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Complexity made simple
Feb 9, 2010
By Matin Durrani
With their passion for analysing the world by breaking it down into ever-smaller pieces, most physicists are “reductionists” at heart. Whether through tradition or instinct, our natural inclination is to reduce matter first to molecules and then to atoms and on to nuclei, nucleons, quarks and beyond.
But this approach, while astonishingly successful in terms of understanding the fundamental particles and forces of nature, does not always work. In other words, the whole can often be more than the sum of the parts.
Just consider the beautiful patterns created by large flocks of birds flying in the sky, which cannot be explained by understanding in ever greater detail the physiology of those birds. It is the interactions between the birds that are the key: the patterns form if each individual simply keeps a steady gap between it and its neighbours and flies in their average direction.
The February 2010 special issue of Physics World magazine, which can be downloaded for free via this link, looks at the science of “complex systems” — a rapidly growing field that tackles any system with lots of individual elements that interact in some way, be they birds flying in formation, car drivers moving along a highway or computers linking to form the Internet.
One active area of complexity, where physicists are making much of the running, is network science. Mark Buchanan and Guido Caldarelli (p22) kick off the issue by charting the rise of the field, which involves studying any system where its properties lie not in the behaviour of the individual components of the network but in the nature and structure of the connections between them.
It is important to note that while networks are complex systems, not all complex systems are networks. A colony of ants, for example, might co-operate on building a nest, but their connections are not formalized in any way. A network of traders, computers or phones, in contrast, do have such links.
Much of the fascination of network science lies in its roots in everyday life. For example, as Vittoria Colizza and Alessandro Vespignani explain, tools from physics can be used to model how infectious diseases, such as the H1N1 swine-flu pandemic, spread in real time.
Dirk Brockmann then reveals how information garnered from the geographical movement of banknotes and the location of mobile phones can reveal patterns in how people travel.
Finally, James Crutchfield and Karoline Wiesner chart a roadmap for the future of complexity, which they think lies in applying ideas from complex systems to the social sciences. It is a brave notion — but one that may make hard-core reductionists shudder.
Download the issue via this link
Sweeping away myths about curling
Feb 8, 2010
By Hamish Johnston
Canadians take curling very seriously — indeed, the CBC has a website dedicated to the sport where you can catch up on the latest results.
In a few days Canada will be hosting the Winter Olympics, and to ensure a bumper crop of medals, the Canadian government has invested CDN$22 million into sports research.
Not surprisingly, some of that money has been spent on studying the physics of curling.
In this TV clip, you can watch Tom Jenkyn of the University of Western Ontario use an infrared camera to study the effect of “sweeping” on the temperature of ice.
For any non-curlers, the sport involves sliding large polished rocks along a sheet of ice and towards a target. Each rock is guided to the target by two sweepers who brush the ice in front of the rock. Sweeping makes the ice more slippery and is used to make the rock go further and to also to modify its “curl” — or its tendency to swerve off a straight line.
Jenkyn discovered that — contrary to popular belief — even the most vigorous sweeping does not melt the ice in front of the rock. Rather, it raises its temperature by about 1.5 degrees, which is enough to affect the motion of the rock.
In the video clip Jenkyn claims to have made dozens of other discoveries that could boost Canada’s curling fortunes at the Olympics — but he’s sworn to secrecy until June, well after the games and the curling season are over.
While most of his findings will only benefit serious competitors, Jenkyn has also designed a new type of broom that is to be commercialized and available to one and all.
Rockstar DJ airs Sagan and Hawking
Feb 8, 2010
By James Dacey
I was listening to the dulcet tones of Jarvis Cocker hosting his radio show last night - incidentally, the perfect way to wind down after a busy weekend - when he surprised everyone with this choice.
The song, A Glorius Dawn, features Carl Sagan and Stephen Hawking singing extracts from Sagan’s celebrated TV series Cosmos. It was produced by composer John Boswell who released the track back in November to coincide with the 75th anniversary of Sagan’s birth.
“I’m not very good at singing songs, but here’s a try…” says Sagan, before breaking into a beatbox intro.
You’ll still be laughing from the hilarious first verse when we reach the chorus:
“A still more glorious dawn awaits
Not a sunrise but a galaxy rise
A morning filled with 400 billion Suns
The rising of the Milky Way…”
Those of you familiar with Jarvis Cocker - who fronted the UK band Pulp before going solo in 2002 - will perhaps not be that surprised by his eclectic taste. Like Carl and Stephen, Jarvis is a fantastic communicator especially when it comes to the art of storytelling. His lyrics encompass everything from girls being into palaeontology to the rise of obeisity amongst children, and l remember him exploring his fascination with the cosmos on an early Pulp track Space, which featured the lyrics:
“Tonight … travelling at the speed of thought …
We’re going to escape into the stars…”
You can listen to a repeat of Jarvis Cocker’s Sunday Service here.
Is UK school physics suffering an identity crisis?
