Features

Take a step back from the messy everyday world and you find intriguing patterns and structures in everything from shells to drips of paint.

In his new three-part series The Code, which starts on BBC Two tonight at 9pm, Oxford University's Marcus du Sautoy explores the mathematical stories behind these patterns and how they influence every aspect of our lives.

I asked Marcus about the making of the series and how he set out to bring mathematical ideas to the small screen...

Oxford Science Blog: What was the inspiration for the series?
Marcus du Sautoy: The series grew out of the success of The Story of Maths, my four part series on the history of maths, for BBC4 and the two Horizons I did on maths with comedian Alan Davies on BBC2.

Natural history or astronomy are subjects that translate easily to the screen but the abstract world of mathematics is a much tougher challenge. I think the programmes I have made to date gave the BBC courage that we really can do a major series for BBC2 on mathematics.

OSB: What mathematical ideas did you most enjoy bringing to TV?
MdS: It was fun to meet some of my mathematical heroes. For example meeting the cicadas that use prime numbers for their evolutionary survival was exciting.

The Nautilus shell is one of the iconic images of the mathematical world but I'd never actually come face to face with the strange creature that lives inside the shell. It was also exciting to visit Pixar studios and to discover how many mathematicians they employ to create the fractal landscapes in their films. The company was founded by a guy who read Mandelbrot's book on fractals and realised they were the key to modern animation.

OSB: How are online and social media getting viewers involved?
MdS: TV has been trying to crack how to make the experience of watching telly interactive. With this new series I think we've come up with a unique concept to engage viewers in the ideas of the programme. We are running a mathematical treasure hunt in parallel with the series which challenges viewers to crack puzzles, look for clues in the programmes and play addictive online games.

We wanted to create a Code Community who are working together to crack the Challenge so twitter and Facebook are powerful tools for bringing together people who are watching the series. We have a community challenge to collect photos of all the primes from 2 to 2011 which has really galvanised the community.

OSB: What are your favourite moments from filming the series?
MdS: Filming in Jackson Pollock's studio was fascinating. You can still see all the paint splattered around the studio. We made our own Pollock using a chaotic pendulum. I'm hoping to sell it on eBay for a few million. It can help fund the new maths department for Oxford.

OSB: What do you hope viewers will take away from it?
MdS: I want viewers to see the world they live in through the eyes of a mathematician. To realise how much pattern and structure can be found in our messy chaotic world if you translate it into the code of mathematics. And also to see mathematics in a new light as a subject full of great stories with huge influence on our modern world.

Marcus du Sautoy is Professor of Mathematics and Simonyi Professor for the Public Understanding of Science at Oxford University.

Want your food to make a good impression? Then use a heavier bowl or plate.

That’s the suggestion from research by Charles Spence from Oxford University’s Department of Experimental Psychology and colleagues in Oxford and Spain, recently reported in the journal Food Quality and Preference.

The researchers asked 50 adults to taste yoghurt from three identical-looking bowls they held in their hands. The volunteers were asked to taste a spoonful of the yoghurt and rate it for flavour, quality, and how expensive they thought it was - as well as saying how much they liked it.

But whilst the Greek-style yoghurt was the same for each tasting, the three bowls had very different weights.

‘We found that people rated the yoghurt as being significantly denser, as tasting significantly nicer, and they perceived it as being significantly more expensive when they tasted the yoghurt from the heavier bowl as compared to the lighter bowl,’ Charles Spence explains.

‘These results provide an example of sensation transference. Namely, that the multisensory attributes of the packaging - its appearance, feel and in this case weight - influence our perception of what is inside the packaging, or the food served in the plates and bowls from which we eat.’

The effect is unlikely to be limited to foodstuffs. Charles tells me that further research may confirm what many wine writers have long suspected; that good wine comes in heavy bottles. He has recently submitted a study showing that, for wines up to £35, the average bottle weighs an extra 8g for every £1 increase in price.

‘There is a very exciting area of research now starting to open up at the interface of design and psychology. This is one example of that approach, where psychological experiments can help to demonstrate the impact of certain design decisions. In fact, the first author on this paper is a designer from Spain,’ Charles tells me.

‘No one previously has thought too much about the consequences of how we always eat from a plate or bowl placed on table. These results suggest that our experience of food can really be enhanced by actually holding in our hands the plate or bowl we are eating from.’

The researchers are now working to develop a dish that cannot be rested on a table, forcing diners to hold it in their hands and experience its weight.

Charles adds: ‘We are also investigating whether the fact that the food from the heavier plate was rated as denser might result in people needing less food in order to become sated or full, opening up a potential health angle.’

400 million years ago jawless vertebrates filled the oceans but today they are limited to only a few species: boneless, parasitic creatures such as lampreys and hagfishes.

So what happened to this ‘lost tribe’ of ancient mariners? Were they the victims of environmental change or thrust aside by jawed newcomers? And how did fish evolve jaws anyway?

