Hubble spots a “celestial snow angel”. (Courtesy: NASA)
By Hamish Johnston
Things are winding down for the holidays here at Physics World headquarters and staff are looking forward to a well-earned Christmas break.
While we are catching up with family and friends, there’s plenty to keep you amused over the holiday period – including this fantastic Hubble Space Telescope image of Sharpless 2-106. Experts will tell you that this is a “bipolar star-forming region”, but at Christmas time it becomes a “celestial snow angel” – at least according to NASA.
Back on Earth, don’t miss our top 10 breakthroughs of 2011. This year’s top slot went to Aephraim Steinberg and colleagues at the Universe of Toronto for their work on the fundamentals of quantum mechanics. We’ve also put together a special podcast counting down our top 10 physics books from the last 12 months.
From an argument about whether magnetoreception exists in cows to investigating the best way to board an aircraft, the world of physics has produced its fair share of quirky stories this year. Here is our pick of the best from the physicsworld.com blog.
Do cows align their bodies along the Earth’s magnetic-field lines while grazing? Yep, that is the latest controversy and what zoologist Hynek Burda from the University of Duisburg-Essen in Germany is now calling a “holy war against magnetoreception”. The carfuffle began in 2008 when Burda and colleagues, led by Sabine Begall, shocked the bovine world by claiming that cattle prefer to align their bodies along the Earth’s magnetic field – that is, along north–south lines. Then, earlier this year, Jirí Hert from Charles University in Prague and co-workers reported that there is no evidence for such alignment, following a Europe-wide study of 3412 individual cows in 322 herds. In November Begall’s group hit back, re-analysing all the data used by Hert and co (Journal of Comparative Physiology A 10.1007/s00359-011-0674-1) and arguing that about half of Hert’s data are actually noise – that the resolution of corresponding images is too poor, or the cattle are on slopes or in other locales that could affect their orientation. Look out for the next salvo soon.
Stephen Hawking’s annual pilgrimage to the California Institute of Technology seems to be turning into quite a celebrity tour. In early February the 69-year-old cosmologist met the actress Jane Fonda – known for her starring role in the science-fiction movie Barbarella: Queen of the Galaxy. Hawking presented Fonda with a large bouquet of flowers backstage at the Ahmanson Theatre in Los Angeles, where the 73-year-old actress is starring in the play 33 Variations, which is about how Beethoven created the piano composition Diabelli Variations. Thanks to Fonda’s blog, we are treated to a toe-curling account of the meeting, which so thrilled the cast and crew that “Michael, the head of the costume department, was shaking with emotion”. After quizzing Hawking about how he has continued to work despite his illness, Fonda then gave “the great physicist” her e-mail address so she can meet him during his next trip to Caltech. The encounter ended with Hawking telling the Oscar-winning actress that she was his “heart-throb” for her performance in Barbarella. “I almost fainted and everyone broke into laughter,” recalled Fonda, who went home “enlivened and inspired”.
Most physicists are, of course, a law-abiding bunch. However, during the March Meeting of the American Physical Society (APS) in Dallas, Texas, five physicists took a break from the gruelling conference schedule to break into the derelict site of the Superconducting Super Collider (SSC) just south of the city. Conceived in 1983, the SSC was to be the next big particle collider, with a circumference of 87 km and a maximum collision energy of 40 TeV. But 10 years later the project was cancelled, leaving a few buildings on the surface as well as tens of kilometres of tunnels deep underground. After getting into the site and investigating the abandoned buildings, the physicists, who wish to remain anonymous, blogged about their findings and posted photographs on the Web. “We wanted to see what was left after 17 years,” one SSC interloper told physicsworld.com. “What happens to a science experiment of this size when the government no longer chooses to fund it?” According to the clandestine intruders, the tunnels are well below the water table and are therefore flooded, while many unopened crates containing electronic equipment are lying around.
To mark this year’s 100th anniversary of the discovery of superconductivity Ted Forgan and his condensed-matter group at Birmingham University in the UK celebrated in style with their very own “zero-resistance cake”. Apparently, comments about the cake included “Does it contain super currants?”, “Does it contain pears?” and the less obvious “Is it a Butter–Chocolate–Sugar supercake? (maybe this depends on Tc, the cooking temperature)”. Clearly, superconductivity brings out the puns in everyone.
