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Magnetic shield could protect spacecraft

The idea of shielding spacecraft from harmful cosmic radiation using artificially-generated magnetic fields was once dismissed as unrealistically expensive. But new experiments carried out in the UK show that the technology could be made compact enough, and therefore cheap enough, to protect astronauts on flights to the Moon and Mars.

The existence of harmful radiation in space is one of the most significant obstacles to long-range spaceflight. Some of this is in the form of very high energy particles arriving from deep space, but the greater concern, by virtue of its much larger flux, is the solar wind emitted continuously by the Sun. This magnetized plasma contains protons and alpha particles (together with their disassociated electrons) that can break up DNA and cause cancer.

Astronauts travelling to the International Space Station are protected from much of this radiation by the Earth’s atmosphere as well as by its “magnetosphere”, the magnetized bubble of plasma surrounding the Earth created by its magnetic field. However, people on longer flights will not have this natural shielding and are therefore at greater risk. Indeed, it is reckoned that the astronauts of the Apollo programme escaped the particularly dangerous peaks in solar activity largely through luck.

Getting in a tin can with a rocket on your back and flying to Mars is never going to be a safe thing to do Ruth Bamford, Rutherford lab

Protective bubble

A team of physicists from the UK, Portugal and Sweden led by Ruth Bamford of the Rutherford lab has shown that it should be possible to shield spacecraft using artificial magnetospheres. Like the real thing, these would separate out the electrons and protons of the solar wind, generating a separation of charge in space that would deflect these particles away from the spacecraft. This idea was first put forward in the 1960s, but was considered unworkable because it was reckoned that a volume of space more than 100 km across would have to be shielded. Extending a field over this distance would require magnets with strengths of tens or even hundreds of Teslas, which could not be transported into space.

However, according to Bamford, these previous calculations are inaccurate because they assume that the solar-wind plasma flows like a normal fluid. Decades of research on nuclear fusion have instead shown that plasmas are subject to all sorts of turbulent behaviour not seen in normal fluids, and that, furthermore, this turbulence can occur on roughly human scales.

The researchers believe it is possible to exploit this knowledge of turbulence to create a much smaller protective bubble, and have confirmed this belief — first through computer simulations, and then in a laboratory experiment. The latter involved injecting a supersonic plasma into a 1.5 m long vacuum vessel lined with magnetic coils, with a target magnet placed at the far end of the vessel. Using both optical imaging and an electromagnetic probe, Bamford’s team showed that the target magnet deflected the plasma such that the volume of space surrounding the magnet was almost entirely free of plasma particles (Plasma Phys. Control. Fusion 50 124025).

More work

Bamford and colleagues say these results show that a spacecraft could in fact be protected using a bubble just some 100–200 m across. This, they say, would correspond to a magnet of about 1 Tesla, which would be light enough to be transported into space.

Bamford told physicsworld.com that more work needs to be done in scaling the technique up before it can be tested aboard a satellite, but reckons that it could be perfected in time for a return to the Moon in around 2020. She does point out, however, that even if the technology works it will not provide complete protection. For one thing, it could not shield astronauts against very high energy intergalactic cosmic rays. “Getting in a tin can with a rocket on your back and flying to Mars is never going to be a safe thing to do,” she says.

Electrons put a new spin on chirality

Researchers in the US have shown that the presence of spin-polarized electrons can make a chemical reaction involving “right-handed” molecules occur faster than the same reaction involving “left-handed” molecules. The discovery could help scientists understand why nature favours a certain handedness in many biological molecules.

An important question facing those trying to understand the origins of life is why important biological molecules have a certain handedness or “chirality”? Amino acids, for example, can be either right- or left-handed mirror-images of each other. However, they are always left handed when produced by living organisms. This is important because chirality can affect how a molecule takes part in the chemical reactions crucial for life.

Scientists believe that two external agents could be responsible for chirality in biological molecules: circularly polarized light and spin-polarized electrons.

Life from outer space?

While circularly polarized light is rare on Earth, astronomers know that it can be produced in the interstellar medium — leading some to speculate that the precursors to chiral biological molecules were created in space and somehow transported to Earth.

Low-energy spin-polarized electrons are produced when X-rays and other ionizing radiation strike iron, nickel and other magnetic materials. These materials are relatively abundant and such interactions could have occurred on the early Earth, on other planets and even in space.

