Oxford Science Magazine 9th Edition Michaelmas Term 2011
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In This Issue...
3. News 5. Phantastic Phages 6. Rewriting Memory 7. Sticks and Stones 9. Decisions Decisions 10. Clever Chemo 11. A Medley of Molecules 12. Laying Down the Laws 13. Touching the Sky 15. Going Up... 16. Watch This Space 16. Seeing Stars 17. Bang! talks to… Dr Charles Elachi 19. Heart to Heart With a Jellyfish 20. Spinning Around 21. Model Organisms 23. How to Fold a Gut 24. Food vs Fuel 25. Tiny Technology 26. Comfortably Numb 27. Over the Limit 27. Riddler’s Digest
Editor-in-Chief - Samuel Pilgrim Deputy Editors - Kathryn Atherton & Alex Gwyther Sub-Editors - Kathryn Boast, Philip Crowley, Gabriel Rosser, Isobel Steer & Alisa Selimovic Creative Directors - Charlotte Mason & Anna Pouncey Layout Editor - Sofia Hauck Artists - Kinda Al-Hourani, Inez Januszczak, Ilse Lee, Clementine McAteer, Olivia Shipton, India Stephenson & Hanna-Liisa Vilu Website - Jack Binysh & Jai Juneja Publicity and Distribution - Jack Sennett Business - Alejandra Albuerne, Thomas Bosley & Christian Camm
Published by Oxford Student Publications Limited Chairman - Mark Brakel Managing Director - Katie Chung Company Secretary - Alistair Smout Finance Director - James Gibson Directors - Isabelle Fraser & Rob Morris Printed by Mortons Print Limited Copyright Bang! 2011
Blast Off With Bang! We are seeking talented applicants to join our Editing, Creative, Writing, Web, Publicity and Business teams. To apply, email:
email@example.com by Friday 6th Week, 18 November. 1
That’s here. That’s home. That’s us. On it, everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives… on a mote of dust suspended in a sunbeam.
The words of the inimitable Carl Sagan will be familiar to many. The astronomer and science communicator extraordinaire was referring to the Pale Blue Dot, an infamous photo of Earth taken in 1990 by the Voyager 1 probe as it reached the edge of the solar system. A tiny blue dot—less than the size of a single pixel—is suspended motionless in the inky blackness of space. It is a humbling reminder of our place in the universe and of our insignificant size relative to the rest of creation. But it also serves as inspiration, spurring us onwards and outwards into space. With our telescopes and satellites we scan the skies for new wonders, and we build spacecraft to carry us up into orbit and beyond, pushing back the dark that surrounds our lonely dot. In this issue we explore the mysteries of space, as well as the methods we use to reach it. We bid farewell to the Space Shuttle, NASA’s workhorse for 30 years and a machine that inspired a generation. We also talk to Dr. Charles Elachi, director of NASA’s Jet Propulsion Laboratory, about his views on the future of space exploration. Join us as we launch ourselves up through the atmosphere, and out into the stars. Samuel Pilgrim Editor
News Tevatron: Legacy
he Large Hadron Collider (LHC), the world’s largest and highestenergy particle accelerator, has been ramping up the power in an attempt to find the Higgs Boson, the elusive particle posited to explain how elementary particles obtain their mass. But the scientists at CERN can put themselves at ease with the search for the Higgs now appearing to be a one-horse race, as the LHC’s only rival ceased operations this October. Fermilab’s Tevatron, so named for its maximum energy range of 1 teraelectronvolt (about the energy of a flying mosquito, but all packed into each sub-atomic collision), studied the collisions between protons and their anti-particles, but has now succumbed to the axe of funding cuts. Physicists at the Chicago-based accelerator were the first to observe such inhabitants of the ‘particle zoo’ as the top quark and the tau neutrino. Back in March, scientists at Fermilab announced the possible discovery of a new (non-Higgs) particle, and proclaimed the Tevatron “the frontrunner in the hunt for the Higgs Boson”, after data potentially indicated the presence of the Higgs. Both ultimately came to nothing, as the particle-that-wasn’t seems now to have been a statistical fluke, and for all the Tevatron’s efforts, the experimental energies it was able to measure came up Higgs-less. Despite ending on a quiet note, the Tevatron’s 28-year career and its discoveries have showed that the model of ‘big science’, or ‘Physicsby-committee’ as it became known, does work, with its constituent groups regularly churning out papers, albeit with several hundred authors for each.
Laughter is the Best Medicine
espite the large part it plays in our daily lives, there has been relatively little research into the importance of laughter in our society. However a paper recently published by an international research team, led by Oxford University, claims to have discovered the role of laughter in our social evolution—to promote socialising among humans—by demonstrating that laughter in a group elevates your pain threshold. The research collaboration used over ten years of research to investigate what determines our level of pain tolerance. In experiments, participants watched television clips or live shows, and their pain threshold was measured before and after. According to the paper, laughing properly—defined as a relaxed, unforced laugh that creases the eyes, as opposed to a polite titter— while watching just 15 minutes of comedy with others, increased the pain threshold by ten per cent on average. When we laugh ‘properly’ we produce a series of exhalations without drawing breath. This physical exertion leaves us exhausted, triggering the release of protective endorphins, which manage pain and promote feelings of well-being. The paper points out that many studies have already shown that laughter is 30 times more likely to occur if you are with others than when alone. Lead author Professor Robin Dunbar, Head of the Institute of Social and Cultural Anthropology at the University of Oxford, said: “We think that it is the bonding effects of the endorphin rush that explain why laughter plays such an important role in our social lives.” Alex Gwyther
Hunt the Higgs Boson With LHC App
ctober saw the launch of a free Android app, developed by Oxford scientists, to allow users to get up close and personal with the Large Hadron Collider (LHC). The new app, LHSee, will allow anyone with an Android phone or tablet PC to view live 3D displays of collisions from the LHC for the first time ever. App users can learn more about the LHC using the animated tutorials, while a game, Hunt the Higgs, allows players to try to find the elusive Higgs Boson. While the app does not display every collision, as the LHC generates gigabytes of data every second, it provides a unique opportunity for the public to watch cutting-edge science in action. It is even possible to pick out the individual proton-proton collisions. The inspiration for the app came from Dr Alan Barr, a lecturer in particle physics and fellow of Merton College, and a prototype was developed by Chris Boddy, a graduate student from the Department of Physics. With the help of a grant from the Science and Technology Facilities Council, live data from the LHC has been brought to our phones. Three days following the launch, the app had already been downloaded more than 10,000 times. Kathryn Atherton
Looking Through the Eyes of the Mind
rom delirium-inducing plants used in ancient rituals, to the inspiration behind Aldous Huxley’s Brave New World; man has long enjoyed hallucinogenic drugs for the visions they bring. Now MRI scans have revealed that when on drugs, to the primary visual cortex (part of the brain responsible for processing visual information), there is no difference between seeing and remembering sights. Most of us can easily distinguish between vivid reality and dullyremembered images. As Huxley put it, “such images have little substance and absolutely no autonomous life of their own.” Normally, activity in the primary visual cortex drops dramatically when we imagine rather than see. Volunteers given a dose of Ayahuasca, the favourite hallucinogenic brew of Amazonian tribe folk, responded in a very unusual way to a simple memory task. The levels of activity in the primary visual cortex were virtually indistinguishable when the volunteers were viewing an image and when they were merely imagining it. Other areas of the brain, including those responsible for episodic memory, working memory, intentional imagination and information processing were also stimulated. This research indicates that Ayahuasca visions stem from the activation of an extensive network generally involved with vision, memory, and intention. By boosting the intensity of recalled images to the same level of natural image, Ayahuasca lends a touch of reality to inner experiences. It is therefore understandable why this socalled ‘spirit vine’ was for centuries bred by rainforest shamans to facilitate mystical revelations of visual nature.
Engineering SelfEradicating Insects
recent trial on the Cayman Islands, testing a potential method for suppressing populations of diseasebearing mosquitoes, has produced promising results. In the trial, run by Oxford-based biotechnology company Oxitec, scientists released genetically-modified (GM) male yellow fever mosquitoes, Aedes aegypti, into the wild. These were found to breed successfully with wild females, producing offspring that hatched as larvae, but died before reaching adulthood. Previous attempts to control diseasecarrying insect populations through reproductive competition with GM males have failed, as the modified males were too weak to compete with wild males for mates. In this latest study, the GM mosquitoes made up 16% of the total local population, and managed to father 10% of the larvae. “For this method, you just need to get a reasonable proportion of the females to mate with GM males—you’ll never get the males as competitive as the wild ones, but they don’t have to be, they just have to be reasonably good,” explained Oxitec’s chief scientific officer, Luke Alphey. The Aedes aegypti mosquito is a carrier of dengue fever and yellow fever, and is estimated by the World Health Organisation to cause half a million hospitalizations and up to 20,000 deaths per year around the world. This breakthrough could not only save lives, but has the potential for application to the control of other disease-bearing insects. Gabriel Rosser
Newsflash Puffins scout out best migration routes A team co-led by Oxford University has evidence suggesting individual Atlantic Puffins rely on their own scouting excursions in deciding a migration route, rather than preprogrammed genetic routes or learning from their parents. Using geolocator tags they found that the birds followed a wide range of different migration routes (suggesting their movements were not genetically predetermined) but that they were not merely random as the same bird followed a similar route each year.
First patient receives novel gene therapy to treat type of blindness A novel gene therapy has been used in an attempt to treat a previously incurable form of blindness. The trial surgery was carried out on a patient at the John Radcliffe Hospital as part of a trial led by Oxford University. If successful, the therapy could be used to treat the 100,000 people worldwide who suffer from the form of blindness known as choroideraemia.
DNA “cages” able to survive within cells Scientists from Oxford University have shown for the first time that molecular cages made from DNA can enter and survive inside living cells. The study, using human kidney cells, showed that artificial DNA cages, that could be used to carry cargoes of drugs, can enter living cells, potentially leading to new methods of drug delivery.