The riderless bike is a fairly well-known quirk of mechanics. It refers to the fact that regular bicycles can keep going by themselves for long distances without ever toppling over. But a new bike created this year by researchers in the US and the Netherlands has cast doubt on our understanding of what causes this effect. The mechanics behind it are not as simple as one might think, but most researchers agree that the stability is caused by two features. First, there is gyroscopic motion, which causes the front wheel to correct itself like a spinning top. Then second, there is the “trail” or “caster” effect, which also explains why the front wheel of a shopping trolley automatically turns to follow the pivot. Now, a team including Andy Ruina at Cornell University has put conventional wisdom aside and created a bike that self-balances without relying on these forces – the first of its kind.
Say hello to Tensor. He was one of a band of 60 life-sized decorated gorillas that appeared around Bristol to celebrate Bristol Zoo’s 175th anniversary this year. In 2010 the organizers of this public art exhibition approached IOP Publishing (which publishes physicsworld.com) to ask if it would like to sponsor and design a gorilla for the show. The challenge was taken on by in-house artist Fred Swist, collaborating with art director Andrew Giaquinto, and the pair came up with the idea of using the graphical tensor notation – as inspired by the UK mathematical physicist Roger Penrose. These pictorial elements, used in physics and pure maths, comprise simple shapes connected by lines. In addition to entertaining Bristolians and visitors to the city, the exhibition was also designed to promote the zoo’s gorilla conservation project and Wallace and Gromit’s Grand Appeal, which raises funds for the Bristol Royal Hospital for Children.
Mumbai one month, Moscow the next. Physicists are used to flying to conferences, so it should come as no surprise that they have turned their attention to the issue of how to get on a plane as quickly as possible. In 2008 Fermilab physicist Jason Steffen devised a “theory” that the best way for passengers to board is back to front, but in such a way that adjacent passengers in the queue are seated two rows apart (12A followed by 10A and 8A, for example). By using a mock fuselage of a Boeing 757 aircraft, which contained 12 rows of six seats with one aisle running up the middle, Steffen has put his theory to the test in a pioneering experiment performed earlier this year. Using “passengers” ranging in age from 5 to 65, Steffen found boarding using his method took only three and a half minutes. Boarding the plane in row-number blocks – with passengers seated at the rear section going first – took around seven minutes. Glad that’s sorted then.
Did you manage to catch the noir film The Big Bang, which was released in the US in May? Starring Antonio Banderas as private detective Ned Cruz and directed by Tony Krantz, the film features Cruz searching for a missing stripper while contending with unsavoury Russian boxers and brash police detectives. And the physics connection? As well as an eatery called Planck’s Constant Café, the film features an underground particle-physics lab built by Simon Kestral (played by Sam Elliott) to search for the Higgs boson. The film has enjoyed less than favourable reviews – the New York Times called it a “jumble of notions tossed into a hat” with the movie being a “low point for Mr Banderas”. From the trailer, the physics in the film seems to be fairly accurate, which at least makes a change.
No end of year review would be complete without a musical outro. So take your pick from the best that this year has had to offer. First up came the Edwin Hubble rap by the “science rapper” Zach Powers, which describes the discovery of the expanding universe. Then with the launch of the last and final flight of the Space Shuttle in July, a video emerged (see above) featuring a group of youths dressed in NASA jumpsuits rapping about the history of the Space Shuttle programme. Then finally there was the climate-change rap featuring lines such as “climate change is caused by people, Earth unlike Alien has no sequel”. We have probably missed some other rap videos that emerged this year, but that might not be such a bad thing.
You can be sure of more quirky stories – and raps – from the world of physics next year. See you in 2012!
Physics World has unveiled its top 10 breakthroughs of the year with the top spot going to an ingenious experiment on the fundamentals of quantum mechanics, performed by a group of researchers at the University of Toronto in Canada. The nine runners up include breakthroughs across a range of physics, including astronomy, optics and quantum computing.
Two things not on our list, however, are the recent announcements that have spurred great excitement both within the physics community and far beyond it. The first being the results of the OPERA collaboration in which neutrinos appear to travel faster than light when fired between the CERN particle-physics lab near Geneva and the Gran Sasso underground lab in central Italy. The second is the announcement last week that physicists working at CERN’s ATLAS and CMS detectors may have caught their first tentative glimpses of the long-sought Higgs boson.
