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Physics on film

physicsworld.com's multimedia channel features exclusive video interviews with leading figures in the physics community.

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August 2011 Archives


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By Tushna Commissariat

Last week saw researchers at the Los Alamos National Laboratory (LANL), US, set a new world record for the strongest magnetic field produced by a “non-destructive” magnet. The scientists achieved a field of 92.5 T (tesla) on 18 August, and then surpassed their own achievement the following day with an impressive 97.4 T field. This meant they beat the previous record that had been held by a team in Germany, who achieved 91.4 T on 22 June 2011.

While the total duration of the pulse was 2.5 seconds, the magnetic field was held to within 1% of the peak field (at both 97.4 T and 92.5 T) for approximately 1 millisecond. The 97.4 T achievement was met with jubilation as four main researchers certified with their signatures the data that would be sent to the Guinness Book of World Records.

This advance improves our ability to create non-destructive magnetic fields – higher-power magnets routinely rip themselves to pieces due to the large forces involved – that serve as tools to study the fundamental characterization of advanced materials such as graphene or high-temperature superconductors. They also confine electrons to nanometre-scale orbits, which reveal the fundamental quantum nature of a material.

LANL spokesperson James Rickman told physicsworld.com that “This is the largest non-destructive magnet ever created on Earth to our knowledge. Destructive magnets routinely generate higher fields for microseconds of duration – many thousands of times shorter. Destructive magnets are reported to have reached 2800 T and require the use of tens of kilos of high explosives.” For perspective, the Earth’s magnetic field is 0.0004 T, while a magnet used to move a large amount of metal (like a car in a junkyard) would be 1 T and a medical MRI scan would have a magnetic field of 3 T.

The researchers generated their field using a combination of two electrical pulsed power systems. A massive 1.4 GW generator is used to power the outer coils of the magnet system and a high performance capacitor bank is used to power the inner sections of the electromagnets. Both power systems are run in a “pulse” mode of operation. The image above shows researchers Yates Coulter (left) and Mike Gordon making their final preparations before successfully achieving the record.

With this achievement, the Pulsed Field Facility at LANL will routinely provide scientists with magnetic pulses of 95 T, attracting scientists from all over the globe for a chance to use this technology. The team are now looking to achieve a 100 T field – something that researchers from around the world, including Germany, China, France and Japan are trying to achieve.

By Hamish Johnston

Before the days of the budget airline free-for-all, most aeroplanes were boarded in row-number blocks – with passengers seated at the rear section of the plane going first.

While this method is widely believed to be more efficient than everyone piling on at once (apparently it isn’t) some folks had suspected that better schemes could be found.

There are two main ways in which passengers can interfere with each other and slow down the boarding process. In “aisle interference”, a passenger who is stowing a bag in an overhead locker prevents people from moving further into the plane. In “seat interference”, seated passengers move into the aisle to allow others to sit down, slowing down boarding.

In addition to block boarding, several other schemes have been proposed to minimize interference. These include “Wilma”, which begins with all window-seat passengers followed by all those seated in the middle and finally the aisle seats. Others, such as the method proposed in 2008 by Fermilab physicist Jason Steffen, take a more prescriptive approach, defining the precise order in which each passenger boards the plane.

In Steffen’s scheme, passengers are boarded back to front, but in such a way that adjacent passengers in the line are seated two rows apart (12A followed by 10A and 8A, for example). This is done to ensure that each person has enough room to stow their bags. Those in window seats are also boarded before middle and aisle seats.

Now Steffen, along with the television producer Jon Hotchkiss, has done a series of experiments to try to work out which boarding method is the quickest. The experiment was filmed for a television programme called This vs That and you can watch the trailer above.

The measurements were made using a mock fuselage of a Boeing 757 aircraft in Studio City, California, that is normally usually used for film production. The “passengers” ranged in age from about 5 to 65 and were given hand luggage to load into lockers. The plane had 12 rows of six seats with one aisle running up the middle.

Using the traditional block boarding method, it took nearly seven minutes for all passengers to take their seats – more than two minutes longer than when the passengers boarded at random. The Wilma technique clocked in at just over four minutes, whereas Steffen’s method was the quickest, taking about three and a half minutes to fill the plane.