Research reported in this week's Nature, by a team including Oxford University scientists, investigates the rise of jawed fish and gives us an ideal jumping off point to imagine what a dive through the ancient oceans would be like.

Voyage to the Silurian
‘A scuba diver transplanted to the Silurian would find the kinds of vertebrates swimming around in those ancient seas alien and unfamiliar,’ Matt Friedman of Oxford University’s Department of Earth Sciences, co-author of the Nature paper tells me. ‘At this time, jaw-bearing creatures with backbones (our closest relatives) were something of an oddity, with most vertebrate diversity tied up in various groups of bizarre armoured fishes without jaws.’

These jawless fishes were the ‘ostracoderms’ (‘bony skinned ones’), so called because they were covered in a protective armour made out of plates of bone. Typically between 15 and 60cm long, they had gills and balancing organs, and are thought to have sucked food into their mouths using a muscular pharynx.

They shared the balmy Silurian and Devonian seas with some familiar neighbours, such as sea lilies, snails, and corals, but also more bizarre animals; trilobites, giant predatory sea scorpions (at up to two metres across enough to give any time-travelling diver a fright) and the shelled relatives of squid and octopus - of which the chambered nautilus is the only surviving example.

Ostracoderms seem to have largely been slow-moving creatures that carved out a living at or near the sea floor. They were perhaps well placed to make the most of the vast, shallow oceans which washed over what are now continents due to higher sea levels in comparison to those of today.

‘I think by any reasonable measure you could argue that jawless fishes were pretty successful in the seas of the Silurian and Early Devonian,’ Matt comments. ‘There were many different kinds, and there were considerable anatomical and structural differences between those groups, suggesting a range of ecologies and habits.

‘These armoured ostracoderms seem to have been the dominant group of fish for the better part of 100 million years – by comparison mammals have only been the dominant group of land-living vertebrates for about 65 million years.’

The first jaws
Yet some members of this group began to change, evolving new kinds of mouthparts that would soon set them apart as ‘gnathostomes’ (‘jawed mouth ones’).

‘The closest extinct relatives of jawed fishes, and indeed the most primitive gnathostomes, all seem to have been bottom-feeding mud-grubbers,’ Matt explains. ‘Saying for certain why any new body-part evolves is always fraught with difficulty but perhaps the most straightforward explanation here is that jaws evolved as a means of helping regulate water flow through the mouth and throat.

‘It would have made good sense for them to develop a better way of controlling suction by elaborating the structures surrounding the mouth opening. These same components could then subsequently be modified - particularly after the origin of teeth - to take on a series of brand-new roles such as shell crushing, flesh biting, and more.’

These developments took place at a time of exceptional environmental change, with a major rise in oxygen levels in the atmosphere and then, towards the end of the Devonian, a series of extinction events which hit reefs first and later decimated vertebrate populations. Yet what exactly caused these extinctions, if it was one or a series of factors, is unclear.

Theories about the decline of jawless fishes have focused on either their response to these environmental changes or their being eaten or supplanted by their jawed cousins.

Decline and diversity
In Nature Matt and colleagues report how they put these theories to the test by analysing the functional diversity of early gnathostome jaws. They found that jawed vertebrates achieved high levels of functional - and probably ecological - diversity by the earliest Devonian, when they were still minor players compared to ostracoderms.

‘As it turns out, the range of jaw types in communities with many jawless fishes is indistinguishable from the diversity of mandibles in communities with few or no jawless fishes, and this diversity hardly changes during the Devonian. Collectively, these results cast serious doubt on the idea that the diversification of gnathostomes primarily reflected that group ‘taking over’ ecological roles previously held by ostracoderms,’ Matt tells me.

‘Jaws certainly opened up a series of new opportunities for gnathostomes, but that’s not all. In comparison to ostracoderms, which seem to have largely been slow-moving creatures living at or near the bottom, gnathostomes include many forms that were clearly powerful, active swimmers, suggesting that they were doing something totally different from their jawless predecessors.’

So perhaps it was this different lifestyle, rather than the superiority of jaws themselves, which enabled gnathostomes to weather the stormy waters of Devonian evolution.

Intriguingly, it may even be that it was events on land that would determine the fate of ancient fish: in particular the appearance of forests in the mid-Devonian.

‘In a roundabout way this probably did have a major influence on the future trajectory of jawed fish evolution. With the establishment of productive ecosystems on land, there was plenty of motivation for some fishes to start exploring the world at the water’s edge, and begin to make the transition to life on land,’ Matt comments.

‘These early explorers are, of course, the precursors of terrestrial vertebrates, including humans. This is a huge part of the evolutionary success of jawed fishes, because, in essence, half of jawed fishes alive today have arms and legs and live on dry land!’   

A set of glasses packed with technology normally seen in smartphones and games consoles is the main draw at one of the featured stands at this year’s Royal Society Summer Science Exhibition.

