This week has seen the beginning of Cassini’s Grand Finale. The rather dramatically named final mission for the NASA spacecraft involves 22 dives between Saturn and its surrounding rings. Once complete, Cassini will crash into the planet’s atmosphere in what the scientists hope will be a flurry of data gathering. The spacecraft has already sent back stunning images of storms in Saturn’s atmosphere from its first dive on 26 April. After 20 years since its launch, the mission to Saturn’s system has been a masterclass in space exploration, and NASA highlights the best bits in this theatrical video. The short film, reminiscent of Star Trek, could be considered a bit cheesy, but it’s hard not to form an emotional attachment to NASA’s loyal Cassini as you join in the countdown to its final demise.
Big thinker – Catherine Heymans is an observational cosmologist at the University of Edinburgh and author of the new Physics World Discovery ebook The Dark Universe.
By Matin Durrani
It never ceases to amaze me that we know almost nothing about 95% of the universe. Sure, the consensus is that 25% is dark matter and the rest is something dubbed “dark energy”, but beyond that our knowledge is wafer thin.
The flip side, though, is that there’s plenty for physicists to get stuck into. And if you want to get up to speed with the field and find out more about some of its challenges, do check out a new free-to-read Physics World Discovery ebook by Catherine Heymans from the Royal Observatory, University of Edinburgh, UK.
Available in ePub, Kindle and PDF formats, The Dark Universe explains the dark enigma and examines “the cosmologist’s toolkit of observations and techniques that allow us to confront different theories on the dark universe”. And to get you in the mood for all things dark, I asked Heymans some questions about her life as a research scientist. Here’s what she had to say.
On Saturday, there were almost 600 sister events across the globe in support of the March for Science gathering in Washington, DC. One such event occurred in Bristol, UK, where Physics World magazine is produced, which featured a march and speeches from science communicators. I popped along to the event with my camera and here are some of the most eye-catching signs from the day.
With the World Snooker Championship taking place at the moment, it’s that time of year when those of us who are usually snookered by the game are suddenly in its pockets. Right on cue, Phil Sutton from Loughborough University in the UK helps bridge the gap between science and snooker. In his video big break, he looks at why players use chalk on their cue tips. Interestingly, there is a right way to help you spin out a 147 and a wrong way that could leave you pocketing the white.
If you’re finding the pace of geopolitical news a bit too rapid at the moment, spare a thought for physicists and engineers working in the nuclear energy sector.
Towards the end of last month, the venerable energy firm Westinghouse Electric issued a press release in which it proudly announced that its AP1000 reactor – a relatively new “passively safe” design in which the reactor core is kept cool without the need for powered pumps or other “active” equipment – had passed a major UK regulatory review. Ordinarily, this would be cause for celebration. The so-called “Generic Design Assessment” process takes years, and completing it helps pave the way for building AP1000s within the UK. An international partnership called NuGen has long hoped to do just that, on a site near Sellafield in north-west England, so in normal times, you might expect it to be celebrating, too.
Science has taken motor racing to a whole new, extremely small level with the NanoCar Race. The competition on 28 April will see nanoscale molecular machines “speed” around a gold racetrack for 38 hours. As the tiny-molecule cars are not visible to the naked eye, the race will take place inside a scanning tunnelling microscope (STM) at the Center for the Development of Materials and Structural Studies (CEMES), part of the National Center for Scientific Research (CNRS) in France. The teams behind the NanoCars control their vehicles using electric pulses but are not allowed to push them mechanically. Details about the cars and their teams can be found on this website, where you will also be able to watch the race later this month. There is more about the competition in the above video.
In the above video Brian Anderson of Brigham Young University shows how the acoustic concept of “time reversal” can be used to knock over a series of LEGO figures using sound. The idea is that sound waves are broadcast into an environment and captured by a sensor at a specific location. The signal is then used to work-out how the sound waves bounced about before reaching the location and this information is then used to target that specific location with subsequent sound waves. In the demonstration, sound knocks over 29 LEGO figures one-by-one. It’s very impressive and entertaining as well.
Dangerous affair – an extreme ultraviolet image of a tangle of arched magnetic filed lines in the Sun’s corona, taken in January 2016 by NASA’s Solar Dynamics Observatory. (Courtesy: Solar Dynamics Observatory, NASA)
We all love a good disaster movie, but when it comes to real life it’s all too easy to downplay a dangerous but distant threat. Many people choose to live on active volcanoes, the citizens of San Francisco know that “the Big One” could strike at any moment, and yet they believe that the benefits of living in those locations outweigh the risk of a severe event happening in their lifetime.
The same dilemma faces the community of scientists, engineers and policy-makers who are working to understand the impacts of space weather – changes in the Earth’s environment that are largely are driven by physical processes originating from the Sun. Space weather has the potential to disrupt or even damage critical infrastructures on Earth, such as the power grids, aviation routes and communication systems that modern societies depend on, but the last notable event dates back to 2003.
That’s why Mike Hapgood, who heads up the Space Weather Group at RAL Space, part of the UK’s Rutherford Appleton Laboratory, has written a new, free-to-read Physics World Discovery ebook called Space Weather. “I thought it would be a great opportunity to highlight what space weather is really about, and to show how we are linking our scientific knowledge to a better understanding of the impacts on society,” he comments.
You may remember in 2014 when we reported that entrepreneur Richard Dinan – a former star of the UK reality-TV programme Made in Chelsea – was venturing into fusion energy.
He founded the firm Applied Fusion Systems with the aim of building a prototype fusion reactor. The 30 year old, who doesn’t have a university degree, claims to have taught himself tokamak design and employs a small team of scientists who are working on a design.
Well, the firm has now released its first blueprint for a spherical fusion tokamak and is seeking £200m in investment to build not one, but two of the machines.
“The secret of the blue fog” might sound like a Tintin book, but it’s all about a strange form of liquid crystal that’s the cover story in the April 2017 issue of Physics World magazine, which is now live in the Physics World app for mobile and desktop.
First observed in the late 1800s, only recently have we finally uncovered the structure of these materials, which turn blue when cooled. As Oliver Henrich and Davide Marenduzzo explain, blue liquid crystals could be used for new kinds of display devices.
Elsewhere in the issue, mathematical physicist Jason Lotay explains his work in seven extra dimensions, while science writer Benjamin Skuse examines the challenge for respected physicists with theories outside the mainstream.
Don’t miss either our latest look at Donald Trump’s scientific shenanigans, including an interview with Rush Holt – the physicist-turned-politician who’s now head of the American Association for the Advancement of Science.
Remember that if you are a member of the Institute of Physics, you can read Physics World magazine every month via our digital apps for iOS, Android and desktop.