However, the most surprising result occurred when the plane was boarded in back-to-front order. This started with the passenger in the rear right window seat, followed by the rear left window seat, the rear right middle seat and so on. This highly regimented method took over six minutes to fill the plane – showing that a free-for-all can be more efficient than a highly regimented plan.

You can read a preprint describing the experiment here.

MINOS

By Michael Banks

Blink and it’s gone.

No, it’s not the latest in the search for the Higgs boson at the Large Hadron Collider near Geneva, but instead a slight difference in the mass between neutrinos and their antimatter counterparts, antineutrinos.

Neutrinos come in three “flavours” – electron, muon and tau – that change or “oscillate” from one to another as they travel though space.

It is generally thought that neutrinos and antineutrinos should have the same mass. Last year, however, results from the MINOS experiment at Fermilab, near Chicago, showed a 40% difference between muon neutrinos and muon antineutrinos (converting into tau neutrinos and tau antineutrinos, respectively) as they travelled from the accelerator to the MINOS detector (shown above) some 735 km away in the Soudan mine, Minnesota.

The results were presented with a “confidence level” of around 90–95%, which in statistical terms is approximately “two sigma” (usually a “discovery” requires five sigma).

Although the two sigma significance was small, the result was backed up three days later by a three sigma effect at another detector in the Soudan Mine – MiniBooNe. They saw a difference when muon neutrinos oscillate into electron neutrinos compared with the related process for muon antineutrinos.

Physicists noted that if the result turned out to be true it would not come as a surprise, but as an “overwhelming shock”.

But now it seems as though those fears have at least been partially allayed. After gathering twice as much data, researchers at MINOS announced yesterday at the Lepton Photon 2011 meeting in Mumbai, India, that they found the difference had dropped from 40% to 16%.

So it seems that there is still a disparity, but more data will be needed before we can be sure whether there is any mass difference between neutrinos and antineutrinos.



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By Tushna Commissariat

With scientists and politicians debating over the fate of the James Webb Space telescope, this week we are asking your thoughts on the subject. Following over-run costs, a US congressional committee has moved to cancel the $6.8bn James Webb Space Telescope, poised to be the successor to Hubble Space Telescope. Should funding be reinstated or should NASA focus on other projects?

Do feel free to explain your position by posting a comment on the poll. You can vote on this poll on our Facebook page.

Results just in

Last week we asked you what you thought was the main benefit of studying physics at university. Options ranged from “Learning how the physical world works” to “Developing strong problem-solving skills”, “The wide range of career opportunities it can bring” and “The chance to play with some cool hi-tech equipment”. Among the 229 people who voted, “Learning how the physical world works” was the most popular with a 137 votes followed by “Developing strong problem-solving skills” at 63 votes. Interestingly, our “other” option that encouraged people to let us know what reasons they had for studying physics that did not fall in any of the above categories had 16 votes, with a few people pointing out that they chose physics to have a career in military research labs or, in one case, to “make something go boom”.

For some, like reader Craig Levin it was more about the type of course one was subscribing to. “If you’re taking ‘Physics for Poets’, you get a whizz-bang tour of the universe and how it works. If you’re taking a lab course, you’re getting a more in-depth picture and picking up some problem-solving skills and a little bit of project management.” he sagely pointed out. A tongue-in-cheek comment from reader Russell Davies read “I abandoned physics at age 18, because it appeared fraught with problems of limited career opportunities, limited income potential and a distinct lack of babes.”

Thank you for taking part in the poll and for taking the time to provide your thoughts. And don’t forget to vote in this week’s poll on our Facebook page.

Test match physics

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A cricket ball sitting in grass

A cricket ball at rest

By Margaret Harris

Late yesterday afternoon, I was pottering around with the BBC’s Test Match Special on in the background when something in the cricket commentary caught my attention. In-between the usual chatter about English bowling (good), Indian batting (bad) and the latest cakes delivered to the TMS commentary box (excellent), the conversation suddenly turned to physics – specifically, to the question of whether a ball could gain speed after nicking the edge of a bat.

The matter was raised after an Indian batsman, V V S Laxman, edged a delivery from Jimmy Anderson, an English bowler. The ball spurted off towards England’s captain, Andrew Strauss, who couldn’t quite catch it. After lamenting the missed opportunity, one of the TMS commentators suggested that Strauss might have mistimed his catch because the ball gained speed after glancing off Laxman’s bat. The commentators then spent the next several minutes talking a load of old rubbish about whether this was physically possible.

