Archive for Particle Physics

Knit your own Neutralino

Posted in The Universe and Stuff with tags , , , , on June 21, 2014 by telescoper

I thought I’d give you a sneak preview of something soon to feature at the forthcoming Royal Society Summer Science Exhibition. With input from particle physicists from the Department of Physics & Astronomy at the University of Sussex, the inestimable Dorothy Lamb has designed a “Knit your own Neutralino” pack, which contains a knitting pattern and embellishments (wool not included), that can be used to construct a plushie representing the lightest neutralino, χ01, a candidate for the dark matter that pervades the Universe.

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Here are some examples, as produced by Dorothy herself:

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Here are some more elaborate variations, representing (I think) different types of chargino.

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Whatever they are, they’re a lot of fun and in my opinion more than a little bit camp!

I think we should introduce knitting as part of the “transferable skills” element of our physics courses. If we did, Dorothy would definitely graduate with first class honours!

Ode to SnarXiv

Posted in The Universe and Stuff with tags , , , , on April 30, 2014 by telescoper

So many things pass me by these days that I’m not usually surprised when I have no idea what people around me are talking about. I am however quite surprised that, until yesterday, never heard of the snarXiv. As its author explains:

The snarXiv is a ran­dom high-energy the­ory paper gen­er­a­tor incor­po­rat­ing all the lat­est trends, entropic rea­son­ing, and excit­ing mod­uli spaces. The arXiv is sim­i­lar, but occa­sion­ally less ran­dom.

The snarXiv uses “Context Free Grammar” together with a database of stock words and phrases to generate its content, which is actually just limited to titles and abstracts rather than entire papers. It’s just a matter of time, though. The results are variable, with some making no sense at all even by the standards of theoretical particle physics, but the best are almost good enough to pass off as real abstracts.

Here’s an example in the form of the abstract of a paper called (P,q) Brane Probe Predicted From Conformal Blocks:

Recently, work on new inflation has opened up a perturbative class of braneworld matrix models. We make contact with observables, moreover investigating trivial Beckenstein-Boltzmann equations. Next, using the behavior of a left-right reduction of models of WIMPs, we reformulate instanton liquids at the LHC. After discussing positrons, we check that worldsheet symmetric central charges are equivalent to electric-duality in gravity. Finally, we make contact with a special lagrangian brane, surprisingly obtaining models of inertial fluctuations.

Why not have a go at arXiv versus SnarXiv to see if you can spot the genuine article titles?

I’m tempted, with a nod in the light of the Sokal Affair, to suggest that a similar approach used in the social sciences, but the thing that really struck me is that someone should do a snarXiv for astronomy and astrophysics. Or is someone going to tell me it already exists?

Come to think of it, judging by some of the proposals I’ve read while serving on the Astronomy Grants Panel over the years, a similar generator may already exist for writing grant applications…

NOvA and Neutrinos

Posted in The Universe and Stuff with tags , , , , on March 11, 2014 by telescoper

Yesterday’s Grauniad blog post by Jon Butterworth about neutrino physics reminded me that I forgot to post about an important milestone in the development of the NOvA Experiment which involves several members of the Department of Physics and Astronomy in the School of Mathematical and Physical Sciences here at the University of Sussex. Here’s the University of Sussex’s press release on the subject, which came out a couple of weeks ago.

The NOvA experiment consists of two enormous  particle detectors, one at the Fermi National Accelerator Laboratory “Fermilab” near Chicago and the other in Minnesota. The neutrinos are actually generated  at Fermilab; the particle beam is then aimed  at the detectors the, one near the source at Fermilab, and the other in Ash River, Minnesota, near the Canadian border. The particles, sent in their billions every couple of seconds, complete the 500-mile trip in less than three milliseconds.

The point is that the experiment has managed for the first time to actually detect neutrinos through the 500 miles of rock separating the two ends of the experiment. This is obviously just a first step, but it’s equally obviously a crucial one.

Colleagues from Sussex University are strongly involved in  calibrating and fine-tuning the detector, which produces light when particles pass through it. Dr Abbey Waldron and PhD student Luke Vinton have developed a calibration procedure that uses known properties of  muons to calibrate precise measurements of the neutrinos, which are less well understood.  The detector sees 200,000 particle interactions a second, produced by cosmic rays bombarding the atmosphere, and scientists can’t record every single one. Sussex’s Dr Matthew Tamsett has developed a trigger algorithm that searches for events that look like neutrinos among the billions of other particle interactions.

Neutrino physics is an interesting subject to someone like me, who isn’t really a particle physicist. My impression of the field is that was fairly moribund until 1998 when the first measurement of atmospheric neutrino oscillations was announced. All of a sudden there was evidence that neutrinos can’t all be massless (as many of us had long assumed, at least as far as lecturing was concerned).  Now the humble neutrino is the subject of intense experimental activity, not only in the USA and UK but all around the world in a way that would have been difficult to predict twenty years ago.