Our reason for not including these results in our list is that while they pose some incredibly exciting questions for physics, they are not as yet bona fide research discoveries. But that is not to say that ongoing experimental and theoretical work will not lead to more concrete results next year. So we want to hear your thoughts on this matter. In the final poll of the year we are asking the following question:
Which of the following is most likely to become a confirmed discovery in 2012?
The Higgs boson Neutrinos travel faster than light in a vacuum Both Neither
To cast your vote, please visit our Facebook page, and feel free to explain your answer by posting a comment.
In last week’s poll we asked you a question related to another of our end-of-year-lists, namely our top 10 popular-physics books reviewed in 2011. The honour of topping this list went to Lawrence Krauss for his biography of Richard Feynman, entitled Quantum Man. You can see the full list in this news article and you can hear about all the books in this special podcast presented by myself along with Margaret Harris (Physics World’s books editor) and Matin Durrani (Physics World’s editor).
One thing that came out of our debates when drawing up this list was the acceptance that there will always be an element of subjectivity in this kind of exercise. After all, the beauty of a great book is that it can inspire readers in different ways. So in our poll we asked you the question: When reading popular-science books, what do you find most stimulating?
The results showed that respondents appear unafraid of getting their teeth stuck into some solid science, as 48% of people chose the option “the technical details underpinning the science”. 24% said they get more inspiration from “the sense of wonder conveyed by the author”. 15% prefer to read about “the impact of science on culture and society”. Just 13% said they prefer to read about the “personal stories of the scientists”.
Patrick Andrews, one pollster based in the UK who opted for the technical details, commented: “The fact that this genre exists at all shows that many people want to understand. Why are so many science books so unpopular? Surely because they fail to deliver clear, pithy explanations.” A different perspective was offered up by Dean Smith, also in the UK, who favours writing that focuses on the impact of science on culture and society, and wrote: “If you wanted vast detail then you should read a journal. When the author describes the effect of a discovery on culture and society it is something everyone can read, understand and debate with reasonable understanding.”
Thank you for all your responses and we look forward to hearing from you again in this week’s poll.
One of my favourite programmes on BBC Radio 4 is Profile, which presents bang-up-to-date biographies of people in the news.
Recent subjects have been as varied as the American politician Newt Gingrich, when he announced his interest in the Republican presidential nomination, and the singer Ian Brown, when he and his band members announced a Stone Roses reunion.
On Saturday it was the turn of Peter Higgs, famous for the eponymous boson that he predicted back in the 1960s. Last week physicists at the Large Hadron Collider caught what may turn out to be the first glimpse of the Higgs boson, inspiring Radio Four to profile its namesake.
The story begins with Higgs’ school days in Bristol, where he was at the same grammar school as Paul Dirac – although separated by about 30 years. The story goes that Higgs became fascinated with the work of his school’s Nobel-winning alumnus, sparking a lifetime love of theoretical physics.
Earlier this week we at Physics World revealed our top 10 popular-physics books of the year as we released this specially recorded podcast. I won’t spoil the surprise by mentioning any of the titles here, but I can say that the list spans a wide variety of books, including biographies, the history of physics and even a tome about cookery.
As with any “best of” listing exercise, we fully expect that some listeners will disagree with our choices and some may feel strongly that other books have been cruelly overlooked. Of course, there is always going to be some degree of subjectivity in making these choices, and it is not always straightforward to explain what lifts a book from being great to being inspirational. But give the podcast a listen and let us know what you think about our choices by posting a comment on the accompanying article.
In the meantime, it would be great if you could share your thoughts on popular science in general writing by responding to our poll question.
When reading popular-science books, what do you find most stimulating?
The technical details underpinning the science The personal stories of the scientists The impact of the science on culture and society The sense of wonder conveyed by the author
To cast your vote, please visit our Facebook page, and feel free to explain your answer by posting a comment.
In last week’s poll we wanted to gauge your opinion on a topic close to the hearts of both nuclear physicists and chemists. We asked whether you liked the names flerovium and livermorium, which have recently been proposed by the International Union of Pure and Applied Chemistry (IUPAC) for the two new elements 114 and 116, respectively.
