Tag archives: particle physics
By Tushna Commissariat and Hamish Johnston
Folk and country music often blends the sharp twang of a banjo with the mellow and sustained tone of a guitar. While the two instruments appear to be very similar – at least at first glance – they have very different sounds. This has long puzzled some physicists, including Nobel laureate David Politzer, who may have just solved this acoustical mystery.
By Tushna Commissariat
This week, we came across the above video on “extra dimensions”, in which physicist Don Lincoln talks about the possible physical reality of such dimensions and why we need them. The video begins with Lincoln pointing out just how weak a force gravity is, especially when compared with, say, magnetism. He then goes on to talk about how gravity may exist in more than the three dimensions we experience, making sure to point out that these “extra dimensions” are not of the Hollywood variety in which a different reality may exist. This video is part of Fermilab’s “Big Mysteries” video series – be sure to take a look at the rest.
By Matin Durrani in Cheltenham
I made the short journey yesterday from Bristol to the regency spa town of Cheltenham, which this week is hosting its annual science festival. One of the largest such events in the UK, it’s been running since 2002 and has a packed programme of A-list speakers and topics ranging from genetics to geology, from cocktails to cake, and from the human brain to the Higgs boson.
My main reason for attending the festival, though, was to meet Caltech physicist Sean Carroll, whose book about the search for the Higgs boson (called The Particle at the End of the Universe ) was picked by Physics World last year as one of our top 10 books of 2013. Carroll was in the Gloucestershire town to give a one-hour talk about the Higgs, although the festival organizers were clearly working him hard as he also spoke in separate lectures on dark matter and dark energy, and on his role as a science adviser to Hollywood. (Carroll’s worked on films including Thor, Avengers Assemble and TRON: Legacy and even played a tiny role on TV’s The Big Bang Theory – stay tuned for more on that in our upcoming audio interview with him.)
By Margaret Harris
When particle physicist Jon Butterworth and cosmologist Pedro Ferreira took the stage last night at the Bristol Festival of Ideas, they did so as representatives of the two pillars of modern physics. Butterworth, a leading member of the ATLAS collaboration at CERN’s Large Hadron Collider, spoke about the discovery of the Higgs boson and the effort to understand the nature of matter on the quantum level. Ferreira, a theorist at the University of Oxford, focused on Einstein’s general theory of relativity, which describes the behaviour of colossal objects such as galaxies and black holes.
The equations of quantum mechanics and general relativity are famously incompatible, but far from starting a Harry Hill-style confrontation (“FIIIIGHT!”), the advocates of the two theories shared the stage amiably, fielding questions from audience members and talking about their respective new books (Smashing Physics for Butterworth, The Perfect Theory for Ferreira). You can hear Ferreira and Butterworth’s responses to some common (and not-so-common) questions in the clips below.
By Hamish Johnston
A bird of prey swoops out of the sky, grabs its victim from the ground and flies off into the distance. It’s what a bird does instinctively, but how could we get a drone aircraft to do the same thing? That’s the subject of one of the papers in a special issue of the journal Bioinspiration & Biomimetics that focuses on “Bioinspired flight control”.
The above sequence of images is from a paper entitled “Toward autonomous avian-inspired grasping for micro aerial vehicles” by Vijay Kumar and colleagues at the University of Pennsylvania. The special issue also includes work on aircraft inspired by flying snakes, flocking birds and incredibly stable moths.
By Michael Bishop in CERN, Geneva
As CERN ramps up its preparations for “Run 2″ of the Large Hadron Collider (LHC) at the start of 2015, many are wondering where the next big discovery will come from and whether it will emulate the success, and popularity, of the discovery of the Higgs boson in 2012.
There appears to be no hangover from that landmark event and a genuine excitement among the scientists at CERN, which I witnessed first-hand earlier this week during a two-day tour of CERN’s facilities organized by the UK’s Science and Technology Facilities Council (STFC).
Many of the UK-based scientists that I spoke to during the tour showed a remarkable enthusiasm for the experiments they were working on and confessed to expecting similar, if not bigger, discoveries when the particle collider starts smashing protons together at higher energies.
By Michael Banks
Following the closure of Fermilab’s 1 TeV Tevatron particle collider near Chicago in 2011 – and with no similar facility being planned to replace it in the US – many physicists in the country felt not surprisingly concerned that America was losing its place at the “energy frontier”. That baton had already passed to the CERN particle-physics lab near Geneva when its Large Hadron Collider (LHC) fired up in 2008, and with collisions set to restart there next year at 13 TeV, the US’s day looked certain to have passed.
By Tushna Commissariat
It is always interesting to us at Physics World when a particular topic suddenly attracts the attentions of the physics community, especially when it’s a rather hotly debated subject. The past couple of days, for example, have seen a lot of talk about “sterile neutrinos”, based on two papers – published in quick succession on the arXiv preprint server – that suggest the tentative detection of these hypothetical paricles.
Both papers are based on an unidentified emission line seen in the X-ray spectrum of some galaxy clusters obtained by the European Space Agency’s XMM-Newton observatory. Intriguingly, sterile neutrinos are also considered to be possible dark-matter candidates, meaning that – if discovered – they would be the first fundamental particles to lie beyond the bounds of the Standard Model of particle physics.
By Matin Durrani and Tushna Commissariat
If you’re in the tiny minority of people whose job title says “particle physicist”, chances are you’ll have been to CERN at least once in your career to help build a detector, analyse some collision data or muse in the cafeteria over supersymmetry (or the apparent lack of it so far). But for the rest of the world, going to the Geneva lab is simply not on the agenda, which is one reason why the Science Museum in London has this week unveiled a big new exhibition devoted to CERN’s Large Hadron Collider. Entitled simply Collider, the exhibition “blends theatre, video and sound art with real artefacts from CERN” that will, say organizers, “recreate a visit to the famous particle-physics laboratory”.
By Tushna Commissariat
In June we reported that physicists working on the BESIII experiment in Beijing and the Belle experiment in Tsukuba, Japan found evidence for a new “charged charmonium” called Zc(3900). A “charged charmonium” is a particle that is made of four quarks – something that had never been seen before. Since that discovery, the BESIII collaboration says it has made “a rapid string of related discoveries” of four-quark particles. “While quarks have long been known to bind together in groups of twos or threes, these new results seem to be quickly opening the door to a previously elusive type of four-quark matter,” says Frederick Harris, spokesman for the BESIII experiment. “The unique data sample collected by the BESIII collaboration has continued to yield a stream of clues about the nature of multi-quark objects.”