But then, as the physicist Niels Bohr famously observed, “Prediction is very difficult. Especially about the future.”

Is Inflation Testable?

Posted in The Universe and Stuff with tags , , , , , , , , on March 4, 2014 by telescoper

It seems the little poll about cosmic inflation I posted last week with humorous intent has ruffled a few feathers, but at least it gives me the excuse to wheel out an updated and edited version of an old piece I wrote on the subject.

Just over thirty  years ago a young physicist came up with what seemed at first to be an absurd idea: that, for a brief moment in the very distant past, just after the Big Bang, something weird happened to gravity that made it push rather than pull.  During this time the Universe went through an ultra-short episode of ultra-fast expansion. The physicist in question, Alan Guth, couldn’t prove that this “inflation” had happened nor could he suggest a compelling physical reason why it should, but the idea seemed nevertheless to solve several major problems in cosmology.

Three decades later, Guth is a professor at MIT and inflation is now well established as an essential component of the standard model of cosmology. But should it be? After all, we still don’t know what caused it and there is little direct evidence that it actually took place. Data from probes of the cosmic microwave background seem to be consistent with the idea that inflation happened, but how confident can we be that it is really a part of the Universe’s history?

According to the Big Bang theory, the Universe was born in a dense fireball which has been expanding and cooling for about 14 billion years. The basic elements of this theory have been in place for over eighty years, but it is only in the last decade or so that a detailed model has been constructed which fits most of the available observations with reasonable precision. The problem is that the Big Bang model is seriously incomplete. The fact that we do not understand the nature of the dark matter and dark energy that appears to fill the Universe is a serious shortcoming. Even worse, we have no way at all of describing the very beginning of the Universe, which appears in the equations used by cosmologists as a “singularity”- a point of infinite density that defies any sensible theoretical calculation. We have no way to define a priori the initial conditions that determine the subsequent evolution of the Big Bang, so we have to try to infer from observations, rather than deduce by theory, the parameters that govern it.

The establishment of the new standard model (known in the trade as the “concordance” cosmology) is now allowing astrophysicists to turn back the clock in order to understand the very early stages of the Universe’s history and hopefully to understand the answer to the ultimate question of what happened at the Big Bang itself and thus answer the question “How did the Universe Begin?”

Paradoxically, it is observations on the largest scales accessible to technology that provide the best clues about the earliest stages of cosmic evolution. In effect, the Universe acts like a microscope: primordial structures smaller than atoms are blown up to astronomical scales by the expansion of the Universe. This also allows particle physicists to use cosmological observations to probe structures too small to be resolved in laboratory experiments.

Our ability to reconstruct the history of our Universe, or at least to attempt this feat, depends on the fact that light travels with a finite speed. The further away we see a light source, the further back in time its light was emitted. We can now observe light from stars in distant galaxies emitted when the Universe was less than one-sixth of its current size. In fact we can see even further back than this using microwave radiation rather than optical light. Our Universe is bathed in a faint glow of microwaves produced when it was about one-thousandth of its current size and had a temperature of thousands of degrees, rather than the chilly three degrees above absolute zero that characterizes the present-day Universe. The existence of this cosmic background radiation is one of the key pieces of evidence in favour of the Big Bang model; it was first detected in 1964 by Arno Penzias and Robert Wilson who subsequently won the Nobel Prize for their discovery.

The process by which the standard cosmological model was assembled has been a gradual one, but the latest step was taken by the European Space Agency’s Planck mission . I’ve blogged about the implications of the Planck results for cosmic inflation in more technical detail here. In a nutshell, for several years this satellite mapped  the properties of the cosmic microwave background and how it varies across the sky. Small variations in the temperature of the sky result from sound waves excited in the hot plasma of the primordial fireball. These have characteristic properties that allow us to probe the early Universe in much the same way that solar astronomers use observations of the surface of the Sun to understand its inner structure,  a technique known as helioseismology. The detection of the primaeval sound waves is one of the triumphs of modern cosmology, not least because their amplitude tells us precisely how loud the Big Bang really was.

The pattern of fluctuations in the cosmic radiation also allows us to probe one of the exciting predictions of Einstein’s general theory of relativity: that space should be curved by the presence of matter or energy. Measurements from Planck and its predecessor WMAP reveal that our Universe is very special: it has very little curvature, and so has a very finely balanced energy budget: the positive energy of the expansion almost exactly cancels the negative energy relating of gravitational attraction. The Universe is (very nearly) flat.

The observed geometry of the Universe provides a strong piece of evidence that there is an mysterious and overwhelming preponderance of dark stuff in our Universe. We can’t see this dark matter and dark energy directly, but we know it must be there because we know the overall budget is balanced. If only economics were as simple as physics.