Richard Rosenberg

Now, Richard Rosenberg and colleagues at the Argonne National Laboratory in Illinois and the Ames Laboratory in Iowa have shown that such electrons can affect the rate at which chiral molecules participate in a chemical reaction (Phys. Rev. Lett. 101 178301).

Magnetic surface

The team began with an ultra-clean sample of Permalloy — a magnetic iron-nickel alloy — held in ultra-high vacuum conditions. The Permalloy surface was covered with an ultrathin layer of 2-butanol, which is a relatively simple organic molecule that can occur in either right or left-handed versions. X-rays were fired at the surface, which causes some of the butanol molecules to react by either dissociation or breaking free. The team measured the amount of intact butanol remaining on the surface as a function of X-ray exposure time.

Physicists know that the rate at which such molecules react is affected by their interaction with the secondary electrons that are produced when the X-rays strike the substrate. If the Permalloy is magnetized, these secondary electrons became spin polarized — offering the team an opportunity to study the effect of spin-polarized electrons on chiral molecules.

To do this, the team first covered the Permalloy with three molecular layers of right-handed butanol. A magnetic field was applied along the surface to magnetize the Permalloy in one direction and then that rate at which the butanol molecules react was measured.

This entire process was then repeated with the Permalloy magnetized in the opposite direction — which meant that the secondary electrons were polarized in the opposite direction.

10% difference in reaction rates

After some careful analysis, the team were able to conclude that there was a 10% difference in the rate at which right-handed butanol reacted, depending on the polarization of the secondary electrons. The team then repeated the experiment using left-handed butanol and found the same 10% difference.

Remarkably, they found that electrons polarized in the “+” direction enhanced the reaction rate of right-handed butanol, while electrons polarized in the opposite “-” direction enhanced the reaction rate of left-handed butanol.

The reaction rate is a measure of the relative propensity for the butanol to dissociate or leave the surface — and Rosenberg’s experiment shows that for chiral molecules, the rate can be affected by the spin-polarization of the secondary electrons. In other words, they have shown that a chemical reaction involving chiral molecules can proceed differently in the presence of spin-polarized electrons.

The team is now planning to repeat their experiments using alanine, an amino acid that comes in right and left-handed versions.

While Rosenberg did not measure the spin-polarization of the secondary electrons, measurements by other physicists suggest that it is about 10%. The team is now working on measuring the polarization from its Permalloy sample and is also interested in repeating their experiments using substrates that emit secondary electrons with polarizations as high as 70%.

PAMELA bares all

The European collaboration PAMELA has put an end to months of speculation by claiming that its Earth-orbiting satellite could have found the remnants of dark-matter annihilation.

In a preprint uploaded to the arXiv server last week, the collaboration presents data suggesting that cosmic rays above the Earth’s atmosphere contain an excess of high-energy positrons. This excess, the authors say, “may constitute the first indirect evidence of dark-matter particle annihilations” — although they add that there could yet be other explanations, such as the presence of a nearby pulsar (arXiv:0810.4995).

The PAMELA data briefly saw the light of day on a presentation slide at a high-energy physics conference in Philadelphia, US, at the start of August. At the time scientists in the audience spoke of the implicit significance of a positron excess for searches of dark matter, an unknown entity that is believed to make up 23% of the universe’s energy budget. But because the PAMELA researchers were planning to submit their work to Nature, which has a strict embargo policy, they avoided making any comments of their own.

Given that our preliminary conference data are starting to be used by people, we felt this was a necessary step Mirko Boezio, PAMELA collaboration

In an unusual twist, however, it emerged that at least one conference attendee had taken photos of the fleeting slide when a month later other preprints began appearing on arXiv making analyses of the data.

“We wanted to make our final results available to the scientific community once the data analysis was finalized,” PAMELA member Mirko Boezio told physicsworld.com, pointing out that Nature permits its authors to upload preprints to arXiv. “Given that our preliminary conference data are starting to be used by people, we felt this was a necessary step — not least because it provides a proper reference that correctly acknowledges the whole PAMELA collaboration and is available to the scientific community at large.”

