The waves caused by a pebble that falls into the water. From the point of contact, an energy, a reaction modifying the surface from calmness and immobility to a state of agitation. A periodic deformation of time and space variables whose wave motion draws concentric circles. This reversible disturbance gradually fades. From turbulence to tranquility, from noise to silence, then … waiting. From the fluidity of the water to the rigidity of the stone, from the voids to the mass, from the external interior perspective, from the front to the back, from the visible to the invisible.