MathsJam Gathering 2014
This is a list of the talks presented at the 2014 conference, along with slides where we have them. If you'd like to send us your slides, or more detail about your talk, please email manchester@mathsjam.com.
The gathering took place on 1st-2nd November 2014.
Saturday
Session 1
An Interesting Sequence - Ross Atkins
Ross told us about an interesting sequence - and an unexpected relationship to Φ.
- Sequence A019444 on OEIS
Matt Parker doesn't know when to stop - Matt Parker
Matt explained his new obsession with Optimal stopping problems - assuming you'd rather get something good than not miss something perfect.
- Optimal Stopping, on Wikipedia
The Double Pendulum - Richard Gould
Richard applied Lagrangian mechanics to a double pendulum, with animations (and a little accidental DJ-ing).
Joining the dots - Noel-Ann Bradshaw
Noel-Ann talked about the game of Match Dots, and how it can be used to teach graph theory. She also showed us a few other mathematical phone app games.
- Slides (PDF)
- Slides (PPTX)
- Match dots, on Google Play
- Match dots, on the Apple Store
Optimal Finger Counting - Michael Gibson
Michael proposed a fairly easy way to count to 399 (and do some simple arithmetic) on your fingers.
Make your own Soma cube in 122 easy steps - Alison Kiddle
Alison talked us through an origami Soma Cube, and made use of our casual labour creating Sonobe units to make one.
- Slides (PDF)
- Slides (PPT)
- Soma cube, on Wikipedia
dVq, or five 500-year-old recreations - Tiago Hirth
Tiago showed us five interesting puzzles, and maybe three solutions.
Shuffling Perfectly - Dave Gale
To finish the first session, Dave talked about how soon repeating a 'perfect' (non-random) shuffle will get back to the original order.
Session 2 - 15:30 - 16:30
Everything Old is New Again - Adam Atkinson
Adam showed an oldie but a goodie - proving that a right angle is equal to a right angle plus a small non-zero angle. Hang on a minute...
How to see inside a cake without cutting it - Martin Whitworth
Martin explains the process of x-ray microtomorgaphy, and uses it to look inside some delicious cakes.
A Sequence: 1,2,4, ... - Noel France
Noel's sequence starts 1, 2, 4, 6, 16,... but how does it continue? We were left guessing.
- Noel's sequence, on OEIS
Fun with Microsoft Excel. No, really. - Phil Ramsden
Phil has used MS Excel spreadsheets to display photos (inspired by Matt Parker), and to generate some even more exciting graphics, including fractals.
Table cloths on wobbly tables - Tarim
Tarim shared with us the wobbly table theorem, and his issues with the practicality of the question.
A new circle dissection - Stephen Worsley
Stephen showed us some variations on the classic pizza-slicing problem - can you cut a circle into congruent pieces so that not all of them touch the centre?
Estimating log 3 using a piano - Francis Hunt
Francis talked about how logs can be calculated from musical intervals.
Discriminants and Resultants - Joel Haddley
Joel talked discriminants and resultants, matrices and determinants and showed us some Geogebra.
Games used at the Maths Arcade - Peter Rowlett
Peter presents the Maths Arcade, and how well it's doing at universities around the country - plus introduces some of the games played there.
- Slides (PDF)
- Maths Arcade, on the IMA Website
Maths with your eyes closed - geometrical callisthenics + Gestalt ambiguity - John Bibby
Session 3 - 17:00 - 18:00
Squaring the Torus - Geoffrey Morley
Can the surface of a torus be split into different sized squares? Geoffrey showed us how.
Negative Prices in Supermarkets - Adam Atkinson
According to Adam, certain products in Waitrose are discounted and reduced in such a way that you can actually end up paying negative amounts of money for them.
Harmonograph Revisited - John Bradshaw
John showed us his modern reimagining of a harmonograph - using an electronic graphics tablet and stylus.
- Harmonograph, on Wikipedia
- Photo of John's harmonograph, by @standupmaths on Twitter
Entropy is Your Friend - Andrew Macdonald
Andrew explained the concept of entropy - just how much information does a message really contain?
