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Maths in and out of the zoo Chris Budd. Where does an Oxford trained applied mathematician go to find some maths in action?. Maths masterclass students at a maze. Didcot Power Station?. Hyperboloid of revolution. By the beach?.
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Maths in and out of the zoo Chris Budd
Where does an Oxford trained applied mathematician go to find some maths in action? Maths masterclass students at a maze
Didcot Power Station? Hyperboloid of revolution
By the beach? Chevron folding caused by the geometry forced by the interaction of rock layers Singularities in rock folding described by the Swallow tail catastrophe:
Some problems from the zoo: Fish, penguins, flocks, crowds, bees, and the gift shop …. Bristol Zoo
Heat into tank Heat out of reservoir In detail!
Water temperature Fan velocity Solar temperature
Preservation of rare bird species requires them to be bred in captivity One way is to incubate eggs artificially • Need to control • Temperature • Humidity • Turning of the egg Very sensitive to the turning strategy! Eggs are turned by mother every 20 minutes
Questions ….. Why do birds turn their eggs? Could we develop a mathematical model which will allow us to optimise the turning strategy and save the penguins at ..
Blastoderm of lower density • Yolk is free to rotate
Some possible reasons for turning eggs …. • Convection of heatX Penguins sit on the top of the egg! • Conduction of heat … this is what the zoo believes! • Dispersal of nutrients • Removal of baby penguin poo
Modelling the conduction of the heat Radius of egg R = 2cm Temperature = T Thermal diffusivity k = Q. Is turning needed to maintain an even temperature? Heat equation Thermal conduction timescale = 40 minutes Too short!!! Consistent with results from incubator
In fact … turning is actually needed to move the nutrients and remove the waste matter Monitor the turning using an artificial nylon egg … And then reproduce this in the incubator
3.Birds of a feather flock together How do birds flock, fish shoal or people crowd? Each bird interacts with its nearest neighbours but the flock behaves like a single organism.
Flocking movie here and ABM simulation Equations for: alignment, vision, avoidance, intent
Idea: Individual at location is acted on by several forces • Global force : Intentions of the individual • Local (social) force .. Avoidance strategy • of people : • or obstacles : • Cohesion of families and groups • Random effects
Global force Intended direction Local force
First take your X-ray Source X-Ray Detector Object ρ : Distance of the X-Ray from a fixed point θ : Angle of the X-Ray from a fixed line Measure attenuation of X-Ray R(ρ, θ)
REMARKABLE FACT If we can measure R(ρ, θ) accurately we can calculate the X-ray attenuation factor f(x,y) of the object at any point Knowing f tells us the structure of the object • Mathematical theorem proved by Radon (1917) • Took 60 years before computers and machines were developed by Cormack to use his results
Radon’s formula: basic equations of Tomography Radon’s formula leads to a large set of equations Solving these (in a regularised form) tells us what f is! Problem … there are typically over 1 000 000 equations to solve
HAEMOLYMPH VENTRICULUS 0.05mm Good news … can now solve these equations rapidly using the Conjugate Gradient Method! And .. can then monitor the honey bees in high detail, and in real time
At last .. A trip to the gift shop Problem 6:What do you buy?
Maths can help you make the perfect gift Crease patterns are worked out using mathematics and obey strict mathematical rules. Moose Stag Beetle Eg. At any vertex the sum of all odd (even) angles is
I hope that you liked your trip to the zoo Good maths really is everywhere!!!