Posts by: Louise Mayor

Become a Wikipedian!

By Louise Mayor

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Being online right now, chances are you’ve recently been to the fifth most visited site on the Web: Wikipedia.

I am happy to admit that I use Wikipedia frequently and find it very useful – particularly for physics. It’s great when I want an introduction to a phenomenon or technique, or to get the cogs going again on something I learned long ago at university.

However, I do remember a time when using Wikipedia was a bit more hit and miss. It was pot luck whether an article would be either well written and accessible, or an impenetrable wall of techno-speak and equations.

Now, thanks to more than a billion edits since Wikipedia’s inception, the odds of finding a well-written article are much higher and article quality continues to improve every day.

But there’s still a long way to go before the site’s eventual goal is achieved: to assemble a complete overview of human knowledge. And this is where you come in. Yes, you! With a lay or professional interest in physics, you are ideally placed to contribute.

According to Martin Poulter, a new media manager at the University of Bristol, and Mike Peel, an astrophysicist at the University of Manchester, it is rewarding work. In “Physics on Wikipedia”, an article published this month in Physics World, Poulter and Peel argue that if you have knowledge you can share, Wikipedia needs you.

Also, how about images you can share? You may be ideally placed, for example, to capture photographs of things the public would not normally be able to see, such as pieces of equipment or research facilities. The image at the top of this blog entry (By ESO/Yuri Beletsky (ybialets at eso.org) (http://www.eso.org/public/images/potw1036a/) [via Wikimedia Commons is a great example of this, and was picture of the year 2010 on Wikimedia Commons, an online respository where you can upload your images for free use.

Read “Physics on Wikipedia” now to find out why you should click that edit button.

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Messing with your brain

By Louise Mayor

Last night I attended an event at the Royal Society in London celebrating 100 years of superconductivity. Hosted by Oxford Instruments and the Institute of Physics, the evening’s entertainment included talks by top scientists Stephen Blundell, Mark Lythgoe, Steven Cowley and Jonathan Flint.

A take-home message from Blundell was that it took 50 years from the discovery of superconductivity until we got to the point of commercializing the science – something that funding bodies and policy-makers should keep in mind. But as well as such sensible opinions, there were some unusual goings-on that I won’t forget in a hurry.

One such highlight was the video below. Lythgoe showcased what we’ve learned about the human brain through magnetic resonance imaging (MRI), which only has such high resolution due to superconducting magnets. Lythgoe challenged the audience to watch the following video and count how many times the people in white T-shirts pass the ball between each other. Have a go yourself, but try not to be distracted by the people in black T-shirts, who will try to confuse you by running around and throwing a second ball.

So, how many times did the white ball get passed? The answer is 15. Well done if you got that right – it shows you have good attention. However, this was an example of a selective attention test. Did you see the gorilla?

In a particularly curious moment, a group of people stood up and made their way to the front of the room; in hindsight they were conspicuously young and gender-balanced compared with the rest of the crowd. It was explained that we were in for a musical treat – a music/art performance called Brainwaves, one of the composers having been inspired by an MRI scan. The experience was immersive, with visual effects from design studio loop.Ph, and Mira Calix and Anna Meredith’s electronic music sounding menacing and grating next to the more soothing tones of the Aurora string quartet. I’ve never been in an MRI scanner, but watch for yourself and see what you think.

None of the evening’s events would have taken place were it not for that serendipitous discovery of superconductivity 100 years ago. This April, Physics World produced a special issue to celebrate the centenary, a free PDF of which can be downloaded by following this link.

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Zero resistance to cake

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By Louise Mayor

We had a good chuckle in the Physics World office when we saw how Ted Forgan and his condensed-matter group at Birmingham University in the UK are celebrating the centenary of superconductivity.

As Forgan explained, “According to my info, today is the actual day, so in our group we celebrated with a cake.” He does, however, acknowledge his “amateur icing skills”.

Apparently, comments about the cake have included “Does it contain super currants?”, “Does it contain pears?”, and the less obvious “Is it a Butter–Chocolate–Sugar supercake? (maybe this depends on Tc, the cooking temperature)”.

I had to get this last one explained to me; if you need a clue too, it refers to the Bardeen–Cooper–Schrieffer (BCS) theory of superconductivity.

Once the pun-groans have subsided, if you want to know more about what superconductivity is all about and what’s hot in superconductivity right now, then look no further than this free PDF download of our April special issue. In fact, we’re in touch with Forgan because he contributed a piece about high-temperature superconductivity called “Resistance is futile”.

