0,m etc . Luckily, gravitational lensing is sensitive to the geometry of the universe and to the growth of structure, and so allows an independent method of the determination of Ωm .I won’t attempt to summarize Anthony’s talk but the main result is that the gravitational lensing results from PLANCK are very much consistent with the parameters derived from the power spectrum.

Finally, Professor Paul Shellard gave a talk ‘ Beyond the Standard Paradigm’. This lecture discussed possible signs of physics beyond the standard cosmological model in the new PLANCK measurements (for example, hints of support for non-inflationary models of the infant universe). The first point of interest is that the famous ‘spectral index’ of the power spectrum is close but not equal to one (0.96), just as expected for inflation. More specifically, probing the shape of the power spectrum gives a powerful tool for selecting or rejecting models. A shape that is decidedly non-Gaussian would effectively rule out ‘slow roll’ inflation, the simplest model.  On the other hand, a closely Gaussian shape would rule out two-field inflationary models, and impose serious constraints on most non-inflationary models. The new result: almost no deviations from Gaussianity, at least within a factor of one in a million. This places important new restraints on models such as cosmic strings,  global textures etc. It seems the result also makes ekpyrotic cyclic models a lot less likely (something to do with the mechanism proposed by most cyclic models, must look this up). Finally, another result was a clear lack of evidence for a fourth generation of neutrinos (was anyone really expecting otherwise?)

All in all, some fantastic results, I’m glad I was here to hear the exciting news at firsthand.  At the end, Paul Shellard joked that one can now read the initials SWH in the PLANCK spectrum (some people claimed that Stephen Hawking’s initials were clearly visible in the WMAP spectrum). It was a fun way to finish the morning’s seminars, but I couldn’t see really it! The main overview paper is here and you can access the full set of papers here.

IMG_0490

What I thought was the Institute of Astronomy at Cambridge (actually the library)

IMG_0492

The real Institute of Astronomy; not quite as majestic but buzzing with activity

3 Comments

Filed under Uncategorized

The God particle at Trinity College

On Monday evening, I gave a public lecture on the Higgs boson at Trinity College Dublin. The talk was organised by Astronomy Ireland and I think it was quite a success; 200 tickets were sold and quite a few people had to be turned away.

In the Joly lecture theatre at Trinity College Dublin

How to explain the basics of particle physics to a public audience? As always, I presented the material as a short history of discovery: from the atom to the nucleus,  from protons and neutrons to Gell-mann’s quarks. I also included some theory on the fundamental interactions, right up to the Standard Model,  electro-weak unification and the role of the Higgs field in electro-weak symmetry breaking. Not for the first time, I came away with the impression that the Standard Model isn’t as intimidating for the uninitiated as you might expect. As for physics beyond the Standard Model, the audience seemed to take the hypothesis of grand unification in their stride, and the connection between particle experiments and the early universe struck a chord, as always.

The results  It was a pleasure to present the fantastic results of the ATLAS and CMS teams, first announced at CERN last July. Giving such talks is a lot easier now that the data are publicly available in two beautiful papers on the ArXiv here and here. I gave an overview of the main findings in the context of previous experiments at CERN and at the Tevatron,  and I think the audience got a feel for the historic importance of the result. Certainly, there were plenty of questions afterwards, which continued in the pub afterwards.

The famous bumps ( excess decay events) seen by both ATLAS and CMS at around 125 GeV in the di-photon decay channel

Combined signal (all decay channels) for both ATLAS and CMS

So what about that title? Yes, I did agree to the title ‘The God particle at last’? I am aware that most physicists have a major problem with the moniker; it is sensationalist, inaccurate and incurs a completely gratuitous connection with religion. (Some religious folk consider it blasphemous,  while others misunderstand the term as evidence for their beliefs).

