Artistic impression of cascading sound cones (in the geometrical acoustics limit) forming an acoustic black hole when supersonic flow tips the sound cones past the vertical.
Artistic impression of trapped waves (in the physical acoustics limit) forming an acoustic black hole when supersonic flow forces the waves to move downstream.
A moving fluid will drag sound pulses along with it.
A moving fluid will tip the “sound cones” as it moves. Supersonic flow will tip the sound cones past the vertical.
A moving fluid can form “trapped surfaces” when supersonic flow tips the sound cones past the vertical.
A collapsing vortex geometry (draining bathtub): The green spirals denote streamlines of the fluid flow. The outer circle represents the ergo-surface while the inner circle represents the [outer] event horizon.
Gravity waves in a shallow fluid basin with a background horizontal flow.
Domain wall configuration in .
Ripplons in the interface between two sliding superfluids.
Velocity profile for a left going flow; the profile is dynamically modified with time so that it reaches the profile with a sonic point at the asymptotic future.
One-dimensional velocity profile with a black hole horizon and a white hole horizon.
One-dimensional velocity profile in a ring; the fluid flow exhibits two sonic horizons, one of black hole type and the other of white hole type.
© Max Planck Society and the author(s)