USF Mathematics Colloquium

Spring 2013  

  • Wednesday, May 08, 2013
    End of Semester career panel, awards, and pizza party!

    Last Math Tea of the semester:     3.00pm in HR 222

    Career panel (and awards):     4.00-5.30pm in McLaren 252.
    More details on speakers, here.

    Pizza Party:     6.30pm, at Villa Romana [map]
    731 Irving St., betw. 8th & 9th Aves.  We have a private room in back.
     
     

Past talks

     

  • Wednesday, April 24, 2013 -- Chad Topaz (Macalester College)
    When:     Wednesday, April 24, 2013 at 4pm
    Preceded by Math Tea in Harney Room 222 at 3pm
    Where: Harney Science Center 127

    Patterns, Swarms, and the Unreasonable Effectiveness of Mathematics
    Abstract:     From fish schools to zebra stripes to fluid waves, the world is full of patterns that form spontaneously. I will discuss natural pattern formation from the point of view of mathematical modeling, highlighting how minimal models can effectively -- and perhaps surprisingly -- describe real pattern-forming phenomena. As an extended example, I will discuss biological aggregations, which are arguably some of the most common and least understood patterns in nature. More specifically, I will present work performed with undergraduate students on modeling locust swarms with high-dimensional systems of nonlinear differential equations.
     
     
  • Natural Optimization: The Story of Farmer Ted
    Speaker:     Matt DeLong (Taylor University)
    Wednesday, April 10, 2013
    Abstract: The problem of minimizing the perimeter of a rectangle of a given area is familiar to all introductory calculus students. Its solution was not at all natural, however, to Farmer Ted, a fictitious character introduced in a 1999 Mathematics Magazine article. Farmer Ted required integer solutions to his farming needs. Three articles in the Magazine (two by first-year undergraduate authors) used elementary number theory to help Farmer Ted do his business naturally and efficiently. In this talk I will share the mathematics of, as well as the story behind, these cute problems. I will also discuss some lessons learned from directing undergraduate research, and tell you why my Erdös number is not exactly four.
     
    Short bio: Matt is a visiting professor in the Department of Mathematics at Harvey Mudd College for 2012-2013, while on sabbatical from his roles as Professor of Mathematics and Fellow of the Center for Teaching and Learning Excellence at Taylor University, in Upland, IN. He is also one of the Associate Directors of the MAA’s Project NExT. Matt has a B.A. from Northwestern University and a Ph.D. from the University of Michigan. He was awarded the 2005 Alder Award and the 2012 Haimo Award for distinguished teaching from the MAA.
     
     
  • An Introduction to Surface Tension (Or Why Raindrops are Spherical)
    Speaker:     Andrew Bernoff (Harvey Mudd College)
    Wednesday, March 20, 2013
    Abstract: A common misconception is that raindrops take the form of teardrops. In fact, they tend to be nearly spherical due to surface tension forces. This is an example of how at small scales the tendency of molecules to adhere to each other is the dominant effect driving a fluid’s motion. In this talk we will explain how surface tension arises from intermolecular forces. We will also examine some examples of the behavior that can occur at small scales due to the balance between fluid-fluid and fluid-solid forces, with applications as varied as understanding how detergents help clean clothes to designing fuel tanks in zero gravity environments.
       
  • Are Umpires Racist?
    Speaker: Jeff Hamrick (USF)
    Wednesday, March 6, 2013
    Abstract: We investigate the racial preferences of Major League Baseball umpires as they evaluate both pitchers and hitters from 1989-2010, including the 2002-2006 period in which "QuesTec" electronic monitoring systems were installed in some ball parks. We find limited, and sometimes contradictory, evidence that umpires unduly favor or unjustly discriminate against players based on their race.

    Variables including attendance, terminal pitch, the absolute score differential, and the presence of monitoring systems do not consistently interact with umpire/pitcher and umpire/hitter racial combinations. Most evidence that would first appear to support racially-connected behaviors by umpires vanishes in three-way interaction models. Overall, in contrast with some other literature on this subject, our findings fall well short of convincing evidence for racial bias.

  • Why Nature Rarely Assembles into Spheres
    Speaker:     David Uminsky (USF)
    Wednesday, February 20, 2013
    Abstract: Soap bubbles on their own naturally select a sphere as their preferred shape as it is the solution which best balances the desire to minimize surface area while capturing a fixed amount of volume. Despite their natural beauty Nature rarely selects empty shells, or spheres, as the preferred shape to assemble into, especially when particles to talk to one another do so over different length scales.

    Two notable exceptions are virus self assembly and the spontaneous assembly of macro-ions into super molecular spherical structures call "Blackberries." In this talk we will show how mathematics is just the right tool to explain this phenomena and help us predict when spheres will be the favored structure. The same tools will allow us to design nano particles to assemble into a variety of spherical patterns.
      

  • Tic-Tac-Toe and the Topology of Surfaces
    Speaker:     Linda Green (Dominican University)
    Wednesday, February 06, 2013
    Abstract: Informally, two objects have the same topology if the first object can be deformed to look like the second by bending and stretching it, without making any violent changes like tearing or fusing.  In this talk, we'll represent 2-dimensional surfaces as "gluing diagrams" of polygons whose edges are identified in pairs.  We'll develop techniques to decide if two gluing diagrams represent surfaces with the same topology.  By generalizing these ideas to 3-dimensional spaces, we can gain an understanding of possible shapes for the universe.  Along the way, we'll build our intuition for unusual surfaces by playing familiar games like tic-tac-toe ...  with a twist.

 



Past talks (2010–2012)