Lots of data

Launched in June 2006, the PAMELA (Payload for Antimatter/Matter Exploration and Light-nuclei Astrophysics) satellite was designed by institutions in Italy, Russia, Germany and Sweden to examine the nature of antiparticles in cosmic rays. Unlike other cosmic-ray missions, which mostly consist of short balloon flights, PAMELA operates in space where there is little noise from antimatter generated in the atmosphere. Moreover, the satellite has been working non-stop since its launch and will continue to do so until the mission ends after December 2009.

The result of this so far is a large body of cosmic-ray data which is both statistically robust and which extends high energies of about 80 GeV. It indicates that the fraction of positrons to electrons does not decrease steadily with energy, as would be suggested by theoretical “baseline” predictions (that is, predictions that only take into account the production of positrons from interactions between cosmic rays and interstellar gas). Rather, the positron fraction appears to rise after 10 GeV, implying that there is another, unknown source of positrons.

The PAMELA results are interesting, and they deserve the attention they are receiving Stéphane Coutu, HEAT collaboration

The PAMELA collaboration says that possibilities for this source could be a nearby pulsar or, more interestingly, dark-matter particle annihilations.

“The PAMELA results are interesting, and they deserve the attention they are receiving,” says Stéphane Coutu, an experimental high-energy physicist at Penn State University who has worked on the NASA-supported HEAT mission to study cosmic rays from balloons. But, Coutu adds, “the exact interpretation of what the PAMELA high-energy excess truly means will remain uncertain for some time, and the subject of much debate, I’m afraid.”

Positrons or protons?

Part of the debate over the PAMELA data will likely revolve around how effectively the satellite overlooks protons, which have the same charge as positrons and which are a thousand times more abundant in the cosmos. While a magnet spectrometer can effectively distinguish between an electron and positron by the sign of the charge, it is the length of the electromagnetic showers in an adjacent calorimeter that has to determine whether each positron is not in fact a proton.

The PAMELA collaboration says it has performed tests at the CERN lab near Geneva that showed that just one proton in 100,000 fools the calorimeter into believing it is a positron. But Coutu says that the satellite could have benefited from a “transition radiation detector” (TRD), which would have helped rule-out protons unambiguously. “If the discrimination capabilities of their instrument are any less than they think, as one could imagine in the absence of a TRD, then the outcome could be exactly what they observe: a rise with increasing energy in the fraction of positively charged particles, which could be due to something other than positrons themselves.”

Fermilab ‘ghosts’ hint at new particles

Physicists at the Tevatron collider at Fermilab in the US, which is enjoying extended status as the world’s most powerful particle collider while CERN’s Large Hadron Collider (LHC) awaits repair, have reported signals in their data that hint at the existence of new fundamental particles. Last week members of the CDF experiment, one of the Tevatron’s two huge particle detectors, posted a preprint detailing a large sample of proton–antiproton collisions that cannot be accounted for either by quirks of the CDF detector or by known processes in the standard model of particle physics (arXiv:0810.5357 , submitted to PRD).

If the result does turn out to be due to some unexpected new process, it would be the most significant discovery in particle physics for decades. However, almost a third of CDF’s 600 or so collaborators (including some entire university groups) decided not to put their names on the paper, many believing that publication was premature because more checks need to be done.

“This is a very interesting and statistically significant effect,” says CDF member Mark Lancaster of University College London, who was one of those who removed his name. “The spirit of this paper is to get the result out there so that it can be checked by others, but the analysis is a work in progress.”

No claims

Claiming a discovery of physics beyond the 35-year-old standard model is not something physicists take lightly, which is why the 70 page long CDF paper does not make such a claim. Rather, it describes a subset of proton–antiproton collisions in which newly produced B mesons and anti-mesons fly a certain distance before decaying into pairs of muons, which are tracked by CDF’s inner detector. From some 300,000 events in which at least one muon originated beyond the Tevatron’s 1.5 cm radius beam pipe, CDF finds some 70,000 which contain more muons than expected.

“We present the bare facts,” analysis leader Paulo Giromini told physicsworld.com. “We poked fun at ourselves by publishing the paper on Halloween and calling the events ghosts, but we have performed all the sanity checks we could possibly think of. While each single feature of the signal can be explained by stretching the systematic uncertainty of our detector response, we cannot think of a way to construct a correlation between the different features.”

