Fall 2009

10/03/2009 | Mirrors, Anti-Matter, & the Left-Handed World -- Dan Amidei (U-M Physics)

Can you know whether you are looking at the world or its mirror reflection? Does any fundamental physical process break that symmetry to distinguish “right” from “left”? This simple question has a deep connection with the interactions of elementary particles and the nature of anti-matter. Professor Amidei will discuss some examples of right/left asymmetry in nature, explain how radioactivity shows the world to be intrinsically left-handed, and end with a puzzling new observation through the looking glass of high energy proton-antiproton collisions.

10/10/2009 | How Fast is Evolution? -- Phillip Gingerich (U-M Geological Sciences/Director, Museum of Paleontology)

Charles Darwin wrote that natural selection will always act very slowly, over long intervals of time, and generally on a very few inhabitants of a region at the same time. What did he know 150 years ago about rates? And what do we know now?

10/17/2009 | The Museum of Zoology -- A Priceless Collection of Life: William Fink (U-M Ecology and Evolutionary Biology/Director, Museum of Zoology)

Can mice predict the future climate of Michigan? How long can a bass remember something that tastes really bad? Is changing sex a good thing? Can a scientist find happiness in Tahiti? These and other questions will be answered by Professor Fink as he provides some highlights of research and teaching in the Museum of Zoology, a center of biodiversity sciences at the University of Michigan. Some of the most treasured specimens from the research collections will be on hand.

10/24/2009 | Protein, Fat, or Politics? Big-Game Hunting in Human Evolution -- John D. Speth (U-M Museum of Anthropology)

Ever since publication of The Descent of Man (1871), Darwin’s classic treatise on human evolution, paleoanthropologists have assumed that the protein provided by big-game hunting played a pivotal role in transforming a small-brained quadrupedal ape into the brainy bipeds that we are today. Surprising new discoveries, however, are beginning to cast doubt on the traditional “man the hunter” view, and suggest instead that the importance of hunting lay more in the realm of politics than nutrition.

10/31/2009 | Light of The Living Dead: The Remarkable Radiation from Neutron Stars -- Keith Riles (U-M Physics)

A neutron star is a stellar corpse remaining from the cataclysmic explosion (supernova) that marks the death of a giant star. These tiny but massive remnants are roughly 100 trillion times denser than ordinary matter and, as a result, produce radiation that is equally extraordinary. Neutron star radio wave pulses rival in precision the best atomic clocks on Earth, while their X-ray and gamma-ray bursts can flash brighter than ten trillion suns. In the future these "living dead" stars are expected to yield our first signal for that most ghostly of radiation known as gravitational waves.

11/07/2009 | Dynamics of Spinning, Rolling, and Skating -- Tony Bloch (U-M Mathematics)

Professor Bloch will discuss some of the physics and mathematics of the classical motion of rigid bodies and general mechanical systems. The basic principle underlying most dynamics is the principle of least action. He will discuss some of the history of this principle and how it gives rise to motion of particles and rigid bodies. He will describe important related concepts such as the role of symmetry and the conservation of angular momentum and energy. For bodies, which roll or skate a more general principle, the Lagrange-D'Alembert principle, must be used to obtain the dynamics. In such cases, angular momentum is not necessarily conserved and one obtains rich and sometimes surprising dynamics. Professor Bloch will give examples of rotating bodies that spontaneously change their direction of motion and that can proceed uphill without the application of outside force.

11/14/2009 | The Science of Music -- Jim Allen (U-M Physics)

Professor Allen will take a holistic look at the relationship between science and music -- the phenomena of traveling and standing waves, and how they manifest in the working of musical instruments, the human voice, human hearing, and human perception of sound.

Part 2 here

11/21/2009 | Sparks and Wiggles -- Thomas B. Greenslade Jr. (Kenyon College)

Professor Thomas Greenslade has made a career of examining the beautiful apparatus that our scientific ancestors used to study physics. He will talk about the apparatus used to demonstrate the phenomena of Electrostatics ("Sparks") and Oscillations and Waves ("Wiggles") in the 19th and early 20th centuries. The path from shocking and illuminating discoveries to modern physics will be explored, and he will look at a connection between physics and art.