Knit stitch: Frédéric Lechenault talks about the physics of knitted materials. (Courtesy: James Riordon/APS)
By Tushna Commissariat in Baltimore, Maryland, US
You may think that a simple occurrence such as a tree shedding its leaves or an everyday activity such as knitting or ribbon-curling does not involve a great deal of physics, but you would be wrong. In a press session here at the APS March meeting entitled “The physics of everyday life”, three different groups of researches talked about the unexpectedly complex physical principles that govern all of the above mentioned instances.
Sunny Jung of the Bio-Inspired Fluid Lab at Virginia Tech in the US studies the shapes of different leaves and the thickness of their “petioles” or stalks – both of which determine the stresses a leaf can withstand on a windy day and what happens when it ultimately falls. Jung’s team studies this because leaves are actually very good at withstanding all kinds of stress and strain without buckling – something that could be applied to large man-made industrial objects such as suspended road-signs.
The researchers found that slender leaves are more likely to bend under high winds, whereas a flat leaf is more likely to twist at the stem before falling. They also discovered that the length of the stalk is determined by the size of the leaf, with larger leaves needing longer stems so that sunlight can cover more of their surface area.
Go with the flow: physicist Rogjia Tao has a clever way to cut the fat in chocolate. (CC BY-SA 2.0/rore)
By Matin Durrani in Baltimore, Maryland, US
A couple of years ago my colleague James Dacey decided to give up eating chocolate, crisps, biscuits and cakes over Lent and it’s a virtuous – if very dull – decision I’ve been following every year since (even if James has long since strayed from the path of righteousness).
It was therefore with a dollop of smug satisfaction that I attended a talk at this year’s APS March meeting by Rongjia Tao – a physicist from Temple University in the US. He has developed a way of cutting the amount of fat in chocolate without, apparently, losing any of the taste.
Now, reducing the fat content in chocolate might seem straightforward – you just get rid of the fat, right? But it’s a harder problem than you’d think for chocolate manufacturers, who have to send liquid chocolate – a suspension of spherical cocoa particles in a melted fat of cocoa butter and other oils – down pipes and tubes.
As the abstract of his talk suggests, Leggett looked at the ways, means and even the very definition of “condensed-matter physics” has changed and “evolved since its inception in the early 20th century, with particular reference to its relationship to neighbouring and even distant disciplines”. He went on to “speculate on some possible directions in which the discipline may develop over the next few decades, emphasizing that there are still some very basic questions to which we currently have no satisfactory answers”.
I missed the beginning of his talk as I was attending the morning’s first set of press briefings (more on those later) but when I did walk into the packed hall for his talk, his slide had the rather interesting title: “Would I encourage my grandchildren to go into condensed-matter physics?” Happlily enough, his answer at the end of his talk was a resounding “yes”.
March madness: the APS March meeting at the Baltimore Convention Center (top) and the IOP Publishing stand at the exhibition. (Courtesy: Tushna Commissariat)
By Matin Durrani and Tushna Commissariat in Baltimore, Maryland, US
So here we are in Baltimore to attend the 2016 March meeting of the American Physical Society (APS). We’re writing this at the window seats in a burrito bar on Pratt Street while staring at the hulk that is the Baltimore Convention Center, where nigh-on 10,000 physicists will be congregating all week.
We’ve been playing a game of “spot the APS attendee” while tucking into our burritos. Without wishing to stereotype physicists (okay, go on then, we will) they’re the ones with the backpacks stuffed with poster tubes, pulling little trolley suitcases, looking lost before veering towards the convention centre.
There are also some physicists inside Chipotle Mexican Grill – you can tell because they’re huddled around laptops looking at PowerPoint presentations showing graphs of Fermi surfaces and topological insultators. Probably not the usual subject of discussion in here.