Unlike some scents of discovery in particle physics, such as claimed sightings of the Higgs boson at CERN’s previous collider LEP in 2000, the CDF data are not limited by statistical uncertainties due to a small event sample. Instead, researchers have to be sure the readings from the CDF detector can be fully trusted in the region close to the Tevatron’s beam pipe and must convince themselves (and one another) that the standard model “background” processes — many of which rely on a detailed understanding of quantum chromodynamics — do not provide a more mundane explanation.

Peter Renton of Oxford University says that independent studies within CDF are investigating possible standard-model backgrounds. “The Oxford CDF group [which did not appear on the paper] believes that these studies should be completed before drawing any conclusion on the nature of the events,” he said.

Your model or mine?

CDF’s vetting procedure, during which publications are assigned “godparents” and must be “blessed” before being released to the outside world, forced some of the original wording about possible interpretations of the excess events to be removed from the paper since July when it was unveiled to the collaboration. But shortly after it was posted last week, Giromini and six others released a separate preprint late on Friday in which they suggest the anomalous events can be explained by the existence of three new particles with masses of about 15, 7.3 and 3.6 GeV (arXiv:0810.5730v1).

Although the team does not know what mechanism could produce the heavier particle to begin with, the idea is that this particle decays into the lighter ones which subsequently decay into pairs of tau particles (heavy copies of muons) and, finally, into muons. Because the lightest state is presumed to decay into a pair of taus with a lifetime of about 20 ps, this can account for the mysterious muons originating beyond the beam pipe.

Other interpretations are sure to follow. In fact, last month Nina Arkani Hamed of the Institute for Advanced Study at Princeton and Neal Weiner of New York University predicted a CDF-like signal from a “superunified theory of dark matter” that was constructed in part to explain possible sightings of dark matter by the PAMELA experiment, which recently detected an excess of positrons in cosmic ray data (arXiv:0810.0714v2).

“Simple explanations of the PAMELA excess seem to require new particles at the GeV scale decaying into leptons [which include taus and muons],” said Weiner. “That CDF may be seeing a similar signature is certainly exciting, but the signature we discussed appears to be at far too low a rate to explain what they see and a lot of work remains before we can determine if the signatures are consistent.”

Cross check

The CDF analysis has parallels with one led by Giromini in 2003, which concerned signs of new physics via an excess in the number of particle “jets” in earlier CDF data. It is exactly this kind of painstaking comparison between data and simulations that LHC physicists will be undertaking in the next few years in their search for new particles, only with detectors considerably more complicated (and presently less well understood) than those at the Tevatron.

All eyes are now on CDF’s sister experiment D0 to see if it can spot the same muon excess and thus harden the case for new physics. “We just learned of this result on Friday, but the D0 detector has an excellent muon system so we should be able to do a meaningful crosscheck of this excess,” explained D0 spokespersons Darien Wood and Dmitri Denisov. “We are not putting everything else on hold, but we will try to investigate it seriously.”

Meanwhile, Giromini is keen that the CDF muon excess does not get overhyped. “In my personal opinion the CDF analysis was not particularly controversial, but definitely the outcome scared the living daylights out of number of people,” he says.

Although highly unusual for so many members of a particle physics collaboration to remove their names from a paper, CDF co-spokesperson Jacobo Konigsberg of Florida University says that overall it was a nice discourse. “It’s expected that some people will feel uncomfortable signing such a technical preprint presenting results that cannot fully be explained, and which may turn out to have a mundane origin,” he said.

Ice: a most curious substance

Ice fishing on the Ottawa River — no Periodic Hartree-Fock Calculations required. (Courtesy: AlainV).

By Hamish Johnston

One of my favourite memories of childhood is travelling across a frozen lake in the backseat of a circa-1975 Buick LeSabre (a very large car) on our way to do a bit of ice fishing.

The ice was over a foot thick, and we were secure in the knowledge that it would hold the LeSabre — and the hundreds of other cars on the lake.

What I didn’t know back then was just how complicated the stuff we were driving on is — and how much grief it has given to physicists brave enough to try to understand it.

For example, Andreas Hermann and Peter Schwerdtfeger of Massey University in New Zealand have just published a paper entitled Ground-State Properties of Crystalline Ice from Periodic Hartree-Fock Calculations and a Coupled-Cluster-Based Many-Body Decomposition of the Correlation Energy .

