Two discs moving from opposite points in space, overlapping and stopping at the other disc's starting point, can be seen as either bouncing or streaming through each other. With silent displays, observers report the discs as streaming, whereas if a sound is played when the discs touch each other, observers report the discs as bouncing. The origin of the switch from streaming to bouncing respons...

We investigate the skill of rhythmically bouncing a ball on a racket with a focus on the mathematical modeling of the stability of performance. As a first step we derive the deterministic ball bouncing map as a Poincaré section of a sinusoidally driven bouncing ball. Subsequently, we show the ball bouncing map to have a passively stable regime. More precisely, for negative racket acceleration a...

The Kinect sensor was introduced in November 2010 by Microsoft for the Xbox 360 video game system. The sensor unit is connected to a base with a motorized pivot. It was designed to be positioned above or below a video display and to track player body and hand movements in 3D space, which allows users to interact with the Xbox 360. The device contains a RGB camera, depth sensor, IR light source,...

We study a particle moving in R2 under a constant (external) force and bouncing off a periodic array of convex domains (scatterers); the latter must satisfy a standard ‘finite horizon’ condition to prevent ‘ballistic’ (collision-free) motion. This model is known to physicists as Galton board (it is also identical to a periodic Lorentz gas). Previous heuristic and experimental studies have sugge...

In this paper we study the periodic motion and bifurcations of the Frictional Impact Oscillator, which consists of an object with normal and tangential degrees of freedom that comes in contact with a rigid surface. The Frictional Impact Oscillator contains the basic mechanism for a hopping phenomenon observed in many practical applications. We will show that the hopping or bouncing motion in th...

We argue that the closed string energy in the bulk bouncing tachyon background is to be quantised in a simple manner as if strings were trapped in a finite time interval. We discuss it from three different viewpoints; (1) the timelike continuation of the sinhGordon model, (2) the dual matrix model description of the (1+ 1)-dimensional string theory with the bulk bouncing tachyon condensate, (3)...

Dynamic behaviors of a particle or a bouncing ball in a generalized Fermi-acceleration oscillator are investigated. The motion switching of a particle in the Fermi-oscillator causes the complexity and unpredictability of motion. Thus, the mechanism of motion switching of a particle in such a generalized Fermi-oscillator is studied through the theory of discontinuous dynamical systems, and the c...