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Spring 2004

UConn Math Club
Organizational Meeting Link: View Poster
Speaker:
Time: Wednesday, February 4, 2004 at 4:30 pm
Place: MSB 117 (UConn - Storrs)
Abstract: The UConn Math Club is starting up again, this week. On Wednesday, there will be an organizational meeting in MSB 117 at 4:30. In the following weeks, some of the scheduled talks are

K. Conrad: Relativistic Addition and Real Addition

D. Pollack (Wesleyan): An Introduction to Elliptic Curves

W. Wickless: The Impossibility of Trisecting Angles

For general information, see the webpage http://www.math.uconn.edu/~kconrad/mathclub. Send email to Prof. Conrad (the address is at the website) if you are interested in attending, so enough pizza and soda is ordered.
Comments: Free Refreshments


UConn Math Club
Relativistic Addition and Real Addition Link: View Poster
Speaker: Keith Conrad (University of Connecticut)
Time: Wednesday, February 11, 2004 at 5:00 pm
Place: MSB 117 (UConn - Storrs)
Abstract: In classical physics, velocities add like real numbers. For instance, if you are traveling on an open-air platform moving at 10 mph, and throw a baseball at 50 mph in the direction of motion, then an observer on the ground sees the ball move at 10+50 = 60 mph. However, according to the (special) theory of relativity, no particle travels faster than the speed of light, c. If your platform is moving at (3/4)c and you throw the ball at (1/2)c in the direction of motion, then it appears to an observer on the ground that the ball's velocity is not (3/4)c + (1/2)c = (5/4)c, which exceeds the speed of light, but instead (10/11)c.

We can think about these two situations from a mathematical point of view, without worrying about the physics involved. They describe two different types of addition, one on R using ordinary addition, and the other on the interval (-c,c) using relativistic addition. It turns out that there is a "relativistic logarithm," that converts relativistic addition on (-c,c) into ordinary addition on R. This means relativistic addition is just ordinary addition in disguise, even though they may seem quite different.

We will explain what it means for any interval (a,b) to have an "addition law," and then prove that all such addition laws are just a disguised form of ordinary addition on R. The proof involves an interesting mix of calculus and algebra. No physics will be assumed or used.
Comments: Free Refreshments


UConn Math Club
The Impossibility of Trisecting Angles Link: View Poster
Speaker: Bill Wickless (University of Connecticut)
Time: Wednesday, February 25, 2004 at 5:00 pm
Place: MSB 118 (UConn - Storrs)
Abstract: Everyone who has been around a math department awhile has seen an ominous bulging manila envelope arrive in the department mail. On the outside of the envelope is written something like "Do you care about the truth?" Inside is a 256-step procedure for trisecting a general angle, using only compass and straightedge. The author wants somebody to spend time to check through this, in order to verify that nothing is wrong.

I will explain why it's not necessary to check through this. More precisely, what do we mean when we say one cannot trisect a general angle with compass and straightedge? This question leads to another interesting topic, the notion of a constructible number. Everyone is welcome. No special background is needed for the talk.
Comments: Free Refreshments


UConn Math Club
An Introduction to Elliptic Curves Link: View Poster
Speaker: David Pollack (Wesleyan)
Time: Wednesday, March 3, 2004 at 5:00 pm
Place: MSB 118 (UConn - Storrs)
Abstract: What are all rational number solutions to the equation y2 = x3 + 17? An easy rational solution is (x,y) = (2,5). Other rational solutions are less apparent, such as (-64/25,59/125) and (5023/3249,-842480/185193)! How were they found?

The graph of an equation like y2 = x3 + 17 is called an elliptic curve, and such curves are a central topic in number theory. In recent years elliptic curves played a crucial role in the proof of Fermat's Last Theorem, and they are of great use in cryptography. We'll give an overview of elliptic curves, discussing some of their main properties and ending with several open questions.
Comments: Free Refreshments


UConn Math Club
Coin-flipping Over the Phone: an Introduction to
Provably Secure Two Party Computation
Link: View Poster
Speaker: Alex Russell (University of Connecticut)
Time: Wednesday, March 17, 2004 at 5:00 pm
Place: MSB 118 (UConn - Storrs)
Abstract: We will introduce some basic notions of modern provably secure cryptography, including one-way functions and pseudorandom generators. Applications to natural cryptographic problems such as encryption and secure function computation will be discussed. No knowledge of cryptography is assumed.
Comments: Free Refreshments