They say their result “hints at the possibility to accurately simulate ab initio water”. In other words, at some point in the future we may be able to understand why a seemingly simple combination of hydrogen and oxygen has myriad wonderous and life-giving properties.

Indeed, one of the most curious (alleged) properties of water is the Mpemba effect whereby hot water freezes faster than cold water. I’m guessing that it will be a while before this can be explained using Periodic Hartree-Fock Calculations.

Condensed-matter physicist to head DESY

Helmut Dosch will be the next director of Germany’s DESY Research Centre, effective 1 March 2009. Dosch will be the first condensed-matter physicist to lead the accelerator lab. He takes over from Albrecht Wagner, who has been in charge since 1999.

The Deutsches Elektronen-Synchrotron (DESY) was founded in Hamburg in 1959 and currently employs about 1900 people there and at a second site in Zeuthen in the former East Germany. Originally conceived as a particle-physics lab, DESY was home to several colliders — the last being HERA, which shutdown last year.

Today however, much of the lab’s activities are focussed on using the synchrotron radiation created by particle accelerators to do condensed matter physics, materials science, chemistry and biology. DESY is home to several accelerators and numerous beamlines dedicated to such research including the HASYLAB synchrotron facility and the FLASH free electron laser.

It not surprising, therefore, that the lab has chosen a new director who has spent much of his career using synchrotron radiation to investigate solid interfaces and nanostructures. Dosch, 53, is currently director of the Max Planck Institute for Metals Research in Stuttgart and chair of Experimental Solid State Physics at the University of Stuttgart. He is also vice-chair of the Administrative Council of the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.

Dosch will see DESY take an important role in XFEL, the European X-ray Free Electron Laser, which is being built next to the lab’s Hamburg site. He will also oversee DESY’s ongoing contribution to the development of new technologies for the International Linear Collider — the next big particle physics experiment after the LHC.

Memristors model primitive learning

Physicists in the US have modelled a simple electronic circuit that they say is an analogue of how a single-celled organism learns.

The circuit consists of a capacitor, an inductor and a resistor — together with the recently discovered fourth basic circuit element, the “memristor”. The researchers claim it is this element that provides the memory needed for learning, and that the circuit could help in the understanding of primitive intelligence.

Single-celled memory

Earlier this year, Yoshiki Kuramoto of Kyoto University and colleagues showed how the amoeba Physarum polycephalum learns to respond to its environment. They found that when they subjected it to three regularly-spaced dips in temperature and humidity — both of which the organism finds unpleasant — it slowed down with the arrival of each. But they also found that the amoeba continued to oscillate in speed for a while after the last dip, and that in the future just a single dip would set the speed oscillating again. This implied that the amoeba expected a single dip in temperature or humidity to lead to more regular bursts.

Kuramoto’s group argued that the amoeba’s response could be explained by systems of chemicals in which properties fluctuate, known as “chemical oscillators”. The learning, they said, took place when external stimuli, such as the dips in temperature and humidity, synchronize the phase of the different oscillators.

However, Massimiliano Di Ventra, Yuriy Pershin and Steven La Fontaine of the University of California San Diego point out that the many-oscillator model cannot explain how an amoeba responds to a single temperature dip later on. For this, they say, the amoeba requires memory.

Simple circuit

To demonstrate the principle of how this memory could work, Di Ventra and his group linked a resistor, an inductor and a capacitor in series and then placed a memristor across the capacitor. A memristor is a device, predicted in the seventies and realized by scientists in California earlier this year, in which resistance varies according to the amount of charge that has flowed through it.

The result of this property is that when the external voltage is stable or varying non-periodically the memristor exists in a low-resistance state, which dampens the oscillation in voltage across the memristor set up by the inductor-capacitor combination. However, when the external voltage varies periodically — and with a frequency close to the inductor-capacitor resonant frequency — the memristor switches to a high resistance state, and the oscillations are much less damped. This high-resistance state can persist for so long that a single voltage dip in the future can also trigger low-damped oscillations. In other words, after the circuit receives a series of dips at its input it then it “remembers” that, given just a single dip in the future, it should continue to produce a periodic output (arXiv:0810.4179).

Di Ventra’s group points out that an analogue of the memristor exists inside Physarum polycephalum, which is a viscous gel. This gel normally impedes the motion of the organism, but with changing environmental conditions can increase the pressure inside to the point where the gel breaks up, forming low-viscosity channels that alter the organism’s motion. The organism can revert to its initial motion only after a while, which in effect allows it to “remember” how to respond to the new conditions.

