Séminaire régulier IUSTI – 3 mai 2019 – 11h salle 250

Water waves: a unique medium to study exotic wave physics

Sander Wildeman – ESPCI, Paris

“[Water waves] that are easily seen by everyone and which are usually used as an example of waves in elementary courses […] are the worst possible example […]; they have all the complications that waves can have,” Richard Feynman remarked in his famous lectures. In this talk I will show that if one stays away from some of these complications, water waves can offer a versatile playground to study elementary and exotic wave physics. First I will discuss a new digital Schlieren technique which allows for (almost) effortless real-time quantitative measurement of surface waves. I will show several studies where this technique has recently been applied in our lab: from measuring the wave field around bouncing oil droplets, to visualizing the wake behind supervelocity rotating wave sources. Finally, I will discuss how one can steer water waves using strong electric fields, opening up the possibility to simulate wave propagation through exotic materials with space and time varying refractive index in a way that would be hard to achieve with other types of waves (such as light or sound).