Phantastic Phages Expanding our arsenal against infectious disease “
he war against diseases has been from reaching the rest of the world by In addition to these benefits, phages can won,” announced the US Surgeon the scientific barriers of the Cold War era. be used in scenarios where antibiotics General William H. Stewart in 1969. Highly Phage therapy was most extensively used are ineffective. For example, phages effective polio and measles vaccines had in Georgia, where even today it is routinely have been shown to be able to cross the been developed, and antibiotics could prescribed for patients. blood-brain barrier whilst in most cases seemingly cure any antibiotics cannot. Additionally, unlike bacterial infection On contact most antibiotics, phages can penetrate Phages are able to people suffered with their target the polymicrobial biofilm, or ‘slime’, layers sustain an evolutionary from. However bacteria, phage that many colonies of bacteria produce to arms race with bacteria this golden age, viruses inject their protect themselves against environmental which ran from the genetic material hazards. mid-1950s to the into the host and mid-1980s, would not last. Resistance rapidly hijack the cell. Using the bacteria’s But phage therapy is not without its to antibiotics was spreading, and by the own machinery the virus is replicated. disadvantages. The specificity of phages is 1990s could be found in a wide range of It consumes all of the resources in one of the most attractive features but also bacteria; antibiotic-resistant E. coli, C. the bacteria, before the host is finally one of the biggest flaws. A single phage is difficile and MRSA, the culprits behind destroyed, releasing thousands of new typically unable to tackle the full range of meningitis, intestinal diseases and viruses ready to bacteria that cause abscesses, had become a significant infect new cells. an illness or disease. problem. Coupled with the significant Phages are specific Cocktails of different As such, cocktails of decline in the discovery of new classes to their target phages are needed different phages are of antibiotics, this has resulted in renewed bacteria, making needed to treat most focus on alternative treatments. them harmless to ailments, presenting other ‘friendly’ bacteria and humans. many problems. Large-scale production Around years before Sir Alexander of phage cocktails is expensive and each Fleming’s discovery of penicillin in 1928, One of the main individual phage in the cocktail needs to be Frederick Twort of the Brown Institution of advantages of phage approved and certified as safe for human London and Felix d’Hérelle of the Pasteur therapy over antibiotics is use with separate clinical trials—which Institute in Paris discovered phages— that the phages themselves are also expensive. Obtaining patents on viruses that target specific bacteria. are subject to natural biological organisms is inherently difficult, Phages were immediately recognized selection. Evolution of but the problem is exacerbated by the for their potential therapeutic use, an antibiotic resistance potential need for multiple patents for mechanism is relatively each treatment, making it a less attractive straightforward, as the prospect for private investors. antibiotic itself is not able to adapt to Scientists are currently working on new any attempts ways to exploit phages in their efforts to to resist it. fight infectious disease. In an attempt to but initial sidestep the problems involved in cocktails experiments of drugs, current work is focusing on the were unreliable and generation of broad-spectrum phages research was all but capable of being used individually. abandoned in the West However, most agree that if phage following the discovery of therapy is to become successful in the antibiotics, which seemed However, in phages West, regulatory changes are needed to more effective. any mutation that provides an enable cocktails to be treated and trialled advantage over a bacterium’s as single drugs. Given that the war on During the Second World resistance mechanism will propagate to diseases is far from won, phages would War, Russian scientists began the next generation via natural selection. be a welcome addition to our arsenal. to develop phage therapy to As a result, phages are able to sustain an treat wounded soldiers. While evolutionary arms race with the bacteria. Marcus Blagrove is a third-year DPhil in their success fuelled continued Zoology at Green Templeton College. research, it was prevented Art by Hanna Liisa-Vilu. 5
Rewriting Memory How memories can be disrupted, changed and erased W
hen first formed, memories are fragile things. To stand any chance of retaining a new memory, your brain must strengthen it through a process known as consolidation. This involves the synthesis of certain proteins that bolster the connections between the brain cells that represent the memory. Until recently, psychologists thought this was the whole story: that consolidation ‘sets’ a memory for long-term storage. However, it is now recognised that memory is far more dynamic in nature; remarkably, each time you retrieve an already consolidated memory, you briefly render it unstable once more. This memory must then be ‘reconsolidated’ in order to be retained. This short ‘reconsolidation window’ gives you the opportunity to modify the memory—to update it with new information.
rehearsed immediately before learning the second one, accuracy on a test of the original sequence on the following day was severely impaired by the new learning. Accessing the old memory had made it unstable and therefore susceptible to interference.
suffering from severe depression associated with traumatic experiences, a more extreme alternative to behavioural therapy would be for the patient to recall problematic memories shortly before
In some situations it is beneficial to erase a memory: if new information conflicts with our existing memories, this may be an indication that the memories were always a poor The first suggestion that accessing a representation of the world or that they memory could actually make it vulnerable are no longer useful. More typically, we came in 1968. James Misanin and his need to integrate new information with colleagues at Rutgers University in New established memories, allowing us to learn Jersey made the revolutionary discovery incrementally as we go about our lives. In that a rat’s day-old memory could be 2007, researchers at McGill University in erased with an electroconvulsive shock Montreal taught participants two different if, and only if, the shock was preceded lists of objects on consecutive days. with a reminder of When a reminder that memory. of the first list was each time we revisit administered just Animal experiments a memory we have prior to the second have also revealed the opportunity to alter it learning session, that once a memory some items from has been accessed, the second list were new proteins must be produced if the incorporated into the participants’ memory memory is to survive. In 2000, a research of the first. team at New York University found that a protein synthesis blocker could produce The discovery that the reactivation of amnesia for a specific memory if that memories allows us to modify them has memory was accessed within shortly important ramifications. For example, it before the injection. leads to a possible treatment for Post Traumatic Stress Disorder. Studies have Three years later, a group at Harvard shown that in both rats and humans the Medical School demonstrated that human reconsolidation window (which starts memories also become labile when they roughly ten minutes after accessing the are reactivated. The researchers trained memory, lasting for a few hours) is an people to tap a specific sequence on a opportunity to update traumatic memories keyboard. The next day, these participants with non-fearful information. For those were taught to tap a different sequence. If, and only if, the original sequence had been 6
electroconvulsive therapy. This treatment may then block the reconsolidation process as it did in Misanin’s rats.
There are also important implications for the reliability of eyewitness testimony. If a witness were to read a slightly different version of events in a newspaper prior to the trial, for instance, their existing memory would be accessed and could assimilate the new information. Even more worrying is the potential to use this ability to change or even erase another person’s memories against their will—an idea usually restricted to horror films or conspiracy theories, but gradually becoming more feasible as the process is further understood. It may come from a movie script, but one day electroconvulsive therapy or drug delivery could follow reminders to eliminate coherent memories of abuse in psychiatric wards or disciplinary facilities. Each time we revisit a memory we have the opportunity to alter it. This provides hope for those afflicted with traumatic memories, but sinister applications of the power to rewrite and even erase memory are all too easy to imagine. Kathryn Atherton is a second-year DPhil student in Neuroscience studying the role of sleep in memory consolidation at New College. Art by Charlotte Mason.
Sticks and Stones Observing chimpanzees using tools
decade after the 1949 release of Chimpanzees KP Oakley’s book Man the Toolmaker, new observations challenged the The most remarkable observations have perception that this trait was a purely come from wild chimpanzees, whose human one. Famous diverse forms of primatologist Jane tool use are the Goodall observed most prominent An infant remains close to chimpanzees and varied its mother until four years using sticks to of any single old, providing the youngster with fish for termites. species. To list ample opportunity to scrutinize Archaeologist and but a hilariouslyits mother’s nut-cracking naturalist Louis named few, Leakey noted: “Now there’s the antwe must redefine tool, redefine Man, or dip, the termite-fish, the algae-scoop, the accept chimpanzees as humans.” leaf-cushion, the fly-whisk, the pestlepound, the leaf-sponge and, a personal Since then, reported sightings of nonfavourite, the nasal-probe. Using a small human tool use have poured in. Tool use stick to pick your nose might not sound has been observed in both the wild and like an especially impressive feat, but the lab. In particular, capuchin monkeys, it demonstrates that these animals can chimpanzees and New Caledonian crows use inanimate objects to have impressed scientists with their use problem-solve. of tools to overcome the obstacles placed between them and a tasty treat. One behaviour that has But what exactly constitutes ‘tool use’? garnered Though there are many different definitions, particular the American behavioural ecologist John interest is nutAlcock broadly categorised tool use as cracking in “the manipulation of an inanimate object, West African not internally manufactured, with the effect of improving the animal’s efficiency in altering the form or position of some separate object.” This basic form of tool use can be supplemented with ‘tool manufacture’, such as bending a piece of wire to form a hook, or extended to ‘sequential tool use’, which is when a tool is used to acquire another tool. Furthermore, some animals use ‘composite tools’, such as the hammer and anvil tools used by chimps to crack nuts, which can include ‘metatools’—tools that are used to increase the efficiency of other tools, such as a wedge to balance out an anvil. 7
chimpanzees. Considered one of the most complex forms of tool use seen in the wild, it involves the use of three objects (hammer, anvil and nut) in a specific arrangement. Near the small Guinean town of Bossou, researchers are conducting ongoing studies into the use of stone tools and the apparent social transmission of this behaviour in groups of chimpanzees. Archaeologists and anthropologists believe that this work might provide an insight into early man’s mastery of stone tools and the cultural propagation of skills. A chimp cracks its first nut at around the age of three, taking several more years to gradually perfect the skill. Prior to their first successful cracking they show many varied attempts. At around the age of one and a half they are first observed to manipulate single objects (a nut or a stone), later progressing to two objects in combination (e.g. putting a nut on a stone, or pounding two stones together), and finally three objects, but
not necessarily in the correct manner (such abandoning their own tools to do so. availability of stones and nuts. Some as placing a nut on top of two stones). It is most likely to be in this period of scientists have claimed this to be proof Those that fail to succeed by the age of observation that juveniles learn the most of culture in wild animals; nature takes around seven apparently never acquire efficient hammer-anvil combinations. on another supposedly uniquely human the skill later in life. Further studies characteristic. To study how these cultural This suggests that have shown the differences arise researchers at the there may exist a chimps to select Bossou site laid out two new types of To list but a hilariouslysensitive period particularly effective nuts, not local to the area, and recorded named few there’s the for learning and stone tools (from the chimpanzees’ reactions to them. It was ant-dip, the algae-scoop, the that perhaps you those provided by discovered that the younger the chimp, the leaf-cushion, the fly-whisk, can’t teach an old researchers) on the more interest they showed towards the the pestle-pound, the leafchimp new tricks. basis of a variety of novel nuts, and the more eager they were sponge and the nasal-probe factors including to watch older individuals attempting to Extensive studies its characteristics crack them. Surprisingly, one adult female on the developmental stages of this (material, size and weight)and portability chimp immediately started successfully behaviour suggest that chimpanzees rely and the hardness of the nut to be cracked. cracking the new nuts, with an efficiency mainly on social influences in a system For example, individuals preferred to use not seen in the others. This lead the of ‘education by master-apprentice’, with stones made of granite rather than the scientists to conclude that she had long the details established through individual softer quartz and would even discard a ago emigrated from a region where the trial and error. An infant remains close to tool, or alter its function, if it fractured. nuts were found locally and so was adept its mother until approximately four years at cracking them. These observations old, providing the youngster with ample Regional Specialities suggest that the spread of such cultural opportunity to scrutinize its mother’s nutdifferences relies cracking. During this period, mothers It is only in the on immigration, tolerate their young interacting with their Bossou site that This transmission invention and stones and even eating the nut kernel chimpanzees use predominantly flows social transmission. they have just cracked open. However, movable anvil downwards, from the This transmission the infant’s own nut-cracking attempts stones. Other West elders to the youngsters, predominantly are never directly reinforced with food African groups and horizontally through a flows downwards, and years of unsuccessful trying precede seem to use only community, mainly relying from the elders to their own successful nut-crack. In fact fixed anvils, such on curious juveniles to the youngsters, and researchers have stressed that young as tree roots or pick up the new skill horizontally through chimpanzees are driven not simply to rocky outcrops. a community, obtain food, but also to imitate their Eastern and Central mainly relying on mother’s (and later their peers’) actions. African chimpanzees use no such curious juveniles to pick up the new skill. percussive technology With age, juvenile chimpanzees leave at all, despite the Primat-Archae-Anthrop-ology? their mothers and start observing other nut-crackers in their group. These Behaviour does not fossilise, but juveniles observe individuals the same the ongoing work in this area gives age or older than themselves, but archaeologists insights into the never younger. A similar age pattern evolutionary processes relating to has been suggested for ‘recycling the emergence of stone technology. events’—when an individual Chimpanzees and humans share many appropriates another ancestral traits, so it is reasonable to chimp’s recently suspect that tool use may be another. abandoned With chimp tool use recognised as stone tools, one of the most advanced seen in sometimes any wild animal population, and with further etho-archaeological studies ongoing, this species may help us to understand the factors that influenced the emergence and development of tool use technologies in our own ancestors—though, thankfully we have moved on from nasalprobes.
