Time-lapse image of the asteroid Euphrosyne as seen by NASA’s WISE space telescope, which is used by NEOWISE to measure asteroid sizes. (Courtesy: NASA)
By Hamish Johnston
First-up in this week’s Red Folder is a tale of killer asteroids, hubris and peer review from the Washington Post. The science writer Rachel Feltman has written a nice article about a claim by physicist-turned-entrepreneur Nathan Myhrvold that NASA’s research on asteroids that could potentially collide with Earth is deeply flawed. On Monday, Myhrvold posted a 111-page preprint on arXiv that argues that asteroid radii measured by NASA’s NEOWISE project are far less accurate than stated by NASA scientists. What’s more, Myhrvold seems to suggest that NEOWISE scientists have “copied” some results from previous asteroid studies.
Myhrvold began his career as a theoretical physicist and, after a stint as Microsoft’s chief technology officer, founded an intellectual-property firm. He has never worked in the field of asteroids, yet he has taken great exception to some of the physics and statistical analysis underlying the NEOWISE results. His paper has been submitted to the journal Icarus, but has not yet passed peer review – unlike the NEOWISE results. In her article, Feltman ponders why Myhrvold is actively promoting his controversial work – he was featured in a New York Times article on Monday – before it has passed peer review. She also speaks to several NEOWISE scientists, who are not amused.
Free-body problem: how do skateboarders do an “ollie”? (Courtesy: Paulo Simeão Carvalho/Physics Education)
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.
Space missions and insects are not the most usual of bedfellows. But in a wonderful example of how space technology can be translated into practical devices for use here on Earth, a UK company has repurposed and adapted an analyser used onboard the Rosetta mission – that in 2014 landed a probe on a comet for the first time – to sniff out bedbugs. The pest-control company, Insect Research Systems, has created a 3D-printed detector that picks up bodily gas emissions from bedbugs – such a device could be of particular use in the hotel industry, for example, where many rooms need to be quickly scanned. The device is based on the Ptolemy analyser on the Philae lander, which was designed to use mass spectroscopy to study the comet’s surface.
“Thanks to the latest 3D-printing capabilities, excellent design input and technical support available at the Campus Technology Hub, we have been able to optimize the design of our prototype and now have a product that we can demonstrate to future investors,” says Taff Morgan, Insect Research Systems chief technical officer, who was one of the main scientists on Ptolemy. In the TEDx video above, he talks about the many technological spin-offs that came from Ptolemy – skip ahead to 13:45 if you only want to hear about the bedbugs, though.
Ring of fire: spiralling global temperatures. Created by climate scientist Ed Hawkins of the University of Reading.
By Tushna Commissariat
As we face up to the realities of global warming and see the effects of climate change become apparent, it’s more important than ever that people the world over truly grasp its impact. With this in mind, University of Reading climate scientist Ed Hawkins has created the above animated spiral, which shows how the global temperature has changed over the past 166 years. Using data from the Met Office’s Hadley Centre observations datasets, Hawkins’ animation presents data in a a clear and artistic way. “The pace of change is immediately obvious, especially over the past few decades. The relationship between current global temperatures and the internationally discussed target limits are also clear without much complex interpretation needed,” says Hawkins, who is based at the university’s National Centre for Atmospheric Science. Take a look at his webpage to learn more about the project and for a list of specific weather events that are noticeable in the data.
Futuristic views: Peter Knight opening the conference at the Royal Society in London. (Courtesy: Tushna Commissariat)
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”.
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.
In case you have ever wondered why so many theoretical physicists study climate change, physicist Tim Palmer from the University of Oxford in the UK has a simple answer: “because climate change is a problem in theoretical physics”. Indeed, Palmer, who won the Institute of Physics’ 2014 Dirac medal, studies the predictability and dynamics of weather and climate, in the hopes of developing accurate predictions of long-term climate change. The answer, according to Palmer, lies at the intersection between chaos theory and inexact computing – which requires us to stop thinking of computers as deterministic calculating machines and to instead “embrace inexactness” in computing. Palmer talked about all this and more in the latest public lecture from the Perimeter Institute in Canada – you can watch his full talk above.
When someone says the word “physicist”, what image or persona comes to mind? That is the question the Institute of Physics (which publishes Physics World) was hoping to answer with its recent member survey based on diversity, titled “What Does a Physicist Look Like?” The Institute’s main aim with this diversity survey, which about 13% of its members responded to, was “to understand the profile of our members and gain some insights into who they are – diverse people with different ages, ethnicities, beliefs and much more”. You can read its entire results here.
Easy does it: this computer simulation of a motorbike following a cyclist shows a drop in pressure (red area) that cuts the aerodynamic drag on the cyclist by almost 9%. (Courtesy: Eindhoven University of Technology)
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. Continue reading →
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).
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.