A black hole can acquire not one, but three horizons if you add quantum loops and dark energy to it. This changes its shadow and 'ringing' — meaning astronomers might one day peer into the heart of these monsters and test quantum gravity theory.
🎯 When matryoshka black holes collide, they ring not with a single tone, but a chord: each horizon contributes its own frequency. From this sound, you could deduce the thickness and number of layers.
🎬 In the movie 'Interstellar,' the black hole had only one horizon; if it had been a triple matryoshka, the journey would have turned into crossing three boundaries with different properties — and who knows what would have awaited inside.