They talk about light's unique dual nature, that it can be both a wave and a particle (photon). One illustration for that is the following experiment, a single photon can go through one hole, and leave a particle like mark, or it can go through two holes, and leave interference marks. However there was an interesting experiment with sound, they cleaned a chimney with ultrasonic waves, and it left particle like marks, as small bubbles formed, and they teared into the soot. Isnt it possible the describe light as a pure wave, and photon is a smallest portion of this wave that we can measure, or emit? I also found interesting, that there is a concept : sonic black hole. "They are called sonic, or acoustic, black holes because these trapped phonons are analogous to light in astrophysical (gravitational) black holes. Physicists are interested in them because they have many properties similar to astrophysical black holes and, in particular, are predicted to emit a phononic version of Hawking radiation."