Then, shortly after 6 p.m., a secondary-school physics student, Laurence Copson, sent a message to the BBC’s online commentary team claiming that no, it wasn’t possible. “Removing all external forces on the ball, under no circumstance would the ball gain speed after a nick…as [the] bat would be slightly hitting the ball in the opposite direction,” he wrote. However, he did add a caveat: “What may be deceiving is if the batsmen swipes, catches an edge and then the ball gains top-spin and seems to reach the ground quicker than usual.”

This analysis was quickly contradicted by Rob, a university astrophysics student, who pointed out that Copson was neglecting both the elastic coefficients of ball and bat, and (more importantly) “the spin on the ball before it hits the bat which, if very fine, may accelerate the ball…in the direction of spin (like a car with its wheels spinning hitting the ground goes forward)”.

This seemed fair enough, but Rob’s parting shot – ”this is the real world, external forces on the ball can’t be discounted!” – struck me as rather snide, so I decided to do some analysis of my own.

By Margaret Harris

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Today is the day when hundreds of thousands of students across England, Wales and Northern Ireland receive the results of their A-level exams, which will determine where (and whether) they go to university in the coming academic year. The subsequent flood of exam statistics will keep education-policy experts busy for the next few days, but it’s already emerged that the number of students taking the physics A-level exam has gone up, rising 6.1% since 2010 and 19.6% over the past five years.

This is welcome news, and it’s the inspiration behind this week’s Facebook poll, which asks:

What is the main benefit of studying physics at university?

As usual, you can cast your vote on our Facebook page.

Now, as for the reasons behind the increase in physics A-level students, several commentators have cited the improving image of physics in pop culture, as evidenced by television shows like Brian Cox’s Wonders of the Universe and the US comedy The Big Bang Theory. Even the IOP’s president, Peter Knight, has suggested that the “Brian Cox effect” and publicity surrounding CERN’s Large Hadron Collider (LHC) may have helped propel physics back into the list of the 10 most popular A-level subjects for the first time since 2002.

But with all due respect to Knight, I’m personally dubious about the influence of pop culture in this case. The UK’s education system forces students to specialize early, so the current crop of A-level students will have begun narrowing down their options at least three years ago. Back then, The Big Bang Theory had only been on UK television for a few months, the LHC was still under construction and the two Wonders programmes were but gleams in Cox’s eye. So it’ll be a few years before we’ll know the true extent of their impact.

I’d place more weight on the second half of Knight’s statement, in which he noted that “Many students are also responding to calls from university leaders, businesses and the government to choose subjects which will provide the skills our country needs.” Campaigns by all these groups to boost science have been going on for years, and economic uncertainty (which, in the UK, dates back to 2007, when the bank Northern Rock collapsed) has probably made students more receptive to them. It’s worth noting that the last time the UK had so many physics students was in 2002, when the world economy was still recovering from the dot-com bust.

Anyway, regardless of the reasons behind physics’ new-found semi-popularity, we wish all students luck with their results – and those who plan to continue their physics education at university should watch this space next week, when we’ll discuss your views on the benefits of studying physics.

What physicists do

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By Margaret Harris

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Last week’s Facebook poll asked a pretty straightforward question:

If you have a physics degree, what do you do for a living?

The options we offered were engineering, finance, IT, research and teaching, and voters could also add their own choices. Among the 161 people who voted, “research” was by far the most popular category, accounting for 45% of the total (N.B. we went ahead and classed the three people who said they were graduate students under “research”). The runner-up was engineering, with 16% of the vote, closely followed by teaching (15%) and IT (13%).

The only user-generated option to attract more than two votes was “science communication”, which picked up six – just shy of 4%. That’s more than finance got, but maybe most physicists in finance are too busy dealing with the financial crisis to vote in Facebook polls.

One final note: could the person who said they were an “inflatable entertainment company owner” please e-mail us at pwld@iop.org? We publish a column in Physics World called Once a physicist that profiles physicists with unusual jobs and, frankly, you’re a shoo-in for a future edition.

Space shuttle rap

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By Michael Banks

It had to come didn’t it? With the launch of the last and final flight of the Space Shuttle Programme last month when NASA’s Atlantis shuttle landed back on Earth after an 11-day mission to the International Space Station, the rap video couldn’t be too far off.