Flerovium was devised because both elements were created in 2004 by researchers at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, which was founded by the prominent Soviet nuclear physicist Georgi Flerovm. Livermorium arose because both elements were confirmed by scientists at the Lawrence Livermore National Laboratory (LLNL) in California and the Centre for Heavy Ion Research (GSI) in Darmstadt, Germany. (The German contribution is not recognized because the element Darmstadtium already exists.)
Despite this relatively logical approach to naming, it seems that many respondents are not too impressed with the proposals. Just 30% selected “I like both”, while 49% opted for “they’re boring and unimaginative”. Some 13% said they “like flerovium but not livermorium”. And just 8% said the converse, they “like livermorium but not flerovium”. One pollster, Chandan Dasgupta based in Calcutta, India, took a particular dislike to flerovium, commenting that it “sounds like a health drink!”.
Thank you for all your responses and we look forward to hearing from you again in this week’s poll.
The Physics World podcasters. Left to right: Margaret Harris, James Dacey and Matin Durrani.
By Margaret Harris
’Tis the season of “Top 10” lists here at physicsworld.com, and to kick off our commemorations of the year in physics, my colleagues James Dacey, Matin Durrani and I have recorded a special podcast on our choices for the 10 best popular-physics books of 2011. You can listen to the podcast here or by subscribing to our podcast service.
You’ll find a list of all 10 featured books below, along with links to their reviews on physicsworld.com. However, to find out which of them gets our vote for the 2011 Book of the Year – and why we thought all of them were worth including in the top 10 – you’ll have to listen to the podcast.
If your favourite didn’t make the shortlist, keep in mind that there were many other good physics books published this year – including several that featured in our previous podcast – and also some promising ones that we haven’t had a chance to review yet. Look out for them in 2012!
The artwork The 5th Dimensional Camera, which explores the theme of parallel worlds. (Courtesy: EPSRC Press Office)
By Matin Durrani
I’m sure we’ve all go our own personal wishes for a parallel universe – perhaps it’s a world where physicists are flush with cash, the Superconducting Super Collider had never been cancelled and CERN press conferences discussing the search for the Higgs had a bit more oomph about them.
But writing in the December issue of Physics World magazine, Stony Brook University philosopher and historian Robert P Crease examines how the idea of parallel universes and parallel worlds also appear frequently in art and literature.
We’ve all heard of Lewis Carroll’s beloved story Alice’s Adventures in Wonderland, of course, but did you know that Jorge Luis Borges described the concept of a “multiverse” in his 1941 anthology The Garden of Forking Paths? Or that Alan Ayckbourn wrote a series of plays called “Intimate Exchanges”, in which a single opening scene branches out into 16 different endings?
As Crease points out, the idea that parallel worlds should attract novelists is “perhaps not surprising” – after all, as he puts it, they deal with “events shaped by contingencies that unfold over time”.
But the theme of alternative worlds that are similar (but not identical) to our own, branching off from each other, has featured in films as well, including last year’s Rabbit Hole, starring Nicole Kidman, which was based on the celebrated 2005 play of the same name by David Lindsay-Abaire.
It also crops up in the new film Another Earth, which was released earlier this year. Examining the consequences of a promising student who causes a fatal car crash, the film has unfortunately received a bit of a panning, being dubbed by the Daily Mail as “pretentious twaddle” and by the Guardian as “ponderous and contrived”.
Still, let’s not forget that multiple worlds have even inspired some sculptors, including Jon Ardern and Anab Jain of the Superflux studio in London, who created an interesting work called The 5th Dimensional Camera, pictured above, which appeared last year in an exhibition called “Talk to Me” at the Museum of Modern Art in New York.
Members of the Institute of Physics (IOP) can read the article “Other-worldly tales” online free of charge via the digital version of the magazine by following this link or by downloading the Physics World app onto your iPhone or iPad or Android device, available from the Apple store and Android Marketplace, respectively.
If you’re not yet a member, you can join the IOP as an imember for just £15, €20 or $25 a year via this link. Being an imember gives you access to a digital version of Physics World both online and through the apps.
The International Union of Pure and Applied Chemistry (IUPAC) has unveiled the proposed names for elements 114 and 116. Named after Georgi Flerov, founder of the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, element 114 will, if approved, be called flerovium and have the symbol Fl. Element 116, meanwhile, will be named livermorium after the Lawrence Livermore National Laboratory (LLNL) and given the atomic symbol Lv.