You might also want to check out this video feature about superconductivity by Paul Michael Grant called “Down the path of least resistance”.

Clearly, superconductivity brings out the puns in everyone.

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The flip-flop world of research

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By Louise Mayor

Life in research involves a turbulent rollercoaster of emotions. But often the only glimpse we see is the success and jubilation of when things work out and results get published.

This new video report (below) offers a behind-the-scenes look into the whole research process, from the long hours spent working in the lab to that day when the results finally get accepted for publication in a journal. It features researchers at Nottingham University achieving a breakthrough in part of their broader aim: to construct 3D objects on surfaces, atom by atom, using scanning probes. “The novel aspect of this video is not so much the science but the fact that we’ve filmed the entire research process over the course of a year or so,” says Philip Moriarty, the main protagonist in this adventure.

The joy that results when experiments go well comes across nicely when, while being filmed in the lab, Moriarty breaks off mid-sentence to throw his fists in the air and exclaim “yes!” However, he reveals that the groundwork preceding what looks so effortless has been 18-months-plus in the making and has sometimes involved 24- and even 36-hour shifts.

But research is rarely over once you’ve got that crucial result: there are then the highs and lows of trying to get the work published in as prestigious a journal as possible. Moriarty highlights that there’s a definite hierarchy of journals to which physicists submit papers. In this case their work was rejected from both Nature and Science before finally being accepted in Physical Review Letters.

Film-maker Brady Haran really digs deep with a frank set of questions that would make many less-composed subjects squirm, such as: “Why is this impressive?”; “What you’ve written…looks really hard to read and really boring – who’s this for?”; and “If only you and a select number of people in the world can understand that paper, how is it doing the world any good?”

The up-and-coming Haran highlights this video on his blog as a great example of what he hopes to achieve with science films. Haran is the mastermind behind the Test Tube project where this video is featured alongside a veritable trove of other gems, as well as The Periodic Table of Videos and Sixty Symbols.

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Four steps to success

By Louise Mayor

Today CERN announced on its Twitter feed that “the first 7 TeV LHC [proton] collisions of 2011 were recorded last night, round midnight, with low intensity beams”.

But how do particle physicists work out from the millions of detected collision events per day whether they are observing a new particle or phenomenon?

Tommaso Dorigo, a collaborator on the Compact Muon Solenoid collaboration at CERN and the Collider Detector at Fermilab, has described just what researchers are looking for and how they go about their search in a fabulous new article, “On the road to discovery”, in the March 2011 issue of Physics World. You can read it here.

In his article Dorigo breaks down the search for new physics into four general steps and to make this clear he sent us these four charming hand-drawn sketches (below).

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In the sketches, Dorigo imagines looking for a particle that theory says will decay to a pair of particle jets which fly out back-to-back. But before even looking for new physics, the detector must first be checked – does it do everything we expect for particles and phenomena that we do know about already? That’s step 1.

Now we’re ready to take on the maelstrom of data – huge files where as much as possible about each collision has been recorded. To make a detailed analysis of every single file would take ridiculous amounts of computer power, so step 2 involves culling anything that’s obviously not what we’re looking for. Here we’re looking for two jets back-to-back, so anything else – no jets, three jets, or two jets not back-to-back – is scrapped.

In step 3, the remaining events are split into either “background” or “signal”, and the background events – those we already understand with the Standard Model – are discarded. These are in effect considered to be background noise, and the aim is to remove this so that any signal is easier to spot.

Events are classed as “background” if the particles produced are only at a small angle to the beam so have not undergone much momentum change – you can imagine these events to be like a truck that hits a stray goose and does not go far off course, as opposed to a head-on truck-on-truck crash where debris might fly off sideways.

In the fourth and final step, the mass of the jet pairs is plotted on a histogram along with all the other events analysed so far. The shape of this distribution is compared to the “null” hypothesis – the shape if the particle being searched for doesn’t exist – and the “alternate” hypothesis – the shape if the particle does exist. Statistics are used to say how confidently the data agrees with the new idea – usually converted into units of “standard deviations”.

You can read more about this in Dorigo’s feature article: On the road to discovery.

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Pulling power

By Louise Mayor

Love moves in mysterious ways, and try as we might to find one, there is no formula that will unlock the secrets of how to find and sustain romantic love.

So if you’re looking for foolproof tips on your love life this Valentine’s Day, I’m afraid they don’t exist. But you’ve come to the right place if you fancy watching three physicists from the University of Nottingham explain something even deeper – the four fundamental forces of attraction.