Feb 5, 2010
Physics hasn’t gone away but the students have Credit: Wikimedia Commons
By James Dacey
Just a quick question for you to ponder over the weekend: what could the UK do to improve the quality and popularity of physics in secondary education?
I ask this now because several UK newspapers have run stories this week about the decline of physics education in the UK. The headlines emerged following a meeting at the Houses of Parliament on Wednesday, the beginnings of a select committee inquiry into the teaching of science, maths and English in schools.
When it came to physics, the focus was on the decline of the A-level award, which students typically study at age 16-18, where the closest US equivalent is probably the AP higher. The two damning statistics that have been doing the rounds are:
a) More than one in four state schools are unable to offer A-level physics due to a lack of specialist teachers.
b) The number of students taking A-level physics has dropped to 29,000 from 44,000 in the 1980s.
The UK Institute of Physics (IOP) responded by pointing to six main problem areas for physics education, which included: the quality of teaching; access to learning; the nature of assessment; the ethos; and the pull of the subject.
The other category is the curriculum itself, where the Institute says that declining standards are deterring students from taking physics or leaving them woefully underprepared for a university education in physics. The Insititute believes that too much change too quickly in STEM [science, technology, engineering and mathematics] has left the curriculum piecemeal and incoherent.
“Physics should have a distinctive place in the curriculum,” reads the IOP’s statement. “The invention of a subject called science has led to a loss of identity of the sciences.”
Jacko spotted in droplet, claims physicist
Feb 4, 2010
Polymer surgery Is the King of Pop in this mound?
By James Dacey
Just before Christmas, I caused a bit of a splash in the blogosphere when I spotted the face of Ringo Starr in a bouncing water droplet - an image captured by physicists at Duke University in the US.
Here is another physics experiment that contains a spooky resemblance to a human face, sent to us by David Fairhurst, a physicist at Nottingham Trent University in the UK.
The ugly-looking globular mound is a droplet of polymer solution, the kind of substance you might find in the ink cartridges of your printer. As the solution began to dry, Fairhurst noticed a number of small “spherulites” begin to crystallise on the droplet surface revealing what appears to be a tiny human face.
“I noticed it immediately and showed it to the other guys - we had a really good laugh about it,” Fairhurst told physicsworld.com.
The physicist and his group of PhD students reckon the face looks like a small girl, or possibly even the King of Pop, Michael Jackson.
I ran the image through an online face-recognition programme and the names that came out included: Rachel Carson, the American environmentalist; Marlene Dietrich the German-born actress; and (tenuously) Iggy Pop.
Oops, I think I’ve started something here!
Peer reviewers accused of nepotism
Feb 2, 2010
Are reviewers looking out for their own? Credit: David Dennis, Wikimedia Commons
By James Dacey
Every researcher understands the prestige and career opportunities that can present themselves if they can just get their work published in a major academic journal. If that paper contains a genuine “world first” then a young researcher can be set up for a glorious career. How would you feel then if this process was being abused by reviewers seeking to steal glory for themselves and their mates?
This is the accusation made by 14 stem cell researchers in a letter to several major journals in their field. The researchers believe that the peer review process is being corrupted by reviewers deliberately stalling, or even stopping, the publication of new results so that they or their associates can publish the breakthrough first. They also blame the journals for not doing enough to prevent this behaviour from happening.
“It’s hard to believe except you know it’s happened to you where papers are held up for months by reviewers asking for experiments that are not really fair or relevant,” says Austin Smith, director of the Wellcome Trust Centre for Stem Cell Research in Cambridge, UK.
Smith, who was speaking this morning on BBC Radio 4’s Today programme, is concerned that reviewers can no longer remain objective when there is so much at stake with these publications. “A paper in Nature or a paper in Cell is worth your next grant - it could be worth half a million pounds,” he says. Very serious allegations indeed…
You can hear the full broadcast here.
Bohr, Dirac, Rutherford — and tea and buns in the library
Jan 27, 2010
By Matin Durrani
Skimming through the latest issue of CavMag — a glossy newsletter about the latest developments at the Cavendish Laboratory, Cambridge — I at first thought I had misread an article that stated: “In 1930, when I gratefully accepted a research studentship from Girton College…”
Marie Constable visiting the Cavendish Laboratory with director of development Malcolm Longair (right) and Geoffrey Constable (right)
In fact, it was not a misprint but part of a wonderful article by Marie Constable, a 101-year-old physicist who had done her PhD at the Cavendish back in the early 1930s.
Constable, who was writing all about her visit to the Cavendish in September last year to attend its Alumni Open Day, gave some marvellous insights into several legendary figures from physics.
Lord Rutherford, she writes, was “a big, bluff and hearty New Zealander”, who was “friendly and helplful”. He would, apparently, make random visits around the lab to his research students, knocking loudly on their door before asking if they needed any help. It was Rutherford, she says, who also instituted the practice of the Cavendish afternoon tea break, serving tea and buns every Wednesday in the library.