According to Di Ventra, the fact that periodic signals trigger the memory mechanism suggests that their circuit could be used to recognize particular inputs, in other words carry out pattern recognition. The three researchers believe that their circuit is in a sense conceptually similar to neurons in the brain, and are currently trying to model multiple memristive circuits to study the complex behaviour that results.

Beauty and the beast

She sounded sceptical. “Beautiful?”

The reporter had asked about the Large Hadron Collider (LHC) in preparation for a radio interview. I had mentioned that CERN was hosting an official inauguration event on 21 October to include an art exhibition, concert and thousands of guests. She expressed surprise that the celebration was so elaborate. I tried to explain why a machine that is huge, complicated and buried underground — and already so damaged by last month’s severe accident that it will not be operational again until at least the spring (see p7, print version only) — nevertheless generated enough excitement to warrant the partying. Off-handedly, I remarked that the LHC might turn out to be beautiful. That puzzled the reporter.

She had only another minute, and I did not have time for a lengthy explanation. But readers who have followed my previous 99 columns can predict what I might have said.

Experiments as performances

A scientific instrument is not an appliance like a toaster or microwave that we build to make something specific happen. A scientific instrument is more like a stage. On it, we mount performances to help answer our questions about nature, the outcomes of which cannot be predicted. Whatever happens reveals more than we already know; we get back more knowledge than we put in (see “Critical Point: The Newton-Beethoven analogy”). Experiments are thus creative acts with similarities to dramatic performances. One similarity is that they have to be carefully planned, executed and analysed. Another is that their outcome is enthralling — cause for curiosity, excitement and wonder (Physics World November 2002 p19; April 2005 p17; print versions only).

Occasionally, what happens in experiments deepens and transforms our understanding of the world in a way that we call beautiful. Examples include Eratosthenes’ measurement of the circumference of the Earth, Galileo’s falling-body experiments and Newton’s decomposition of sunlight with prisms. These three experiments, indeed, were among the winners of a poll I conducted among readers of Physics World to find the most beautiful experiment (see “Critical Point: The most beautiful experiment…”; “Critical Point: The most beautiful experiment – the result”).

Beautiful performances

So is the LHC beautiful? Certainly the images of particle collisions, real or computer-reconstructed, are pleasing to the eye. The collider’s two main detectors ATLAS and CMS are majestic, colourful and symmetric. And the LHC is conceptually neat and easy to explain — it makes two counter-rotating beams of protons collide and tracks the resulting debris. But these are superficial aspects, not reasons to call the machine beautiful.

In certain columns and the book that grew out of them — The Prism and the Pendulum: The Ten Most Beautiful Experiments in Science (2003 Random House) — I discussed the reasons why we call things beautiful. For thousands of years, formal and systematic accounts by philosophers and artists have tended to emphasize three criteria. One is that a beautiful entity satisfies us; it convinces us that this is what we were looking for. Another involves the composition of the beautiful object; its symmetry and the fact that each element is necessary to the whole with nothing superfluous. The third criterion is that a beautiful thing points beyond itself to fundamental things: the true and the good. Could the LHC possibly meet these criteria?

Why not? The results from ATLAS and CMS may well provide conclusive answers to questions about the origin of mass and the existence of extra dimensions. And although the LHC was not cheap — cost over-runs lifted its price tag to €6.3bn — years of reviews have tended to cut anything superfluous and make sure that nothing extraneous was added. Finally, few issues in high-energy physics today are more fundamental than the origin of mass and the existence of other dimensions. The LHC, I would claim, has a chance of meeting the three criteria of beauty.

We do not yet know what will happen. But any great performance involves risk. By risk, I mean more than technical glitches, such as the electrical fault in September that resulted in as many as 29 superconducting magnets being damaged, details of which the laboratory was slow to disclose. Even this injury, grave as it is, only affects the props. By risk, I mean the possibility that the Higgs will not be found, and that the results turn into a theoretical mess involving complex statistical arguments.

An experimental result, like a beautiful object, has the aura of the gratuitous about it, as if it were a gift from the beyond, for the universe could have been different than it is. If things could not have been different, then we would not have needed to do the experiment. If the Higgs does appear at the LHC — and perhaps even if it does not and something else appears instead — we will be quite justified in calling it a beautiful moment in science.

