Mathematical Colloquium 
Falling Paper and Flying Insects 

By  Anders Andersen 
From  Department of Physics, Danish Technical University 
When  November 16, 2007 4pm 
Where  Engineering E104 
Abstract  Leaves, tree seeds, and paper cards which flutter (oscillate from side to side) or tumble (rotate and drift sideways) are beautiful everyday examples of solid objects moving in a fluid. To predict their complex trajectories requires the knowledge of instantaneous fluid forces which have many aspects in common with the aerodynamic forces used by flying insects in complicated maneuvers. In this talk I will present trajectories and fluid forces measured in a simple experiment on fluttering and tumbling plates, describe a theoretical model of the fluid forces, and explain the nature of the transition between fluttering and tumbling. 
Further Information 
Vakhtang Putkaradze 
There will be Refreshments in Weber 117 at 3.30pm
The Colloquium counts as Seminar Credit for Mathematics Students.