Cool physics topics featuring Saint Louis University professors.
From Parachutes to Whales
Lunge feeding is one of several strategies employed by baleen whales to catch in only one gulp a large amount of krill and other small prey that typically swim in schools. In many ways, the water-filling process that expands the initially folded, highly-extensible and compliant buccal cavity skin shares a lot of commonalities with the unsteady fluid dynamics of parachute inflation.
Jean Potvin, Ph.D., joined forces with faculty from the University of British Columbia Zoology Department to propose a new theory of the drag force that is generated during lunge feeding.
The result is a new simulation program that computes the full trajectories of the whale and water that it is engulfing. This new tool should give biologists the means to compute the entire energy budget of this peculiar feeding strategy, a key element needed to understand why whales have evolved to be so large.
Probing the Roots of Quantum Mechanics
For many years, Thalanayar Santhanam, Ph.D., has been studying one of the root concepts of quantum mechanics - the so-called "commutation rules".
These form the basis of the well-known Uncertainty Principle of Quantum Mechanics, which specifies which physical quantities — such as position, momentum and energy — can be measured simultaneously, and which cannot. These commutation rules not only depend on the specific physical quantities, but also on the type of physical system that is being studied, i.e. individual atoms and particles, group of atoms, and so on.
Most importantly, they also depend on the type of energy spectrum that they have. Santhanam's interest has been on finding out those commutation rules that apply to systems possessing only a finite number of energy levels (in contrast to those systems that have an infinite number of levels, like ordinary atoms). With collaborators, he has come up with relationships that have attracted the attention of theoretical physicists from around the world.