Computer Simulation of the Cosmic Web

The concordance cosmology has been constructed not only from observations of the cosmic microwave background, but also using hints supplied by observations of distant supernovae and by the so-called “cosmic web” – the pattern seen in the large-scale distribution of galaxies which appears to match the properties calculated from computer simulations like the one shown above, courtesy of Volker Springel. The picture that has emerged to account for these disparate clues is consistent with the idea that the Universe is dominated by a blend of dark energy and dark matter, and in which the early stages of cosmic evolution involved an episode of accelerated expansion called inflation.

A quarter of a century ago, our understanding of the state of the Universe was much less precise than today’s concordance cosmology. In those days it was a domain in which theoretical speculation dominated over measurement and observation. Available technology simply wasn’t up to the task of performing large-scale galaxy surveys or detecting slight ripples in the cosmic microwave background. The lack of stringent experimental constraints made cosmology a theorists’ paradise in which many imaginative and esoteric ideas blossomed. Not all of these survived to be included in the concordance model, but inflation proved to be one of the hardiest (and indeed most beautiful) flowers in the cosmological garden.

Although some of the concepts involved had been formulated in the 1970s by Alexei Starobinsky, it was Alan Guth who in 1981 produced the paper in which the inflationary Universe picture first crystallized. At this time cosmologists didn’t know that the Universe was as flat as we now think it to be, but it was still a puzzle to understand why it was even anywhere near flat. There was no particular reason why the Universe should not be extremely curved. After all, the great theoretical breakthrough of Einstein’s general theory of relativity was the realization that space could be curved. Wasn’t it a bit strange that after all the effort needed to establish the connection between energy and curvature, our Universe decided to be flat? Of all the possible initial conditions for the Universe, isn’t this very improbable? As well as being nearly flat, our Universe is also astonishingly smooth. Although it contains galaxies that cluster into immense chains over a hundred million light years long, on scales of billions of light years it is almost featureless. This also seems surprising. Why is the celestial tablecloth so immaculately ironed?

Guth grappled with these questions and realized that they could be resolved rather elegantly if only the force of gravity could be persuaded to change its sign for a very short time just after the Big Bang. If gravity could push rather than pull, then the expansion of the Universe could speed up rather than slow down. Then the Universe could inflate by an enormous factor (1060 or more) in next to no time and, even if it were initially curved and wrinkled, all memory of this messy starting configuration would be lost. Our present-day Universe would be very flat and very smooth no matter how it had started out.

But how could this bizarre period of anti-gravity be realized? Guth hit upon a simple physical mechanism by which inflation might just work in practice. It relied on the fact that in the extreme conditions pertaining just after the Big Bang, matter does not behave according to the classical laws describing gases and liquids but instead must be described by quantum field theory. The simplest type of quantum field is called a scalar field; such objects are associated with particles that have no spin. Modern particle theory involves many scalar fields which are not observed in low-energy interactions, but which may well dominate affairs at the extreme energies of the primordial fireball.

Classical fluids can undergo what is called a phase transition if they are heated or cooled. Water for example, exists in the form of steam at high temperature but it condenses into a liquid as it cools. A similar thing happens with scalar fields: their configuration is expected to change as the Universe expands and cools. Phase transitions do not happen instantaneously, however, and sometimes the substance involved gets trapped in an uncomfortable state in between where it was and where it wants to be. Guth realized that if a scalar field got stuck in such a “false” state, energy – in a form known as vacuum energy – could become available to drive the Universe into accelerated expansion.We don’t know which scalar field of the many that may exist theoretically is responsible for generating inflation, but whatever it is, it is now dubbed the inflaton.

This mechanism is an echo of a much earlier idea introduced to the world of cosmology by Albert Einstein in 1916. He didn’t use the term vacuum energy; he called it a cosmological constant. He also didn’t imagine that it arose from quantum fields but considered it to be a modification of the law of gravity. Nevertheless, Einstein’s cosmological constant idea was incorporated by Willem de Sitter into a theoretical model of an accelerating Universe. This is essentially the same mathematics that is used in modern inflationary cosmology.  The connection between scalar fields and the cosmological constant may also eventually explain why our Universe seems to be accelerating now, but that would require a scalar field with a much lower effective energy scale than that required to drive inflation. Perhaps dark energy is some kind of shadow of the inflaton

Guth wasn’t the sole creator of inflation. Andy Albrecht and Paul Steinhardt, Andrei Linde, Alexei Starobinsky, and many others, produced different and, in some cases, more compelling variations on the basic theme. It was almost as if it was an idea whose time had come. Suddenly inflation was an indispensable part of cosmological theory. Literally hundreds of versions of it appeared in the leading scientific journals: old inflation, new inflation, chaotic inflation, extended inflation, and so on. Out of this activity came the realization that a phase transition as such wasn’t really necessary, all that mattered was that the field should find itself in a configuration where the vacuum energy dominated. It was also realized that other theories not involving scalar fields could behave as if they did. Modified gravity theories or theories with extra space-time dimensions provide ways of mimicking scalar fields with rather different physics. And if inflation could work with one scalar field, why not have inflation with two or more? The only problem was that there wasn’t a shred of evidence that inflation had actually happened.