UConn Math Club
Why Suspension Bridges Sometimes Fall Down Link: View Poster
Speaker: Joe McKenna (University of Connecticut)
Time: Wednesday, March 24, 2004 at 5:00 pm
Place: MSB 311 (UConn - Storrs)
Abstract: This week's talk will use some hi-tech equipment, so it is in MSB 311 instead of our usual meeting place.
Comments: Free Refreshments

UConn Math Club
An Introduction to Topology Link: View Poster
Speaker: Ralph Kaufmann (Oklahoma State Univ.)
Time: Tuesday, March 30, 2004 at 12:30 am
Place: MSB 118 (UConn - Storrs)
Abstract: The branch of mathematics called topology has its origin in the observation that certain geometric properties of a figure (e.g., whether it is bounded or has a hole) are unchanged by bending or stretching. Professor Kaufmann will explain some of the basic ideas of this beautiful area of mathematics.
Comments: Free Refreshments

UConn Math Club
The Geometry of Quaternions Link: View Poster
Speaker: Obi Rej (University of Connecticut)
Time: Wednesday, March 31, 2004 at 5:00 pm
Place: MSB 118 (UConn - Storrs)
Abstract: Quaternions were introduced in 1843 by the Irish mathematician Hamilton. They are numbers of the form a+bi+cj+dk where a,b,c,d are real numbers. They generalize complex numbers, with a more interesting rule of multiplication. Quaternionic multiplication can be seen as a precursor to the vector cross product in R3.

In this talk, I will describe the algebra of quaternions and an application to rotations in three-dimensional space. We will also see the connection between quaternions and more familiar algebraic objects such as matrices, as well as their role in studying spins of elementary particles such as the electron. En route, we will encounter an extraordinary historical saga of ambition, obscurity, and resurgence which will exemplify the very human face of mathematical discovery.
Comments: Free Refreshments


UConn Math Club
Orders of Infinity Link: View Poster
Speaker: Reed Solomon (University of Connecticut)
Time: Wednesday, April 7, 2004 at 5:30 pm
Place: MSB 118 (UConn - Storrs)
Abstract: The concept of infinity has intrigued and puzzled mathematicians for centuries. Near the end of the 19-th century, Cantor made the shocking discover that not all infinite sets have the same size. Shortly afterwards, Russell found a paradox in Frege's system of set theory and showed that mathematicians did not understand the idea of a "set" as well as they thought they did. Together, these discoveries helped launch the modern study of set theory and of infinite sets.

In this talk, we will discuss these ideas and examine related questions. How can we measure the size of a set? How can one infinite set be bigger than another infinite set? How big is the set of real numbers? This last question is one that is still debated today!
Comments: Free Refreshments


UConn Math Club
Random Thoughts (In Two Acts) Link: View Poster
Speaker: Davar Khoshnevisan (University of Utah)
Time: Thursday, April 15, 2004 at 5:00 pm
Place: MSB 118 (UConn - Storrs)
Abstract: Randomness affects all of us every day. So perhaps we should ask ourselves, "What does it mean to be random?" I will describe two short stories that might convince you that the honest answer is "No one really knows." The only formal prerequisite to this talk is a term of freshman calculus.

Act 1: It may be chaotic, but it's surely not random!

Act 2: Is that a normal number in your hands?
Comments: Free Refreshments


UConn Math Club
The Banach−Tarski Paradox Link: View Poster
Speaker: Tom Weston (Amherst College)
Time: Wednesday, April 21, 2004 at 5:00 pm
Place: MSB 118 (UConn - Storrs)
Abstract: The Banach−Tarski paradox is the suprising fact that any three-dimensional solid object can be "cut" into finitely many pieces which can be rearranged to form any other solid object. For example, a pea can be cut up and rearranged to form the sun. In this talk, we will discuss the proof of the Banach−Tarski paradox and especially the role of the infamous "axiom of choice." No specific mathematical background is required.
Comments: Free Refreshments