Looks as if LIGO’s gravitational-wave discovery is still rocking all over the world, as you can now groove to the dulcet tones of singer and physicist Tim Blais, who runs the acapellascience channel on YouTube. With some help from the Perimeter Institute in Canada, the singer has created his latest “nerd-pop” parody, titled “LIGO Feel That Space” (sung to the tune of The Weeknd’s “Can’t Feel My Face”). After you listen to the catchy tune above, take a look at this interview with Blais on the Perimeter website to find out just how he creates his songs and how he went from physicist to a viral YouTuber.
Google’s DeepMind AlphaGo programme has won the first two games against Go champion Lee Sedol from South Korea. (Courtesy: iStock/Peerayot)
By Michael Banks
It is a battle between man and machine, but one that has been ultimately won by the brute force of computation.
Yesterday as well as today, Google’s DeepMind AlphaGo program has made a breakthrough in artificial intelligence by defeating Lee Sedol – the current world champion from South Korea – at the game of Go.
Galactic views: the Scottish countryside stretches out beyond the Milky Way. (Courtesy: Crawick Multiverse)
By Hamish Johnston
What to do with an abandoned mine? “Turn it into a neutrino and dark-matter detector” is probably what most physicists would say. But we have lots of those already, so how about “A cosmic landscape worthy of the ancients”? That’s how the artist Charles Jencks describes the Crawick Multiverse, which is located in a former open-cast coal mine in the Scottish countryside about 50 miles south of Glasgow. The “striking landscape of distinctive landforms” includes two mounds representing the Andromeda and Milky Way galaxies and a Comet Walk that uses standing stones to emulate a comet’s tail. If the photograh above is any indication, it looks like a lovely day out.
Sound engineer Paul Waton and soprano Lesley Garrett discussing theatre acoustics at the Royal Opera House. (Courtesy: Brian Slater)
By James Dacey
Concert hall acoustics was the theme of a fascinating panel debate last night at the Royal Opera House (ROH) in London. Among the speakers was British soprano and presenter Lesley Garrett who shared her views on the acoustics of some of the great concert halls in which she has performed. She was joined by acoustics engineer Trevor Cox, acoustics consultant Helen Butcher and sound engineer Paul Waton, who has recorded a range of classical concerts for the BBC. Insight: the Art and Science of Acoustics was co-hosted by the Institute of Physics, which publishes Physics World.
Cox – who featured in our 2014 podcast about sonic wonders – set the scene by describing some of the fundamental acoustic considerations in designing a concert hall. We heard clips of Cox playing a saxophone in an “anechoic” chamber, followed by the same sax lick performed in an oil tanker – the place with officially the longest echo in the world. Cox’s point was to show the difference between high clarity at the one extreme and intense reverberation at the other. The sound wasn’t quite “right” in both cases. “Concert hall design is about finding a pleasing balance between these two extremes,” he said.
Valley state: real-life landscapes can be as beautiful as their condensed-matter counterparts. (CC BY-SA BorisFromStockdale)
By Hamish Johnston
Condensed matter is a physicist’s paradise because of the seemingly endless number of ways that atoms can be rearranged to create systems with new and exciting behaviours. A great example of this is the emerging field of “valleytronics”, which is concerned with a property of electrons that emerges in some semiconductors and 2D materials such as graphene.
The eponymous valley is a local minimum in the conduction band of a solid that “traps” electrons into a specific momentum state. Things get interesting when a material has two valleys that result in two distinct momentum states. In some materials these states resemble the quantum-mechanical property of spin: an electron can be in one of two spin states (up or down) and it can also be in one of two momentum states. As a result, this property is sometimes referred to as valley pseudospin.
The new issue looks at ways to make physics a more inclusive discipline, including spotting your unconscious bias, tuning in to talent and tackling “microaggressions” – small acts of injustice that make people uncomfortable because of who they are, not what they do.
We also look at what life’s like for gender and/or sexual minorities at CERN – one of the most international physics labs on the planet – and explore how to find an employer who understands the value of a diverse workforce. There are plenty of practical tips for how you can make a difference.