This episode provides a fascinating glimpse into the historical and sociological development of cosmology in the eighties and nineties. Inflation is undoubtedly a beautiful idea. But the problems it solves were theoretical problems, not observational ones. For example, the apparent fine-tuning of the flatness of the Universe can be traced back to the absence of a theory of initial conditions for the Universe. Inflation turns an initially curved universe into a flat one, but the fact that the Universe appears to be flat doesn’t prove that inflation happened. There are initial conditions that lead to present-day flatness even without the intervention of an inflationary epoch. One might argue that these are special and therefore “improbable”, and consequently that it is more probable that inflation happened than that it didn’t. But on the other hand, without a proper theory of the initial conditions, how can we say which are more probable? Based on this kind of argument alone, we would probably never really know whether we live in an inflationary Universe or not.

But there is another thread in the story of inflation that makes it much more compelling as a scientific theory because it makes direct contact with observations. Although it was not the original motivation for the idea, Guth and others realized very early on that if a scalar field were responsible for inflation then it should be governed by the usual rules governing quantum fields. One of the things that quantum physics tells us is that nothing evolves entirely smoothly. Heisenberg’s famous Uncertainty Principle imposes a degree of unpredictability of the behaviour of the inflaton. The most important ramification of this is that although inflation smooths away any primordial wrinkles in the fabric of space-time, in the process it lays down others of its own. The inflationary wrinkles are really ripples, and are caused by wave-like fluctuations in the density of matter travelling through the Universe like sound waves travelling through air. Without these fluctuations the cosmos would be smooth and featureless, containing no variations in density or pressure and therefore no sound waves. Even if it began in a fireball, such a Universe would be silent. Inflation puts the Bang in Big Bang.

The acoustic oscillations generated by inflation have a broad spectrum (they comprise oscillations with a wide range of wavelengths), they are of small amplitude (about one hundred thousandth of the background); they are spatially random and have Gaussian statistics (like waves on the surface of the sea; this is the most disordered state); they are adiabatic (matter and radiation fluctuate together) and they are formed coherently.  This last point is perhaps the most important. Because inflation happens so rapidly all of the acoustic “modes” are excited at the same time. Hitting a metal pipe with a hammer generates a wide range of sound frequencies, but all the different modes of the start their oscillations at the same time. The result is not just random noise but something moderately tuneful. The Big Bang wasn’t exactly melodic, but there is a discernible relic of the coherent nature of the sound waves in the pattern of cosmic microwave temperature fluctuations seen in the Cosmic Microwave Background. The acoustic peaks seen in the  Planck  angular spectrum  provide compelling evidence that whatever generated the pattern did so coherently.

Planck_power_spectrum_orig
There are very few alternative theories on the table that are capable of reproducing these results, but does this mean that inflation really happened? Do they “prove” inflation is correct? More generally, is the idea of inflation even testable?

So did inflation really happen? Does Planck prove it? Will we ever know?

It is difficult to talk sensibly about scientific proof of phenomena that are so far removed from everyday experience. At what level can we prove anything in astronomy, even on the relatively small scale of the Solar System? We all accept that the Earth goes around the Sun, but do we really even know for sure that the Universe is expanding? I would say that the latter hypothesis has survived so many tests and is consistent with so many other aspects of cosmology that it has become, for pragmatic reasons, an indispensable part our world view. I would hesitate, though, to say that it was proven beyond all reasonable doubt. The same goes for inflation. It is a beautiful idea that fits snugly within the standard cosmological and binds many parts of it together. But that doesn’t necessarily make it true. Many theories are beautiful, but that is not sufficient to prove them right.

When generating theoretical ideas scientists should be fearlessly radical, but when it comes to interpreting evidence we should all be unflinchingly conservative. The Planck measurements have also provided a tantalizing glimpse into the future of cosmology, and yet more stringent tests of the standard framework that currently underpins it. Primordial fluctuations produce not only a pattern of temperature variations over the sky, but also a corresponding pattern of polarization. This is fiendishly difficult to measure, partly because it is such a weak signal (only a few percent of the temperature signal) and partly because the primordial microwaves are heavily polluted by polarized radiation from our own Galaxy. Polarization data from Planck are yet to be released; the fiendish data analysis challenge involved is the reason for the delay.  But there is a crucial target that justifies these endeavours. Inflation does not just produce acoustic waves, it also generates different modes of fluctuation, called gravitational waves, that involve twisting deformations of space-time. Inflationary models connect the properties of acoustic and gravitational fluctuations so if the latter can be detected the implications for the theory are profound. Gravitational waves produce very particular form of polarization pattern (called the B-mode) which can’t be generated by acoustic waves so this seems a promising way to test inflation. Unfortunately the B-mode signal is expected to be very weak and the experience of WMAP suggests it might be swamped by foregrounds. But it is definitely worth a go, because it would add considerably to the evidence in favour of inflation as an element of physical reality.