James Chadwick, who discovered the neutron and was Rutherford’s effective second-in-command, is described as being “friendly and kind” although he had a reputation for not tolerating silly mistakes and could sometimes “get cross”.
Meanwhile, Constable recalls Patrick Blackett, another Nobel laureate who had served in the Royal Navy, as being “tall, handsome and helpful” and “a remarkable addition to the Cavendish staff”.
Marie also once attended a lecture by Niels Bohr although, perhaps not surprisingly given his taciturnity, she says little about Paul Dirac, other than he “was often seen in the Cavendish and regularly attended the Wednesday afternoon tea-break”.
As for life at the Cavendish, it was apparently “serene and decent” and the atmosphere was “collaborative rather than adverserial”.
But despite being the only female graduate student at the Cavendish at the time, Constable says she did not encounter much discrimination. However, she admits that when she was an undergraduate, women had to sit at the front of the lecture room — “for fear their attention might be distracted by too much male proximity”. And she was later prevented from attending a workshop course for research students, forced to enrol instead at a local technical college instead.
Luckily that worshop experience proved handy and Marie carved out a career as a safety expert.
It’s a great little story and marvellous to see there are still living links with the glory days of Cambridge physics. The full article can be read at CavMag, which will be put online at this link shortly
Throwing some (laser-generated) shapes
Jan 26, 2010
Light show at Photonics West
By Margaret Harris
The last time I saw a laser light show, I was six years old. Judging from last night’s “Cirque du Laisaire” event at the Photonics West conference (sponsored by the professional optics society, SPIE), the technology has moved on considerably since then.
Unfortunately, this photo doesn’t really do it justice. Lasers are hard to photograph at the best of times, and on this occasion I think my camera had been drinking too many of the event’s signature drink: the “Laser Martini”.
Fancy a laser martini?
This violently blue concoction is made from (so the barmaid informed me) vodka, blue curacao, white cranberry juice and triple sec, with a twist of lemon. And, since another part of the evening’s entertainment was a clip from the James Bond film Goldfinger (you know, the bit where the villain tries to cut Agent 007 in half with a giant laser), it was of course served shaken, not stirred.
The highlight of the evening was the laser magic show, in which a magician called Latimer appeared to pick up a laser beam and spin it around his head. The trick didn’t get much applause, but there’s a reason for that; as the man next to me commented, “Right now, 400 physicists in this room are too busy trying to work out how the hell he did that.” You can watch a version of the show here”.
50 years of the laser
Jan 26, 2010
View of the Moscone convention centre and San Francisco Bay
By Margaret Harris
Fifty years ago, lasers were “a solution looking for a problem”. Today there seems to be no limit to their reach. There are lasers in space and lasers underground; lasers in the lab, factory, hospital and office; lasers that could scarcely singe a fly and lasers that cut through metal as if it were butter. Scientists use lasers in precision measurements of systems that range from atoms to planets. Medical doctors use them to perform delicate surgery. Nearly everyone uses them to listen to music or read other kinds of data. For astronomers, lasers can be a tool for making an artificial star in the sky; for fusion physicists, they may someday be the key to creating a very different kind of artificial star, this time down here on Earth.
Oh, and they look cool, too.
Dreaming of Northern Lights
Jan 21, 2010
Aurora Borealis over Tromsø, Norway photo: Bjørn Jørgensen
By James Dacey
There are occasions during my reporting when I come across jobs that make me really quite envious…
Siobhan Logan, a writer in the UK, was given the opportunity to travel to northern Norway where she meet a group of auroral scientists and local reindeer herders, before documenting her adventures in writing and film.
Her work will feature as part of an upcoming show at the National Space Centre in Leicester that will feature poetry, physics and film inspired by Aurora Borealis, or the Northern Lights.
“For a writer, it was such an inspiring place. I was interested in the myths indigenous Arctic people have created about the Northern Lights but also what the scientists can tell us about the aurora. I came back with my head full of the creatures, characters and stories of the north,” says Logan of her experience.
The spectacular natural light displays of Aurora Borealis have always been a regular feature in the myth and folklore of northern peoples, like the Cree groups of northern America who describe this phenomenon as the “dance of the spirits”.
In recent years, the popular author Philip Pullman has brought the magic of auroras to a new generation of children through the His Dark Materials trilogy - a fantasy series tracking the adventures of bright young girl Lyra Belacqua as she passes through the aurora into a parallel universe.
Logan’s trip was made possible by sponsorship from the University of Leicester, which has strong links with a research base in Tromsø. This facility is owned by EISCAT - a project designed to study the interaction between the Sun and the Earth as revealed by disturbances in the magnetosphere and the ionised parts of the atmosphere.
Stan Cowley of the Radio & Space Plasma Physics Group at the University describes why he is excited by the project. “Science may tell us of the mechanisms of the auroras, but another language is required to express our reaction to the sight of flickering lights over frozen landscapes.”
The performance at the National Space Centre will takes place on February 23 at 7.30 pm - tickets are free but you need to book in advance.