So yesterday a tweet from @NASAKennedy – the official Twitter stream of NASA’s Kennedy Space Flight Center – allayed any fears that the rap wouldn’t emerge when it posted a link to the video saying “You know your curiosity will get the better of you so you might as well click.”

Featuring a group of youths dressed in NASA jump suits rapping about the history of the Space Shuttle Programme, I will leave it up to you to decide whether the rap beats the likes of the Climate Change Rap, the Hubble Rap or the Large Hadron Rap.

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By Tushna Commissariat

Yesterday, on 14 August, the arXiv preprint electronic server celebrated its 20th birthday. In 1991 physicist Paul Ginsparg (right), who had then just moved to the Los Alamos National Laboratory in New Mexico, set up the online physics archive, initially know as the Los Alamos Preprint Server (xxx.lanl.gov), as a place where high-energy physicists could share preprints of their upcoming work. The initial idea, according to Ginsparg’s recent comment piece in Nature, was for 100 full-text articles or so to be submitted every year, each of which would be stored for three months. “By popular demand, nothing was ever deleted” writes Ginsparg.

The server received close to 400 subscriptions in the first six months alone. By 1999 when xxx.lanl.gov had changed its name to arXiv, the repository was collecting almost two thousand new articles every month. In 2001, when the server turned 10, Ginsparg moved to Cornell University in Ithaca, New York and took the server with him. By 2008 the world’s favourite e-print server officially had half a million papers published on it.

In 2008, when Physics World celebrated its 20th anniversary, Ginsparg recounted the early days of the Web and looked at how it has changed scientific communication. You can read his thoughts on the subject here.

Over the years, the arXiv server has had a huge impact on physics and paved the way to open-access publishing for scholarly journals. Many scientific journals now publish their content with unrestricted online access, and this has allowed scientific information to become freely accessible to researchers and the public.

Now, the server contains “about 700,000 full texts, receives 75,000 new texts each year, and serves roughly 1 million full-text downloads to about 400,000 distinct users every week. It has broadened, first to cover most active research fields of physics, then to mathematics, nonlinear sciences, computer science, statistics and, more recently, to host parts of biology and finance infiltrated by physicists,” according to Ginsparg.

Early last year, librarians at Cornell University asked for extra external funding to support the server, as the running costs were “beyond a single institution’s resources”. Its budget – which covers personnel as well as operating expenses – was predicted to increase from $400,000 in 2010 to $500,000 in 2012. Ginsparg says that an international meeting of sponsor institutions will be hosted by the Cornell Library next month and will look into transforming the arXiv server into a more community-endorsed resource. “My hope is that the barrier to implementation of new ideas in this realm will remain low enough that, if all else fails, some young researcher elsewhere can launch another tiny ship on a fateful trip.”

By Margaret Harris

In last week’s Facebook poll we asked

Do you consider yourself a physicist?

This proved to be one of our most popular polls yet, with 214 responses. Of these, a narrow majority (55%) said that yes, they considered themselves physicists, while 15% chose “no” and 30% agreed that for them, “it’s complicated”.

A number of people were kind enough to explain their responses in the poll’s comments section. We really appreciate this, because it tells us a lot more than the raw numbers can. For example, judging from the comments, there seems to be some difference of opinion over the question of what makes a physicist a physicist.

For some, it’s primarily down to training or education. “I feel that I really can’t call myself a physicist because I don’t have anything hanging on the wall saying ‘Tom Sullivan is hereby granted and honoured as a physicist’, “ wrote, er, Tom Sullivan, who answered “it’s complicated”. Another who mentioned training was Kate Oliver, a science writer who regularly contributes to Physics World’s “Lateral Thoughts” humour column. “I like to consider myself a physicist as I have the relevant training, read about it and think like it,” she wrote, explaining her “yes” vote. However, she added, “since I haven’t been in the lab for three years, my ‘physicistique’ may have expired”.

The idea that physicist-hood might carry an expiry date suggests an alternative definition – one that focuses not on who you are or what you know, but on what you do. (The philosopher Jean-Paul Sartre, who believed that “to do is to be”, would love this definition.) Like Oliver, Bruce Etherington is a science communicator with a physics degree, but he answered “it’s complicated” because “Most practising physicists would probably not consider me to be one.” Another in the “it’s complicated” camp, Steve Douglas, wrote “I think to be a physicist you’ve got to specialize in it, rather than just be pretty good at it.”