But would even detection of primordial gravitational waves really test inflation? Not really. The problem with inflation is that it is a name given to a very general idea, and there are many (perhaps infinitely many) different ways of implementing the details, so one can devise versions of the inflationary scenario that produce a wide range of outcomes. It is therefore unlikely that there will be a magic bullet that will kill inflation dead. What is more likely is a gradual process of reducing the theoretical slack as much as possible with observational data, such as is happening in particle physics. For example, we have not yet identified the inflaton field (nor indeed any reasonable candidate for it) but we are gradually improving constraints on the allowed parameter space. Progress in this mode of science is evolutionary not revolutionary.

Many critics of inflation argue that it is not a scientific theory because it is not falsifiable. I don’t think falsifiability is a useful concept in this context; see my many posts relating to Karl Popper. Testability is a more appropriate criterion. What matters is that we have a systematic way of deciding which of a set of competing models is the best when it comes to confrontation with data. In the case of inflation we simply don’t have a compelling model to test it against. For the time being therefore, like it or not, cosmic inflation is clearly the best model we have. Maybe someday a worthy challenger will enter the arena, but this has not happened yet.

Most working cosmologists are as aware of the difficulty of testing inflation as they are of its elegance. There are also those  who talk as if inflation were an absolute truth, and those who assert that it is not a proper scientific theory (because it isn’t falsifiable). I can’t agree with either of these factions. The truth is that we don’t know how the Universe really began; we just work on the best ideas available and try to reduce our level of ignorance in any way we can. We can hardly expect  the secrets of the Universe to be so easily accessible to our little monkey brains.

Yesterday in Parliament

Posted in Science Politics, The Universe and Stuff with tags , , , , , on October 9, 2013 by telescoper

Yesterday afternoon I arrived in a rather muggy Westminster to attend a reception at the Houses of Parliament associated with an exhibition called Unveiling the Universe in all its Light which is currently set up inside the Palace of Westminster but will later go on tour around the UK.

Parliament

It took me a while to find the way in. I lived in London for the best part of 9 years but never bothered to visit the Houses of Parliament (at least not the interior), so I was quite excited as, clutching my invitation in a rather sweaty hand, I eventually joined the queue to go through the security checks. That didn’t take very long, so despite getting lost in the corridors of power en route – it’s a bit of a maze inside – I had plenty of time to see the exhibition before joining the assembled throng in the Strangers’ Dining Room. There, surrounded by walls covered in expensive but tasteless flock wallpaper, I had a couple of couples of glasses of wine and ate some posh sandwiches while chatting to various astronomers, particle physicists and others, including a contingent of familiar faces from the Science and Technology Facilities Council.

It was a coincidence, of course, that this event took place on the day that the Nobel Prize for Physics was announced; it was impressive that posters were already there celebrating the award to Peter Higgs. General opinion was delight that Higgs had won a share of the prize, but sadness that Tom Kibble had been left out.

There were upbeat speeches by Minister for Universities and Science David Willetts (who isn’t as tall as he looks on telly), Andrew Miller (Chair of the Parliamentary Select Committee on Science and Technology), John Womersley (Chief Executive of STFC) and Lord Rees (Astronomer Royal). I think everyone present came away with a strong sense that astronomy and particle physics had strong political backing. Martin Rees in particular said that he thought we were living in a “golden age” for fundamental science, involving an exciting interplay between the inner space of subatomic particles and the outer space of cosmology. I couldn’t agree more.

The 2013 Nobel Prize for Physics .. goes to Englert and Higgs

Posted in Science Politics, The Universe and Stuff with tags , , , , , , on October 8, 2013 by telescoper

Well, there we are. After an excruciating (and unexplained) delay the 2013 Nobel Prize for Physics has gone to François Englert and Peter Higgs. You can find the full press release here; the first section of text reads:

François Englert and Peter W. Higgs are jointly  awarded the Nobel Prize in Physics 2013 for the  theory of how particles acquire mass. In 1964, they  proposed the theory independently of each other  (Englert together with his now deceased colleague  Robert Brout). In 2012, their ideas were confirmed  by the discovery of a so called Higgs particle at the  CERN laboratory outside Geneva in Switzerland. The awarded theory is a central part of the Standard  Model of particle  hysics that describes how the world is  constructed. According to the Standard Model, every­thing, from flowers and people to stars and planets,  consists of just a few building blocks: matter particles.  These particles are governed by forces mediated by force  particles that make sure everything works as it should. The entire Standard Model also rests on the existence  of a special kind of particle: the Higgs particle. This  particle originates from an invisible field that fills up  all space. Even when the universe seems empty this  field is there. Without it, we would not exist, because  it is from contact with the field that particles acquire  mass. The theory proposed by Englert and Higgs  describes this process.

