Category Archives: General
By Hamish Johnston
2016 is shaping up to be a bumper year for physicists trying to detect gravitational waves. In February the LIGO collaboration announced the first ever direct detection of gravitational waves using two kilometre-sized detectors in the US.
Now, it looks like an even bigger detector will get permission to launch. Researchers working on the LISA Pathfinder space mission have just announced that they were able to isolate a 2 kg test mass at a special “Lagrangian point” between the Earth and the Sun. This is important because the planned LISA gravitational-wave observatory will use test masses located at three points in space (each separated by about one million kilometres) as the basis for a huge detector.
By Margaret Harris
The “reproducibility crisis” in science has become big news lately, with more and more seemingly trustworthy findings proving difficult or impossible to reproduce. Indeed, a recent Nature survey found that two-thirds of respondents think current levels of reproducibility constitute a “major problem” for science. So far, physics hasn’t been affected much; the crisis has been most severe in fields such as psychology and clinical research, which, not coincidentally, involve messy human beings rather than nice clean atomic systems. However, that doesn’t mean it’s irrelevant to physicists. Last month, I had the pleasure of speaking to three physics graduates who have become personally involved in addressing the reproducibility crisis within their chosen profession: medicine.
Henry Drysdale, Ioan Milosevic and Eirion Slade are third-year medical students at the University of Oxford. All three earned their undergraduate degrees in physics, and they now make up one-third of COMPare – an initiative by Oxford’s Centre for Evidence-Based Medicine (CEBM) that tracks “outcome switching” in clinical trials. As Drysdale explained to me over coffee in an Oxford café, researchers who want to perform clinical trials have to state beforehand which “outcomes” they intend to measure. For example, if they are trialling a new drug to treat high blood pressure, then “blood pressure after one year” might be their main outcome. But researchers generally keep track of other variables as well, and often their final report focuses on a positive result in one of these other parameters (a dip in the number of heart attacks, say), while downplaying or ignoring the drug’s effect on the main outcome.
By Michael Banks
It’s been a great month for the people behind the Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO), which recently discovered gravitational waves.
In early May, Ron Drever, Kip Thorne and Rainer Weiss – who co-founded LIGO – together bagged a cool $1m share of a special $3m Breakthrough Prize together with more than 1000 LIGO scientists, who shared the remaining $2m.
By Matin Durrani
Physicists can turn their hands to some unusual subjects. But in the June 2016 issue of Physics World magazine – now live in the Physics World app for mobile and desktop – we reveal the unexpected link between physics and ancient Icelandic sagas. If you don’t believe us, check our cover feature out.
Meanwhile, with the UK referendum on its membership of the European Union (EU) looming, we examine what impact the EU has on UK physics – and how remaining in or leaving the EU could affect the country’s science.
Don’t miss either our review of the new film The Man Who Knew Infinity, while our forum section this month has advice from Barry Sanders of the University of Calgary for how best to collaborate with scientists in China. There’s also a great interview with the new president of the US National Academy of Sciences Marcia McNutt.
By Hamish Johnston
Here’s a problem for keen students of classical mechanics: how can a skateboarder cause their board to leap into the air by pressing down on it with their feet?
What I’ve described is a trick called the “ollie”, which first emerged on the skateboarding scene in the late 1970s and is now an essential part of the skating repertoire. There’s a fascinating paper in the journal Physics Education, which shows how digital videos of people doing an ollie can be analysed to get to grips with the physics underlying the trick.
The above image shows six video frames of someone executing an ollie – with time moving from right to left over a period of about 2 s. If you delve into the paper, you will find out how its authors – Marco Adriano Dias, Paulo Simeão Carvalho and Deise Miranda Vianna – used video images to track the motion of the tail of the board as well as its front and back wheels. This was then compared to a free-body diagram analysis of the forces of the board.
By Tushna Commissariat
Not a week goes by here at Physics World that we don’t cover some advance in quantum mechanics – be it another step towards quantum computing or error correction, or a new type of quantum sensor, or another basic principle being verified and tested at new scales. While each advance may not always be a breakthrough, it is fair to say that the field has grown by leaps and bound in the last 20 years or so. Indeed, it has seen at least two “revolutions” since it first began and is now poised on the brink of a third, as scientific groups and companies around the world race to build the first quantum computer.
With this in mind, some of the stalwarts of the field – including Peter Knight, Ian Walmsley, Gerard Milburn, Stephen Till and Jonathan Pritchard – organized a two-day discussion meeting at the Royal Society in London, titled “Quantum technology for the 21st century“, which I decided to attend. The meeting’s main aim was to bring together academic and industry leaders “in quantum physics and engineering to identify the next generation of quantum technologies for translational development”. As Knight said during his opening speech, the time has come to “balance the massive leaps that the science has made with actual practical technology”.
By Hamish Johnston
The transit of Mercury across the face of the Sun has begun. Alas here in Bristol the skies are grey and I have been watching a live feed of the transit from the Royal Observatory in Greenwich – which has been blessed with clear skies. That’s a real shame, because I had brought a small telescope into work and I was looking forward to projecting a magnified image of the Sun onto a screen to see the transit for myself.
By Matin Durrani
Some of the world’s top cyclists are gathering today in the Dutch city of Apeldoorn to take part in the opening stage of the 2016 Giro d’Italia – the 99th running of a race that is one of the three big European professional cycling stage races, along with the Tour de France and the Vuelta a España.
Today’s stage is a short (10 km) time trial and will be followed by two, longer stages in the Netherlands before the action moves to Italy, where the race is due to end on 28 May in Turin. Now, even if you have no interest in cycling – and mine stretches no further than tootling back and forth to work each day – one thing that looks truly scary about professional cycle races such as the Giro d’Italia is the phalanx of motorbikes following in the wake of the cyclists.
These motorbikes can carry everyone from TV camera operators and press photographers to doctors, traffic managers and support staff, all keen to keep as close as possible to the action. Now, however, researchers in the Netherlands and Belgium have discovered that having a motorbike right behind a cyclist could give the latter an advantage. Led by Bert Blocken, a physicist in the Department of the Built Environment at Eindhoven University of Technology, the study reveals that a motorbike at a distance of 25 cm behind a cyclist can cut aerodynamic drag on the person on the bicycle by almost 9%. That amounts to a reduction of almost 3 s for every kilometre travelled. (more…)
By Michael Banks in Shenzhen, Guangdong province, China
It is well documented how China seems to be able to build cities within weeks. But how quickly could it build its very own Silicon Valley?
Well, that question may well be answered very soon. Today, I was at the South University of Science and Technology of China (SUSTC), which is located in Shenzhen, Guangdong province.
The university was only created in 2011 and currently the physics department has a sole focus on experimental and theoretical condensed-matter physics, with around 20 undergraduate students each year (that number is expected to rise as the department expands into other areas of physics).
By Michael Banks in Dongguan, Guangdong province, China
Today I took the 60 km trip north from Shenzhen to Dongguan – home of the China Spallation Neutron Source (CSNS).
China has two nuclear reactors that generate neutrons for research via nuclear fission, but the CSNS is the country’s first spallation source. This type of facility accelerates protons before smashing them into a target to produce copious amounts of neutrons. They are then sent to numerous instruments that are used by researchers to study materials.