When you think of cutting-edge experimental physics, you might picture the grandiose detectors of the Large Hadron Collider (LHC), or perhaps a lab-coat-wearing scientist hunched over a shiny new microscope. Sometimes, however, all you need is a bucket of sand, a balloon and a pin.
Spinning around: The air flow from the wing of a plane, made visible by using coloured smoke. (Courtesy: NASA)
By Ian Randall
If you’re as impatient as I am, the worst part about flying off for your summer vacation is the interminable hold-up that sometimes occurs right before take-off – waiting for the plane to taxi onto the runway and desperately hoping the in-flight entertainment will kick off soon. But these annoying delays may soon be cut down thanks to Georgios Vatistas and colleagues at Concordia University in Montreal. The team has developed a new mathematical airflow model to help refine the safe separation distances needed between planes during take-off and landing.
As an aeroplane moves along, the lift-generating difference in pressure between the top and bottom surfaces of its wings causes air to flow out from beneath each wing and up around the wing tip. This creates a circular vortex pattern behind each tip (pictured above), with a downwash in-between – forming a turbulent wake that can be hazardous to any craft that passes through it. If large enough, this turbulence can roll the next aircraft, faster than they can resist – leading to a crash.
“A surprising amount of stuff gets wasted every year because consumers can’t get it out of the packaging it came in,” writes Katie Palmer, who covers the science beat at Wired. In her article “The physics behind those no-stick ketchup and mayo bottles”, she explains how the company LiquiGlide has developed its slippery coating for the insides of bottles. The challenge was to create a permanently wet coating that would stick to the inside of the bottle but not mix with the liquid foodstuff – and it also has to be safe for human consumption.
LiquiGlide spun out of the lab of Kripa Varanasi at the Massachusetts Institute of Technology and has just announced that an international food-packaging supplier will be using the coating on its mayonnaise bottles. You can watch a demonstration of the coating in the video above.
Sometimes, nature does something unexpected – something so rare, transient or remote that only a lucky few of us get to see it in our lifetimes. In the July issue of Physics World, we reveal the physics behind our pick of the weirdest natural phenomena on our planet, from dramatic rogue waves up to 30 m tall, to volcanic lightning that can be heard “whistling” from the other side of the world, and even giant stones that move while no-one is watching. We also tackle tidal bores on rivers and the odd “green flash” that is sometimes seen at sunset.
Plus, we’ve got six fabulous full-page images of a range of weird phenomena, including salt-flat mirrors, firenadoes, “ice towers”, beautifully coloured nacreous clouds, mysterious ice bubbles of gas trapped in columns, as well as my favourite – the delicately wonderful “frost flowers” seen very occasionally on plants.
Recently I blogged about quark novae, which are a passion of the University of Calgary astrophysicist Rachid Ouyed. I caught up with Ouyed at the Canadian Association of Physicists Congress in Edmonton last month, where between sessions he was busy writing a paper about quark novae.
I managed to coax him away from his calculations for long enough to record the above video, in which he talks about quark novae – huge explosions that some astrophysicists believe could occur shortly after some supernovae. Ouyed also talks about the quark stars that may be left behind and how quark novae could affect how astronomers measure cosmological distances.
A galaxy far away: this false colour image of CR7 was taken by several telescopes. (Courtesy: David Sorbal et al.)
By Hamish Johnston
Over the past decade or so the Real Madrid football club has acquired a string of high profile players dubbed the “Galácticos”. Now the most expensive of these footballers – the Portuguese forward and Real Madrid number 7 Cristiano Ronaldo – has a distant galaxy named after him. The galaxy is dubbed “CR7” and was discovered by a team of astronomers led by David Sobral of the University of Lisbon using several different telescopes.
CR7 actually has two meanings, the second being “COSMOS Redshift 7”. COSMOS refers to the Cosmological Evolution Survey, which is using a number of telescopes to search for very old galaxies.
The closing panel. From left to right: Patrick Brady, Stefania Gori, Immanuel Bloch, Sara Seager and Ian O’Neill.
By Hamish Johnston
I have just returned from the Perimeter Institute (PI) in Waterloo, Canada where I enjoyed a fantastic few days immersed in discussions involving some of the sharpest minds in physics. The great and good were at the PI for the first Convergence conference and from what I have heard, the participants are calling it a great success.
While at the Convergence conference at the Perimeter Institute (PI), Physics World’s Louise Mayor and I had dinner with Sean Gryb. He did his PhD at the PI and is now doing a postdoc at Radboud University Nijmegen in the Netherlands. In the above video he shares some of his highlights of the conference.
Gryb is working on “shape dynamics”, which is a new idea for re-evaluating Albert Einstein’s general theory of relativity (GR). The idea was initiated by Julian Barbour and Gryb became involved in the development of shape dynamics while he was at PI. He now belongs to a small international band of physicists who are developing the concept. While shape dynamics is an alternative treatment of GR, the ultimate goal of their work seems to be the creation of a new framework for a theory of quantum gravity – an important goal of theoretical physics.
Today is the third day of Graphene Week, a conference at the University of Manchester devoted to the fundamental science and applications of 2D materials. While many of the talks require a PhD in materials science to even understand the title (I for one am struggling), one session taking place this evening has the refreshingly simple title: Women in Graphene. Intrigued, I caught up with the session organizer Katarina Boustedt from Chalmers University of Technology in Sweden.
Graphene Week is an annual event organized by the Graphene Flagship, the EU’s biggest ever research initiative with a budget of €1 billion. As promoting equality is a key part of the Flagship’s mission, Boustedt has launched this initiative to support women working in 2D materials research. Tonight’s two-hour session is designed to start the conversation and find out the types of support that women researchers would like.