Alex Gwyther is a third-year undergraduate reading Biological Sciences at Magdalen College. Art by Olivia Shipton.
Decisions Decisions The minefield of making our minds up W
e are all constantly making publications are predominantly ‘success decisions, particularly when decisions in every part of our lives, stories’, reporting positive findings. Whilst the subject is one with whom we but thankfully the vast majority of these positive outcomes are of vital scientific can empathise. In such cases, we choices demand little conscious effort. importance, the reporting bias conceals easily allow the anecdote to carry more A combination of habit and experience null results and the potentially useful weight than any evidence to the contrary. ensures that we are able to select information that can be gleaned from them. The MMR vaccine scare, which began our outfit for the day and our food for in 1998, is a key example. Whilst the breakfast without serious deliberation. Even when the available evidence is not media reported distressing cases of young Surprisingly though, we also make far already unbalanced, our biased sampling children who had been diagnosed with more consequential technique ensures autism following vaccination, the number of choices in the that the picture such cases was tiny. Nevertheless, many blink of an eye; The information of the evidence parents withdrew their children from the crossing a road available to us is rarely that we get is not immunisation scheme, creating a measles at an inopportune complete or representative a representative epidemic. The link to autism was never moment can have a one. A common substantiated. huge cost, yet most approach to people are well conditioned to time the reaching conclusions is to form an initial When past decisions play an important role operation without much thought. However, hypothesis and to then attempt to test in current decision-making, our memories some decisions are substantially less trivial it. Unfortunately, confirmation bias often may be untrustworthy. Psychologists Beyth and require contemplation before we take occurs in such situations; people readily fall and Fischhoff conducted experiments action. Worryingly, research suggests that into the trap of seeking only to confirm their in 1975 in which students were asked to in precisely these situations humans are beliefs, rather than looking for evidence estimate the likelihood of a number of prone to a series of major biases. that would contradict their hypothesis. possible outcomes of President Nixon’s Scientist and philosopher Francis Bacon trips to Peking and Moscow. After the One problem is that we often fail to described this trait in his Novum Organum, trips, the students were unexpectedly recognise that the information available to writing “The human understanding when asked to recall their own predictions, or us is neither complete nor representative. it has once adopted an opinion... draws all to reconstruct them in the event that they Nassim Taleb, author and statistician, things else to support and agree with it.” had forgotten. The students were also has pointed out the flaw in concluding A series of experiments by Clifford Mynatt asked to recall the actual outcomes of that risk-taking and self-confidence are and colleagues in the trips. There was characteristics that lead to financial Ohio have shown a strong tendency success on the basis of autobiographies that even science Students only for the students to published by multi-millionaires. People who students readily performed tests that re-predict greater have made this mistake overlooked the exhibit such flaws. would confirm their beliefs probabilities for ‘silent evidence’: the unpublished tales of Participants were events that they the equally risk-taking and self-confident asked to run tests believed to have failed businessmen, who far outnumber the to discover the rules that constrained occurred. This is evidence of hindsight successful ones. The science world is not a spot’s movement across a computer bias, colloquially termed ‘I knew it all immune to this bias; scientific screen. In all cases, the students only along’ bias. performed tests that would confirm their beliefs. These examples barely scratch the surface of the myriad obstacles we must Our judgement processes are overcome in attempting to rationally yet further skewed when assess a potential decision. Experimental emotions are involved. psychologists have uncovered a Anecdotal evidence bewildering array of cognitive biases. Not exerts powerful only do we easily make poorly considered influences on the choices, we often forget our mistakes human ability and leave misleading evidence for those to assess who follow. When our consciousness is outcomes involved, the truth is that there’s no such and make thing as an easy decision.
Gabriel Rosser is a final year DPhil in Mathematical Biology studying the swimming behaviour of bacteria at St. Anne’s College. Art by Ilse Lee.
Clever Chemo An alternative approach to ‘slash, burn and poison’ I
n the Western world, one in three people develop cancer at some point in their lives. Despite the millions of pounds spent each year on research in the UK alone, cancer rates have continued to rise. Whether or not this increase is the result of increased life expectancy, and significant improvements in the treatment of other diseases, one thing remains clear: improved treatments for cancer are desperately needed.
effectiveness. Furthermore, correlations in predictive medicine and result in faster between successful treatment and identification of the optimal drugs and expression of a single gene are often found dosages for cancer sufferers. However to be very weak. This problem of predicting there are risks with too much reliance the effectiveness of specific chemotherapy on algorithms; in many cases biology is drugs based upon the expression of the too complicated for computer models to many genes in the cancer cells is so predict, which could lead to sub-optimal complex that algorithms must be used treatment regimens. But more worryingly, to tackle it. So, there is a potential for each drug, danger for COXEN, One in three people the genes which if it predicts an develop cancer at correlate best expensive but some point in their lives with the drug’s desirable drug to Until recently, cancers have been effectiveness are be ineffective, to categorized according to their organ used to create be used to justify of origin, biological structure and a model that predicts how well it will withholding this drug from patients whom aggressiveness. However, these factors perform in another cancer based on the it could still partly benefit (for example tell us very little about the cancer, let alone cancer cells’ gene expression. This could by prolonging life or reducing pain). It is how best to treat it. Cutting edge research potentially avoid having to conduct lengthy important that the predictive power of such has generated predictive algorithms that trials in which the effectiveness of many an algorithm must therefore only be used aim to match specific cancer cells to the different drugs are tested on a patient. as a tool to suggest drugs and dosages, most effective chemotherapy drug. This not becoming embroiled in the concerns individually tailored selection of drugs One such algorithm is COXEN of cost, with the sole goal remaining the offers the prospect of shorter, more (COeXpression ExtrapolatioN). COXEN welfare of the patients. effective treatments and reduced side was tested on a set of 40 different bladder effects. cancer cell lines and successfully predicted Marcus Blagrove is a third-year DPhil in the response of these cells to two drugs. Zoology at Green Templeton College. Scientists compared the effectiveness COXEN was again tested, this time using Art by Clementine McAteer. of most chemotherapy drugs on a set the data generated from two clinical trials of 60 cultures of carefully grown cancer of two breast cancer treatments. Again, cells, known as cell lines, which were COXEN successfully predicted the clinical grown ‘in vitro’ in the laboratory. The response to both drugs, demonstrating level of expression that this algorithm, of all the genes in developed on ‘in Cutting edge research these cell lines was vitro’ cell lines, has has generated predictive also independently predictive power on algorithms that aim to match measured. Gene ‘in vivo’ cancers. specific cancer cells to the most expression is effective chemotherapy drug the process in Currently, COXEN which a gene is is limited to bladder used to make a and breast cancers, gene product. Gene products, such as and for research purposes only. The power proteins, are the molecules that determine of the algorithm is reliant upon public a cell’s make-up and function. These data databases of gene expression data and allowed scientists to look for genes whose as a result it is not possible to apply the expression correlated with the drug’s algorithm to cancers which have not been effectiveness. If a gene is not expressed studied in this manner. Considerably (i.e. is switched ‘off’) in drug-susceptible more research into the effectiveness of cell lines and highly expressed (switched COXEN must be done before it can be ‘on’ in resistant ones, the scientists can used as a tool to aid the prescription of use this gene’s expression to predict which chemotherapy drugs. cancers will respond to the drug. If COXEN does indeed prove to be However, there are complicating factors: a reliable predictive tool, it could genes are rarely on or off, but are instead represent a significant advancement expressed on a sliding scale, and the drugs similarly exhibit a spectrum in their 10
A Medley of Molecules
Why space isn’t as empty as it seems