Anyway, congratulations to the two Laureates. I did get a bit excited when the rumour started that the winner this year would be someone born in Newcastle upon Tyne whose first name is Peter, but I guess I’ll have to wait until next year..

Oh, and François Englert is the first ever Belgian winner of the Nobel Prize for Physics!

I have to head off to London for a Parliamentary Reception organized by the Science & Technology Facilities Council, so I’ll have to leave it there but please feel free to add reactions to the announcement via the Comments Box.

P.S. Yesterday’s poll is now closed.

Physics Nobel Betting

Posted in Science Politics, The Universe and Stuff with tags , , , , , , , on October 7, 2013 by telescoper

I’m back in circulation just in time for tomorrow’s announcement of the 2013 Nobel Prize for Physics. The smart money is going on an award for the discovery of the Higgs Boson, but to whom should it be awarded. Today’s Grauniad summarizes the difficulties thus:

The committee can contrive the wording of the prize to narrow the number downwards and this is likely to happen. The prize could go to François Englert, who published the idea first, and Peter Higgs, who was second, but crucially was first to flag up the new particle. But that would rebuff the trio of Gerald Guralnik, Carl Richard Hagen and Tom Kibble, who developed the theory separately and published just a month after Higgs. The possibility has already caused acrimony among the scientists. Guralnik and Hagen, two US researchers, believe European physicists have conspired to erase their contribution from history.

This doesn’t seem to me to be entirely accurate, though. As far as I understand it, Higgs was the only one of the names above to mention a massive scalar particle, There is, I believe, therefore a strong case that the Nobel Prize should be awarded to Peter Higgs outright. Or if not to him, to some other person called Peter who was born in the North East…

However, I am used to being in a minority of one so there will undoubtedly be many others who feel differently.  Time for a poll! This one is different from my usual ones, in that you are allowed to vote more than once. Please use up to three votes: if you think Peter Higgs should win it outright vote three times for him. If you think it should be a three way split then vote for three different people, etc.

I should say that I don’t think the Nobel Committee for Physics is allowed to make an award to an institution such as CERN, but I’ve left that option in to see whether folks think that tradition should change..

UPDATE: Here are the Thomson-Reuters predictions, including Marcy, Mayor and Queloz for Extra Solar Planets…

 

Neutrino Physics in a Small Universe

Posted in Biographical, The Universe and Stuff with tags , , , , , , , on April 23, 2013 by telescoper

I’ve only just got time for a quick lunchtime post before I head off to attend an afternoon of Mathematics presentations, but it’s a one of those nice bits of news that I like to mention on here from time to time.

It is my pleasure to pass on the wonderful news that one of my colleagues in the School of Mathematical and Physical Sciences here at the University of Sussex,  Dr Jeff Hartnell,. has been awarded  the High Energy Particle Physics prize of the Institute of Physics, which means that his name has now been added to the illustrious list of previous winners. The prize is awarded annually by the HEPP Group, a subject group in the Nuclear and Particle Physics Division of the IOP, to a researcher in the UK who has made an outstanding contribution to their field of study early in their career (within 12 years of being awarded their first degree).

There’s a very nice piece about this award here which reveals, amongst other things, that many moons ago at Nottingham I was Jeff’s undergraduate tutor! In fact Jeff also attended a third-year course on Theoretical Elementary Particle Physics I taught in those days. That he survived those experience and went on to be a world-leading physicist speaks volumes! Not only that, it’s also evidence that the world of physics is smaller than we sometimes suppose. I’ve crossed paths with a number of my new colleagues at various times in the past, but it’s particularly rewarding to see someone you taught as an undergraduate go on to a highly successful career as a scientist. Jeff was awarded a prestigious ERC grant this year too!

Jeff is currently in the USA helping to set up the largest-ever experiment in neutrinos to be built there, called NOvA. You can click on the preceding links for more technical details, and I also found this interesting video showing the NOvA detector being assembled. Particle physics experiments are never small, are they?

p.s. Why do they insist on writing “metric ton” instead of “tonne”?

Should UK Research Funding Be Reorganized?

Posted in Finance, Science Politics with tags , , , , , , , , , , on April 13, 2013 by telescoper

A couple of recent news items spurred me on to reflect a bit about the system of research funding in the UK. The first of these was an item I noticed a while ago in Research Fortnight about the (ongoing) Triennial Review of the research councils, and specifically, input from the Wellcome Trust to that review that was rather critical of the Science and Technology Facilities Council and suggested it might be dismantled.