The elements were created by researchers at the JINR back in 2004 and were both confirmed by scientists at the LLNL in California and the Centre for Heavy Ion Research (GSI) in Darmstadt, Germany.
Commenting on the suggested names has now opened to anyone for a five-month period, which will end in April. So what do you think? In this week’s Facebook poll, we want you to answer the following question.
Do you like the element names livermorium and flerovium?
I like both of them
I like livermorium but not flerovium
I like flerovium but not livermorium
They’re both boring and unimaginative
To cast your vote, please visit our Facebook page; you are also free to suggest your own names by posting a comment.
In last week’s Facebook poll we asked you when you thought we will see the first working nuclear-fusion reactor supplying electricity to a grid? Nearly half of you (49%) chose the most optimistic option, saying that we could be running our toasters on fusion within 30 years. Some 21% foresee fusion reactors in 30–60 years and 7% think they will be a reality within 60–90 years. However, 23% of you believe that it’s unlikely ever to happen.
Commenting on a related Facebook posting about an article on the Canadian company General Fusion, Michael Simmons wrote “In high-school physics in 1968, I was told practical fusion power was 20 years away. In 1971, in college-modern physics, it was 20 years away. As a high-school physics teacher, I attended a conference on the energy future in 1985 and fusion was 20 years away. In 2005, at a local conference on future energy sources, fusion was mentioned as being 20 years from becoming economically feasible. I don’t believe it is never, but I have come to believe it won’t be in my lifetime.”
There’s nothing better in physics than a bit of a ding-dong, and you can, of course, rely on string theory to supply the ammunition for it.
String theory, after all, polarizes opinion seemingly like nothing else: its proponents deem it a rigorous framework that could unify the fundamental forces, while its critics dub it preposterous guff that makes no testable predictions of the world.
One of string theory’s masterminds – Michael Duff of Imperial College London – has now hit back at his critics with a paper in a special issue of the journal Foundations of Physics published to mark 40 years of the theory. You can read Duff’s 19-page paper either in Foundations of Physics, which is open to all until 31 December 2011, or as a preprint on arXiv.
Duff reckons that “much of the criticism has been misguided or misinformed” and goes on to outline why string theory is valid, before taking a pop at various critics – not only other researchers, notably Lee Smolin and Peter Woit (who he calls “a single-issue protest group”), but also the media, including Physics World.
Duff’s complaints about the media are a little confused in my eyes, stemming in part from the fact that journalists paid too much attention, in Duff’s eyes, to the work of Garret Lisi, who in 2007 published a (non-peer-reviewed) paper entitled “An exceptionally simple theory of everything” that controversially claimed to unify “all fields of the standard model and gravity”.
Although Duff says Lisi is “by no means a crackpot”, he complains that “journalists love [crackpots]” and seems to suggest it was for that reason that so much coverage was given to Lisi’s work, even though the latter does not have much to do with string theory. All I can say is that we at Physics World are no fan of crackpots either.
Duff’s paper has, not surprisingly, drawn a vigorous response from Woit himself, whose blog post can be read here. Woit thinks that attempts by Duff and other string theorists to respond to their critics has “damaged not just the credibility of string theory, but of mathematically sophisticated work on particle theory in general”.
With all those rumours flying around of possible sightings of the Higgs boson in among the proton–proton collisions at CERN’s Large Hadron Collider, you might find this video of a very different type of collision interesting.
It involves not protons but pool balls, as performed by Philadelphia-based “professional pool trick-shot artist” Steve Markle.
“The trick shots I do are an excellent showing of defining the laws of physics,” Markle claims.
And if you think pool balls behave in a pretty predictable way according to the rules of classical physics, well yes they do, but it’s still surprising to see what some good old-fashioned spin can do. Take a look, for example, at 3.46 min, when Markle manages to bend a pool ball in a curve through an entire 90° angle.
And if you want to see Markle in action for real, he’s due to be performing at the Artistic Pool World Championship (yes, there is such a thing) in Oaks, Oaklahoma next March.
As for whether the Higgs is going to show up at CERN, you’ve now got just a week to wait. In the meantime, these pool-ball collisions are sure to keep you amused.