called ethyl formate, is, in contrast, opens a door with an ungloved hand. It can plentiful on Earth. It is the characteristic be challenging to spot them though; the odour of rum and part of the flavour light may pass through multiple molecules of raspberries. Last year’s discovery and all of the fingerprints arrive at once in pace is probably not the first of Buckminsterfullerene molecules the same snapshot of light, making it hard place you would look if you were (‘footballs’ of carbon, comprised of 60 to untangle them—imagine 100 people searching for interesting chemistry. The atoms) in the Orion Nebula shows just how leaving their fingerprints on a door handle! word itself suggests an absence of things, large the molecules in space can get; we and it is hard to imagine that space could have only been able to reliably make this Perhaps the most interesting fingerprint compete with planet Earth’s rich variety of elaborate form of carbon here on Earth identified so far is of a molecule called flora, fauna and minerals. After all, it is an for a few decades. The existence of such aminoacetonitrile. On its own, it is rather extremely volatile environment, with stars complex chemistry mundane. Expose it emitting high energy radiation powerful is puzzling; to water, however, The discovery of enough to tear molecules apart. perhaps space is and it is converted aminoacetonitrile may not as hostile as to glycine, a very give credence to the idea You may be surprised, then, to hear that we first thought. common amino that the building blocks of the chemistry of space is quite literally out acid. Amino acids life originated in space of this world. Thanks to the fact that the So how do we are the building deaths of stars are often explosive affairs, know all this? It blocks of life—they interstellar space is littered with chemical seems incredible make up proteins, debris—grains of dust, bits of molecules that we can identify compounds millions which are responsible for providing both and millions of atoms. Occasionally, these of light years from Earth. The trick is to structure and function within a cell. The pieces come together. For example, a harness infrared light from nearby stars, discovery of aminoacetonitrile may give reactive atom might stick to a grain of which has wavelengths too long for us credence to the idea that the building dust. Then, another atom might stick to to see but which can be readily detected blocks of life originated in space. the dust as well. In this way, chemical with the right tools. Importantly, light in fragments can get close enough to each the infrared region of the electromagnetic As we venture further from Earth in the other to react and, over a long time (and spectrum is absorbed by molecules, with coming decades, we will surely make a lot of accidental collisions), there’s no each different type of molecule absorbing more surprising discoveries—we’re only end to the variety of molecules that can different wavelengths of light. scraping the surface of what is out there, be made. Many simple combinations of limited by our own expectations of what atoms have been discovered—water, Down here on Earth, we can identify we hope to find. It is entirely possible hydrogen gas, and even oxygen—and the ‘fingerprint’ of each molecule (the that all the complexity of life that we see that’s just the start. wavelengths that here on Earth was born out of the unlikely it absorbs) and molecules formed in space. So, next time We can identify Long molecules compare these you look up into the sky at night, just think the ‘fingerprint’ called cumulenes to what we see —even in the black expanses between of each molecule —essentially from space. Light the stars, there’s plenty going on. ’sticks’ of carbon— from a distant star are rarely found on may pass through Matt Rattley is a fourth-year Earth because they are highly reactive. an interesting molecule and when it undergraduate reading Chemistry at In space, however, where atoms and arrives at Earth it will carry a trace of Somerville College. Art by Charlotte molecules are spaced very far apart, they that fingerprint, much like when a criminal Mason. survive long enough for us to observe them. Another molecule detected in space, 11
Laying Down the Laws K
A look at the life of Johannes Kepler
epler was born, prematurely, on 27 Kepler’s academic subversion should be December 1571 to the son of the forgiven, for it led him on a vital path of mayor in the city of Weil der Stadt in discovery. Brahe’s data revealed that the Germany. He was a sickly child, suffering orbit of Mars differed by eight minutes from from small pox, which left him with a what would be expected if the orbit was crippled hand and poor vision. Although circular. Rather than dismissing it as an physically frail, he had a keen mind. His error in Brahe’s measurement, he boldly fascination for the night sky blossomed remarked: “Upon these eight minutes I will into an interest in yet build a theory astronomy when of the universe!” It was Kepler, not he observed the Kepler postulated a falling apple, that Great Comet of just three laws to inspired Issac Newton’s 1577 at the age explain the motion description of gravity of six, and a lunar of all the planets eclipse three years known to him at later. His work the time. The first would later earn him the title of the ‘father states that the planets move around the of celestial mechanics.’ sun in elliptical orbits rather than circular ones, contrary to contemporary belief. In 1589, young Kepler was granted a This accounted for the discrepancy in scholarship to attend the University of the orbit of Mars, which was the most Tubingen to study philosophy, theology, elliptical of all the orbits recorded by mathematics, and astronomy, where he Brahe. His second law states that a line received his M.A. in 1591. It was there that joining the Sun and a planet would he first learnt about the two contrasting sweep out equal areas in equal theories of planetary motion which were intervals of time as the planet popular at the time. The Ptolemaic model revolved around the sun. This held that the Earth is stationary and at the explains why a planet moves centre of our solar system, while the Sun, faster when it is closer to the moon and other planets orbit in perfect Sun. Kepler’s third law relates circular paths around it. In Ptolemy’s the time that a planet takes model, the observed paths—which were for a complete revolution to far from circular—were explained by a the size of its orbit. The first combination of several regular circular two laws were published in motions called ‘epicycles’. An epicycle 1609 in his work Astronomica is a circular orbit with a centre which, in Nova, but it took him much turn, orbits in a perfect circle about the longer to discover the third Earth. The Copernican model, on the other law, which he published in hand, stated that all planets orbit the Sun, his Harmonices Mundi although it also assumed perfect circular in 1619. motion of the planets. Eighty years later, Impressed with Kepler’s publications, the Kepler’s laws Imperial Mathematician Tycho Brahe hired would prove to Kepler as his assistant in 1600. It was be an important not, however, a harmonious union: Brahe stepping stone believed that the Sun revolved around the towards another Earth while Kepler firmly subscribed to landmark in scientific the Copernican model. Brahe accurately thought. It was Kepler, observed and recorded the positions of not a falling apple, planets, but he never shared his data that inspired with Kepler during his lifetime. Only after Issac Brahe died in 1601 did Kepler somewhat dishonestly appropriate Brahe’s data, later describing his actions as “taking the observations under my care.
Newton’s description of gravity. Isaac Newton realized that the acceleration of falling objects and the movement of a planet in accordance with Kepler’s three laws, could both be accounted for by one very fundamental law: The Law of Universal Gravitation. Like many geniuses before and after him, Kepler was unpopular with the church and had to relocate many times. He died in 1630, having never known fame or fortune in his lifetime, despite now being known as one of the greatest astronomers in history. Although physically weak, his scientific boldness led him to speak out against contemporary established doctrine and his legacy continues to inspire astronomers to this date. Pinky Raychaudhuri is a fourth-year DPhil in Chemical Biology at Exeter College. Art by Anna Pouncey.
Touching the Sky A tribute to the space shuttle On the morning of 8 July 2011, more than a million people gathered at Cape Canaveral, Florida to see the final launch of the space shuttle program. With the help of two giant solid rocket boosters, each providing several million pounds of thrust, the orbiter Atlantis lifted slowly off the launchpad for the last time. Used to carry large payloads into orbit, the shuttle was NASA’s workhorse for 30 years. Both the orbiter and rocket boosters were designed to be used repeatedly, making the shuttle the world’s first reusable spacecraft. But in the face of rising costs, and after 135 missions and the Challenger and Columbia disasters, NASA has finally retired the ageing space shuttle. Join us as we explore the machine that helped to construct the International Space Station (ISS), put the Hubble Telescope into orbit and inspired a generation to dream of space.
A 15-metre mechanical arm was used to deploy and retrieve satellites and other equipment.
Each shuttle launch cost NASA $450 million. The total cost of the program was about $200 billion.
The five orbiters travelled a combined distance of 513 million miles. That’s 1.3 times the distance from the Earth to Jupiter.
When in orbit around the Earth, the crew experienced a sunrise or sunset every 45 minutes.
Columbia makes its first orbital flight
Challenger explodes shortly after launch
Challenger sees first spacewalk by a space shuttle crew
Hubble Telescope is launched by Discovery
Atlantis launches Magellan probe to Venus
The onboard flight computer ran on only 1 MB of RAMabout a hundredth of that of a Nintendo Wii.
Atlantis sees first shuttle docking to Russia’s MIR space station
Endeavour launches ISS module during space shuttle’s first ISS mission
By the time it reached an altitude of 235 miles, the orbiter would be travelling at a speed of 17,500 mph, covering the length of 75 football pitches every second!
The shuttle’s external fuel tank separated from the orbiter nine minutes into the flight, and would burn up in the Earth’s atmosphere.
The orbiter was made up of more than 2.5 million components, including over 200 miles of wire.
The SRBs were jettisoned two minutes into the flight, at an altitude of 44 km. Their momentum carried them up to 65 km before they fell back to Earth.
There were two smaller engines for manoeuvring and making orbital adjustments.
There were about 25,000 heat-resistant tiles on the orbiter, which had to withstand a temperature range of almost 1800 °C.
Columbia disintegrates upon re-entry
Europe’s Columbus laboratory carried to ISS by Atlantis
Discovery, Endeavour and Atlantis make their final flights
Fully-fuelled, the shuttle weighed 2000 tonnes. Two-thirds of the thrust needed for lift-off was provided by the solid rocket boosters (SRBs). The orbiter’s main engines provided the remainder.
Text and art by Samuel Pilgrim.
The orbiter’s three main englines ran on liquid hydrogen and oxygen, generating a total of 37 million horsepower.