For context it’s probably a good idea to look back to the formation of STFC in 2007 via the merger of the Particle Physics and Astronomy Research Council (PPARC) and the Council for the Central Laboratories of the Research Councils (CCLRC). Previously, PPARC had looked after particle physics and astronomy (including space science) and CCLRC had run large experimental facilities in other branches of science. The idea of merging them wasn’t silly. A large chunk of PPARC’s budget went on managing large facilities, especially ground-based astronomical observatories, and it was probably hoped that it would be more efficient to put all these big expensive pieces of kit under the same roof (so to speak).

However, at the time, there was considerable discussion about what should happen in general with science grants. For example, physicists working in UK universities in areas outside astronomy and particle physics previously obtained research grants from the Engineering and Physical Sciences Research Council (EPSRC), along with chemists, engineers and even mathematicians. Some experimentalists working in these areas used facilities run by the CCLRC to do their work. However, astronomers and particle physicists got their grants from PPARC, the same organisation that ran their facilities and also paid subscriptions to international agencies such as CERN and ESA. These grants were often termed “exploitation”  or “responsive mode” grants; they involved funding for postdoctoral researchers and staff time used in analysing observational or experimental data and comprised relatively little money compared the the cost of the PPARC facilities themselves. PPARC also funded PhD studentships and postdoctoral fellowships under the umbrella of its Education and Training division, although needless to say all the Education and Training involved was done in host universities, not by PPARC itself.

The question was whether the new merged organisation, STFC should continue giving grants to university groups or whether the responsibility for doing this should be moved elsewhere, perhaps to EPSRC. At the time, most astronomers were keen to have their research grants administered by the same organisation that ran the facilities. I thought it made more sense to have research scientists all on the same footing when it came to funding and in any case thought there were too many absurd divisions between, say, general relativity (EPSRC) and relativistic astrophysics (PPARC), so I was among the (relatively few) dissenting voices at the time.

There were other reasons for my unease. One was that, during a previously funding squeeze, PPARC had taken money from the grants line (the pot of money used for funding research groups) in order to balance the books, necessarily reducing the amount of science being done with its facilities. If STFC decided to do this it would probably cause even more pain, because grants would be an even smaller fraction of the budget in STFC than they were in PPARC. Those EPSRC physicists using CCLRC facilities seem to have managed pretty well so I didn’t really see the argument for astronomy and particle physics being inside STFC.

The other reason for me wanting to keep research grants out of STFC was that the (then) new Chief Executive of PPARC, Keith Mason, had made no secret of the disdain he felt towards university-based astronomy groups and had stated on a number of occasions his opinion that there were too many astronomers in the United Kingdom. There are two flaws with this argument. One is that astronomy is essential to the viability of many physics departments because of its appeal to potential students; without it, many departments will fold. The other problem is that Mason’s claim that the number of astronomers had grown by 40% in a few years was simply bogus.  This attitude convinced me that he in particular would need only the slightest excuse to divert funds away from astronomy into areas such as space exploration.

It all seems a very distant memory now, but six or years ago UK physics (including astronomy) was experiencing a time of relative plenty. The government had introduced a system whereby the research councils would fund research groups on the basis of the Full Economic Cost of the research, which meant more money coming into research groups that were successful at winning grants. The government increased funding for the councils to pay for this largesse and probably diminished the fear of another funding pinch. Astronomers and particle physicists also felt they would have more influence over future strategy in facility development by remaining within the same organisation. In the end what happened was that STFC not only kept the portfolio of astronomy and particle physics grants, but also acquired responsibility for nuclear physics from EPSRC.

But then, in 2007, just after STFC came into existence,  a major financial disaster broke: that year’s comprehensive spending review left the newly formed STFC with a huge gap in its finances. I don’t know why this happened but it was probably a combination of gross incompetence on behalf of the STFC Executive and deliberate action by persons higher up in the Civil Service. The subsequent behaviour of the Chief Executive of STFC led to a public dressing down by the House of Commons Select Committee and a complete loss of confidence in him by the scientific community. Miraculously, he survived, at least for a while. Unfortunately, so did the financial problems that are his legacy.

I don’t like to say I told you so, but that’s exactly what I am going to dp. Everything that happened was predictable given the initial conditions. You might argue that STFC wasn’t to know about the global economic downturn.As a matter of fact I’d agree. However, the deep cuts in the science budget we have seen have very little to do with that. They all stem from the period before the Credit Crunch even started. Although Prof. Mason was eventually replaced (in 20111), the problems inherent in STFC are far from solved.

The last Comprehensive Spending Review (2010) was less bad for STFC than some of us feared – with a level cash settlement which still holds. In real times the funds are now being eroded rather than being slashed further, but the situation remains very difficult because of past damage. I don’t think STFC  can afford to settle for flat cash at the next spending review. The new Supreme Leader  Chief Executive of STFC, John Womersley, said much the same thing at last night’s RAS dinner, in fact.

