This week, people all over the world have been celebrating the 100th anniversary of Einstein’s general theory of relativity (GR). Einstein delivered his theory this week in November 1915. Not surprisingly, the Web has been buzzing with tributes to Einstein and explanations of his theory.
In the above video, the physicist Brian Greene and two young assistants demonstrate Einstein’s explanation of gravity using a huge piece of stretched Spandex. Why they have this Spandex ring in what appears to be their living room remains a mystery, but it and a large number of marbles do the trick when it comes to explaining GR.
Dark flow: Adam Townsend ponders the dynamics of a chocolate fountain. (Courtesy: London Mathematical Society)
By Tushna Commissariat
When most people look at a chocolate fountain in a restaurant or maybe at a party, they are mostly thinking about all the yummy treats they can dunk into the liquid-chocolate curtain. But when a physicist or a mathematician looks at one, they can’t help but notice some of the interesting fluid dynamics at play – most visible is how the curtain of chocolate does not fall straight down, rather it pulls inwards, and that melted chocolate is a non-Newtonian fluid.
University College London (UCL) student Adam Townsend decided to work on this topic for his MSci project and has now published a paper on his findings in the European Journal of Physics. To study the inflow effect, he looked into some classic research on “water bells”, where the same flow shape is seen. “You can build a water bell really easily in your kitchen,” says UCL physicist Helen Wilson, who was Townsend’s MSci project supervisor and the paper’s co-author. “Just fix a pen vertically under a tap with a 10p coin flat on top and you’ll see a beautiful bell-shaped fountain of water.”
As readers of Physics World, you probably don’t need me to tell you that this year marks 100 years since legendary physicist Albert Einstein laid the foundations for his revolutionary general theory of relativity (GR). This month marks the exact time when he began giving a series of four weekly lectures – the first of which was on 4 November 1915 – to the Prussian Academy of Sciences in Berlin. Indeed, today is the centenary of the final lecture, when he presented his “Field equations of gravitation”. In the video above, philosopher and one-time physicist Jürgen Renn, from the Max Planck Institute for the History of Science in Berlin, gives a short and sweet explanation of GR and its impact on physics.
Tiny trophy: The Great Wall of China, printed with a Nanoscribe system at the Hamlyn Centre, Imperial College London. (Courtesy: Nanoscribe)
By Hamish Johnston and Tushna Commissariat
Last month, China’s president Xi Jinping’s was on a state visit in the UK and while here, he toured a few academic institutions, including the UK’s new National Graphene Institute (NGI) in Manchester and Imperial College London. As we reported in an earlier blog, Nobel-prize-winning Manchester physicist Kostya Novoselov presented President Xi “with a gift of traditional Chinese-style artwork, which Kostya himself had painted using graphene paint”. This week we found out that the Imperial scientists also presented him with a “tiny gift” in the form of a 50 µm scale version of a section of the Great Wall of China, imaged above, created with a Nanoscribe 3D printer. Prince Andrew, who was also on the visit, was given an image of a panda leaping over a bamboo cane, which was printed on the tip of a needle.
Pillars of light: this week’s meeting at the Royal Society focused on how Maxwell’s equations illuminate physics. (CC BY-SA 3.0 Tom Morris)
By Hamish Johnston
Earlier this week I caught the 6.30 a.m. train from Bristol to London to attend the second day of “Unifying physics and technology in light of Maxwell’s equations” at the Royal Society. It was a particularly damp and gloomy morning as I emerged from Piccadilly Circus station and tramped through St James, my sights set on the Duke of York pillar next to the Royal Society in Carlton House Terrace.
It seemed like the perfect morning to be thankful for the light described by James Clerk Maxwell’s equations, and to ponder how they have since illuminated many shadowy corners of physics.
The meeting was organized by three physicists at nearby King’s College London: biophysicist and nanotechnologist Anatoly Zayats; particle physicist John Ellis and condensed-matter physicist Roy Pike. Already, you can see the breadth of physics covered at the meeting.
Radioactive? Kepler-438b is regularly irradiated by huge flares of radiation from its host star. (Courtesy: Mark A Garlick/University of Warwick)
By Tushna Commissariat
In the past decade or two, exoplanetary research has been booming as NASA’s Kepler telescope and its cohorts have found nearly 2000 exoplanets and 5000 promising candidates. Unsurprisingly, we have been searching long and hard for those planets that could be habitable or are as similar in shape, size and proximity to the host star as the Earth is to the Sun. Indeed, in January this year Kepler scientists announced that they had found the most Earth-like planet to date – Kepler-438b – orbiting within the habitable zone of its host star, the red dwarf Kepler-438, which lies about 470 light-years from Earth.