Going Up... Riding an elevator to the stars
pace travel lends itself to all sorts Now imagine the athlete was the of crazy schemes. Science fiction Earth, spinning a huge weight on a writers have spent decades pondering 40,000 kilometre-long cable (NASA over distant planets and how to reach suggests an asteroid could be used them, but for the most part those ideas for this purpose), and there you have it: the space elevator! have remained purely fictional. We find ourselves still largely earthbound, only able to travel into space in rather But what would be the point of this seemingly ridiculous contraption? inefficient rockets, and even then only as far as the Essentially—to Moon. But one transport objects idea has slightly into space. It cost The construction of a more promise NASA around space elevator may be than most and $50,000 per possible within the century could potentially kilogram revolutionise of goods carried into orbit aboard space travel. Enter the space elevator. the space shuttle, with fuel accounting for The concept is fairly simple, and is similar to the hammer throw event at the most of this expense. Olympics. Take a rotating object (like But if a machine were to instead climb up a an athlete), bolt on a sturdy cable (like the chain on the hammer), and attach cable into space carrying these a weight on the end (like the ball). The goods, without the need for cable stays taut, as the centrifugal force arising from the athlete’s rotation expensive rocket flings the ball fuel the cost outwards. could plummet. Naturally, it would cost a lot to construct a space elevator in the first place (estimates vary by design, but are all in the billions of dollars), although this could be offset by the cheaper running costs.
So why haven’t we built one yet? We already have technology in place to make a climber robot, with competitions held regularly to establish the best design. Additionally, scientists have developed technology
that can ‘beam’ energy from the ground to the climber using lasers, propelling the climber upwards along the rope— although this is not yet an efficient process. That, unfortunately, is where the good news ends. The main problem is finding the right material for the cable; nothing we have currently is really suitable. In order to endure the huge stresses of the opposing centrifugal force, the cable must be able to withstand a force of at least 62 gigapascals, the equivalent of a tug-of-war between two teams of 100,000 people. Not only must it be strong, but the cable must also be thin enough for it to be able to support its own weight. Carbon nanotubes should be strong enough, but how do you make a flawless 40,000 kilometrelong nanotube? At the moment, we can only manage a few centimetres at best. Another issue is the large amount of debris surrounding the Earth. Rocks, parts of old satellites, and chunks of ice are all floating above our heads, and even one collision with the cable could send the whole thing crashing back to Earth. Either we need to clear up all of this debris or we have to track and avoid it, with both of these options posing huge practical and technological challenges. Challenges aside, the idea still shows promise, and with advances in new materials and energy transport, the construction of a space elevator may be possible within the century. If humans are ever going to reach out farther into space, we first need an easy way of getting off our rock, and the space elevator may be the best solution. Matt Rattley is a fourth-year undergraduate reading Chemistry at Somerville College. Art by Ilse Lee.
ith NASA’s Space Shuttle program now drawn to a close, there has been much discussion about the future of space flight (see our interview with Dr Elachi) and the new challengers to the American manned space programme. NASA expects to launch a manned Mars mission within 40 years, contingent on federal funding. There are currently four competing space agencies: the European Space Agency (ESA); The Russian Federal Space Agency; The Indian Space Research Organisation (ISRO); and the China National Space Administration (CNSA).
ESA is an organisation comprised of 18 member states, with a history of aborted missions due to
Seeing Stars Astronomy in Oxford
stronomy and astrophysics are areas of science that have always inspired and captivated the general public. And firmly at the forefront of astrophysical research is Oxford University. Its scientists have been granted coveted observing time using facilities such as Japan’s Subaru Telescope in Hawaii, which observes the formation of new galaxies and planetary systems. Furthermore, last August, Oxford
political discord. A feasibility study was commissioned in 2009 to look into developing a new manned launch vehicle, but it is doubtful whether it will be realised in the current economic downturn. After prodigious spending on the International Space Station, the Russian space agency has little budget left for developing new missions to outer reaches; the only related active project was a 520-day virtual simulation of a manned voyage to Mars. A firm financial commitment to developing a spacecraft capable of transporting a crew to Mars seems to be lacking, however. Despite lacking the technology and experience of NASA and the Russian Space Agency, both ISRO and CNSA are making rapid progress. ISRO sent their first probe to the moon in 2008 and are on track for manned space flight by 2016. The CNSA have made even more substantial progress, thanks to significant contributions from Russian space research. They sent their first man into space in 2003, orbited the moon in
Watch this Space Which country will take the next giant leap in manned space travel? 2006, and will launch a Chinese space station in 2020. A recent CNSA statement of the agency’s long-term goals suggests they have Mars in their sights. So who will make the next giant leap for mankind? While China is making rapid progress, space missions take a long time to develop and are easily derailed by political or economic changes. Meanwhile, NASA’s funding continues to dwarf that of the other space agencies. One thing seems certain: all eyes are on the Red Planet as the next frontier of space exploration. Jack Sennett is a third-year undergraduate reading Physics at Lincoln College. Art by Charlotte Mason.
astronomers were responsible for the discovery of a supernova—a spectacular explosion of a star that has collapsed in on itself—in the Pinwheel Galaxy M101, using a robotic telescope in California.
sort pictures of galaxies online into categories from the comfort of their own home. In this way, members of the public can contribute to data analysis and enable scientists to focus on testing theories.
There are also excellent facilities closer to home, including a telescope presented to the University by Philip Wetton,a graduate of Christ Church, and installed atop the Denys Wilkinson Building on Keble Road. It is used by students to collect data from many hundreds of light sources, but is also open to the public every month.
Another way to get involved is by joining the Oxford University Space and Astronomical Society (OUSAS), which started more than 50 years ago with the aim of encouraging an interest in space science. Evening talks host a range of world-class speakers, whilst rocketry events provide the opportunity to build and launch your own rocket. The popular weekly observing sessions are held in the fields behind St. Catherine’s College, where you can learn to navigate the night sky using binoculars and OUSAS telescopes. This year in particular looks to be an exciting one for observations, with OUSAS planning to build an observatory to house a new large telescope.
There is also plenty going on for amateur astronomers. Several years ago, Oxford’s own Chris Lintott, co-presenter of The Sky at Night, launched an exciting project involving the public in real astrophysical research. Galaxy Zoo allows anyone to analyse and
Sara Lukic is a second-year undergraduate reading Physics at St Catherine’s College and is President of OUSAS. Art by Charlotte Mason.
Bang! talks to...
Dr Charles Elachi
Bang!’s Charlotte Mason had the privilege of speaking to the director of NASA’s Jet Propulsion Laboratory (JPL) in California this summer. NASA has recently terminated its thirty-year space shuttle program. What are your visions for the immediate future of space exploration? Having reached the end of the space shuttle program, we have seen that the shuttle has served its purpose. Its development over more than 30 years allowed us to accomplish a lot of things, but it’s time to move to the next stage in space exploration. One of the most important things is the further integration of robotic exploration. Robotics has advanced significantly over the last few decades and whilst we develop new human space transportation vehicles,
we can use robotic rovers to explore other planets in conditions that would be challenging for humans.
What does the end of the shuttle program mean for human spaceflight? NASA is now focusing on developing a capsule that can go beyond Earthorbit. It will need to be habitable for long periods of time, and we need to develop a launch vehicle to deploy it. We haven’t stopped developing, we’ve just moved on to the next step, and in every step of our discussions we are clear that we want to go to Mars!
Is there still a place for human space exploration? Humans bring a lot to space exploration. Kennedy didn’t start the Apollo program with a scientific purpose in mind: one of the largest benefits of the International Space Station was the collaboration with Russia and other international partners after the fall of the Soviet Union. There’s still a place for humans in space—to bring pride to a nation and enhance international relations—but not necessarily for scientific missions, as we can use robotics for that.
What are JPL and NASA’s goals for the next 20 years? First of all, a continued presence on Mars. We’ve been in orbit there for thirteen years and have had rovers on its surface for seven. I see our approach there as similar to scientific missions to Antarctica—having permanent bases and using rovers to explore the surface to prepare for human exploration. Second, the exploration of places within the solar system that could potentially support life. Our current hopes are the moons Enceladus and Titan (two of Saturn’s moons), and Europa (one of Jupiter’s moons). Third, the search for planets around neighbouring stars. I hope that within the next decade we will have a ‘family photo’ of the nearest 2000 stars. Telescopes like Kepler are able to detect planets as small as our own, and soon we will be able to carry out detailed spectral analysis of them. And of course, the monitoring of our planet and how its climate is changing. We
can clearly see global climate change happening—the causes of it are academic —but we need to continue to monitor the planet so that we can try to understand these changes in order to see if we can reverse them.
What needs to be done before humans can go to Mars? It only takes three days to reach the Moon, but a round trip to Mars is two years. Think of all the rubbish we generate, and all the shopping we do in a day—and then multiply that by 600. Using today’s technology, to transport six people to Mars would require a vehicle the equivalent of four or five International Space Stations. Obviously we still need further investment in technology, for example to find ways to protect astronauts from the strong solar radiation between Earth and Mars, as well as developing more effective propulsion systems. We also need to develop technology that will allow us to use local resources on Mars—is there something there we can use to generate fuel or oxygen?
descent until the craft hovers above the surface, and finally a sky-crane to gently lower the rover to the ground).
How has the public’s perception of space exploration changed over NASA’s 50 years? 50 years ago, spaceflight was completely novel; it was exciting and it grabbed the world’s attention. I see it as a sign of success that it is now taken as routine. Another NASA director told me that a US congressman once asked him why we need weather satellites when he can just look at The Weather Channel. Spaceflight has become as ordinary to us as electricity. But every time people see images from the Hubble telescope, from Mars rovers, or from probes exploring the outer planets, they see new worlds. And these images are on the front page of every newspaper in the world—we see so much negative news in the media, it’s great that every once in a while the latest missions bring us something so positive.
The next stage of unmanned missions will involve returning samples, which will give us the experience of landing on the surface and then returning to Earth. We also want to make sure that we send humans to the most interesting areas of the planet, so we can use rovers to explore and find interesting features first.
I don’t think that public excitement has declined; I often start talking to people on planes and they are always so excited when I say I work for NASA!
But political will, not scientific debate, will determine when we send humans to Mars; it is very unlikely to happen in the next 20 years, but I think it will happen in the next 40. It will be an extremely expensive and complicated mission, and so will require an international effort, although so far, NASA is the only organisation to have landed anything on Mars successfully.
