24 November 2010
Early words - what do they mean?
Dr Graham Schafer University of Reading
Sherborne Science Café were asked by Dr Graham Schafer to ponder the true meaning of the early attempts at speaking by infants. In fact the word ‘infant’ comes from a Latin root meaning ‘without language’.
Some words seem to be common to most languages. For example ‘Mumma’, or similar variants, is often used for mother or ‘mummy’, but can also mean ‘food’ or ‘drink’. Research shows that babies understand their first words some months before they are used, with the earliest intelligent use by about 9 months old. By 12 months 50% of babies have about 50 words, followed by a ‘vocabulary spurt’ starting at about 14 months. By two years some children have a vocabulary of hundreds of words.
Babies apparently start to acquire the cultural nuances of language within the womb itself, where twins first learn to communicate with each other. Very early language involves the whole brain but eventually is concentrated predominantly in the left hemisphere. Girls learn to talk before boys, and children with ‘voluble’ mothers before those with less communicative parents. We also learned that children learn ‘no’ before ‘yes’ and ‘Dadda’ before ‘Mumma’. Dr Schafer did explore the probability that these two events were linked in some way - but did not go too far as different groups of parents would soon start to disagree!! An interesting talk was followed by a lively session of questions.
27 October 2010
Securing our low-energy carbon future
Keith Wheaton Green, Climate Change Officer, South Somerset District Council
On 27 October 2010 Sherborne Science Café was entertained by a wide-ranging talk on the potential for exploiting sources of renewable energy to meet the needs of Dorset from within the county. The current average domestic electricity use in Dorset is 4.8 MWh/y, with average gas usage c15 MWh/y. Hydropower and small wind turbine schemes are currently being installed, but could at best supply about 1% of electricity needs. Large on-shore and off-shore wind turbines could supply considerably more, but are controversial. Tidal and wave power schemes would seem to offer the largest resource. Of interest to the audience was the possibility of photo-voltaic systems installed at home, with the chance of a financial return from the Feed-in-Tariff Scheme.
The talk continued with a discussion of a number of topical issues, including the carbon impact of fossils fuels and their future scarcity. Energy saving and the impact on future building design was illustrated by the planned eco-town near Yeovil. Finally some other relevant energy efficient systems were mentioned, including solar hot water, combined heat and power, bio-fuel and mixed waste plants for the generation of bio-methane. The recently announced Renewable Heat Incentive scheme was explained.
The evening concluded with a lively discussion. A fuller account of the talk is available on request.
22nd September 2010
Dr Andrew Hindle
Andrew Hindle told us of the Company's plan to use 220-million year old salt layers nearly
8 000 feet below Portland to create 14 impermeable caverns to store natural gas, which will be equivalent to one percent of our total annual demand. The caverns will be created by pumping brine solutions in a controlled way. These Triassic salt deposits are beneath the former naval base on Portland.
Once the gas is needed it will enter a pipeline which goes across Weymouth Bay and under Redcliff Point near Osmington, White Horse Hill, and Frome water meadows, the A35, the West Stafford bypass and the railway before reaching a central gas control point at Mappowder where it will be linked to the national gas transmission system to provide gas to homes in the South West.
28th July 2010
Embedded software - programming the computers you can't see
The common image of a computer is dominated by the ubiquitous PC, with a keyboard and display. Much more numerous are the computers we don’t see. At Science Café on 28th July Mike Tarlton introduced us to an area of computing that many were unaware of: the programming of small, embedded computers. Cheap and versatile microprocessors now control a wide range of everyday devices including mobile phones, digital cameras, household appliances and car electronics. Their use makes possible modern telecommunications, medical electronics, aerospace and industry.
Mike outlined the basic design of a computer, and how computing power, speed and compactness have progressed enormously enabling the manufacture of the computer on a single chip. He described the requirements of good software design, and the constraints placed on the software engineer, using examples of devices he has been involved with developing.
The audience was entertained with a live demonstration of programming a simple device to switch two lights on and off. Increasingly sophisticated software was shown, including controlling the lights with interrupts, and as part of a multi-tasking environment.
