Tag archives: particle physics
By Tushna Commissariat
As I am sure all of you know, the 2015 Nobel Prize for Physics was awarded yesterday to Arthur McDonald and Takaaki Kajita “for the discovery of neutrino oscillations, which shows that neutrinos have mass”. Following on from yesterday’s neutrino-flavoured excitement, here’s an explanation of why it’s so important that we better understand neutrino mass.
Our current observations and theories of neutrino oscillations suggest that at least two of the currently known three flavours of neutrinos have non-zero mass. While we know the mass differences between the different neutrino flavours accurately, their actual masses have not been measured. It’s not for lack of trying, it has simply proven very difficult to make the measurements.
By Hamish Johnston and Michael Banks
You may remember back in 2013 when researchers at the National Institute of Standards and Technology (NIST) in the US entangled the motion of a tiny mechanical drum with a microwave field for the first time ever. Not content with that feat, NIST physicist Ray Simmonds, who was involved in the work, has now made a dance about it (but no song, yet). Teaming up with choreographer Sam Mitchell, the duo has created a modern dance piece entitled Dunamis Novem (“The chance happening of nine things”). Featuring four dancers, their movements are based on nine quantized energy levels of a harmonic oscillator – like the microscopic drum in the NIST work. For each level, Mitchell created corresponding dance actions, while Simmonds created a random-number generator – to add some “quantum randomness” – for the sequence of levels that the dancers perform at. If the dancers happen to touch each other, their actions become synchronized, which can then only be broken by a beam of light – demonstrating that a measurement collapses the entanglement.
NIST has published a Q&A with Mitchell and Simmonds with links to videos of the dance and the animations of the corresponding energy levels of the harmonic oscillator. A video of the first half of Dunamis Novem is shown above and a video of the entire dance is also available.
By Matin Durrani
For nearly three decades, physicists have been unable to answer a seemingly simple question: where does proton spin come from? Adding up the spins of the three quarks that make up the proton seems, in principle, straightforward, but physicists have been struggling with a strange problem: the sum of the spins of its three quarks is much less than the spin of the proton itself.
Known as the “spin crisis”, the topic appears as the cover story of the June 2015 issue of Physics World, which is out now in print and digital formats. In the feature article, science writer Edwin Cartlidge examines the origins of the problem – and whether new experiments could mean we are about to solve it at last.
If you’re a member of the Institute of Physics (IOP), you can get immediate access to the feature with the digital edition of the magazine on your desktop via MyIOP.org or on any iOS or Android smartphone or tablet via the Physics World app, available from the App Store and Google Play. If you’re not yet in the IOP, you can join as an IOPimember for just £15, €20 or $25 a year to get full digital access to Physics World.
The issue also includes a great Lateral Thoughts article by Felix Flicker that’ll have you twisting and bending your arms as you try to follow what he’s on about.
By James Dacey in Mexico
Yesterday was day three of the Physics World Mexican adventure and it turned out to be a really exciting 24 hours. Matin Durrani and I visited Teotihuacan – the “City of the Gods”– located 30 miles north-east of Mexico City. We were there to witness some of the closing moments of a 15-year particle physics experiment designed to “see” inside the Sun Pyramid, the world’s third biggest pyramid by volume.
By Hamish Johnston
Peter Woit is lauded by some for having the courage to speak the truth to the physics establishment, while others see him as an enemy of science. Woit writes the Not Even Wrong blog, which has the same title as a controversial book he once wrote about the merits of string theory. In an article in the latest issue of Nautilus, Bob Henderson profiles Woit and his three decades of doubt over various incarnations of the theory that culminated about 10 years ago in the “string wars”. Henderson’s article is called “The Admiral of the String Theory Wars” and provides a fascinating insight into how the rise of string theory caused Woit to switch from physics to mathematics and his relationships with string theorists – some of whom work in the same building as Woit at Columbia University.
By Hamish Johnston and Tushna Commissariat
As it’s Good Friday today, it can only mean that this week’s Red Folder will include a selection of the best physics-related April Fool jokes from earlier this week. Fermilab’s daily e-bulletin Fermilab Today had an entire joke edition up in the morning – their lead story was probably our favourite as the lab announced its new breakfast cereal dubbed “Neutrin-Os”, but their new day spa sounds pretty good too. CERN went for the funny if slightly obvious Star Wars joke, confirming the existence of the Force, but a slightly more subtle joke came earlier in the week from CERN Bulletin, which ran a story about CERN’s computer-security department handing out prizes for best password – we are still not quite sure if they were joking or not! Astronomy Picture of the Day had a truly fantastic image (see above) of a Lunar Grazing Module described as a “multipurpose celestial bovine containment system”.
By Michael Banks
Fancy a bit of particle-physics electronica?
Then make sure you download the latest album from Isle of Wight electronic duo Cosmic Mind Warp.
In a “unique crossover” between the worlds of cosmology, quantum physics and electronic music, Alister Staniland and David Holmberg have just released a new concept album dubbed Subatomic Particles.
The 15-track album, which features songs such as “Large Hadron Collider”, “Quantum Tunnelling” and “Down Quark”, is described by the duo as a “hallucinogenic head-trip through the microscopic world of subatomic particles and the strangeness of quantum physics”.
By Tushna Commissariat at CERN
Regular readers of Physics World will know that I am currently visiting the CERN particle physics lab in Geneva, ahead of the restart of the Large Hadron Collider (LHC) in the coming weeks. My first stop yesterday afternoon was a press conference in which CERN’s director-general Rolf Heuer and other leading physicists briefed us about “Run 2” and what researchers are hoping to discover. You can read about what they had to say here: “Large Hadron Collider fires up in a bid to overturn the Standard Model“.
I managed to squeeze in a quick last-minute visit to the Compact Muon Solenoid (CMS) detector before it is sealed up tight for the next three years. My host was CMS communications officer Achintya Rao, who took me and a few others deep underground into the bowels of the CMS – and what a sight it was!
By Hamish Johnston
Loyal sports fans often need a reason for losing beyond “their team was better than ours”, and the latest blame-game in American football comes with a twist of physics to it. The run-up to this year’s Superbowl is no exception. Some disgruntled Indianapolis Colts fans claim that the New England Patriots had taken advantage of deflated footballs to make their decisive 45-7 victory on 18 January, which sends them to the championship game.
By James Dacey
Who discovered the Higgs boson? Was it Peter Higgs and a combination of other great minds? The experimentalists at CERN who analysed reams of data? The magnificent machinery of the Large Hadron Collider (LHC) itself? By the time that the next great breakthrough in particle physics comes along, the debate about who makes the discovery could become even more complex. That’s because a new citizen-science project is encouraging anyone with an Internet connection to search for new curiosities in the Higgs data.
“Higgs Hunters” launched this week and invites the public to sift through collision images from the LHC’s ATLAS detector. The task at hand is to look for the paths of charged particles that seem to appear out of thin air in what are known as off-centre vertices. As explained on the Higgs Hunters website, “some scientists think the Higgs could break apart into exotic particles entirely new to science”. On the Higgs Hunters website, citizen scientists help to count the number of particle tracks and can notify the science team if they spot anything out of the ordinary.