The critical point

I did not have time to say all this to this reporter. Instead, I said something like “When human beings build something as ambitious as the LHC, whose actions have such an awesome scope — linking infinitesimally small particle collisions and cosmic quantities of mass, the microcosm and the macrocosm, the infinite and the finite — that’s the kind of thing we appropriately call beautiful.”

In saying that, I was describing activities of science from a different perspective than scientists themselves are accustomed to adopting, describing how the reporter’s ordinary experience of beauty might be transformed into the context of scientific research. I was, in short, trying to bring about a kind of conceptual phase transition that you might call a critical point.

Blog life: The Adventures of My Pet Hamster

Blogger: Steve Sekula
URL: steve.cooleysekula.net/blog
First post: January 2005

Who is the blog written by?

Steve Sekula is a physics postdoc at Ohio State University in the US. Much of his recent work has been on the BaBar experiment, which studies the decay of B-mesons and is based at the Stanford Linear Accelerator Center (SLAC). Although BaBar’s detecting phase ended in April 2008, data-sifting is expected to continue for several years as physicists search for clues about the origin of charge—parity violation (the subject of this year’s Nobel Prize for Physics). Sekula also plays drums in a rock band, which makes a few cameo appearances in his blog.

What topics does the blog cover?

Archived categories include computing and physics, alongside non-science subjects like politics and education. Many entries filed under “random” and “rant” also have a strong science focus. One “rant”, for example, describes a pseudoscientific pamphlet Sekula received in the post, and his subsequent deconstruction of the leaflet’s so-called theory of a geocentric universe. A recent series of entries describes life on the seminar circuit, as Sekula tours universities in the eastern US and Canada talking about his work on BaBar.

How often is it updated?

Almost daily. In September, for example, there were 29 entries, with the combination of US presidential politics and the switch-on of the Large Hadron Collider providing plenty of post fodder. “Each day, I try to find one topic that I find funny, inspiring, frustrating or unique,” Sekula told Physics World. The act of writing things down helps him make sense of life, he says.

Why should I read it?

Although entries on Sekula’s personal life may have limited appeal for outsiders, the sheer volume and variety of posts means that most readers will find something interesting at least once a week. Those seeking a more in-depth treatment of the physics and foibles of BaBar may also want to look at Sekula’s “professional” blog Going Up Alleys (steve.cooleysekula.net/goingupalleys).

Can you give me a sample quote?

The high-energy physics story is “We ask it, we build it, we learn something, and the technology is useful for other purposes we didn’t foresee”. It’s a great story, I think. But Washington wants a better story. They want a “Theory of Spinoffs” — a story that tells them and the public that investment in HEP inevitably leads to new technology, something which changes the world (and makes big bucks for the economy). This [theory] goes more along the lines of “We ask it, we build it, we learn something, and we will use the technology to do other things that weren’t foreseen but were inevitable”. It’s this inevitability that worries me.

Where does the hamster come into it?

Sekula says that when he was an undergraduate, one of his mentors joked that physics students were like hamsters — always running on little wheels, thinking they’re going somewhere fast but never getting anywhere. “This idea stuck with me,” he says. “It makes me ask myself, ‘Am I actually making progress in understanding the universe, or am I spinning my wheels?’ This perspective can be very helpful at times.”

Has Bush been good for science?

Today, the scientific enterprise in the US is strong, highly productive and significantly greater than it was eight years ago. Contrary to popular mythology, President Bush has devoted more attention to science and technology in his official actions than most of his predecessors. Strains and imbalances exist among the various research fields, but the Bush administration has initiated programmes to address many of these on a prioritized basis. However, despite the magnitude of competing national needs and fiscal constraints affecting all domestic federal programmes, science in the US has moved forward substantially during the Bush years.

About one-third of US research and development (R&D) funding comes from federal sources appropriated by Congress, with most of the rest coming from the private sector. The total spent on R&D — $368bn in 2007 — remains remarkably steady year on year as a fraction of Gross Domestic Product (GDP) at about 2.7%. This is the highest figure of any large economy except Japan, where the proportion is 3.4%, and South Korea, where it is 3.2%. China, in contrast, ploughs back just 1.4% of GDP into research.