After a look at possible future developments, and an invitation to try computing ourselves, the meeting ended with a lively round of questions.
23rd June 2010
All things bright and beautiful
Dr Pete Vukusic
Dr Peter Vukusic gave a lecture/demonstration on the evolutionary use of colour entitled “All things bright and beautiful”. He was able to show how many living organisms have evolved to make great use of colour, an advance that coincided with the development of the first eyes, about 520 million years ago. His main focus however was on insects and how their incredible diversity is accompanied by an enormous variation in colour. But, how do they do it?
Two methods are used in making different colours: a) non-structural – using pigments, and b) structural – using the refraction of light. A coloured pigment reflects back the wavelengths of light it cannot absorb, and this is a common method of colouration, the pigments often coming from the food plant of the insect. Meanwhile fluorescent substances reflect back a different colour. In fact colours that we see as blue often reflect light in the in UV region. Luminescent insects such as ‘Fire-flies’ (beetles) actually mix two chemicals together which react and then emit light. Structural colour in insects arises from their exoskeleton, which is laid down in layers of a material called chitin. The spacing of the structures is the same order as the wavelength of light, and can give rise to astonishing colours when light is refracted.
The ‘stars’ of the evening were the Morpho blue butterflies, of which there were several specimens on show. Dr Vukusic was able to demonstrate with a powerful microscope how the angle of the incident light rays as they strike the scales affected the colour. He described how the molecular structure (photonic crystals) helps to determine the final colour we see. Scientists are attempting to copy many such processes found in nature – an area known as bio-mimetics. The cosmetic giant L’Oreal is now making lipstick using similar principles.
26th May 2010
How to mend a broken heart
Dr Nicola Smart
Nicola’s research concerns the ways in which we may seek to repair heart muscle. Damage may occur during life, or at birth, and Nicola has done much work with children in this respect with research at Great Ormond Street Hospital. In an average lifetime our hearts will beat an amazing 2.5 billion times - pushing our blood through 60,000 miles of blood vessels! But hearts do go wrong. We learned that coronary heart disease (CHD) is the biggest killer world-wide, greater than all the cancer deaths put together. Surprisingly the biggest risk for CHD is high cholesterol in the blood; nearly 3 times more dangerous than smoking.
The main problem for humans is that we are born with a finite number of heart muscle cells (cadiomyocytes) and if they get damaged we are not able to make new ones. There are a number of ways in which researchers are trying to solve this problem:
using embryonic stem cells – which still have the power to generation new muscle cellsusing induced stem cells from our own skinusing bone marrow as a source of stem cellsunderstanding the fundamentals of heart development in embryo, and in certain animals that can regenerate heart muscle e.g. Amphibians and Zebra fish.
Nicola’s research is based on the last approach, and she has found that a certain protein, Thymosin β 4 (TB4), is an essential organizing chemical for cell migration. TB4 controls the behaviour of the cardiomyocytes when they form heart muscle. Her results are very promising which is why she now spends a lot of time in aeroplanes - explaining her work to other people around the world.
28th April 2010
The Particles of Physics
We were introduced to the basic concepts of particle physics by Jon Ling, one time Director of Studies for Physics and Astronomy at the University of Hertfordshire. Jon was well qualified to do this difficult task, having degrees in physics and electronics from theUniversity of London.
Having reminded us of the well-known particles i.e. the electron (the first particle to be discovered by JJ Thompson in 1897), the proton and the neutron, he then moved on to discuss the more exotic particles discovered in the last decades of the twentieth century.
Jon pointed out that these particles obeyed the rules of quantum mechanics, which were discovered in the first three decades of the twentieth century. He also pointed out that the electron and the photon displayed, under different circumstances, both properties of waves and of particles. Before moving on to the describe the Standard Model of particle physics, Jon introduced the concept of the classification of particles, and the different types of statistics obeyed by some of the classes.
In the Standard Model there are seventeen particles; 12 particles that obey Fermi-Dirac statistics, and hence called Fermions, four vector bosons and one scalar boson. According to the standard model the proton and neutron consisted of smaller particles, called quarks, which were held together by gluons. Although the Standard Model has been found to agree with almost all experimental tests conducted to date, most particle physicists believe that it is an incomplete description and that a more fundamental theory awaits discovery.
