Did you know black holes can exist in a flat world? Scientists took such a toy black hole and tested a new theory of gravity on it. It turned out it behaves almost like a real one, but with altered rules. This is a tiny step toward understanding dark energy — the force accelerating the cosmos.
🎯 In a two-dimensional universe, a black hole is not a sphere but a circle, and its event horizon is a simple line. Yet the formulas for an infalling observer are almost the same as in the three-dimensional case.
🎬 Physicists often construct worlds with fewer dimensions — like in Edwin Abbott's novel "Flatland", where flat beings are unaware of height. The BTZ black hole is their version of a black hole.