Posts by: Tushna Commissariat

Moving meridians, Stradivarius violins, sunspots and more

The Prime Meridian and the modern reference meridian

Walk the line: Airy meridian is marked as the “Prime Meridian of the World” (dotted line), and the modern reference meridian indicating zero longitude using GPS (solid line).
(Courtesy: 2014 Google Maps, Infoterra & Bluesky)

 

By Tushna Commissariat

A visit to the Royal Observatory in Greenwich is incomplete without walking along the Prime Meridian of the world – the line that literally divides the east from the west – and taking some silly photos across it. But you may be disappointed to know that the actual 0° longitudinal line is nearly 100 m away, towards the east, from the plotted meridian. Indeed, your GPS would readily show you that the line actually cuts through the large park ahead of the observatory. I, for one, am impressed that the original line is off by only 100 m, considering that it was plotted in 1884. A recently published paper in the Journal of Geodesy points out that with the extreme accuracy of modern technology like GPS, which has replaced the traditional telescopic observations used to measure the Earth’s rotation, we can measure this difference. You can read more about it in this article in the Independent.

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Former Indian president APJ Abdul Kalam was a ‘scientist and a statesman’

A. P. J. Abdul Kalam

Missile Man: APJ Abdul Kalam delivering a speech in 2010.
(CC BY 3.0/Pushrakv)

By Tushna Commissariat

This week, India is mourning the loss of an esteemed leader – the country’s 11th president APJ Abdul Kalam, who died on Monday. Kalam was in office from 2002 to 2007 and enjoyed country-wide popularity, even post his presidency. Described by US president Barack Obama as a “scientist and a statesman” in his eulogy, Kalam was a physicist and an aeronautical engineer before he turned to politics, first acting as a science administrator and adviser for nearly four decades before his office run. Indeed, he was heavily involved in India’s nuclear tests and its military missile programme, earning him the moniker of “Missile Man”. In 2007 he was awarded the Royal Society’s King Charles II Medal, which is “awarded to foreign heads of state or government who have made an outstanding contribution to furthering scientific research in their country”.

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Balancing bicycles, looking back on Trinity, pricing up Pluto and more

 

By Tushna Commissariat

Mechanics was never my favourite topic when I was studying physics for my BSc, but I think I might have been more interested if we had looked at real-world situations rather than square blocks sliding down an incline plane. A bicycle that carries on, sans rider, without toppling over for quite a long time, for example, would have got my attention. This is a rather well-known quirk of mechanics though and it isn’t even the first time we have discussed it on the blog. Indeed, Physics World‘s James Dacey, a keen cyclist, delved into the topic in 2011. This week, we spotted a a new Minute Physics video on the subject, over at ZapperZ’s Physics and Physicists blog. Watch the video to get a good, if a tiny bit rushed, explanation of the three forces that come into play to allow a bicycle at a certain speed to zip along without its human companion. As the video suggests, all is not known about the secrets of free-wheeling bicycles just yet though, and I have a feeling that we will blog about it again in the years to come.

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Pluto fly-by: New Horizons sails past cold, distant world

Image of Pluto todate taken by the New Horizons spacecraft

Perfect view: the sharpest image of Pluto to date taken by the New Horizons spacecraft. (Courtesy: NASA)

By Tushna Commissariat

After trundling through our solar system for more than 10 years, NASA’s New Horizons mission made its closest approach to the dwarf planet Pluto earlier today, at 12:49 BST. It was a mere 12,472 km from the planet’s surface – roughly the same distance from New York to Mumbai, India – making it the first-ever space mission to explore a world so far from Earth.

If you want to find out more about the New Horizons mission, read this recent news story by physicsworld.com editor Hamish Johnston. Above is best close-up view of this cold, unexplored world that the spacecraft sent back before its closest approach (when it was still 766,000 km from the surface), revealing in clear detail many of the planet’s surface features, including the “heart” at the bottom.

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Converging streams, secret science and more

 

By Tushna Commissariat

Regular readers will know that Physics World‘s Hamish Johnston and Louise Mayor will be attending the “Convergence” conference at the Perimeter Institute in Canada from tomorrow onwards.  While the conference will undoubtedly prove exciting – just look at this list of speakers – it looks like the institute already has convergence on its mind as this month’s Slice of PI contemplates the “converging streams” of art and science. The video above features Perimeter researcher and artist Alioscia Hamma, who finds solace and symmetry in both his art and physics. Watch the video and read more about his work on the Perimeter blog.

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Is dark energy becoming marginalized?

By Tushna Commissariat

Supernovae secrets: Chandra image of G299 -- a Type 1A supernova remnant.  (Courtesy: NASA/CXC/U.Texas)

Supernovae secrets: Chandra image of G299, a type Ia supernova remnant. (Courtesy: NASA/CXC/U Texas)

Here at Physics World, we enjoy a good debate and late last week, a paper appeared on the arXiv server that is bound to kick up quite the storm, once it has been peer-reviewed and published. Titled “Marginal evidence for cosmic acceleration from type Ia supernovae”, the paper was written by Subir Sarkar of the Particle Theory Group at the University of Oxford and the Niels Bohr Institute in Copenhagen, together with colleagues Alberto Guffanti and Jeppe Trøst Nielsen. It suggests that the cosmic expansion may not be occurring at an accelerating rate after all, contrary to the findings of previous Nobel prize-winning work and most of our current standard cosmological models, including that of dark energy.