But the exhibit isn’t about the latest gadget must-have, it’s all about aiding those with poor vision and giving them greater independence.

‘We want to be able to enhance vision in those who’ve lost it or who have little left or almost none,’ explains Dr Stephen Hicks of the Department of Clinical Neurology at Oxford University. ‘The glasses should allow people to be more independent – finding their own directions and signposts, and spotting warning signals,’ he says.

Technology developed for mobile phones and computer gaming – such as video cameras, position detectors, face recognition and tracking software, and depth sensors – is now readily and cheaply available. So Oxford researchers have been looking at ways that this technology can be combined into a normal-looking pair of glasses to help those who might have just a small area of vision left, have cloudy or blurry vision, or can’t process detailed images.

The glasses should be appropriate for common types of visual impairment such as age-related macular degeneration and diabetic retinopathy. NHS Choices estimates around 30% of people who are over 75 have early signs of age-related macular degeneration, and about 7% have more advanced forms.

‘The types of poor vision we are talking about are where you might be able to see your own hand moving in front of you, but you can’t define the fingers,’ explains Stephen.

The glasses have video cameras mounted at the corners to capture what the wearer is looking at, while a display of tiny lights embedded in the see-through lenses of the glasses feed back extra information about objects, people or obstacles in view.

In between, a smartphone-type computer running in your pocket recognises objects in the video image or tracks where a person is, driving the lights in the display in real time.

The extra information the glasses display about their surroundings should allow people to navigate round a room, pick out the most relevant things and locate objects placed nearby.

‘The glasses must look discrete, allow eye contact between people and present a simplified image to people with poor vision, to help them maintain independence in life,’ says Stephen. These guiding principles are important for coming up with an aid that is acceptable for people to wear in public, with eye contact being so important in social relationships, he explains.

The see-through display means other people can see you, while different light colours might allow different types of information to be fed back to the wearer, Stephen says. You could have different colours for people, or important objects, and brightness could tell you how near things were.

Stephen even suggests it may be possible for the technology to read back newspaper headlines. He says something called optical character recognition is coming on, so it possible to foresee a computer distinguishing headlines from a video image then have these read back to the wearer through earphones coming with the glasses. A whole stream of such ideas and uses are possible, he suggests. There are barcode readers in some mobile phones that download the prices of products; such barcode and price tag readers could also be useful additions to the glasses.

Stephen believes these hi-tech glasses can be realised for similar costs as smartphones – around £500. For comparison, a guide dog costs around £25-30,000 to train, he estimates.

He adds that people will have to get used to the extra information relayed on the glasses’ display, but that it might be similar to physiotherapy – the glasses will need to be tailored for individuals, their vision and their needs, and it will take a bit of time and practise to start seeing the benefits.

The exhibit at the Royal Society will take visitors through how the technology will work. ‘The primary aim is to simulate the experience of a visual prosthetic to give people an idea of what can be seen and how it might look,’ Stephen says.

A giant screen with video images of the exhibition floor itself will show people-tracking and depth perception at work. Another screen will invite visitors to see how good they are at navigating with this information. A small display added to the lenses of ski goggles should give people sufficient information to find their way round a set of tasks. An early prototype of a transparent LED array for the eventual glasses will also be on display.

All of this is very much at an early stage. The group is still assembling prototypes of their glasses. But as well as being one of the featured stands at the Royal Society’s exhibition, they have funding from the National Institute of Health Research to do a year-long feasibility study and plan to try out early systems with a few people in their own homes later this year.

The Royal Society’s Summer Science Exhibition begins today and runs all week until Sunday 10 July. It includes 20 exhibits showing some of the latest UK science that is changing our world and gives the chance to talk to and question the researchers involved.

Half the elephants from West and Central African savannahs have vanished in the past 40 years, scientists report in PLoS One.

A team, including Iain Douglas-Hamilton of Oxford University’s Department of Zoology, estimate that around 7,750 elephants remain in the Sudano-Sahelian zone, which covers 20% of the continent, a 50% decline in four decades.

Of the 23 elephant populations studied half are now thought to number fewer than 200 animals and so are unlikely to survive. The survey covered protected areas so populations in unprotected regions are likely to have fared even worse.

A reduction in rainfall and increasing competition with humans for land and water resources used for livestock and agriculture are, the researchers believe, the main factors behind the decline. Warfare and the illegal trade in ivory have also helped to drive some elephant populations to the brink of extinction.

The loss of these elephant populations would affect many other species which rely on the habitat created by these giant herbivores as they browse, clear the brush and disperse seeds.

To protect the remaining animals the researchers propose that eight new protective corridors be established as soon as possible to connect the main elephant populations.

They also recommend working with private sector wildlife initiatives and channelling more wildlife revenues to local communities as a way of securing the future for elephants on Africa’s northern savannahs.