The federal portion of R&D for 2008 is $144bn. This is 12.7% of the “discretionary budget” — the part that is subject to the annual budgeting process and that excludes “mandatory” expenditures for social security, medical insurance and interest on the national debt. This figure is now higher than at the start of the Bush administration in 2001, when it was 12.3%.

Table 1

In his second term, President Bush has aimed to reduce the overall budget deficit and keep discretionary budget growth below inflation. Nevertheless, on average, R&D budgets during this period fared better than other domestic programmes and have kept ahead of inflation. Over both terms, overall federal R&D has grown 41% in inflation-adjusted dollars to $147bn, and non-defence research has grown by 31% to $61bn. The total inflation-adjusted expenditures in various science categories during the Bush years compared with the previous administration are shown in table 1.

Compared with other countries, these are huge numbers, and it is remarkable that they have held up under the budgetary pressures of the past decade. Surveys, such as the Science and Engineering Indicators carried out this year by the National Science Foundation (NSF), show that scientific research is viewed positively by the US public — a view that is also shared by the Bush administration and both houses of Congress.

Rising above the storm

Beneath this impressive “top line” for US science are issues of emphasis and priority. These issues have energized critics and advocates of every stripe in the politically intense era following the presidential election of 2000, in which all of the administration’s actions were scrutinized. Issues like embryonic stem-cell research and responses to climate change, among others, are contentious for many reasons, but most of these have little to do with science. They comprise a small fraction of the total US science activity, and they do not reflect the deepest or even the most serious challenges in the overall R&D enterprise such as funding imbalances, lagging interest in technical careers and the impact of increased homeland-security measures on the conduct of science.

During the election year of 2004 these topics ballooned into caricatures of the underlying reality. Since then, the public discourse in the US has evolved to reflect a more balanced spectrum of opinion on these issues, especially about climate change. But myths remain about the administration’s attitudes.

It has fallen to the Bush administration to begin a major reorientation of federal science policy in the post Cold War era. Agencies within the Department of Defense (DOD) and the Department of Energy (DOE), the large basic-research programmes of which were generously supported by Congress during the Cold War, came under immediate scrutiny as the former Soviet Union disintegrated.

By the end of the 1990s, the US had withdrawn from the international fusion project ITER, cancelled the Superconducting Super Collider and sustained NASA’s International Space Station by the narrowest of margins in Congress. The DOD began closing research centres, while funding for the DOE’s highly productive physical-science laboratories flattened as Congress demanded a new rationale for their very existence.

Funding for the NSF failed to grow significantly with the booming economy of the 1990s, and the total R&D budget was essentially flat in “constant dollars” during the entire decade. Meanwhile, opportunities in biomedicine were outstripping the resources available at the National Institutes of Health (NIH), the primary sponsor for this field, and a broad consensus formed to double NIH budgets in five years, beginning in 1998.

During the first three years of the Bush administration, budgets for the NIH grew rapidly to half the total of all federal non-defence research. Meanwhile, the relative stagnation of basic research in the physical sciences was causing alarm in those industrial sectors that depend on it for innovation, especially in electronics and IT.

These fields were featured in a series of reports beginning in 2002 and culminating in the highly publicized 2005 report by the National Academies of Science entitled “Rising above the gathering storm”. The report made a dramatic case for economic competitiveness, not national security, as the new rationale for physical-sciences funding. It was also clear that any significant response to climate change and growing demands for energy independence would require major new investments in energy-related R&D.

John H Marburger

The administration quickly reorganized and focused programmes in climate science and technology, rejoined the ITER project and launched substantial new energy-research programmes in the DOE. Following the completion of the NIH budget doubling, and while the aforementioned advisory reports were being written and released, the administration developed the American Competitiveness Initiative. This, among other important objectives, doubles the budgets of the NSF, the DOE science office and the National Institute for Standards and Technology, and reorients DOD research. Congress supported this initiative in its America COMPETES Act in 2006, and has maintained funding for the key agencies, but it has yet to follow through on its commitment of increased funding.

This story of budgets and balances is only one aspect of the vast US science enterprise, but no other has comparable strategic importance. I expect future administrations will sustain the bipartisan momentum that has been achieved in the Bush administration to build basic research in areas vital to the nation’s long-term interests.

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