Feldt S, Olafsen J S
Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA.
Phys Rev Lett. 2005 Jun 10;94(22):224102. doi: 10.1103/PhysRevLett.94.224102. Epub 2005 Jun 7.
We present an experimental investigation of gravitational billiards where the particle undergoes inelastic collisions with its boundary. The motion is mapped for an inelastic particle contained within parabolic, wedge, and hyperbolic boundaries. For the parabola, stable orbits are found and the wedge demonstrates a characteristic instability for its vertex angle. In the instance of the hyperbola, there are several features of the dynamics similar to the parabola at low driving and the wedge for higher driving. However, the low driving case for a hyperbola can only be completely understood by considering inelasticity effects predicted by a numerical simulation and the observation that the velocity dependent inelasticity allows the particle to sample several nearby trajectories for fixed driving.
我们展示了对引力台球的实验研究，其中粒子与其边界发生非弹性碰撞。对包含在抛物线、楔形和双曲线边界内的非弹性粒子的运动进行了映射。对于抛物线，发现了稳定轨道，而楔形对于其顶角表现出特征性的不稳定性。在双曲线的情况下，在低驱动时动力学有几个与抛物线相似的特征，在高驱动时与楔形相似。然而，双曲线的低驱动情况只有通过考虑数值模拟预测的非弹性效应以及速度相关的非弹性允许粒子在固定驱动下采样几个附近轨迹的观察结果才能完全理解。