At physicsworld.com, we tend towards a pretty broad definition of physicist – one that encompasses, at minimum, those who have studied physics at degree level (or higher) and who remain interested in learning about it.

But since these Facebook polls are about your views, not ours, we’ll leave the last word to Michael Eliachevitch, a soon-to-be physics student who wrote that “being a physicist means [being] part of a large adventure to discover the world we are living in”. Good luck on your adventure, Michael!

By Margaret Harris

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We had so many responses to last week’s Facebook poll – which asked “Do you consider yourself a physicist?” – that we’re giving everyone a few more hours to respond before we blog about the results. So if you haven’t yet answered yes, no or it’s complicated, there’s still time to do so via our Facebook page.

In the meantime, I’d like to conclude this round of career-related polls with a somewhat less metaphysical question:

If you have a degree in physics, which option best describes what you do for a living?

We’re interested in sectors here, not specific job titles, so to get you started, we’ve listed five options – engineering, finance, IT, research and teaching – that more rigorous surveys suggest are popular among physics graduates. However, if you don’t fit in any of these boxes, you’re more than welcome to add your own category (legal? medicine/health? communications?).

Speaking of being rigorous, we at physicsworld.com are well aware that Facebook polls aren’t. However, that does not mean they’re useless, or even “just a bit of fun”. We’re interested in hearing from you and we take your opinions seriously – they help us keep in touch with what individual members of the physics community think and care about. So treat these polls like the office water cooler, departmental common room or anywhere else that people gather to share their views – and if you want proper statistics on physics education and research, try the Institute of Physics’ policy department instead.


By Joe McEntee, group editor at IOP Publishing

The latest video report from our globe-trotting multimedia team offers an “up close and personal” take from the bleeding edge of the Earth sciences, as told to us by faculty and graduate students in the geosciences department at the University of Texas at Dallas (UT Dallas).

Filmed in the spring as an add-on to our coverage of the American Physical Society March Meeting in Dallas, the interviews cover a lot of ground – to be expected for a discipline that aims to unlock the secrets of the solar system’s most active planet.

Carlos Aiken and colleagues, for example, are using an approach called cybermapping (which integrates laser scanning, digital photography and satellite positioning, among other sensors) to build 3D photorealistic models of surface geology around the world. Their work is being applied in oil exploration and education (for virtual field trips).

Meanwhile, fellow researcher John Ferguson is applying a technique called 4D microgravity – essentially ultraprecise gravitational measurements, a few parts per billion of the Earth’s gravitational field – to monitor the success (or otherwise) of CO2 sequestration in underground reservoirs.

Another important strand of the UT Dallas geosciences programme is the use of remote sensing (specifically, space geodetic satellite observation) to understand changes in Earth systems over time. “There’s much more to it [remote sensing] than pretty pictures,” explains Alexander Braun.

“You can actually measure real physical parameters – such as the [Earth’s] gravity field or magnetic field – and, more importantly, you can detect surface deformation. The Earth is a very active planet and it is crucial for us to understand when and where it is moving.”

In the second video (below), senior scientists in the UT Dallas geosciences programme explain what attracted them to a career in the Earth sciences. It seems if you like to travel and have a hankering for the outdoors then Earth sciences could be just the ticket.

Or, as Bob Stern puts it, “It’s really a remarkable opportunity to get out and see things that no-one else gets to see – that you would never see as a tourist.”

By Hamish Johnston

Scientists have long wondered whether life originated on Earth or was seeded by biological-like molecules that arrived here from space. Meteorites could offer clues to this mystery because they are prime examples of extraterrestrial material that has made its way to our planet.

While such molecules have been discovered in meteorites since the 1960s, researchers could not be sure whether this is simply the result of contamination that occurred once the rocks reached Earth.

In this video, NASA scientist Michael Callahan explains why he and his colleagues are convinced that “DNA building blocks” discovered in 12 meteorites were formed in space – rather than being contamination picked up on the ground.