A poster for the talk; naughty

All of this is true, yet I must admit I’ve got to like the nickname; it is catchy and just mysterious enough to cause one to think. I imagine a tired lawyer catching sight of the poster as she walks home after work;  ‘God particle’ might cause a moment of reflection, where ‘Higgs boson’ will not. At least the former expression contains the word ‘particle’, giving the reader some chance to guess the subject. Of course the ‘God’ part is hubris, but is hubris so bad if it gets people thinking about science? Also, I disagree with commentators who insist that the Higgs is ‘no more important than any other particle’. Since all massive particles are thought to interact with the Higgs field, finding the particle associated with that quantum field is of great importance.

So is it found?  CERN Director General Rolf Heuer stated in Dublin, “As far as the layman is concerned with have it. As far as the physicist is concerned, we have to characterize it”. Such characterization has been going on since July. Without question, a new particle of integer spin (boson) and mass 125 +- 0.5 GeV has been discovered. So far, the branching ratios (the ratio of various decay channels to lighter particles) match the prediction of a Standard Model Higgs boson very well. So it looks and smells like a Higgs, and we are all getting used to the idea of the Higgs field as reality rather than hypothesis. (That said, there is still the possibility of spin 1 or 2 for the new particle, but this is not very likely).

All in all, a very enjoyable evening. The slides and poster I used for the talk are available here.  No doubt, some Trinity professors may have been none too pleased to see ‘God particle’ posters in the Hamilton building. Me, I’ve decided I can live with the name if that’s what it takes to get the public excited about particle physics…

Update

Some bloke called Zephyr is upset and accuses me of misleading the public (comments). His point is that I refer to the Higgs as a particle, instead of a quantum field. There is a valid point here; what were once thought of as elementary ‘particles’ of matter are now considered to be manifestations of quantum fields. However, in the business of communicating physics to the public, each physicist must find their own balance between what is accurate and what is comprehensible. My own experience is that people grasp the idea of the Standard Model reasonably well if it’s told as a story of particle discovery (phenomenology). A small amount on quantum theory is ok, but too much soon leaves ‘em bewildered. For this reason, I much prefer books like Particle physics: A Very Brief Introduction by Frank Close to books like Higgs: The Invention and Discovery of a Particle  (Jim Baggot)

39 Comments

Filed under CERN, Particle physics, Public lectures, Uncategorized

2010 blog reviews

WordPress send an annual review of blog readership to bloggers every New Year’s day; below are the stats for ANTIMATTER. I notice that the readership figures are quite high (for a science blog). This is probably because my posts are reprinted on international science websites such as Interactions.orgParticle Physics Planet and Irish websites such as Ninth-level Ireland – thanks for that everyone.  Perhaps another reason is that bloggers tend to list other blogs of interest alphabetically, so ANTIMATTER sits at the top of the blogroll in quite a few science blogs. (I notice from the stats that I get most traffic from NOT EVEN WRONG, RESONAANCES and CENTAURI DREAMS, thanks guys). I also notice that ANTIMATTER attracts a lot more viewers than commentators; this seems to be a feature of technical blogs. That said, it’s interesting that last year’s most popular post was one on skiing!

*********************************************************************

The stats helper monkeys at WordPress.com mulled over how the blog ANTIMATTER did in 2010, and here is a summary of its overall blog health:

Healthy blog!

The Blog-Health-o-Meter™ reads Wow.

Crunchy numbers

Featured image

Madison Square Garden can seat 20,000 people for a concert. This blog was viewed about 66,000 times in 2010. If it were a concert at Madison Square Garden, it would have performed about 3 times.

In 2010, there were 33 new posts, growing the total archive of this blog to 169 posts. There were 69 pictures uploaded, taking up a total of 15mb. That’s about 1 pictures per week.

The busiest day of the year was November 18th with 664 views. The most popular post that day was Skiing in Tignes.

Where did they come from?

The top referring sites in 2010 were math.columbia.edu, resonaances.blogspot.com, interactions.org, centauri-dreams.org, and facebook.com.

Some visitors came searching, mostly for antimatter, einstein, doolin, anti matter, and fridge.