Selected at random - Martyn Parker
Martyn showed us some different methods of selecting a chord at random from a circle, and how they can have very different distributions.
Infinitely many infinities - Julia Collins
Julia challenged us to the task of drawing uncountably infinitely many infinity symbols on a piece of paper. Is it possible?
MegaMenger - Katie Steckles
Katie described the MegaMenger project, and listed the many locations around the world in which menger sponges have been built in order to constitute a distributed Level 4 Menger Sponge around the world.
- Slides (PDF) - mostly photos of Menger Sponges
- MegaMenger project website
Martin Gardner - a Celebration of Mind - Matt Parker
In honour of Martin Gardner's centenary, Matt said a few words about Martin Gardner and his work, and the activities that take place in his honour - including the MathsJam itself.
Sunday
Session 1 - 09:00 - 09:30
Let's talk about x - Christian Perfect
How do you write the letter x? Christian P did a quick survey, then got us all thinking about multiplicative inverses, and why negative numbers are written the way they are but the same doesn't apply to division.
- Let's Talk About X, at The Aperiodical
A proof of Pythagoras' theorem - Paul Taylor
Paul demonstrated a simple proof of Pythagoras' theorem which surprised us with its elegance and neatness.
Spurious Chat - Martyn Parker
Martyn showed us some spurious correllations between unrelated variables - which, as mathematicians, we understand don't imply causations.
Superpermutations - Robin Houston
Robin told us about Superpermutations, which contain every possible permutation as a substring.
More MegaMenger - Ben Sparks
Ben continued the MegaMenger-related chat by describing his experiences building the Bath sponge (no puns), and told us some of the Menger Sponge's interesting properties.
Session 2 - 10:10 - 11:00
Squaring a chessboard - John Foley
John discussed the problem of covering a chessboard with squares of integer size.
How to break Excel - Tom Button
Tom showed us a way in which Microsoft Excel doesn't, and explained why that happens.
A Stab at Promoting Motivation - Ken McKelvie
Ken got us all motivated to learn about maths, including showing us a nice picture hanging puzzle.
Yuen Ng - Maths of the London Underground
Yuen shared with us some of the graph theory behind the modern tube map, as well as ways to estimate the number of people using the tube in a given year.
Waves in a car park - Ben Ashforth
Ben described the time he stuck a sensor on a broom handle out of his car window to measure the waves coming from a transmitter across a car park, and how this information can be reconstructed into an image of the coverage in the area.
- Slides (PDF)
- Slides (PPTX)
- Ben's video of waves (AVI, 6MB)
Phil Ramsden - Goodstein Sequences
Phil described some sequences which get impossibly big and then implausibly go to zero.
- Slides (PDF)
- Slides (PPTX)
- Goodstein Sequences, on Wikipedia
16 tiles and a hidden item - Colin Wright
Colin demonstrated an impossible mathematical magic trick, in which his assistant flips one of sixteen tiles while he is absent, and Colin is able to determine which one.
Session 3 - 11:30 - 12:30
An unusual proof that 1 equals 2 - Colin Beveridge
Colin presented a proof that 1=2.
The Hypergame Paradox - Miles Gould
The Hypergame is a game in which players make a move by choosing a game to play, and making a move in that game. But is it a finite game, and if so can you choose hypergame as your game? Miles explained the paradox.
Nut Spinner - Alistair Bird
Alistair presented the Nut Spinner, an object found on the SS Great Britain, but whose use is a mystery - maybe for a game of chance?
Sofia Kovalevskaya: Nihilist Girl - Nicholas Jackson
Nicholas told us about the mathematician Sofie Kovalevskaya.
- Slides (PDF)
- Sofia Kovalevskaya, on Wikipedia
- Sofia Kovalevskaya Google Doodle
My difficulty with applied mathematics - Tony Mann
Tony explained some of his difficulties when applying maths to the real world - does the amount of liquid a cup can hold depend on your altitude?
Overhanging Bricks - David Bedford
David demonstrated a nice fact about divergent series by building an improbable and dangerous stack of bricks, hopefully not above someone's laptop...
- Slides (PDF)
- Slides (PPTX)
- Video of David, by @peterrowlett on Twitter