# Influence of memory on trajectory in a harmonic potential

Posted by on Jan 22, 2017 in Blog | 0 comments

These are trajectories of a dotwave in a central harmonic potential

Both trajectories have same parameters, only the memory of the bath differs.

Memory = 5

Memory = 50

# emergence of statistical pattern in a 1D cavity

Posted by on Aug 5, 2016 in Blog, Original videos, Videos | 0 comments

On this video you will see how a walking droplet in a small 1D cavity moves “randomly” if the memory of the system is high enough (ie if the forcing is strong enough, but still below the Faraday Thresold)

And how a statistical pattern emerges with time

# Rainbow colored dotwave

Posted by on May 22, 2016 in Blog, Original Photos, Photos | 0 comments

These pictures illustrate path memory : in the wake of the drop, there is a superposition of a circular wave due to latest impact and of “line waves” Â created by the many previous bounces

# Dotwave picture on Phys.org

Posted by on May 22, 2016 in Blog, Original Photos, Photos | 0 comments

Russian Physicians fromÂ Moscow Institute of Physics and Technology have chosen a dotwave.org picture to illustrate an article published on phys.org concerning their latest paper,

Des physiciens russes de l’institut de physique et de technologie de Moscou ont choisi une de mes photos pour illustrer un rĂ©sumĂ© d’un de leur papier sur les ondes de Faraday publiĂ© sur phys.org

# Physics Today : letters to the editor

Posted by on Apr 11, 2016 in Blog, On the web | 3 comments

Some (heated ?) exchanges on the april edition of Physics today … with answers from John BUSH

# Emergent quantization in a square box

Posted by on Apr 5, 2016 in Blog, Original Photos, Original videos, Photos, Slider, Videos | 11 comments

# Goal of the experiment :

A walking droplet is placed in a square box, at the onset of Faraday thresold.

The trajectory of the droplet is mapped.
In the long time limit, does a self-interference pattern appear ? what’s its shape ? How does it relate to the square cavity surface wave eigen-modes ?

cf. experiment by Bush et al. : in a circular corral
http://dotwave.org/wavelike-statistics-from-pilot-wave-dynamics-in-a-circular-corral/

In short, we try to reproduce the experiment of Bush et al, but in a square box.

# First result :

A walking droplet in a square cavity shows random motion, but with time, its trajectory is building a statistic reminiscent of the resonant mode of the cavity.

This can be seen by the naked eye in this movie excerpt :

This isÂ thenÂ confirmed with optical tracking measurment of the trajectory :

Trajectory of the walking droplet

The position distribution (~probability density) is then computed :

Probabilty density

Emergent quantization of trajectories in a square box

Posted by on Mar 15, 2016 in Blog | 5 comments

I was lucky enough to attend this mini-colloque !!

# DotWave Keynote at XLIM Lab in Limoges

Posted by on Jun 19, 2015 in Blog | 6 comments

A live demonstration with a brief theoretical introduction to walking droplets and their wonders was held successfully at XLIM labs in Limoges last week.

50 attendees, mainly professionnal researchers in the field of photonics and microwave and their PhD student.

# “Fingers and Holes in a Shaken Cornstrach Solution” sur YouTube

Posted by on Aug 17, 2014 in Blog | 0 comments

Quasi particles in the middle of faraday waves :

Fingers and Holes in a Shaken Cornstrach SolutionÂ : http://youtu.be/DrcShENMaoI

# Video Lesson – 07/06/2013 – Hydrodynamic Modelling of Pilot-Wave and boucing droplet coupling in a Faraday Problem

Posted by on Jul 21, 2014 in Blog, On the web, Videos | 0 comments

“Recent experiments by two groups, Yves Couder (Paris) and JohnÂ
Bush (MIT) have shown experimentally that droplets will bounce on theÂ
surface of a vertically vibrated bath (instead of coalescing with it),Â
generating a Faraday-type wavefield at every bounce. From this state, aÂ
pitchfork symmetry breaking bifurcation leads to a “walking” state wherebyÂ
the bouncing droplet is “guided” by the self-generated wavefield – theÂ
droplet’s pilot wave. Once this state is achieved a large array ofÂ
interesting dynamics ensues with surprising analogies to quantumÂ
mechanical behaviour. We will present a coupled particle-fluid model thatÂ
can can be used simulate the dynamics of this problem. This is joint workÂ
with John Bush, Andre Nachbin (IMPA) and Carlos Galeano (IMPA)”

# Bouncing droplet project — single-slit diffraction

Posted by on Jul 21, 2014 in Blog, Videos | 0 comments

A video from TAFLAB at Berkeley University

# SPH Simulation of a walking droplet

Posted by on Jul 20, 2014 in Blog, Numerical Simulation, Videos | 0 comments

A new kind of simulation usingÂ Smoothed particleÂ hydrodynamicsÂ by Diego Molteni,Â UniversitĂ  degli studi di Palermo, Dipartimento diÂ FisicaÂ e Chimic

# Vortex-mediated bouncing drops on an oscillating liquid

Posted by on Jul 20, 2014 in Bibliography, Blog, Core Bibliography, Photos | 0 comments

Chu, H. Y., & Fei, H. T. (2014). Vortex-mediated bouncing drops on an oscillating liquid.Â Physical Review E,Â 89(6), 063011

Â http://journals.aps.org/pre/abstract/10.1103/PhysRevE.89.063011Â (Subsrciption required)

Stunning Vizualisization of undersurface flows

Abstract :

We have investigated the behavior of bouncing drops on a liquid surface by using particle image velocimetry analysis. A drop on an oscillating liquid surface is observed to not coalesce with the liquid and to travel along the surface if the oscillation is strong enough. A streaming vortex pair, induced by the alternatively distorted liquid surface, shows up below a bouncing drop. The time-averaged flow fields of the vortices are measured. In our quasi-one-dimensional setup, there are three stable distances for the drops, which can be characterized by the Faraday wavelength. The interactions of the vortex-mediated bouncing drops are deduced from the streamlines in the liquid bulk. We further show that a three-dimensional vortex ring is induced by a bouncing drop in a square cell.

# Dotwave @ 240 frame per Seconds with modified GoPro

Posted by on Jul 20, 2014 in Blog, Featured, Original videos, Videos | 1 comment

This is how precise my temporal resolution can be with my modified goPro and (at last) a good lens : 240 fps ( @848Ă480 )

Forcing freq is 60 Hz, so Faraday Freq is 30Hz, so for the usual walking mode we have 8 frame during the period of the vertical dynamic. Hence we can observe the dynamic without any strobe effect.

Question: What is the (m, n) mode of the first droplet shown in the movie ?