I try to! I’m still the Principal Investigator on the Cassini Radar (the Cassini probe is studying Saturn and its moons) and I am still involved in other radar projects. I manage to write a few papers every year, but I get most satisfaction now from helping other people to do science.
Our heaviest lander to date is the Mars Science Laboratory (MSL), which is launching this November and weighs around one tonne. A spacecraft carrying humans, on the other hand, would weigh at least six tonnes. And Mars is a very difficult environment to land on—it has a only a thin atmosphere, which does not slow down a descent much—and we cannot rely on a propulsion system, as we would still need to get the rover off a lander and the turbulent atmosphere would produce uncertainty in the descent. (MSL will be landing using a several stage descent—first a parachute, then a powered
You started out as a scientist—do you still have time for research?
NASA’s ten centre directors all come from technical backgrounds; they aren’t political appointments. In fact, nearly everyone at NASA headquarters has a technical background, even those in the finance department. This gives us a lot more stability, we’re not driven by the latest political fad, and it grants us more respect from politicians.
How does NASA hope to inspire the next generation of scientists and engineers? I believe that space exploration and Earth observation are probably the most exciting areas young people could wish to work in. The work at NASA is fulfilling, forward looking and there’s a huge team spirit. Just imagine: you can spend your life getting paid to explore space! As well as being director of NASA’s JPL, Dr Elachi is also the vice president of Caltech (the California Institute of Technology), where he also holds a professorship in electrical engineering and planetary science. In 1989, an asteroid was named after him in recognition of his contribution to the exploration of the Solar System. Charlotte Mason is a third-year undergraduate reading Physics at Merton College. Portrait by Anna Pouncey.
Heart to Heart With a Jellyfish What our aquatic friends can tell us about ourselves
o understand how a jellyfish moves, cup your hands and then squeeze them together to expel the air from the hollow. When a jellyfish contracts underwater in this way, the contraction forces out jets of water, propelling it along. Although the basic structure of a mammal’s heart is somewhat different, the mechanism of propulsion is similar. In the same way that the water is expelled from the jellyfish, blood is expelled from the chamber of the heart and pumped around our bodies. George Romanes and Walter Gaskell were two great physiologists of the Victorian era. Working together at the Cambridge Physiological Laboratory under its founder, Michael Foster, they made surprising and important discoveries about the similarities between jellyfish and the heart, more fundamental than the likeness observed above.
spirally, producing a single strip of tissue. Upon electrical stimulation of the strip of tissue, Romanes found that a wave of contraction would pass down its length, demonstrating that the tissue retained its conductive properties even after dissection. These and other experiments led Romanes to formulate the concepts of conduction block and pacemakers.
A natural pacemaker is a cell that sets a rhythm in a larger piece of tissue. Pacemakers are automatic—an external stimulus is not required for them to become active and stimulate their surrounding Romanes was a ‘man of private means’. tissue. Conduction block occurs when After completing contractile tissue his studies at becomes sufficiently Cambridge, he The principle of damaged that it no had a marine conduction block longer contracts. laboratory built at that Romanes formulated In the jellyfish, his home on the for the jellyfish also Romanes found that Scottish coast. applies to the heart conduction block Initially with an occurred when the interest in the strips of tissue that physical basis of consciousness, Romanes he cut were sufficiently narrow. began studying the jellyfish, which was considered to have the most primitive Many would have thought of Romanes’ nervous system of any animal. The jellyfish work as scientific indulgence – was also a practical organism to study as inconsequential except to a small its swimming bell (the main, bell-shaped interested minority. History, however, has part of its body) is still responsive to shown otherwise. Concepts that Romanes electrical stimuli after dissection. One of formulated in his work on the jellyfish, such the key experiments that Romanes devised involved cutting the bell of the jellyfish 19
as pacemaker cells and conduction block, have now become part of the standard vocabulary of cardiology and form the basis of much of our current understanding of arrhythmic heart disorders. Gaskell is the key figure forming the connection between Romanes and clinical cardiology and is considered by many to have founded modern cardiology. Gaskell applied Romanes’ methods of tissue dissection to investigate conduction block in the heart. The electrical signal that propagates through the heart passes from the upper chamber, the atrium, to the lower chamber, the ventricle. Gaskell induced an artificial block in a tortoise heart by removing increasing portions of the muscular tissue from part of the atrium. As the tissue bridge between atrium and ventricle was made more narrow, the ventricle became less responsive to stimuli from the atrium. Through this experiment, Gaskell showed that the principle of conduction block that Romanes formulated for the jellyfish also applies to the heart. As well as being an interesting discovery in its own right, Gaskell’s unexpected finding of similarities between the electrophysiology of the jellyfish and the heart has had important consequences for clinical cardiology. The story of Gaskell and Romanes shows that scientific research can have important unforeseen medical applications, warning us against the short-sightedness of an entirely application-focused approach. Philip Maybank is a third-year DPhil student in Computational Biology at Linacre College. Art by Inez Januszczak.
How a pendulum can demonstrate the Earth’s rotation
n 1851, against the backdrop of the To better illustrate this point, consider is parallel to the Earth’s axis when Panthéon, Leon Foucault presented placing the pendulum at the North Pole, it is swung at one of the poles. Napoleon III and the rest of the Parisian its wire attached to a crane, and having community with a mystery. They stood the hovering observer release the bob. Thus, the pendulum rotates once a day before a circle of pegs on the floor. A To them, the pendulum’s plane of swing at the poles and not at all on the equator, 70-metre wire, delicately suspended is fixed, with the Earth rotating beneath whilst at intermediate latitudes, like from the roof of the it. However, the Paris, the rotation is a mixture of these building far above observer standing two effects. As the pendulum is carried The Coriolis force and ending at their on the Earth rotates around with the rotation of Earth, the plane is experienced by feet, as thin as a around this fixed of the pendulum’s swing appears, to the a person on the Earth hair and tipped plane once each earthbound observer, to rotate, but more as a consequence of with a lead bob to day, and so to slowly than if it were at the North Pole. the Earth’s rotation form a pendulum, them it seems as Foucault’s took about 32 hours to complete was behaving though the plane is a full rotation. inexplicably. rotating. If placed at either pole, the plane of the pendulum’s The Foucault pendulum is only one of The bob was set swinging, having been swing rotates once every 24 hours; a the many examples of the effect that the carefully released from rest. At first, not rotation which is seen by the earthbound Coriolis force has upon the world; the much happened. Soon though, onlookers observer as caused by the Coriolis force. same force causes hurricanes to rotate began to notice that the pegs around the and bends rivers. Despite everything that circle were being knocked over. With Now consider another pendulum, this science tells us, it is sometimes easy to each swing, the vertical plane in which time placed on the equator, where to forget that we are not the stationary centre the pendulum moved was rotating an the observer above it appears to be of the universe, but rather a small spinning imperceptible amount. It was not simply carried around the equator once a day ball on the outer rim of one of billions of swinging around the axis of the pendulum by the Earth’s rotation. In this case, the galaxies. The pendulum reminds us that due to some accidental sideways push, earthbound observer would not see the the evidence for this is all around us. but was being deflected by an unseen plane of the pendulum’s swing turn at all. force, which turned the pendulum at a This is because the axis of the pendulum Jack Binysh is a third-year steady rate of 11° per hour. At the time, is perpendicular to the axis of the Earth’s undergraduate reading Physics at the explanation for the phenomenon was rotation. In contrast, the pendulum’s axis Lincoln College. Art by Charlotte Mason. uncertain but was eventually determined to be a force described 20 years earlier For a pendulum at the North Pole by another Frenchman, Gaspard Coriolis.
The Coriolis force is experienced by a person on the Earth as a consequence of the Earth’s rotation. This can be explained from two perspectives. The first is for an observer hovering above the Earth, who, seeing the Earth’s rotation, knows that although you and I feel stationary, we are actually on the surface of a spinning sphere. The other perspective is that of the observer upon the Earth, who, instead of seeing the Earth’s rotation, experiences it as stationary, but in addition, unlike the hovering observer, experiences the Coriolis force. The two pictures are completely equivalent, and the pendulum’s motion can be understood from either perspective.
Observer in space sees: - Earth rotate - Pendulum’s plane as stationary
Observer on Earth sees: - Earth as stationary - Pendulum’s plane rotate
time = 0
Model Organisms The creatures at the heart of biological research
curious pattern has emerged over the last century in biological and medical research. A tiny subset of the millions of species of creatures that crawl, swim and fly over the surface of our planet has come to dominate the work of biologicallyminded scientists worldwide. Physically unremarkable, small in stature and, to the untrained eye, insignificant. You’ve probably walked by (or on) them without noticing, squealed at them or swatted them. A bacterium, a fungus, a worm, a fly and a rodent. These are the model organisms.
they are able to reproduce quickly (E. coli can replicate in 20 minutes). Finally, and perhaps most importantly, each will produce huge numbers of progeny (one pair of mice can have over 150 offspring in a single year).