The masses of these particles arise from their interaction with the Higgs Boson. One of the major experiments planned for the Large Hadron Collider is the detection of the Higgs Boson. The results of this experiment are eagerly awaited by scientists all over the world.
24th March 2010
Serious crime solved by forensic dentistry
Prof David Whittaker
A full house at Sherborne Science Café was entertained to a grimly fascinating talk on forensic dentistry by Professor David Whittaker. Prof Whittaker asked the question: “what’s so special about teeth?” and described how scientific techniques applied to the study of teeth can help in solving serious crimes. The arrangement of a person’s teeth is unique, and information about an individual’s life history, from before birth, is “trapped” in the teeth. Being biologically inert teeth survive after death and resist decomposition and exposure to high temperatures. A range of scientific techniques is used to examine teeth, including radiography, electron microscopy and spectrophotometry. A more recent advance has been the measurement of the racemisation (the transition from left-handed to right-handed forms of a molecule) of certain amino acids in the teeth, which is strongly correlated with age. All these factors can help in the identification of a dead body, and can be the first step in solving a crime.
The role of the forensic dentist at a crime scene was described and illustrated with suitably gruesome examples, including a number of the more notorious recent murder cases. The presentation of evidence in court, and the need to explain complex scientific tests to the jury was described.
In addition to identifying victims, forensic dentistry can also identify the criminal, if he has been stupid enough to leave evidence of his bite at the scene of the crime.
The talk was delivered with enthusiasm and a degree of black humour which kept the audience informed and entertained all evening.
24th February 2010
The world through a pigeon's eyes
Prof Stephen Lea
At the monthly meeting of Sherborne Science Café Professor Stephen Lea invited his audience to see the world from a different perspective. Birds, Insects and other mammals, and even Octupuses were considered in his wide – ranging discussion of how other animals perceive colour and shape.
Vision itself was defined as having two components, perception, and cognition. Vertebrates have a common set of receptors in the form of light sensitive cells in their retinas called Rods and Cones. We vary in the number and concentration of each type. However the greatest difference between humans and other animals is in the size and complexity of the cognitive part, -the brain.
We also vary in the number of types of cone cells that we have in the retina of the eye. These cells are responsible for detecting colour and UV light. Horses have two (dichromatic), whereas humans (98% of them) have three (trichromatic). Thus 2% of the population have a reduced perception of colour, and rely more on shape to interpret objects.
Pigeons however come out on top! Not only do they have 4 types of cone cell, concentrated in multiple foveas, giving a wider range of colour perception than humans, but they can also perceive UV light. So the large audience were given a fascinating insight into understanding how birds are so good at navigation. With 4 cones and a pair of wings –‘Who needs a Sat-nav’ ?!
27th January 2010
Who's afraid of conscious machines?
Prof Igor Aleksander
Professor Igor Aleksander treated the Café to an interesting and thought provoking talk, with a great deal of audience feedback. He started by mentioning the depiction of thinking robots in some films, from the 1920s to the present day, and suggested that this was why some people were rather anxious about thinking machines. He then went on to discuss the concepts of the soul, the biological basis of thinking and the possibility that self mobility and targeted movements might be the beginnings of thinking. He also discussed the computer simulation of hurricanes and the construction of models of hurricanes in the virtual world of the computer.
He then posed the question: “How does the brain create mind with the whole capacity of conscious thought?” He listed some of the properties of being conscious, including sensations, what we perceive, remembering and planning.
His own line of research was on developing neural networks and could be used for specific tasks, such as that of deciphering car number plates photographed by speed cameras. He pointed out the differences between a photograph taken by a digital camera and an image processed by a neural network. In the case of the pixels in a digital photograph there was no co-operation between neighbouring pixels, but in an image processed by a neural network there could be links between the individual neurons and thus such a network could be used for pattern recognition.
The evening ended with a lively discussion on several of the topics raised in the talk.