Indeed, the researchers’ work suggests that the evidence for acceleration is nowhere near as strong as previously suggested – it is closer to 3σ rather than 5σ, and allows for expansion at a constant velocity. Nielsen et al. have come to this conclusion after studying a much larger database of type Ia supernovae – 50 of which were studied in the original work, while this study looks at 740 – that are used as “standard candles” to detect cosmic acceleration.

This study is sure to make many cosmologists sit up and take notice, and an interesting discussion is sure to follow. So watch this space and check back in with us, once the paper is published and we catch up with Sarkar and his colleagues.

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Breathing new life into the Rashba effect

By Tushna Commissariat

Spintronics is often touted to be a field of research that one day soon will revolutionize computing as we know it, helping build the next generation of superfast and energy-efficient computers that we long for. Future spintronic devices will tap into the inherent spin magnetic moment of the electron, rather than just its charge, to store and process information. As an electron’s spin can be flipped much quicker than its charge can be moved, these devices should, in theory, operate faster and at lower temperatures than their current electronic-only counterparts.

Photograph of Rashba from 2008

Father of spintronics: Rashba at his 80th birthday celebration at Harvard University in 2008. (Courtesy: Matt Craig/Harvard News Office)

The entire basis of this field is built on research done by Soviet-American theoretical physicist Emmanuel Rashba in 1959. Indeed, he was the first to discover the splitting of the spin-up and spin-down states in energy and momentum with an applied electric field instead of a magnetic field. But Rashba’s original article detailing the effect, written together with Valentin Sheka, was published in a supplement of the Soviet-era, Russian-language journal, Fizika Tverdogo Tela, and is nearly impossible to get a hold of today.

New Journal of Physics (which is published by IOP Publishing, which also publishes Physics World) has now produced a focus collection of articles on the Rashba effect. As a part of this collection, guest editors Oliver Rader of the Helmholtz Centre Berlin, Gustav Bihlmayer of the Jülich Research Centre in Germany and Roland Winkler of the Northern Illinois University in the US worked with Rashba to create an English-language version of his original paper.

You can access the entire “Focus on the Rashba Effect” collection here, and the translated original paper here. In some ways, this highlights the importance of other key research articles that may have been published in journals that are no longer available and so may be in danger of being lost forever. Leave us a comment if you can think of any such papers.

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Big bucks from The Big Bang Theory, the good, bad and ugly of physics writing and more

Jim Parsons and UCLA alumna Mayim Bialik are among the cast, crew and executives funding a scholarship for students in science, technology, engineering and maths. ( Courtesy: Warner Bros. Entertainment Inc.)

Jim Parsons and UCLA alumna Mayim Bialik from The Big Bang Theory TV show. (Courtesy: Warner Bros Entertainment Inc.)

By Tushna Commissariat

It’s not often that one can say that watching TV may help your future career as a scientist, but today, after the hit US TV show The Big Bang Theory announced a scholarship for STEM students at the University of California, Los Angeles (UCLA), it may be possible. The show, revolves around a group of young scientists – mainly physicists, but also an engineer, a microbiologist and a neuroscientist – making it a science-heavy show. Indeed, we at Physics World have delved into the secrets of the show’s success and talked to one of its scientific advisers. Now, the sitcom’s co-creator, cast and crew have announced a scholarship fund at UCLA to provide financial aid to undergraduate students pursuing degrees in science, technology, engineering and mathematics. The show’s executive producer, Chuck Lorrie, told the Deadline website that “when we first discussed it, we realized that when Big Bang started, this freshman class were 10 year olds”, adding that  “some of them grew up watching the show, and maybe the show had influence on some of them choosing to pursue science as a lifetime goal. Wouldn’t it be great if we can help.” For this academic year, 20 “Big Bang Theory scholars” will be picked to receive financial assistance, with five new scholars each year from now. You can read more about it on the BBC website.

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Space-station toilet tour, the Louvre’s particle accelerator and more

 

By Tushna Commissariat

I’m sure that many of us, while watching videos of astronauts on board the International Space Station (ISS), floating around with their halo-like hair, have given much thought to how they shower, wash their hair, brush their teeth and, indeed, poop and pee! Well, you can stop stretching your imagination and take a look for yourself – we spotted this story on the Slate website, where you can see the latest videos from the European Space agency, where Italian astronaut Samantha Cristoforetti, who is currently on the ISS, gives us a tour of both the toilet (above) and the “shower” area (below). She even demonstrates exactly how to wash your hair in space – it looks rather fuss-free if you ask me!

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Hawking on 1D, Chernobyl fires, psychedelic science and more

 

By Tushna Commissariat

It’s not often that physics, or indeed a physicist, has much in common with pop music or exceedingly popular boy bands. But earlier this week, at an event at the Sydney Opera House titled “An Evening with Stephen Hawking, with Lucy Hawking and Paul Davies”, an audience member asked Hawking (who appeared in holographic form) “What do you think is the cosmological effect of Zayn Malik leaving One Direction?” Watch the video above to see what Hawking said to comfort the distraught fan and how theoretical physics truly may have all the answers.

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