Features

What with ash clouds and elections the Large Hadron Collider has been out of the headlines recently.

So I enjoyed this update from Paul Rincon at BBC News online who spoke to Tony Weidberg of Oxford University's Department of Physics about the LHC's ATLAS experiment.

ATLAS is looking for new discoveries in the head-on collisions of protons at very high energy inside the machine. Tony explains that within a few months it could be sensitive enough to probe the 1,000 gigaelectronvolt [GeV] mass scale where particles, such as W prime and Z prime bosons, are thought to exist.

Why do these funny-sounding particles matter?

Well, whilst we already know about their lighter cousins (normal w and z bosons are found at 100 GeV) finding these supersized particles could reveal some strange new physics and help us understand the forces that control our universe.

One possibility is that the 'lighter' bosons, which physicists describe as 'left-handed', could be one of a pair.

Tony tells BBC Online: 'We're into speculation here, but one possibility is that the Universe is really symmetric at high energies and that there are right-handed W bosons as well... For some reason, they happen to be much heavier than the left-handed W bosons we know.'

Of course symmetry is just one thing on the minds of LHC scientists.

As OxSciBlog previously reported Oxford's ATLAS team are exploring a range of phenomena with Caterina Doglioni amongst those looking to 'rediscover' the Standard Model, and assess how it fares in this new high-energy world, and Hugo Beauchemin leading the hunt for early evidence of new physics beyond the Standard Model.

Meanwhile Oxford's Cigdem Issever is planning to use ATLAS to find mysterious (but surprisingly non-threatening) 'mini' black holes.

Exciting stuff. The one downside is that, according to Tony, it's likely to be 2011 at the earliest before researchers can start looking for the biggest piece missing from the physics jigsaw: the Higgs boson.

With new fossil fuel power stations being built every week, and the idea of burying CO2 [carbon sequestration] regarded by many scientists as unproven or even unworkable, coming up with an alternative solution to what to do with CO2 is more pressing than ever.

What chemists dream about is turning CO2 from a dangerous greenhouse gas into a useful fuel. But to make this dream a reality will take more than clever chemistry.

That’s why a team at Oxford University is bringing together expertise in chemistry, materials science, engineering and the social sciences to tackle one of the grand challenges of the 21st Century.

A simple recipe
Peter Edwards of Oxford University’s Department of Chemistry, one of the leaders of this team, starts by telling me about the simplest recipe for turning CO2 into fuel: just add hydrogen, then inject some energy from sunlight and you can produce methanol – a versatile feedstock that can be made into all kinds of fuels.

It’s a nice idea, but there’s a big problem. ‘Where do you get the hydrogen from?’ Peter asks. In fact, he explains, 98 per cent of the world’s hydrogen comes from another fossil fuel, methane: and not only is this a finite resource but turning methane into hydrogen takes additional energy and emits more CO2.

'Back in the 1990s chemists had a thought: what if we could bypass hydrogen and make methane and CO2 react to produce methanol,’ he tells me, an idea given a further green boost by the growing resources of sustainable biomethane, especially in India and China.

The new recipe would see this biomethane added to the CO2 that otherwise would be sent up the power station chimney and would harness the existing heat of this CO2-rich ‘flue gas’ to help make the reaction more energy-efficient.

‘It’s all about the energy balance,’ Peter says, ‘if we can use natural gas or biomethane in this process rather than just burning it we’re winning in terms of the energy we get out and the emissions we eliminate.' Now we’re cooking!

Mix with realism
Yet while this sort of chemical recipe was already shown in the 90s to work with a ‘pure’ gas, the sort of emissions that come from a fossil fuel power station are typically full of impurities.

‘Real flue gas is made up of nitrogen oxide (NOx), nitrogen, and oxygen as well as CO2,’ Peter tells me. Up until now dealing with this sort of realistically ‘dirty’ chemical cocktail of gases has been an almost impossible hurdle – especially as scrubbing out the impurities would use up more energy and generate more CO2 emissions.

And if that wasn’t bad enough NOx is a poisonous pollutant that it takes a lot of effort to remove.