In some introductory comments to this new video, nanoscientist Philip Moriarty explains, “Generally, forces of attraction, when we’re talking about Valentine’s Day, mean people falling in love and what holds them together…Of course, I’m a physicist so I have to look into it a little bit more deeply than that.”

Ed Copeland, who is a particle cosmologist by trade, explains how three of the forces – the strong, weak and electromagnetic – can be beautifully described by quantum chromodynamics, or QCD. But he adds that gravity’s proving most difficult: “That remains the goal – to try and also bring gravity into this big picture.”

While the video might not explain the forces of love, it’s quite instructional if you fancy your chances at impressing the object of your affections with some good old-fashioned geek chic. Moriarty and Copeland, as well as Roger Bowley, are charmingly enthusiastic.

You can find plenty more videos from them, as well as other Nottingham University scientists, on the website Sixty Symbols.

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Integrating electronics with the human body

By Louise Mayor

We’ve come a long way in the fields of both electronics and medicine. But the possibility of intimately combining these – integrating electronics with the human body – has so far remained in the minds of creators of cyborg characters such as the Terminator and Star Trek‘s Seven of Nine.

And there’s a reason for this, which I found out while recording this video interview with John Rogers from the University of Illinois at Urbana-Champaign. As Rogers explains, all known forms of biology are soft, elastic and curvilinear, whereas all known forms of electronic technologies are rigid, planar and brittle. “As a result,” he continues, “if you want to integrate electronics with biology – with human skin or tissue – you have severe challenges in a mechanics mismatch and a geometrical form mismatch.”

But this limitation is now being broken by Rogers and his team, who are developing electronics in formats that are much more tissue-like in their geometry and mechanical properties.

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LED array stretched over the tip of a pencil for scale. (Courtesy: John Rogers)

One specific type of device they’re developing is bio-integrated light-emitting diodes (LEDs), and as proof of principle they have already implanted an LED array under a mouse’s skin.

But does glowing skin bring anything to the table other than futuristic-looking tattoos? In the video, Rogers explains that they can be a diagnostic tool when used for spectroscopy – combining an LED array with sensors allows tissue to be diagnosed based on how it reflects and absorbs light.

But there are therapeutic uses too: Rogers is also interested in putting LEDs in the body along with certain classes of drugs that can be photoactivated. “So you introduce them into the body in an inactive form, and then you can activate them locally by exposing them to light,” he says, adding that there is also evidence emerging that phototherapy – simply irradiating tissue with light – can actually accelerate the wound-healing process.

The above video forms one of a four-part series filmed at the MRS Fall Meeting in Boston. In the video below, Amy Moll – MRS’s head of public outreach – explains why spreading the word about research like this is so important.

We also accosted conference delegates to hear their take on materials science, and had a more in-depth chat with incoming director of the National Science Foundation’s Division of Materials Research, Ian Robertson, about how the agency might allocate their 2011 budget of $320m.

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Nuclear power – the road ahead

By Louise Mayor

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Until recently, the phrase “nuclear power” conjured for me a hazy and somewhat ignorant vision, comprising images of cooling towers, diagrams of fission and a sense of subdued controversy, in which proponents from neither the pro- nor anti-nuclear lobbies seem to know more about the subject that I do from high-school days.

But for the past few months I have been immersed in the landscape of modern nuclear power in preparation for a special issue of Physics World, which should land on readers’ doorsteps any day now. It is also available as a free PDF download.

Something I really wanted to get to grips with, when it comes to nuclear power, is who has what, and where? Well, if you do too, check out our colour-coded nuclear power world map, based on data from the International Atomic Energy Agency. It’s on pages 38 and 39 of the “special issue”.

But where do we go from here? In the long term, newly built reactors could be based on the six designs that the Generation-IV International Forum – consisting of 13 Members including the Russian Federation, the US, China and the UK – identified to meet its goals. Physics World’s Rome correspondent Edwin Cartlidge writes about these in the feature “Nuclear’s new generation”.

We also review four concepts for radically different reactor designs, including the travelling-wave reactor endorsed by Bill Gates; and accelerator-driven sub-critical reactors, which we quiz Nobel-prize-winning physicist Carlo Rubbia about in a Q&A.

Not only are there new designs, but new fuel. Elsewhere in the special issue, award-winning science writer Matthew Chalmers looks at how India is seeking to exploit its vast reserves of thorium as an alternative to uranium.

As well as fission, nuclear power also covers the realm of fusion. In the feature “Hot fusion”, Steve Cowley, chief executive of the UK’s Atomic Energy Authority, looks at the challenges facing the ITER facility being built in southern France. He says that with predictions of net power gain at ITER, we should act now to reduce the time to commercial fusion.