Attractions in 2010

These are the posts and pages that got the most views in 2010.

1

Skiing in Tignes December 2009
2 comments

2

Lecture Notes April 2008
5 comments

3

Science week in Ireland: was Einstein wrong? November 2009
11 comments

4

Genius of Britain; Dawkins vs Hawking June 2010
7 comments

5

Introductory physics: circuits March 2010
4 comments

******************************************************************************

Postscript

ANTIMATTER picked up two awards this year – a Top Science Blog award from Science. Org and a Top 5 Blog award (in the cosmology category) from American Science Technicians.
.

2 Comments

Filed under Uncategorized

Stuck at the airport: that in-between time again

I’m still hoping to get back to Ireland for Christmas Day, but it’s now midday on Christmas Eve and I haven’t made it any further than Boston airport. The problem is, as everybody knows, many European airports like Dublin and Heathrow are experiencing large snowfalls and feezing conditions this week, and simply can’t keep the runways clear; planes can’t get in or out which causing travel chaos.

‘What? Snow in winter?’, you cry sarcastically. Yes, but heavy snow in December is relatively uncommon in countries like Ireland and the UK. Worse, it comes at a time of huge passenger volumes. Many airports simply can’t cope with the double whammy, with knockon effects for all air travel. Delays at Heathrow, in particular, have caused chaos at airports around Europe and elsewhere.

Dublin airport in the snow

As for me, I’m happy enough. I like these in-between times, where one is neither working nor on holiday. A good time to think. Also, Logan airport is very nice, sensibly divided into small terminals (unlike Dublin airport). Of course, travel delays are relatively easy if you don’t have tired kids, financial worries, or have to sleep on the airport floor. Here in Boston, Aer Lingus passengers are being put up in the nearby Hilton while we wait for the next available flight; pretty decent, considering the airline can hardly be held responsible for the weather.

I’m using the time to read through Piers Bizony’s ATOM, the only interesting book I could find in the tiny airport bookstore. The book is based on the excellent BBC TV series of the same name and it’s a very entertaining read, if a little surprising. From the title, I had expected a brief history of particle physics for the layman; from the discovery of the nucleus to the quark etc. Instead, the book concentrates mainly on the story of the evolution of quantum physics. Which is no harm. But it does remind me that there are remarkably few books out there that tell the story of the discovery of the atom and subatomic particles as a simple phenomenological tale . Hmm…

Something to think about. Right now, it’d be nice to get home sometime soon.

Update

We’re finally about to get on a plane to Dublin (arriving 3 am Christmas Day!) and I still haven’t finished Bizony’s book.  I’ve enjoyed my airport sojourn but others are less sanguine. Some passengers are utterly fed up and are less than polite to the airline staff.  It’s amazing how some need someone to blame in situations like this, even when it’s perfectly obvious that it’s weather, not the airline, that is the problem. Human nature I guess…

2 Comments

Filed under Particle physics, Travel, Uncategorized

Festival Interceltique de Lorient

I spent last week in Brittany, France at the Festival Interceltique de Lorient, the largest celtic music festival in the world. The festival was as good as ever, with parades, concerts and performances from pipe bands, music groups and dance troupes from all the great celtic nations.

Le grand defile interceltique

The sheer scale of the celtic world could be seen from the number of delegations – from Asturias (Spain), Galicia (Spain), Brittany (France), Cornwall (England), Scotland, Wales, Ireland, Acadia (Canada), Australia and the Isle of Man. There were concerts every day in the afternoons and evenings, not to mention the Nuit Magiques, chereographed performances on a giant scale in the local football stadium – some say the Lorient Nuit Magiques were the inspiration for Riverdance.

http://www.adelaidepipeband.com/images/photographs/lorient001.jpg
Nuit magique at the Stade Moustoir

Best of all were the sessions in some of the local pubs, with Irish, Bretons and others swapping tunes into the early hours (this is where where yours truly comes in). The sessions were a treat for any musician, with tunes in Quay St orThe Galway Inn, not to mention monster sessions with performers fresh from their gigs at the Pub Glen late into the night. This was the best part for me, as I enjoy playing music with musicians from slightly different traditions. I think folk music has an edge over other types of music when it comes to this sort of jamming – and if there is one thing better than a lively Irish session, it’s a session where there is a mix of cultures and traditions. Also, it’s very moving to hear a tune/song you’ve known your whole life played in a more minor, modal key – an older, deeper version that makes your version seem like a pale modern echo.

