Department of Mathematics
University of Oklahoma

Math Circle Schedule

Fall 2023

	September 10, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 323 601 Elm Ave, Norman, OK 73019. Speaker: Travis Mandel Title: What is an Euler characteristic? Abstract: We know that the number of vertices in a polygon is equal to the number of edges. Is there an analogous statement that holds for surfaces like cubes, prisms, pyramids, etc.? What about for a surface with a hole through the middle, like a donut? What about with two holes? n holes? We'll learn about Euler characteristics to answer these questions and more. Slides. Recording (only accessible via this link). Pictures: 1, 2, 3, 4, 5.
$Picture of Mario Moran Canon$	September 17, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: Mario Morán Cañón Title: May the Codes Be with You: Cryptography in a Galaxy Far, Far Away Abstract: A long time ago in a galaxy far, far away... During the Clone Wars, Jedi Master Obi-Wan Kenobi's ship has been trapped by Separatist General Grievous' fleet. Outnumbered and without a safe way to retreat, he must reach out to the Jedi Council back on Coruscant to request reinforcements and discuss the counterattack strategy. However, the ship's secure channel transmitter has been damaged, and they can only communicate through an open channel, which can also be accessed by the Separatists. Is there any hope for General Kenobi? Yes, thanks to cryptography! In cryptography, we use math to encode a message in such a way that only the intended recipient can read it. Join us, young padawan, and learn how you can share secrets without the enemies of the Galactic Republic knowing how to decipher them. Being a Jedi Knight is not only about using the Force and wielding a lightsaber! Worksheet and Ceaser circle Pictures: 1, 2, 3, 4.
$Picture of Peter Patzt$	September 24, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: Peter Patzt Title: Games: How to always win Abstract: Back to the stone age: We will play games with pebbles (or other small objects I find laying around). The games I will propose to play will all have one player strongly advantaged. In fact, there is always one player that can find a strategy to always win. Some of these strategies will be simple and just use symmetry. Others will be more complicated and use the binary number system. And maybe we can come up with a new game together. Pictures: 1.
	October 1, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: Calvin Lin Title: Games of logic Abstract: Join us for an engaging journey into the world of logic and reasoning! In this interactive talk, suitable for ages 10 to 110, we will challenge your logical thinking abilities and put your reasoning skills to the test. Get ready to participate in hands-on activities, team challenges, and lively discussions. Come explore the fascinating world of deductive reasoning, unravel mysteries, and have a blast while doing it. Slides Pictures: 1, 2
$Picture of James Beyer$	October 15, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: James Beyer Title: An Introduction to Knot Theory Abstract: Take a piece of string, tangle it up, and then tape the two ends together. Can you untangle it without cutting the tape? Is there a way to know whether it's possible to untangle it? If you have two of these tangled loops, can you make them look like each other? If they're different, how can we tell them apart? We will discuss the mathematics of knots and links and a few ways to determine whether two knots are really the same knot or not. Pictures: 1, 2, 3
	October 22, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: Lauren Grimley Title: Double double toil and trouble; fire burn and cauldron bubble Abstract: Place numbers, in order, into cauldrons. If two numbers in the same cauldron add to a third in that cauldron, the potion boils over. How many numbers can we keep placing into the caudrons without boiling over? Are you ready to tackle this unsolved problem? Pictures: 1, 2.
	October 29, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: Pratit Goswami Title: Playing with the Fibonacci Sequence! Abstract: Given a convex polygon with n sides, how many diagonals does the polygon have? How many ways are there to tile a 2 x n floor using a 2 x 1 tile? We will try to answer these questions using what is called "recursion." We will then see how the Fibonacci numbers come up naturally in certain counting problems and how they are related to the "golden ratio." Picture: 1. Fibonacci spiral worksheet. Fibonacci spiral slides. Tiling worksheet (how many ways can you tile a 2xn floor with 2x1 tiles?).
$Picture of Tomasz Przebinda$	November 5, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: Tomasz Przebinda Title: The miracle of a coin toss Abstract: Random processes, like tossing a coin, seem to be unlikely to obey any mathematical rules. However, exactly the opposite is true. Mathematical theory of probability, does predict the outcomes of random experiments very precisely. Moreover, some of these experiments, unlike the firing of a ballistic missile - a popular example in a calculus class - can be performed in a classroom. We shall take a closer look at two such experiments. In one of them we are going to throw matches on the floor and use the results to compute the number "pi" quite precisely. Pictures: 1.
	November 12, 2023 Time: 1pm-3pm Location: University of Oklahoma, Physical Sciences Center, Room 1105 601 Elm Ave, Norman, OK 73019. Speaker: Elizabeth Pacheco Title: How to count. Abstract: How many ways are there to order 6 objects? How many 5-card hands can you make from a 52-card deck? Who is Pascal, and what is his triangle? We'll learn how to answer these counting problems and more! Pictures: 1.