By Margaret Harris

Women in science are more likely than men to have smaller families than they would like because of their demanding academic careers – but men are more likely to be unhappy about it. This is the striking conclusion of a new study that also demonstrated a strong link between concerns about family size and a desire among junior researchers of both sexes to leave science altogether.

The study, which was conducted by two Texas-based sociologists, Elaine Ecklund and Anne Lincoln, is unusual in that it examines the effect of scientific careers on men as well as women. Some of the similarities they found are as intriguing as the differences. For example, although scientists who have children work fewer hours per week than those who do not, the mothers in the data set were working as long as the fathers, averaging 54.5 and 53.9 hours per week respectively. Male and female faculty members were also equally likely (16.6% vs 17.1%) to report being somewhat or strongly dissatisfied with their lives outside work. Among graduate students and postdocs, Ecklund and Lincoln found no significant gender differences in respondents’ career satisfaction or the number of children they had.

However, some of their other results make sobering reading for those concerned about the “leaky pipeline” for women in science. Although male and female grad students and postdocs reported similar levels of career satisfaction, and were almost equally likely to seek jobs in industry or as research scientists, a gender gap opened up in the numbers seeking a tenure-track academic position. While 66.5% of male students said they wanted a faculty role, only 60.1% of women agreed; for postdocs, the gap was larger, 84% to 69.2%. And among survey respondents who had already made it to the top of the academic pyramid, women were somewhat more likely than men (15.% to 11.5%) to report being dissatisfied with their working lives.

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By Hamish Johnston

Try to imagine the world before 1911, when the atomic nucleus was unknown. Much of what we now know about chemistry and nearly all of our understanding of nuclear physics was yet to come.

This was the year that Ernest Rutherford (pictured right) put forward his theory that most of an atom’s mass and all of its positive charge are concentrated in a volume that is tiny in comparison to the rest of the atom.

Although Rutherford was not the first to proffer such a “solar system” model of the atom, he was the first to back it up with experiment – the famous Rutherford back-scattering of alpha particles from gold foil.

This week, physicists are gathering in Manchester – where the back-scattering experiments were done in 1909 – to celebrate 100 years of nuclear physics.

As well as specialist talks, the Rutherford Centennial Conference on Nuclear Physics includes a series of evening lectures. Tonight’s lecture is entitled “From Rutherford to the Large Hadron Collider” and will given by David Jenkins of the University of York. Tuesday will see Alan Perkins of the University of Nottingham discussing “Nuclear medicine: atoms and antimatter matter in medicine” and on Wednesday the University of Manchester’s John Roberts will ask “Is there a safe future for nuclear energy?”.

All public lectures are at 19.30 and are free – but tickets must be obtained here ahead of time.

If you can’t make it to Manchester, Physics World’s James Dacey will be there with a camera crew – so stay tuned for more from the event.


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By Tushna Commissariat

This week has seen its fair share of intriguing space stories, with colliding moons, Trojan asteroids, more evidence for water on Mars and even a hint of evidence for bubble universes. But a press release about another interesting find from the Keck telescope in Hawaii that was seemingly lost in all noise caught my eye – astronomers in the US have discovered a cluster of about 1000 small, dim stars just outside the Milky Way, comprising what is now the darkest known galaxy. The dwarf galaxy is also said to have a treasure trove of ancient stars, some of the oldest ever seen. Using the 10 m Keck II telescope in Hawaii, the astronomers have been gathering data about the galaxy now dubbed Segue 1.

Interestingly, when they call it the darkest galaxy, astronomers are not referring to how much light the galaxy puts out, but the fact that the dwarf galaxy appears to have 3400 times more mass than can be accounted for by its visible stars. In other words, Segue 1 is mostly an enormous cloud of dark matter decorated with a sprinkling of stars. The initial claim of it being the darkest galaxy was made two years ago by Marla Geha from Yale University and Joshua Simon from the Carnegie Institution of Washington, and their colleagues. Their claim was based on data from the Sloan Digital Sky Survey and the Keck II telescope.

Initial observations indicated that the stars were all moving together and were a diverse group, rather than simply a cluster of similar stars that had been ripped out of the nearby star-rich Sagittarius dwarf galaxy. Because some astronomers were doubtful of the results, Simon, Geha and their group returned to Keck and went to work with the telescope’s Deep Extragalactic Imaging Multi-Object Spectrograph (DEIMOS) to measure how the stars move not just in relation to the Milky Way, but also in relation to each other. A paper with the new findings was published in the May 2011 issue of the Astrophysical Journal.

