Type: Seminar

Distribution: World

Expiry: 11 Mar 2009

Auth: garethw@asti.maths.usyd.edu.au

Hello SUMS members, Welcome to Sydney University Maths Society for 2009 !!! Thankyou to everybody for signing up during O-Week. Thanks especially to those people who signed up without me having to blackmail them. Free will is always the preferred option :) In the past, SUMS usually ran weekly talks, occasionally holding other events. We still plan on having talks, however we will likely be increasing the frequency of the "other events" component. These "other events" will include soccer games, cake bakes, maths relays, debates (everyone loves maths debating, right???), puzzle days, concerts, and anything else that the executives come up with. In fact, if you guys have any suggestions as to things that we can do (including topics for maths talks, or talks that YOU want to give), feel free to email us and we might consider them for later in the year. Anyway, our first meeting this year will be this Wednesday, March 11. We will be having a talk, however there should also be time remaining afterwards for members to greet and chat to each other, and talk about their love of maths. We might even do that before the talk. As was mentioned in O-Week, you don’t have to be good at maths or even doing maths at uni to attend these talks, so long as you enjoy maths, you will enjoy SUMS and the talk won’t go over your head. Our first speaker will be PhD student extraordinaire Ivan Guo, and he will be talking about Farey Fractions and Ford Circles. Now usually this is where we provide an abstract of the talk, but Ivan is to lazy to do that (thanks Ivan), so here’s wikipedia to save the day: In mathematics, a Ford Circle is a circle with centre at (p/q, 1/(2q2)) and radius 1/(2q2), where p/q is an irreducible fraction, i.e. p and q are coprime integers. The Ford circle associated with the fraction p/q is denoted by C[p/q] or C[p, q]. If p/q is between 0 and 1, the Ford circles that are tangent to C[p/q] are precisely those associated with the fractions that are the neighbours of p/q in some Farey sequence. I hope to see you there! Talk: Farey Fractions Speaker: Ivan Guo Date/Time: Wednesday March 11, 1-2pm Location: Carslaw 452 Before I finish typing this message, I’d like to mention a few final things. - We have a facebook group: http://www.facebook.com/group.php?gid=24190036266. Feel free to join it. We also have a website, but I won’t give you the link yet because it hasn’t been updated in a while, oh the shame. (Actually, the link is on the facebook group, bugger. I’ll update it this week). We are also planning on expanding the website quite a bit over the year. - If you have any questions or suggestions for SUMS, feel free to send us an email! - Future SUMS messages will be shorter than this one. SUMS President "Now what is the message there? The message is that there are known "knowns." There are things we know that we know. There are known unknowns. That is to say there are things that we now know we don’t know. But there are also unknown unknowns. There are things we do not know we don’t know. So when we do the best we can and we pull all this information together, and we then say well that’s basically what we see as the situation, that is really only the known knowns and the known unknowns. And each year, we discover a few more of those unknown unknowns." - Donald Rumsfeld