Yet the Oxford team - Peter, Tiancun Xiao and Zheng Jiang (the first-ever John Houghton Fellow at Oxford) and colleagues - believe the key to making their CO2-into-fuel dreams a reality lies in new catalyst technology and a different way of thinking.

Instead of getting rid of the NOx the team believe they can use it as a catalyst to help power the reaction. They also cite the fact that the latest technology makes it possible to work with the sort of ‘dirty’ nitrogen-rich gas mix produced in a power station.

To be able to turn the CO2 in this mixed gas and methane into methanol in a power station without an accumulation of carbon causing everything to grind to a halt will take a new generation of nanoscale-structured magnetic catalysts.

Because such catalysts, based on metallic compounds like cobalt oxide, are magnetic they can be moved around by strong magnetic fields, agitating or ‘stirring’ them to ensure that the reaction is more efficient and doesn’t snuff itself out. It’s a novel approach that will require new research in materials science, chemistry and physics to work.

A good result
In the end though, even overcoming these challenges will come to nothing if the new approach isn’t economically viable and environmentally beneficial.

‘There are a lot of broader questions we need answers to: such as, how much natural gas or biomethane is there in the world? And can our solution have a real impact on overall carbon emissions?’ Peter tells me.

But, the team feel, this is where Oxford has an advantage calling on the expertise of the Department of Engineering Science, Begbroke Science Park, the Smith School of Enterprise and the Environment, and Rutherford Appleton Laboratory, as well as partners in the UK and China.

The Oxford team believe that by working on the whole challenge – not just the scientific or technological aspects – they can help to crack one of the world’s biggest and most intractable problems: how to make the CO2 we produce work for us and the planet.

A field in Chilbolton, Hampshire, could help unlock the secrets of peculiar rotating neutron stars known as pulsars.

It's here that an international team, including Oxford University scientists, are building an array that, linked up with stations in the Netherlands, Germany, and France will form LOFAR, one of the world's most powerful radio telescopes.

I asked LOFAR scientist Aris Karastergiou of Oxford's Department of Physics about the new telescope, the search for pulsars, and how games console hardware could help decode their enigmatic signals...

OxSciBlog: What makes pulsars so challenging to study?
Aris Karastergiou: In a sense it is amazing that we can study pulsars at all, as they are compact objects around 10-20 km in diameter. However, they emit very bright beams of light (in the radio frequencies) from their two magnetic poles, which sweep through space as the pulsar rotates.

If Earth happens to be in the path of these sweeping beams of a pulsar, we can point a radio telescope towards it and collect this light. Even then, however, the fact that the most scientifically interesting pulsars rotate over 100 times a second means that observations require not only high sensitivity but also very fast recorders, capable of sampling the incoming light at extremely short intervals.

The fact that pulsar light travels through the Galaxy before reaching us adds further challenges to pulsar studies, as radio waves interact with electrons in the medium between the stars.

OSB: What is LOFAR and how can it help with these studies?
AK: LOFAR (the Low Frequency Array) is a brand new telescope, made up of a large number of receiving elements organised in so-called stations. The core of this telescope is located in the Netherlands, while outer stations are located in Germany, France, the UK and elsewhere. Unlike other radio telescopes, LOFAR is not made up of parabolic reflectors (like satellite dishes), but of little radio antennas.

To point the telescope at a star in the sky, we electronically combine the signals from these antennas with a certain set of time delays LOFAR is a very sensitive telescope and we expect to discover a large number of new pulsars by surveying the northern sky. Compared to the existing giant radio telescopes, pulsars are brighter at LOFAR radio frequencies.

Observing at low frequencies will give us better understanding of the radio emission mechanism, and also shed light on the physical processes associated with the propagation of pulsar light through our Galaxy.

OSB: What difference will the new Chilbolton facility make?
AK: Each of the international LOFAR stations, including Chilbolton, contributes to LOFAR by increasing the capability to tell apart objects in the sky that appear very near to each other. If we imagine that LOFAR can take photographs of the sky, the most distant stations are necessary to reduce the pixel size and make images of greater detail.

