Microorganism billiards

Track Billiards

We study a class of planar billiards having the remarkable property that their phase space consists up to a set of zero measure of two invariant sets formed by orbits moving in opposite directions. The tables of these billiards are tubular neighborhoods of differentiable Jordan curves that are unions of finitely many segments and arcs of circles. We prove that under proper conditions on the seg...

Quantum Billiards

Rigid-body motion, interacting billiards, and billiards on curved manifolds.

It is shown that the free motion of any three-dimensional rigid body colliding elastically between two parallel, at walls is equivalent to a three-dimensional billiard system. Depending upon the inertial parameters of the problem, the billiard system may possess a potential energy eld and a non-Euclidean connguration space. The corresponding curvilinear motion of the billiard ball does not nece...

Microorganism Tracking Microscope System

Continuous observation of individual motile microorganisms is difficult, since their swimming speed is fast compared with their diameters. In fact, some bacteria can swim as fast as 50 diameters/s [1]. At this speed, microorganisms can quickly go out of the range of static measurement instruments, such as the field of view of optical microscopes. This problem can be solved by tracking the micro...

Billiards with Bombs

In this paper, we define a variant of billiards in which the ball bounces around a square grid erasing walls as it goes. We prove that there exist periodic tunnels with arbitrarily large period from any possible starting point, that there exist non-periodic tunnels from any possible starting point, and that there are versions of the problem for which the same starting point and initial directio...