Attitudes are key in an energy future with nuclear power in the mix – a future that is only feasible if it has support. With that in mind, check out the debate between climate scientists who go head to head on the merits of nuclear power. You’ll find this, and much more, in the October issue of Physics World.

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Nano pioneers give food for thought

By Louise Mayor

This week I was at the scientific opening of the Centre for Nanoscience and Quantum Information (NSQI) at the University of Bristol. The event coincided with the Bristol Nanoscience Symposium 2010, and featured great talks from some of the pioneers of nanoscience and nanotechnology.

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(Left) Nobel Laureate Heinrich Rohrer declared the centre officially open. Photo credit: Jesse Karjalainen. (Right) The NSQI centre itself – the labs are out of sight and sound in the basement. Can you spot the nano-inspired architectural feature?

At the opening event on Monday evening, IBM Fellow Charles Bennett talked about how to make quantum information “more fun and less strange”. His educational analogies included the idea of monogamy in quantum information – that the more entangled two systems are with each other, the less entangled they are with any others. “The lesson is this: two is a couple, three is a crowd”, he said. He also talked about how information doesn’t get lost in quantum systems but does in classical ones – how it’s like there are eavesdroppers, and it’s harder to factorize when someone’s looking over your shoulder.

The stage was then passed over to Heinrich Rohrer (pictured), a figure revered by many in the audience. It was Rohrer, along with Gerd Binnig, who invented the scanning tunnelling microscope – an instrument that can image and manipulate single atoms – for which they were co-recipients of the Nobel Prize in Physics in 1986. Rohrer was at the time at IBM’s Zurich lab.

Rohrer commented about the “nano” revolution – that some say it’s hype, while others are more relaxed about it. “Let us not make a discipline out of ‘nano’ ”, he warned. He also said that the new trend is for people to operate using claims and catchphrases rather than careful explanations; he noted that in all his reading of Einstein’s papers he never once found words such as “new” or “unique”.

In his closing comments, Rohrer proposed a litmus test for the centre’s success. He said that if the NSQI can attract a good number of female nanoengineers and nanomechanics then it is a good sign of interesting research being done at the centre – and then you’re on the right track for the future. He then declared the centre officially open, and we all piled in to the centre for champagne and a tour of the labs, which are described in a previous blog entry: Visiting the quietest building in the world.

But for me, the most exciting talk was given the following day by Stanley Williams of Hewlett-Packard (HP)…

(more…)

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Glowing review

By Louise Mayor, Grenoble

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(Left) Suited and booted and (right) Cherenkov radiation from an old reactor core

When I awoke last Thursday morning I didn’t expect that by the end of the day I’d have seen a nuclear reactor. And I don’t just mean looking at a big concrete building from the outside – I saw stuff glowing and had to wear a funny-looking suit and booties.

I was visiting the Institut Laue-Langevin (ILL) in Grenoble, France, where atoms are split not to generate electricity but to use the neutrons in experiments. In fact, that’s the whole purpose of the ILL reactor, known as a “neutron source”.

But why neutrons? Being electrically neutral, neutrons can penetrate deep into matter, right to the nuclei of atoms. Charged particles, in contrast, get scattered by atomic electrons. Neutrons can be thought of as a particle or wave, and with a wavelength on the order of Angstroms like those produced at the ILL, they interact with crystal structures to form a diffraction pattern as described by Bragg’s law. This pattern can be used to find out the positions of atoms in a sample, as well as how they move.

One application of neutron scattering I heard about was to look inside a turbine blade that’s been subjected to a projectile frozen chicken – the experimental version of a real-life, unlucky stray pigeon or seagull. Neutrons have been used to probe inside the turbine blade without having to interfere with it further by cutting it apart.

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(Left) Neutron goings-on and (right) leaving via the air lock

Upon leaving the reactor hall I went back out through an air lock; there is a lower pressure inside the building so that if there is some leak, gas goes in and not out. Not quite the end of it, I then had to put my hands in a hole each and watch a progress bar slowly fill the screen ahead before I got the reassuring confirmation: “NOT CONTAMINATED”.

Another way to generate neutrons is “spallation”, where protons are accelerated towards a heavy metal target and knock neutrons off atomic nuclei. This method will be used in the European Spallation Source (ESS), which Sweden and Denmark won the bid last year to co-host in Lund, Sweden. To find out more, you can watch this video where the ESS is introduced by none other than Sir Patrick Stewart.

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