On the other hand, the international LOFAR stations are very sensitive telescopes in their own right and can be used independently from LOFAR. They can observe large fields in the sky with large sensitivity and very fast sampling of the incoming radiation, making them very useful instruments for searches of bursty signals like giant radio pulses from pulsars.

We are enhancing the LOFAR station at Chilbolton to take full advantage of these capabilities, and we aim to transform it into a fantastic instrument of discovery.

OSB: How does the sort of hardware found in games consoles help you analyse signals?
AK: Modern games consoles use very powerful graphics processors to deliver stunning images and animation. The secret behind this lies in the enormous computing power of these processors at performing certain simple calculations in parallel. When searching for bright, short duration radio pulses of astronomical origin, we need to counter the effects of propagation of light through the Galaxy. This process involves a simple, repetitive algorithm that can be easily run in parallel on graphics processors.

We are currently building a computer cluster based on graphics processing units, which will be capable of performing a real-time search for bright, short duration astrophysical radio pulses in the data from the Chilbolton station.

Dr Aris Karastergiou is based at Oxford University's Department of Physics where he is a Leverhulme Early Career Fellow.

To help mark the centenary of Dorothy Hodgkin's birth a special play will be performed next week at Oxford University's Lady Margaret Hall.

The play, 'Hidden Glory: Dorothy Hodgkin in her own words', is a one-woman show starring Miranda Cook and written by Georgina Ferry, Writer in Residence at OUMNH and Hodgkin's biographer. I asked Georgina about Hodgkin, her achievements and bringing an Oxford legend to life:

OxSciBlog: Why is Dorothy Hodgkin such an important figure?
Georgina Ferry: Dorothy Hodgkin is the only British woman to have won a science Nobel prize. Only 15 women have ever won the prize for physics, chemistry or medicine. By any standards that makes her exceptional. Her significance as a scientist lies in her great skill in pioneering the technique of X-ray crystallography to study the three-dimensional arrangement of atoms in biological molecules. Today, using modern equipment that is many times more powerful, fast and accurate than was available in her time, studies of molecular structure underpin much of biomedical science.

OSB: What were her key achievements at Oxford?
GF: For the first two decades of her career at Oxford, Dorothy's X-ray lab was a basement in the corner of the University Museum of Natural History. There she resolved a debate between the organic chemists about the structure of penicillin, a discovery that contributed to the later development of other antibiotics. She went on to solve the structure of Vitamin B12, which prevents pernicious anaemia. Later she moved with her group to laboratories elsewhere in Oxford's Science Area, and completed her life's work - solving the structure of the protein insulin, which controls sugar in the bloodstream - in 1969.

OSB: Why did you decide to write a play about her?
GF: The Oxford University Museum of Natural History was planning to celebrate Dorothy's centenary this year by unveiling a bust of her in its court, alongside the statues of Newton, Darwin, Galileo and all the other great men of science. I thought it would make the evening more of an event if there were some kind of performance to accompany the unveiling, and that a play with Dorothy as the central character would bring her to life as nothing else could. I'm thrilled that the Museum, with help from the EPA Cephalosporin Fund and Diamond Light Source, decided to support the project.

OSB: What was the most difficult aspect of trying to tell her story?
GF: I wrote Dorothy's biography some years ago, which ran to some 400 pages (and could have been twice as long if I had used all the material available). But I knew that a one-woman show could not be longer than about 40 minutes. So the challenge was to select what to include, making sure there was enough to get across her character and her passion for solving scientific problems, but not so much that people would get bogged down in the detail.

OSB: What lessons can today's scientists learn from her life?
GF: Dorothy grew up believing that it was important to try and make a difference, whatever your chosen field. She was extremely determined without ever being aggressive; she was very good at finding the right people to ask for help, and was never shy about doing it; she was always supportive to her junior colleagues but expected them to stand on their own two feet. She was never motivated by competition with others, only by the challenge of solving nature's secrets.

'Hidden Glory: Dorothy Hodgkin in her own words'  will be performed at the Simpkins Lee Theatre, Lady Margaret Hall on Thursday 13 May at 7:30pm. Tickets are available here.

