Category Archives: General
By Hamish Johnston
This morning I had the pleasure of speaking with Takaaki Kajita, who shared this year’s Nobel Prize for Physics. He won for discovering that some of the muon neutrinos produced by cosmic-ray collisions in the atmosphere change flavour as they travel to Earth. This phenomenon, called neutrino oscillation, tells us that neutrinos have mass – something that was not initially included in the Standard Model of particle physics.
From his office at the University of Tokyo, Kajita told me that the story began in 1986 when he was working on a proton-decay experiment at the Kamioka underground lab in Japan. He was trying to improve some software that was designed to discriminate between electrons and muons created within the detector. He noticed that there were fewer events associated with muon neutrinos than expected. Muon neutrinos are created in the atmosphere when cosmic rays collide with air molecules and a possible explanation for the deficit was that some of the muon neutrinos were oscillating into electron neutrinos on their journey to the detector. Looking back, however, Kajita told me that his initial reaction to the deficit was that he must have made a mistake in his analysis.
By James Dacey
“Genuinely, it could be our generation that first finds life on another planet,” declared astrobiologist Lewis Dartnell last Thursday during a public talk in London. Dartnell was speaking about the possibility of life beyond Earth and what those organisms might be, based on our understanding of life here on Earth. The choice of venue – a pedestrian tunnel near King’s Cross Station bathed in neon lights – brought an appropriate alien vibe to the evening. Part of the reason for choosing the site is because if humans were to one day colonize Mars we would need to spend the first few years living underground to avoid the lethal radiation.
By Michael Banks
An astrophysicist from the University of Cambridge has bagged this year’s Great British Homebrew Challenge award for the quality of his beer.
Seeing off some 200 rival entries, the tipple was created by postdoc Will Alston using rhubarbs from his allotment to provide an extra twist.
By Matin Durrani
Consider a spherical cow.
No, wait, actually, let’s try something different. Consider a rectangular pipe.
In fact, consider what happens when liquid flows along a rectangular pipe, by which I mean one with a rectangular cross section. The flow’s bound to be asymmetrical, right?
Yes, that’s true, but not always. New research published in Physical Review Letters suggests that for liquid flowing along a rectangular pipe that’s exactly 1.87 times wider than it is high, the flow is entirely symmetrical.
Now, I’ll admit that water flowing along a pipe is probably not something that keeps you awake at night, but the new discovery is weird. In fact, Roberto Camassa from the University of North Carolina, Chapel Hill, who was involved in the study, calls it “bizarre”.
By Michael Banks
For physicists who love scattering neutrons off materials, the recent ground-breaking ceremony at the European Spallation Source (ESS) in Lund, Sweden, will have been a long time coming. First proposed more than two decades ago, the ESS will – when it finally opens in 2020 – generate the world’s most intense beams of neutrons and help satisfy demand for these most useful of particles.
Neutron scattering has emerged as a mainstream scientific endeavour over the last 20–30 years, which is one reason why this month sees the first-ever Physics World focus issue on neutron science. We take a look at how researchers at the ESS are designing the facility’s tungsten target, as well as a new neutron source being built in China and how the ISIS Neutron and Muon Source in the UK is looking to bring in more users from industry.
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 Tamela Maciel at the National Space Centre in Leicester
Last week, the planet Mars was under the international spotlight once more as NASA scientists announced that liquid water may still be flowing on the surface of the red planet. Also, the much-anticipated film adaptation of The Martian – a 2011 novel by American author Andy Weir – a science-driven story of human survival on Mars, hit the box office. Mars was also the hot topic at a recent event held at the National Space Centre in Leicester. The guest of honour was Apollo 7 astronaut Walter Cunningham and throughout the hour-long Q&A, he emphasized the need to push the “next frontier” and send humans to Mars.
Cunningham is not a man lacking in confidence or the experience of pushing boundaries. When asked if he ever felt the pressure of the astronaut selection or training process, he said “I thought I could fly anything, any time, anywhere. Was that true? I don’t know. But that’s how I felt.”
By Hamish Johnston
Next Tuesday the Nobel Prize for Physics will be announced at 11:45 CEST and I am making the bold prediction that the winner – or one of the winners – will be an immigrant. Why? Because this year’s Physics World Nobel-prize infographics show that of the 198 people who have won the prize, 51 are immigrants – so I reckon there is a reasonable chance that I will be right.
What do we mean by an immigrant? This is a tough question, especially in science, where people tend to move around a lot and don’t always settle in one place. For the purposes of these infographics, we have used a rather crude definition of an immigrant laureate: someone who died or currently lives in a country other than that of their birth. There is more about how we made the infographics later in this post – but first, what do they tell us?
By Matin Durrani
It’s amazing the lengths physicists will go to get things done – from building telescopes on the tops of mountains to lowering neutrino detectors to the bottom of the sea and from firing satellites into space to colliding particles in tunnels. We’ve covered all those efforts in
Physics World many times, but there’s one extreme activity that’s been off our radar – until now.
That is the new but little-known field of “speleophysics” – or “the physics of caves” – which we tackle in the cover feature of the October 2015 issue of Physics World magazine. For the small band of researchers who brave the journey underground, being a speleophysicist is almost the perfect job. Armed with helmets, ropes, torches and boots, they’re able to combine their love of physics with a fascination for the nether world – and experience the thrill (and danger) of caving, too.
By Hamish Johnston
In December 1938 Enrico Fermi travelled to Stockholm, where he was presented with that year’s Nobel Prize for Physics for his insights into the atomic nucleus. But after the ceremony, Fermi did not return to his native Italy. Instead, he joined his wife and young children on a voyage to the US. Fermi went on to make major contributions to physics in that country – including playing crucial roles in developing nuclear weapons and nuclear energy.