Physicists chatter excitedly at CERN. (Courtesy: Georges Boixader)
By Hamish Johnston
The particle-physics rumour mill is going into overdrive as physicists look forward to next week’s meeting of the CERN’s Scientific Policy Committee – which will include Higgs updates from the LHC’s ATLAS and CMS experiments.
If various blogs are to be believed – and a trusted source assures us that the claims are credible – the two experiments are closing in on the Higgs boson. This undiscovered particle and its associated field explain how electroweak symmetry broke after the Big Bang and why some fundamental particles are blessed with the property of mass.
The latest rumour is that both ATLAS and CMS have evidence that the Higgs mass is about 125 GeV/C2 at confidence levels of 3.5σ and 2.5σ respectively. At 3.5σ, the measurement could be the result of a random fluke just 0.1% of the time whereas at 2.5σ the fluke factor is about 1%.
If you are really optimistic, I believe you can add these two results together in quadrature to get an overall result with a significance of 4.3σ.
While these might sound like fantastic odds to you and me, particle physicists normally wait until they have a confidence of 5σ or greater before they call it a “discovery”. Anything over 3σ is described as “evidence”.
Blogger Lubos Motl has reproduced what he says is an e-mail from CERN director general Rolf-Dieter Heuer inviting CERN staff to a briefing on 13 December to hear about “significant progress in the search for the Higgs boson, but not enough to make any conclusive statement on the existence or non-existence of the Higgs”.
This seems to tie in nicely with the rumoured ATLAS and CMS results, which together are strong evidence for the Higgs at about 125 GeV/C2 – but not yet a discovery.
So why are particle physicists so conservative when it comes to claiming a discovery?
Last year, Robert Crease explored this issue in his regular column for Physics World, and you can read that column here.
Crease wisely cites past experience as the number-one reason for caution. Indeed he quotes University of Oxford physicist and data-analysis guru Louis Lyons as saying “We have all too often seen interesting effects at the 3σ or 4σ level go away as more data are collected.”
As Crease points out, nearly everyone he spoke to in writing his article “had tales – many well known – of signals that went away, some at 3σ: proton decay, monopoles, the pentaquark, an excess at Fermilab of high-transverse-momentum jets”.
So if the rumours are true, 2012 could be a very exciting year for the LHC as more data are collected and this interesting effect grows. But until the key CERN briefing on 13 December, when more information emerges, it would be wise to “keep calm and carry on”.
A Canadian company is planning to build a prototype fusion demonstrator that would be a fraction of the cost of a standard fusion reactor, as physicsworld.com editor Hamish Johnston reported today in this feature. Undoubtedly this is exciting news for those who have been following the development of nuclear fusion as a potential energy source, especially given these times of dwindling fossil-fuel supplies and environmental concerns linked with increasing carbon-dioxide emissions. But even if the prototype is a success, this is still a long way from the real deal: a fully functioning fusion reactor hooked up to a grid.
But we want to know your opinion on this issue. In this week’s Facebook poll, we want you to answer the following question:
When do you believe we will see the first working nuclear fusion reactor supplying electricity to a grid?
Within the next 30 years Within 30–60 years Within 60–90 years Not until the Sun goes supernova
To cast your vote, please visit our Facebook page and please feel free to explain your answer by posting a comment.
Last year, this same question was put to David Ward from the Culham Centre for Fusion Energy in the UK during an interview with Physics World. Ward believes that, realistically, we will not see practical fusion until 2040–2050 at the earliest. IOP members can view this video interview here.
In last week’s Facebook poll we asked you what is your biggest peeve about popular-science writing. 53% of respondents told us that authors “blurring fact and speculation” is their biggest bane, while 24% of pollsters found it more annoying when writers give “bad or unclear explanations”. A further 13% said that they think authors “talking down to readers” is the biggest crime, and just 10% believe that the worst offenders are the writers who use “clichés and overblown language”.
As always, the poll also generated some interested discussion. One respondent, Kate Scaryboots Oliver, who is based in the UK, wrote that authors “not explaining methodology” was her particular pet hate. And you can almost picture the steam escaping from her ears when she added: “Also, if I have to read about space being like a rubber sheet one more time!”