I know this preamble has been a bit long-winded, but I think it’s necessary to see the background to what I’m going to propose. These are the steps I think need to be taken to put UK physics back on track.

First, the powers that be have to realize that university researchers are not just the icing on the cake when it comes to science: they actually do most of the science. I think the new regime at STFC recognizes this, but I’m not sure the government does. Another problem is that  that the way scientists are supported in their research is a complete mess. It’s called the dual support system, because the research councils pay 80% of the cost of research grants and Higher Education Funding Councils (i.e. HEFCE in England) are meant to provide the other 20%. But in reality it is a bureaucratic nightmare that subjects researchers to endless form-filling and costs hundreds of millions in wasteful duplication. This was true enough of the old Research Assessment Exercise, but has been taken to even higher levels of absurdity by the forthcoming Research Excellence Framework, the decisions coming out of which will be more influencing by guesswork and institutional game-playing than actual research excellence.

The Research Councils already have well-managed systems to judge the quality of research grant applications, so do we really needed the REF on top of them?  The second article I referred to in the introduction, on a study showing that Research Council grant income, appeared in last week’s Times Higher. That study shows -at least at institutional level – that the two streams are pretty closely correlated. While REF/RAE income is awarded on a retrospective basis, and grant awards are based on proposals of future activity, it should be a surprise that people with a good track-record are also good at thinking up interesting new projects. Moreover, panels such as the STFC Astronomy Grant Panel (of which I am a member) certainly take into account the applicants’ track-record when assessing the viability of research proposals.

So if we don’t need two systems, what could we have instead? Moving grants from STFC to EPSRC, as some proposed in the past,  would go part of the way, but EPSRC has many problems too. I would therefore prefer to see a new organisation, specifically intended to fund blue-skies scientific research in universities. This organisation would have a mission statement that  makes its remit clear, and it would take over grants, studentships and fellowships from STFC, EPSRC and possibly some of the other research councils, such as NERC.  The new outfit would need a suitable acronym, but I can’t think of a good one at the moment. Answers on a postcard.

As a further suggestion,  I think there’s a strong case to be made that HEFCE should be deprived of its responsibility for research funding. The apparatus of research assessment it uses is obviously  flawed, but why is it needed anyway? If the government believes that research is essential to universities, its policy on selectivity doesn’t make any sense. On the other hand, if it believes that university departments don’t need to be research groups then why shouldn’t the research funding element be administered by a reserch organisation? Even better, a new University Research Council along the lines I have suggested  could fund research at 100% of the Full Economic Cost instead of only 80%. The substantial cash saved by scrapping the REF should be pumped into grants to be administered by the new organisation, reversing the  cuts imposed we’ve endured over past years.

So what should  STFC become after the Triennial Review? Clearly there is still a role for an organisation to manage large experimental facilities. However, the fact that the UK now has its own Space Agency means that some activity has already been taken out of the STFC remit.  The CERN and ESO subscriptions could continue to be managed by STFC along with other facilities, and it could in some cases commission projects in university research groups or industrial labs as it does now. Astronomers and particle physicists would continue to sit on its Board.  However, its status would change radically, in that it would become an organisation whose job is to manage facilities, not research. The tail will no longer be wagging the dog.

I very much doubt if these suggestions are at all in line with current political “thinking” nor with those of many of my colleagues. The input to the Triennial Review from the Institute of Physics, for example, is basically that nothing should change. However, I think that’s largely because most of us working in STFC area,  have much greater confidence in the current management than we did in the previous regime rather than because the structure is right. Some of the bureaucrats in the Treasury, RCUK and HEFCE won’t like my suggestion  either, because they’ll all have to go and do something more useful.  But unless someone stands up for the university sector and does something to safeguard future funding then the ongoing decline in funding levels will never be reversed.

I very much doubt if many of my fellow physicists or astronomers agree with my suggestion either. Not to worry. I’m used to being in a minority of one. However, even if this is the case I hope this somewhat lengthy post will at least get you thinking. As always, I’d be interested in comments..

Authentic Tidings of Invisible Things

Posted in Poetry, The Universe and Stuff with tags , , , , on January 5, 2013 by telescoper

One of my very first blog posts (from way back in 2008) was inspired by an old book of poems by William Wordsworth that I’ve had since I was a child. I was reading it again this evening and came across this short excerpt, near the end of the book, from The Excursion, and entitled for the purposes of the book The Universe a Shell. It struck me as having a message for anyone who works on the science of things either too big or too small to be sensed directly on a human scale, so I thought I’d post it.

I decided to scan it in rather than copy it from elsewhere on the net, as I really love the look of that old faded  typeface on the yellowing paper, even if it is a bit wonky because it went over two pages. I’ve been fond of Wordsworth for as long as I can remember and, like a few other things, that’s something I’ll never feel the need to apologize for…

Shell-a

Shell-b

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