Escherichia coli: the ubiquitous bug
E. coli is a bacterium that makes up around 0.1% of human gut ‘flora’ (a collective term for the billions of microorganisms living inside us), but makes its home inside many An additional advantage to the model other warm-blooded animals. It has been organisms is that all have recently had routinely studied in microbiology for well their genomes sequenced and, as a group, over 60 years, and has taught us much constitute many of what we know in genome ‘firsts’. In microbiology and 1996, S. cerevisiae You’ve probably biotechnology. became the world’s walked by (or on) Using E. coli we first sequenced them without noticing have discovered At the smallest end of the model organism organism with a one of the methods spectrum, Escherichia coli (an intestinal distinct nucleus. by which antibiotic bacterium) and Saccharomyces cerevisiae Just two years later, C. elegans’s sequence resistance can spread between bacterial (baker’s yeast) have contributed invaluably was published, making it the world’s first strains. In a process called conjugation, to our understanding of single-celled sequenced organism with more than one two bacterial cells can share genetic organisms. Moving up the complexity scale, cell. Similarly, the mouse became the first material via a special hair-like structure two invertebrates, Caenorhabditis elegans fully sequenced mammal in 2002. The race (a pilus). The most surprising part of (a tiny worm usually around a millimetre to publish the first human genome was won these interactions is that they can occur in length) and Drosophila melanogaster only the following year, in April of 2003. between completely unrelated species, (the fruit fly), have heavily influenced meaning advantages such as antibiotic genetics and developmental biology. In In the years that followed, the use of resistance can not only be spread quickly, the mammalian order, Mus musculus (the the models became somewhat selfbut also widely. Furthermore, by using house mouse) has served more than any perpetuating. These organisms, sequenced E. coli we have realised the potential of other model to increase our understanding because they had proved themselves microorganisms to mass-produce human of our own species. as useful research tools in the preinsulin and have been able to observe genomics era, were evolution happening in real time. Why is it that these now fully-fledged five creatures experimental Saccharomyces cerevisiae: Advances in have gained superstars. baking, brewing and budding understanding such academic genetics, cell signalling, Researchers were popularity when metabolic processes, cellular able to assign S. cerevisiae, or baker’s yeast, is best we live in a world growth, development and gene functions by known outside of scientific circles for of such staggering manipulating the the miracles of bread and wine. Within biotechnology have all come biodiversity? How organisms’ DNA biological research it is recognised as an about from studying them has this reductionist and observing the incredibly useful tool for understanding approach— effects of these cellular processes, almost on a par with understanding many life forms through artificial mutations. These experiments E. coli. As a fungus, it is more closely the study of a few—benefited our became increasingly easy, and the libraries related to animals than to plants, so it understanding of nature? What marks of knowledge about these organisms grew makes a good system for exploring animal the models as particularly useful research at an ever-increasing rate. cell functions on a small scale. It was in tools? And can these old models continue yeast that the cell cycle proteins were to be useful in the 21st century and We now have an almost unimaginable discovered. The cell cycle is the process beyond? amount of information about the model of DNA replication followed by the splitting organisms, but what discoveries about of the cell into two daughter cells (in yeast The model organisms have several unifying them have actually been made, and which this is called budding), a process that is features. First, they are small, and so easy scientific breakthroughs have they made tightly controlled and regulated by the cell to store in laboratories. Second, they possible? cycle proteins. From understanding how require simple diets, which minimises an embryo becomes a fully-grown human, costs (in both time and money). Third, to the growth of cancerous tumours, the
dividing of one cell into two underlies all developmental biology.
Caenorhabditis elegans: space invader This tiny nematode worm has travelled very far indeed. C. elegans has been used on the International Space Station to explore the effects of zero gravity on muscle development. They fared rather well in space, and this only adds to the already impressive list of environments they can survive, including being frozen indefinitely in liquid nitrogen and superheated during orbital re-entry (C. elegans worms were experimental organisms on board the ill-fated Colombia space shuttle but survived the accident). In addition to being surprisingly durable, C. elegans was used in Nobel-prize winning research to determine how cells specialise to perform different functions and has also been extensively used by neurobiologists as its entire neural network has been mapped.
Drosophila melanogaster: geneticists’ dream Drosophila, or the fruit fly, is one of the oldest model organisms, first brought into a laboratory in 1901 on a hunch that it might be useful for genetics experiments. In 1910 a male fly was found with
white eyes (their eyes are normally brick red), which became the first documented evidence of a sex-linked recessive characteristic. It was this breakthrough that led to the modern understanding of human sex-linked disorders like haemophilia and colour-blindness. The humble fruit fly continued to exceed expectations
Research on these organisms is by no means complete
and in 1933 Thomas Hunt Morgan won a Nobel Prize for his work on them. By using Drosophila, Morgan discovered that genes were arranged on chromosomes and that this was the basis for all inheritance.
Mus musculus: human proxy As a mammal, the mouse remains the most useful of all the model organisms in the field of medicine. Exciting technologies that have emerged in the past couple of decades now allow for any mouse gene to be switched off, and any foreign gene (from another organism) to be introduced. Researchers can then study the effects of re-engineering the genome in great detail. Many diseases with a genetic component, such as Down syndrome, diabetes, epilepsy, heart disease and behavioural disorders, are combated with treatments and therapies derived from using mice as human proxies.
The classic models have made a gargantuan contribution to our understanding of how life works: currently, the vast majority of our knowledge of the functioning of both unicellular and multicellular organisms has come from research using these models. Advances in understanding genetics, cell signalling, metabolic processes, cellular growth, development and biotechnology have all come about from studying them. We stand now firmly in the post-genomic era; sequencing genomes is a matter of day-to-day laboratory research and we have created huge databases of sequence information, not only about the classic model organisms, but also about a host of new models. Recently, the domestic cat has joined the party, having been genetically engineered to express a protein that fights HIV. So is there still a place for a reductionist approach when technologies now exist to genetically alter and study almost every organism on the planet? The simple answer is yes—research on these organisms is by no means complete. Basic molecular processes are still being elucidated, and their genomes still hold many secrets. Important work on polycystic kidney disease, Huntington’s, Parkinson’s and Alzheimer’s diseases and cancerous tumour development, to name a few, is currently being carried out using the models, the results of which will directly impact our future health. The model organisms can and should be allowed to continue to shed light on the functioning of life on this planet. Sarah McCraw is a third-year DPhil student in Plant Sciences studying crop disease at Magdalen College. Art by Ilse Lee.
How to Fold a Gut Unravelling the mysteries of the intestine
he process of gut folding during embryonic development has received relatively little attention in the academic literature of late. Researchers have tended to focus exclusively on the genetics of organ development. However, recent collaborations between geneticists and physicists have provided new insights into how our gut gets its distinctive shape. New research techniques, which combine expertise from biophysics and computation, finally offer a three dimensional insight into the embryology of guts and the formation of growing tissue. It seems that the general attraction to anything 3D, from cinemas to games consoles, may have initiated renewed interest in the intricacies of gut folding. One may have naively assumed that the arrangement of the coils of gut tubing that make up our small intestine were straightforwardly genetically determined— that specific sequences of DNA
somewhere in our genes defined the tube were chosen to mimic the dissected exact twists and turns of each section of chick gut. Applying similar conditions to gut. However, this summer, a research those experienced by the chick’s midgut, group in Harvard discovered that this is the model was found to spontaneously not the case. Instead, the looping patterns deform into a similar configuration to that observed. As can be reproduced predicted by the using a simple model of unguided The shape of the Harvard scientists, uniform growth, intestine is not precisely the size and with the different tightness of the determined by genetics properties of the spirals in this model tube determining could be controlled the final shape. by varying the material’s properties, dimensions and growth rate. From this, Running down the middle of the embryo the researchers were able to derive a is a straight circular tube connecting the mathematical model to fold a gut from mouth to the anus: the midgut. Enveloping scratch! this tube is the dorsal mesentery tissue, which is connected to the abdominal Enter a given set of values for the radius, cavity wall, holding the midgut in place. thickness, strain and inertia, and with the The Harvard group hypothesized that click of a mouse a computer can simulate the shape of the gut was a product of a what that gut looks like. The success of difference in growth rate between these the model has extended beyond chicken two structures—that despite initially being embryos—it has worked for quails, songbirds and zebra finches too. It is the same length, the midgut grows far more quickly than the mesentery tissue even capable of modelling the gut of a and becomes substantially longer during mouse, which is known for its distinct the development of the embryo. Owing coiling structure. to the slower growth of the mesentery sheet, the midgut would soon be forced We now know that the shape of the to bend and bow, folding back on itself intestine is not precisely determined by and eventually forming tight coils, as the genetics. Rather, as the Harvard scientists’ ever-growing tube was restrained by the model shows, it is the biophysical properties of the gut and surrounding now taut surrounding tissue. tissue that dictate its elegant and simple The Harvard researchers tested this structure. This demonstrates that you don’t hypothesis by operating on a chicken need a complex genetic code to produce embryo. They used a glass needle to cut complex patterns and it may encourage away the tissue surrounding the small embryologists to look at the development intestine. This allowed the spiralled gut of many other intricate structures with to unravel. The taut tube relaxed and fresh eyes. To fold a gut yourself, all you straightened itself out, while the webbed need is a calculator and some amateur sheet surrounding it remained distinctly sewing skills. smaller. This observation confirmed the Chenting Zou is a second-year existence of the hypothesised tension undergraduate reading Biological stored in the coiled structure of the gut. Sciences at Wadham College. Art by India Stephenson. In another experiment, the group exercised their ‘Blue Peter skills’ in stitching a stretched out latex sheet along a straight silicone rubber tube. The thicknesses of the tube and sheet and the radius of the
Food vs Fuel A new generation of biofuels could resolve the feud
ith the steadily increasing price and decreasing availability of fossil-derived fuel, finding a new, readilyavailable source of fuel is imperative. Biofuels—fuels derived from plants— initially seemed to be the perfect solution, as their source was abundant and they offered an opportunity to reduce harmful emissions. However, a negative by-product of our hunt for renewable fuel has emerged; the increased demand for fuel in developed countries has increased the incentive for farmers to grow grains for biofuel instead of food, while people go hungry. In 2006, an increase in worldwide grain production occurred, not for human nutritional requirements, but rather in response to an increased demand for fuel. In a world of increasing population and limited space for agriculture, we desperately need a solution, before the balance between food and fuel is tipped. If biofuels are to contribute significantly towards our energy requirements, vast quantities of grain are needed. It is thought that even if the USA put all of its grain into fuel tanks, leaving none for food, it would only cover 16% of its transport fuel requirements. The value of the varieties of grain which can be used to make biofuels has increased globally, meaning that not only are food crops displaced, but the available food is also becoming more expensive. This has a particularly strong effect on less economically developed countries; those with a substantial agricultural industry have seen an increase in income, but the consequences are potentially devastating for nations with little arable land—either their economy suffers or their population starves. Lignocellulosic biofuels are a newly proposed solution to the food vs fuel problem. These so-called ‘second generation biofuels’ are made from the otherwise wasted stems and leaves of food crops, as well as inedible plants such as switchgrass and miscanthus, which can grow on poor-quality land
unsuitable for food crops. In this second eliminate the food vs fuel problem. However, due to a lack of large scale generation technology, the previously unusable cellulose and hemicellulose production technologies, it is currently found in food crops are broken down into far too expensive to derive biofuels from sugars by steam treatment and enzymes, algae on an adequate scale. before being fermented into bioethanol. In addition, a by-product of this reaction Various technologies for making biofuels is lignin, which can be burnt to provide that are not in competition with food have heat and electricity been proposed to power the and demonstrated process, making it Enough grain to fill a single fuel conceptually; the onus is now on more efficient than tank with ethanol would feed scientists and previous biofuel one person for an entire year engineers to find technology. a way of making the methods practical and affordable. The world’s first lignocellulosic bioethanol production plant is currently running in Lignocellulosic technology is currently Canada. The plant is only demonstration viable and could be used as a stopgap scale and produces around 700,000 litres solution whilst the challenges associated of bioethanol per year—enough to power with producing biodiesel from algae are 300-400 typical cars. The demonstration tackled. With sufficient attention, we could is considered a success and further, larger be using a truly sustainable fuel in the scale, lignocellulosic bioethanol plants are next few decades. being considered, predominantly in North America. However, while lignocellulosics are a step in the right direction, the potential fuel production per unit area of land is not sufficient to avoid some degree of food price inflation. In order for enough fuel to be generated within a sufficiently small area, we need a different means of producing biofuel. Algae could be used to produce energy in the form of biodiesel very efficiently; theoretically, it could produce up to 100 times more oil per unit area than any oil-producing crop on earth. It is estimated to be able to replace all of the USA’s petroleum fuel using less than half a per cent of the total land area. Furthermore, algae can be grown in a ‘closed loop system’ inside transparent tubes where it is completely separated from the external environment. As a result, it can be grown on land completely unsuitable for crop production. This could effectively
Marcus Blagrove is a third-year DPhil in Zoology at Green Templeton College. Art by Inez Januszczak.
