# gst: apropos of synchronization of large bubble clouds, self-oscillating acoustic bubbles that bounce

<< Self-oscillations underlie many natural phenomena such as heartbeat, ocean waves, and the pulsation of variable stars. (..) In this study, (AA) consider two closely spaced bubbles pulsating in the kHz range in response to ultrasonic excitation. A translational bouncing motion emerges from their interaction with a much lower frequency than the bubble pulsation frequency. >>

Their analysis << reveals that the observed bubble bouncing exhibits the main features of self-oscillation, such as negative damping and the emergence of a limit cycle. These results highlight unexpected nonlinear effects in the field of microbubbles and give insights into the understanding of synchronization in large bubble clouds. >>️

Gabriel Regnault, Alexander A Doinikov, et al. Phenomenon of self-oscillation in bubble dynamics: Bouncing acoustic bubbles. arXiv: 2404.05822v1 [physics.flu-dyn]. Apr 8, 2024.

https://arxiv.org/abs/2404.05822

Also: bubble, bouncing, behav, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, bubble, self-oscillation, bouncing, behavior, collective behavior, bouncing motion, synchronization

# gst: apropos of bouncing, even balls that undergo rolling are typically found to lift off slipping.

<< A detailed set of experiments are described that capture over a 1000 different instances of the bounce of a golf ball. (..) Data are presented from two different turfs; one artificial and one from a typical tee. >>

<< A better fit to the data is found using a non-physical piecewise-affine landing to lift-off relationship, which distinguishes between cases that bounce in pure slip from those that undergo rolling. Nevertheless, even balls that undergo rolling are typically found to lift off slipping, having undergone spin reversal. >>

Stanisław W. Biber, Kristian M. Jones, et al. Measurements and linearized models for golf ball bounce. arXiv: 2302.02758v1 [physics.class-ph]. Jan 13, 2023. 

https://arxiv.org/abs/2302.02758

Also

keyword 'bouncing' | 'rolling' | 'slipping' in FonT

https://flashontrack.blogspot.com/search?q=bouncing

https://flashontrack.blogspot.com/search?q=rolling

https://flashontrack.blogspot.com/search?q=slipping

Keywords: gst, bouncing, rolling,  slipping