How much do we know about the great female scientists of the past?

As part of researching a new children's book Sunetra Gupta of Oxford University's Department of Zoology has been finding out. OxSciBlog asked her about her new project and the unsung heroines of science...

OxSciBlog: Why choose to write a children's book on female scientists?
Sunetra Gupta: It was really my colleague Martin Maiden's idea. I was trying to think of a suitable project to promote women in science (as part of my application for the Rosalind Franklin Award) and Martin came up with this project. I instantly approached Ted Dewan to see if he was interested in illustrating it, and to my great good fortune he agreed.

Ted is an incredibly versatile  illustrator and author of children's fiction and non-fiction as well as science books for adults. He also has a fantastic sense of humour: his website mentions that "at age 15 he won his first drawing competition at the local Baskin Robbins Ice Cream store. The prize was a pink card entitling him to 31 free ice cream cones" - two of these apparently remain unredeemed…

One of the reasons the project appealed to me was because I had, myself, been inspired at a young age by reading a biography of Marie Curie - and yet, I realised I had never had the opportunity to find out about any other women scientists. There is definitely a niche here waiting to be filled. Also, at a completely selfish level, I was eager to remedy my own serious gaps in knowledge about their lives and their science.

OSB: Which scientists did you most enjoy finding out about?
SG: So far, I have only read about two people in sufficient depth - Rosalind Franklin and Anna Thynne. Rosalind Franklin is an obvious choice and I have very much enjoyed Brenda Maddox's biography, as well the very interesting defence of her by Anne Sayre in response to James Watson's portrayal of her as 'Rosie', the grumpy research assistant.

I might never have come across Anna Thynne but for a lovely little book by Rebecca Stott which I had been sent some time ago when it had been submitted for a prize I was judging. She was a very remarkable woman - wife of the sub-Dean of Westminster Abbey (while Buckland was Dean), mother of many, and can be credited with establishing the first marine aquarium in her living room. This is all in the early 19th century - by the 1850s aquaria were all the craze.

Another woman I felt ashamed not to have known much about is the 18th century astronomer Caroline Herschel; I have been reading about her in Richard Holmes's fantastic new book 'The Age of Wonder' and cannot wait to lay my hands on her diaries.

OSB: What has been the most challenging aspect of your research?
SG: Finding the time to do it. My commitments as an academic are quite extensive, and I am also very far behind on delivering a book on science and literature that I was funded to write by the Arts Council in 2007. There is also the tug of wanting to carry on with my new novel, and to spend time with my two daughters.

Researching the book has been pure pleasure, and writing my fragments (we are currently adopting a scrap-book format) has also been a lot of fun. Ted has been producing some amazing illustrations - he is absolute dream to work with. We've had some crucial decisions to make regarding layout and content - these have probably been the hardest bits so far.

OSB: What do you hope young readers will take away from the book?
SG: Some acquaintance with the lives of these women would probably be as much as I expect, but I'm naturally hoping that they (girls and boys alike) might find some inspiration here. Many of these women had to struggle, to adapt, to compromise, to suffer, and they always carried on. Even if they are not attracted to a scientific career, knowing the stories of these women scientists can have a transforming effect on young minds.

OSB: How has the book changed how you think about the female scientists of the past?
SG: It is embarrassing how little I knew about these women beyond the vague notion that they were brave and had to endure much. Whereas I had a much larger acquaintance with the lives of women writers, thanks to books such as Gilbert & Gubar's 'The Madwoman in the Attic' and, of course, all the biographies that are so readily available, not to mention the films about them.

I hear that a film is being made on Ada Lovelace (daughter of Lord Byron and possibly the first computer programmer) with Zooey Deschanel in her role, so perhaps women scientists will finally be in the public eye.

Again, I will say that the main benefit here is to learn about inspiring personalities - not everyone who enjoys 'Becoming Jane' is destined to become a writer, not everyone who falls in love with Zooey Deschanel as Ada Lovelace in ‘Enchantress of Numbers’ will become a scientist, but something will have been added to each person by learning about their lives and passions.

Professor Sunetra Gupta is based at Oxford's Department of Zoology.