The planet, which is slightly bigger than our own, was found to be rocky, and, thanks to its location, rather temperate, meaning that it could have flowing water on it – two key factors that astronomers look for when accessing a planet’s habitability. Unfortunately, David Armstrong of the University of Warwick in the UK and colleagues have now found that Earth’s twin is regularly bathed in vast quantities of radiation from its star – a real dampener when it comes to the formation of life as we known it.
Wiggling electrons: an undulator at one of FELIX’s free-electron lasers.
By Tim Wogan in Nijmegen, the Netherlands
Tucked away near the German border is the Dutch city of Nijmegen and Radboud University, which has a treasure trove of fantastical physics facilities. I was in town for a two-day, whistle-stop tour of the university that included the the opening of the FELIX facility. FELIX stands for “free-electron laser for infrared experiments laboratory”. It is a cavernous chamber housing four free-electron lasers that together can generate high-intensity, tunable radiation with wavelengths anywhere between 3–1500 μm. Something, I was told, that is possible nowhere else in the world.
Adventures in science: the Magna centre in Rotherham, UK.
By Susan Curtis
At a time when the UK steel industry is close to meltdown, it felt quite humbling to be standing inside a disused steelworks on the outskirts of Rotherham. In its heyday in the 1970s the colossal plant employed 3000 people and housed six electric arc furnaces that set new records for steel production. Since closing in 1993, the facility has forged a new identity as the Magna Science Adventure Centre, which offers visitors an insight into the steel-making process and its heritage in the area around Sheffield.
Recently, I was at Magna for the annual TRAM conference, which showcases the latest technology advances in the aerospace industry. Organized by the Advanced Manufacturing Research Centre (AMRC), one of the UK’s Catapult centres based at the University of Sheffield and supported by Boeing, TRAM highlights how aircraft makers and their suppliers are improving materials and manufacturing processes to reduce cost and enhance performance. But among the talk of powder metallurgy, high-performance machining and the factories of the future, a presentation by Nick English from the UK-based watchmaker Bremont highlighted manufacturing innovation at a much smaller scale.
The comic book artist Frank Espinosa and Princeton University’s Sajan Saini have joined forces to create a comic book called A Star For Us. The book begins with a brief history of our understanding of nuclear fusion in the Sun and goes on to chronicle the challenges of creating a mini-Sun here on Earth.
Espinosa and Saini – who is a physicist turned professor of writing – spent time with physicists at the Princeton Plasma Physics Laboratory. Espinosa says that he was impressed by the researchers enthusiasm for the future of fusion energy. “I was trying to channel that energy of hope,” he explains.
“The mood of the comic tries to really capture a sense of a vast cosmic scale being made palpable, being made into something that we can realize within our own hands,” says Saini. I agree and you can judge for yourself by downloading a PDF of the comic book free of charge.
The physicist and former chief technology officer at Microsoft, Nathan Myhrvold, has a nice essay in Scientific American about the roles of the private and public sectors in driving technological innovation. He explains that when Microsoft Research was created in 1991, the company was keen on not making the same mistakes as AT&T, IBM and Xerox – which were all in the process of winding down their world-famous research labs. The problem was that these firms funded research in areas that they were not immediately able to exploit commercially. Myhrvold points out that many of the technologies first developed in those labs – including the transistor and giant magnetoresistance data storage – made much more money for fast-moving competitors such as Microsoft than they did for the companies that did the basic research.
Nit picker: the cold plasma lice killer. (Courtesy: Fraunhofer IST)
By Hamish Johnston
Do your children have head lice again? Now you don’t have to comb their hair until your arm goes numb or cover their head with goop. Instead, you can zap them away using a plasma. I’m not suggesting that you put your child’s head into ionized gas that’s hotter than the Sun – it turns out that a “cold atmospheric pressure plasma” will do the trick.
That’s the claim of researchers at the Fraunhofer Institute for Surface Engineering and Thin Films in Göttingen, Germany. The team has created the above prototype, which creates a plasma using a high-voltage generator that sends short pulses to the teeth of the comb. The pulses ionize air molecules surrounding the teeth, but they are so short that the resulting plasma does not heat up. The charged ions and electrons in the plasma make short work of killing lice and their eggs, but are harmless to humans – at least according to Wolfgang Viöl and colleagues, who will be unveiling their device later this month at the MEDICA trade fair in Düsseldorf.