Fast tunes and sad songs with Brian Coombe in Quay St

In the thick of it in the Pub Glen.

This year I was asked to do a short solo gig, in a beautiful old mill by the river. It was really good fun to do, and the practice I had to do left me on top form for the sessions. Nothing quite like sitting in a session with friends new and old when it suddenly goes supernova. Not to mention the wired social life when the musicians finally down their instruments…

Overall, this is a great international music festival – a feeling of an inheritance that is shared, yet different. I’m constantly amazed at the sheer diversity of European culture and its effect on the world…there’s a nice discussion of this on the festival website

4 Comments

Filed under Uncategorized

Free speech, AIDS and the HIV virus

Johnny Steinberg has a depressing article on skepticism and the HIV virus in this week’s edition of New Scientist.

The article starts with the story of Christine Maggiore, a 52-year old who died in 2008 from infections typical of AIDS. Apparently, she had tested positive for HIV 16 years ealier, but shunned anti-retroviral therapy (ART), the therapy that is known to hinder AIDS developing from the virus. Her choice, you  might say; until you read that she also denied the treatment to her infant daughter, who died of AIDs-related illnesses at age 3.

Steinberg then goes on to describe the HIV denial movement, starting with arch-skeptic Peter Duesberg. Duesberg’s work with retroviruses – the class to which HIV belongs – led him to conclude that all such viruses are essentially harmless. In fact, many scientists shared Duesberg’s skepticism of the HIV- AIDS link in the late 1980s, but support rapidly fell away as clinical evidence linking HIV to AIDs mounted. In Duesberg’s case, rather than revise his views in the face of emerging epidemiological evidence, he chose to hang on to his old theory – a position he has stuck to ever since.

Professor Peter Duesberg of the University of Berkeley

The publicity afforded to Duesberg and other skeptics has had serious consequences for society. According to the New Scientist, a recent survey suggested that 25% of the US population currently question the link between HIV and AIDS. Even more seriously, NS cites the case of South Africa, a country where AIDS has made devastating inroads. Because President Mkebe chose to believe the skeptics, he strongly resisted the use of ART therapy in South Africa – it is now estimated that over 300,000 AIDS victims died unnecessarily there.

So what is at the root of this sort of skepticism? I have to agree with Steinberg when he states that “no amount of evidence will overturn the entrenched beliefs of some”. Combine this with the tendency of the media to highlight studies that show unorthodox results and you are well on the road to the public misunderstanding of science.

Perhaps we scientists are partially to blame. It seems to me that we do a poor job of communicating the consensus position – and how it is achieved – on important issues, from global warming to the MMR vacinne. There will always be scientists who question the mainstream, even in the face of overwhelming evidence; such is human nature and we cannot censor such views in a free society. Not to mention the fact that science progresses by asking the unthinkable. Perhaps the solution is to convince the media not to allow ‘maverick’ scientists disproportionate publicity – and for the elders of science to take the communication of science to the public more seriously. In Ireland, there isn’t a single university that has a Professorship for the Public Understanding of Science..

Update

In the same issue, New Scientist have an excellent editorial on the importance of scientific heresy. There is no contradiction here – the questioning of ‘accepted science’ from within is a vital part of scientific discovery and long may it continue. It is the misrepresentation in the media of the scientific consensus on a given topic that is of concern..you can find more information on this topic on Seth Kalichman’s ‘s blog denyingaids.blogspot.com

5 Comments

Filed under Science and society, Uncategorized