If the 1000 or so stars were all there was to Segue 1, with just a smidgeon of dark matter, the stars would all move at about the same speed, said Simon. But that was not what they observed. Instead of moving at a steady 209 km/s relative to the Milky Way, some of the Segue 1 stars are moving at rates as slow as 194 km/s while others are going as fast as 224 km/s. The mass required to cause the different star velocities that were observed has been calculated at 600,000 solar masses. But, oddly enough, Segue 1 only has about 1000 stars and they are all close to the mass of the Sun.

The galaxy’s collection of primordial stars is also of interest to the astronomers, as previous searches for primitive stars among the Milky Way’s billions have yielded less than 30. The researchers gathered iron data on six stars in Segue 1 with the Keck II telescope, and a seventh Segue 1 star was measured by an Australian team using the Very Large Telescope. Of those seven, three proved to have less than one 2500th as much iron as our own Sun. “In Segue 1 we already have 10% of the total in the Milky Way,” Geha said. “For studying these most primitive stars, dwarf galaxies are going to be very important.”

Thanks to all the interesting results from Segue 1, other researchers have been looking at it with the space-based Fermi Gamma Ray Telescope. They hope to catch a glimpse of gamma rays, which are predicted by current theories to be the marker for dark matter – they could be created by the collision and annihilation of pairs of dark-matter particles. Unfortunately, the Fermi telescope hasn’t seen any tantalizing flares from Segue 1, but that doesn’t mean that the dark matter is not present, explains Simon. “The current predictions are that the Fermi telescope is just barely strong enough or perhaps not quite strong enough to see these gamma rays from Segue 1,” he said. “So there are hopes that Fermi will detect at least the hint of a collision.”

In the meantime, Simon says that he is working on a study of the seven red giants in Segue 1 that will measure the abundance of elements other than iron in their atmospheres to learn about what Segue 1 looked like at the time those stars formed. But this data relies on new observations. “We have recently obtained much deeper imaging of Segue 1 that we will be using to determine its structure and search for stars that may have been stripped from the galaxy by the tidal forces of the Milky Way,” he says. It will be interesting to see if this dark host has any more secrets to reveal.

By Margaret Harris

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A fortnight ago our weekly Facebook poll asked:

How often do you use physics at work?

The most common answer by far, with 62 out of 80 votes (about 78%) was “a lot – practically every day”.

Given our readership, such a response was hardly surprising, but a few of those who voted with the majority wondered if the poll even made sense. As a reader with the intriguing alias of “Grannie Cool” observed, “Everything is physics, so that’s a loaded question!” while Ahmed Al Bashir pointed out that even human behaviour seems to obey the laws of action and reaction. The most creative response came from the Twitter user @Timewrapper, who claimed that they use the principle of energy conservation every day – by sleeping all day long. Let’s hope their boss isn’t reading this.

Some of the minority responses were also interesting. We particularly liked the one from someone at a company that makes merino outdoor gear, who informed us that one of the company’s partners has an MPhys, “but on a day-to-day basis, it hasn’t much relevance”.

Which leads us nicely into this week’s poll, which is:

Do you consider yourself a physicist?

You can vote here and in the best Facebook tradition, the possible answers are “yes”, “no” and “it’s complicated”. (If you place yourself in the third category, we’d really like to know why!) We’ll discuss the answers next week, and they’ll also help inform our October special section on careers for physics graduates.

CERN seeks cultural renaissance

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By James Dacey

When I visited CERN earlier this year, it was clear that in addition to all of the research there is also a strong focus on the arts. Strolling around the facilities, I stumbled across many works of art, including several pieces by the British sculptor Anthony Gormley. And various researchers told me that they love working at the lab because of all the opportunities to get involved with extracurricular activities, where they mix with people from all over the world.

Today, CERN has reaffirmed its commitment to the arts with the launch of a cultural policy for engaging with the arts, called “Great Arts for Great Science”. The policy outlines a selection process, which the lab will follow when deciding which arts programmes to approve. CERN is also seeking to form partnerships with leading international arts organizations.

I first heard about the policy while at CERN in April when I caught up with the lab’s cultural specialist, Arianne Koek. She told me that her vision was to cast science and art on an equal platform by encouraging more internationally renowned artists to collaborate with the lab.