Phil Barker, another respondent based in the UK, feels disgruntled by the fact that popular-science writers often gloss over the mathematics. “Look at how many people each year now graduate with science, engineering, computing, business and other degrees that require a reasonable amount of maths. I’m not saying that every science book or article should be entirely maths-based, just that there is an audience that can cope with and would appreciate something other than hand-waving.”
Thank you for all your responses and we look forward to hearing from you again in this week’s poll.
The CMS collaboration has so far seen no evidence of sparticles. (Courtesy: CERN/Michael Hoch)
By Matin Durrani
The first full year of data-taking at CERN’s Large Hadron Collider (LHC), which is now drawing to a close, has been a wake-up call for supersymmetry (SUSY) – a theory that has captivated physicists (or at least some of them) for the last 40 years.
SUSY’s central prediction – that for each of the Standard Model particles there exists a heavier “sparticle” sibling – remains firmly in the realm of imagination.
Quite simply, no firm evidence for SUSY has yet emerged, despite its aficionados claiming it’s been round the corner for the last 20 years.
But SUSY’s supporters remain undeterred.
In article in the December issue of Physics World magazine by science writer Matthew Chalmers, Savas Dimopolous of Stanford University insists “it’s very early to draw conclusions”, with Nobel laureate David Gross of the Kavli Institute for Theoretical Physics in Santa Barbara saying supersymmetry’s “alive and well”.
Whether evidence for SUSY emerges at the LHC partly depends on if – and where – the Higgs boson shows. If the Higgs weighs in at about 120 GeV, then “it really smells like SUSY”, according to Oliver Buchmuller of the CMS experiment at the LHC. A Higgs heavier than about 135 GeV could see SUSY running into trouble.
As Chalmers points out, for most physicists, the discovery of SUSY would be more remarkable than that of the Higgs. After all, the Standard Model of particle physics has withstood 35 years of tests at six or more decimal places, suggesting that the Higgs or something like it pretty much has to turn up at the LHC. “SUSY, by contrast, is more a well-founded hope”, writes Chalmers, and “the non-discovery of SUSY or something like it would just leave thousands of physicists felling gutted…and weaken the case for another multi-billion dollar collider”.
All eyes are now on an upcoming meeting at CERN on 12 and 13 December, at which results from the full 2011 dataset are due to be presented and discussed. The key sessions on the Higgs searches are set to take place at 2 p.m. local time on 13 December, featuring talks by Fabiola Gianotti of ATLAS and Guido Tonelli of CMS.
Members of the Institute of Physics (IOP) can read the article “Searching for SUSY” online through the digital version of the magazine by following this link or by downloading the Physics World app onto your iPhone or iPad or Android device, available from the Apple store and Android Marketplace respectively.
If you’re not yet a member, you can join the IOP as an imember for just £15, €20 or $25 a year via this link. Being an imember gives you a year’s free access to Physics World, both online and through the apps.
Condensed-matter physicists have their own particle zoo – a menagerie filled with familiar and exotic quasiparticles including old favourites like holes and phonons, and newer additions such as surface plasma polaritons. Quasiparticles are excitations in a solid that behave like tiny particles and obey quantum mechanics. A phonon for example, is a quantized sound wave that propagates through a crystal.
Now Charles Tahan and colleagues at the Laboratory for Physical Sciences just outside Washington, DC have shown that the interaction between phonons and electronic excitations in certain semiconductors can be described in terms of a brand new quasiparticle called the phoniton.
The team studied phonitons in silicon doped with phosphorous. As a phonon moves through the material it stretches and squeezes the crystalline lattice such than an electron associated with a phosphorous atom absorbs the phonon’s energy and is promoted into a higher energy level. This electron then decays back to its original energy, re-emitting the phonon, which can be absorbed and re-emitted at another phosphorous atom. The propagation of this phonon/excitation hybrid through the lattice can be described as a quasiparticle they have called the phoniton.
So what use could a phoniton be? Because they combine the electronic and mechanical properties of a material, they could be put to work in mechanical sensors that detect vibration, strain or other movement. Looking further into the future, they could also find use in quantum computers that use phonons to store and process information.
If you don’t have access to APS journals, you can read a preprint of the article here. Before you click through to the PDF, look at the comments where is says “Changed ‘phononitons’ to ‘phoniton’ by negotiation with PRL editors…”. I have to agree with the editors, phononitons is a real mouthful!