Tiny Technology Exploring the exciting possibilities of nanotechnology
anotechnology is a young but spheres and cylinders, with very interesting increasingly exciting field of consequences. In stark contrast with the science. It has the potential to change starting material, these nanostructured the world we live in, offering solutions materials are some of the strongest known to health, energy and technological to man. Single sheets of carbon, called problems. Nanotechnology is dependent graphene, are 200 times stronger than on the unusual effects that occur on steel. Making such materials is still difficult, the nanometre but the ability to scale; one billion produce large nanometres make quantities could Nanoscale objects up a metre. That full revolutionise do not obey the usual stop, for example, is transport and laws of classical mechanics. around five million space travel. nanometres across. Despite these successes, At such scales, materials display some the most truly remarkable extraordinarily different properties from demonstrations of the comparatively large objects making nanotechnology are up our normal lives. Due to their tiny still found in nature. size, nanoscale objects do not obey Haemoglobin molecules in our the usual laws of classical mechanics; blood reversibly store oxygen instead, to describe them we must use at body temperature with an quantum mechanics. The ‘quantum effects’ efficiency that scientists’ efforts that necessitate this include changes cannot even come close to in melting temperature, appearance, matching. The DNA in all of our electronic properties and reactivity. Gold cells is constantly unzipped, nanoparticles, for example, are dark red decoded and translated insulators, very different from the familiar into proteins by an gleaming material. Meanwhile, titanium army of nanoscale dioxide, the most common pigment used biological in white paint, becomes transparent in machines. nanoparticle form.
Nanostructured carbon materials— nanoscale arrangements of carbon atoms—have attracted particular research interest. Starting with graphite, the soft, malleable material found in pencils, scientists coaxed the atoms into a variety of sheets,
Scientists hope to harness, control and ultimately rebuild biological nanotechnology for our own ends. The potential applications are vast, with huge implications. The ability of living organisms to reproduce is made possible by the self-assembly of biological molecules on the nanoscale. In this truly remarkable process, molecules spontaneously combine to form elaborate arrangements, based purely on their chemical design and with no external guidance. Harnessing this process for our own devices could allow the creation of molecular
production factories capable of assembling complex structures such as replacement organs. Other applications include ‘nanorobotics’, which harbours a vision of nanoscale robots patrolling our bodies, repairing damage and eradicating disease. However, these prospects are still a long way off. Current commercially available applications have not progressed much beyond simple nanoparticle suspensions, such as radiation-blocking particles in sun cream and antibacterial silver nanoparticles in packaging and clothing. More intriguing are some of the results of cutting edge research in the field. Scientists working in the field of DNA origami have created a variety of nanoscale shapes and machines, which self-assemble from strands of DNA. These early designs, though exceptionally simple in comparison with the natural world, have crucially proven the ability of scientists to manipulate and construct objects on this scale. Yet, as with any major scientific advance, the potential dangers of nanotechnology must be thoroughly assessed. Preliminary studies have revealed potentially worrying responses to nanoparticles in animals, such as DNA damage and tissue inflammation. Antibiotic silver nanoparticles may persist in wastewater and disrupt bacterial ecosystems, which are the basis of many of our waste disposal systems. These effects are relatively simple. As nanotechnology becomes more sophisticated, some fear it could lead to more harmful environmental effects, public health risks or the development of destructive weaponry. For good or bad, to understand the nanoscale world is to understand the processes responsible for life itself, while the ability to control the world on this scale has practically limitless potential. Gabriel Rosser is a final year DPhil in Mathematical Biology studying the swimming behaviour of bacteria at St. Anne’s College. Art by Kinda Al-Hourani.
Comfortably Numb How do anesthetics really work?
urgery without anaesthetics is not as breathing are maintained. The most a pleasant thought. It is only with common targets of general anaesthetics these drugs that we are able to undergo are the gaps between nerve cells, called medical procedures without experiencing synaptic clefts, where one cell ends pain. They interfere with our conscious and the other starts. Here, the action perception of the potentials cause the physical world. release of chemical The most common What exactly messengers. These target of general gives them such a chemicals, or anaesthetics is the gap remarkable ability? neurotransmitters, between nerve cells where travel across the one ends and the other starts Typically we synaptic cleft categorise towards receptors anaesthetics into embedded in the two groups: local membrane of the and general, each of which has distinct target nerve cell. When they bind to the effects on our biology. Local anaesthetics receptors, an electrical signal is elicited in can either be injected directly into or this target nerve cell. General anaesthetics smeared onto the tissue in need of usually bind to and block these receptor numbing. The most commonly used is sites, thereby preventing neurotransmitters called lidocaine. from reaching their destination, blocking the transmission of If pain receptors information from in your skin one nerve cell to are sufficiently Local anaesthetics the next. activated (for block the conduction of electrical signals instance in your But has along nerve fibres mouth while at anaesthesia ever the dentist’s) an gone wrong? electrical signal, Unsurprisingly, the called an action potential, is sent along answer is yes. In fact, there is a condition nerve fibres to your brain, where a called anaesthesia awareness, sufferers conscious perception of pain is elicited. of which wake up, to some extent, during If a local anaesthetic is applied in the surgery. The condition often renders mouth however, these action potentials patients unable to communicate the state are blocked, and the signal never reaches in which they find themselves-a state in your brain. which they may hear the surgeons’ voices, see the operation as it occurs and even The conduction of feel the agonizing action potentials pain of surgery There is a condition relies on the nerve itself. In the words called anaesthesia fibre membrane of Dr. Peter Sebel awareness, sufferers of being permeable of Emory University which wake up to some to specific ions School of Medicine, extent during surgery at specific times. “It’s like being Local anaesthetics alive, but inside a work by blocking corpse.” the protein channels that allow these ions to pass through the membrane. In Robert Blakey is a first-year our example, only information encoded undergraduate reading Experimental by nerve cells in the mouth is blocked, Psychology at St Catherine’s College. leaving mechanisms of sensory perception Art by Anna Pouncey. elsewhere unaffected.
On the other hand, general anaesthetics work in a very non-specific manner. The patient loses total conscious awareness, whilst essential bodily functions such
Over the Limit Is it possible to travel faster than the speed of light?
he speed of light is supposed to be the universal speed limit, but has this ultimate barrier been broken? Scientists have reported finding neutrinos travelling at speeds faster than light. In an experiment that sent the subatomic particles from CERN, near Geneva, to the OPERA detector at the Gran Sasso National Laboratory in Italy, the neutrinos appeared to travel the 730 kilometres a fraction of a second faster than light could. These controversial results have caused uproar in the scientific community, with some claiming that it spells disaster for Einstein’s theory of special relativity, in which the speed of light constraint is a crucial assumption. However, the scientists had anticipated such a reception, and
spent several months trying to find any errors in their results, considering factors as diverse as the curvature of the Earth and tidal effects of the moon. So what does it mean for physics if their results withstand further tests? Unsurprisingly, there has been a lot of speculation, and no real consensus. One of the leading suggestions is that these faster-than-light neutrinos are our first evidence of extra dimensions in space—the neutrinos take a ‘shortcut’ through this extra dimension, in the same way that we could take a shortcut from London to Sydney by travelling through the centre of the Earth, rather than by staying on its surface. By reducing the distance they travel, the neutrinos would be able to arrive at the detector faster than light travelling in the usual three spatial dimensions. As interesting as such ideas are, it would be unwise to take such suggestions seriously until we have confirmation of these astounding results, both from the additional investigations planned by the OPERA team, and from similar
experiments around the world. Because of the extraordinary implications for fundamental physics, such experiments will have to be done extremely carefully, so it will be a while before we see conclusive results. Nevertheless, if these initial findings are upheld, we could be seeing the first indications of a radical new understanding of space and time.
Kathryn Boast is a third-year undergraduate reading Physics & Philosophy at Oriel College. Art by Samuel Pilgrim.
Riddler’s Digest Test your cognitive abilities with our challenging ‘space-doku’. Each of the planets, represented here by classical astronomical symbols, must appear once in every row, column and each of the nine three-by-three grids.
Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Art by Inez Januszczak
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Bang! Science Magazine is Oxford's graphically-gorgeous science magazine. Produced by members of the University of Oxford, Bang! aims to mak...
Published on Nov 11, 2011
Bang! Science Magazine is Oxford's graphically-gorgeous science magazine. Produced by members of the University of Oxford, Bang! aims to mak...