“If you look at the whole history of the Renaissance, arts and science were absolutely on an equal level. And I think it’s absolutely time now to have a contemporary renaissance,” she said. You can see our full interview in the video below.


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By Hamish Johnston

While vacuum technology is common place in the research labs of wealthy countries, scientists in developing nations often lack access to the most basic surface-science facilities.

In Physics World’s latest Vacuum Challenges and Solutions supplement, J J Pireaux explains how the international vacuum association IUVSTA is reaching out to developing countries. In an exclusive interview, IUVSTA’s president explains what the society is doing to attract new members from developing nations. Another key part of IUVSTA’s strategy is its World Transfer Program, which will soon be offering grants to early-career scientists so they can work in another lab for a short period of time.

Moving on to countries that have developed rapidly into top-tier economies, the supplement also has an article by Matthias Wiemer and Wannong Eckhardt that addresses the challenges of operating in the “BRIC” countries. According to Wiemer and Eckhardt, Pfeiffer Vacuum has seen a significant increase in demand for vacuum equipment in Brazil, Russia, India and China – as well as other countries in Asia. Writing in the supplement, the pair argue that simply shipping vacuum kit to BRIC nations is not enough. Instead firms must create “well-established service networks close to customers”.

Going from the “second world” to “out of this world”, Giles Case of the Rutherford Appleton Laboratory explores how vacuum systems are used to test satellite components – and even entire satellites – before they are sent into space.

The supplement also allowed me to put my vacuum experience to good use in researching and writing an article about the reuse and recycling of vacuum equipment. I interviewed people from businesses ranging from industry giant Oerlikon Leybold Vacuum to the four-person outfit PSP Vacuum – and discovered that the used-equipment business keeps on growing.

You can download a free PDF of the supplement here.



By James Dacey

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Here in the UK over the past few weeks the media have been going through a spell of reflection, following revelation after revelation about phone hacking at the now defunct weekly newspaper, News of the World. So the time seemed ripe to use our weekly Facebook poll to ask readers a question relating to the media and our particular patch of the media landscape: science. We asked:

On the whole, how do you find the media’s coverage of science?

Impartial
Occasionally biased
Frequently biased
Almost always biased

And it seems that the majority of respondents take a pretty bleak view of the media in terms of their scientific balance. 59% of respondents feel that the media are almost always biased in their handling of science stories. 29% believe that the media are frequently biased and 12% said that they are occasionally biased. Not a single person felt that the media are never biased in covering science.

One responder who voted for almost always biased, Liam Cresswell, believes that the problem could be related to the culture and hierarchies among media outlets. He commented that, “While there are a small number of decent science journalists: as soon as anything that is deemed major comes up, said science journalists are undermined (by their news establishment) and a generic, high profile, news journalist is put in control of the story.”

Another respondent who cast his vote in the same way, Nigel Deacon, singles out climate science as an area in which the media are particularly bad. “The mainstream media’s coverage of climate science seems to be aimed, in the main, at a juvenile or uninformed audience,” he said. “To read anything approaching a reasoned discussion, one has to go to the Internet. The BBC’s bias is particularly obvious.”

The question that we posed to readers was inspired by a recently published review of the BBC’s science coverage. This concluded, for the large part, that the corporation’s content is accurate and impartial. The findings, published by the BBC Trust, consisted of an independent report from geneticist and popular-science author Steve Jones and a content analysis carried out by Imperial College London.

Jones did, however, warn of instances where scientific debates have been misrepresented in an attempt to create balance or conflict. He refers to climate research as a subject that has only a minor presence in the science literature as a whole, but is heavily overÔÇÉrepresented in news coverage.

In specific reference to man-made climate change, Jones warns that an “over-rigid” application of the corporation’s editorial guidelines on impartiality has created a false debate. This, he concludes, fails to take into account what he regards as the “non-contentious” nature of some stories and the need to avoid giving “undue attention to marginal opinion”. Though he did suggest that the problem could be resolved in part by new BBC guidelines, published in 2010, that incorporate consideration of “due weight” in relation to impartiality.

Thank you for taking part in the poll and for taking the time to provide comments. Check our Facebook page tomorrow for a poll relating to physics careers.