Why Black Holes Remain Unproven ✛ ✦
Strike two metal balls — one solid, the other hollow inside. The sound is almost indistinguishable. Astronomers, catching the "ring" of collisions between ultra-dense objects — gravitational waves — cannot tell from it whether real black holes collided or their twins without an event horizon (the point of no return). Facilities like LIGO, created with the participation of Rainer Weiss, detect vibrations but remain silent about the source's nature.
The famous shadow of galaxy M87, imaged by radio telescopes, and the glowing ring — the result of spacetime curvature. However, any sufficiently compact object would bend light the same way. Falling matter, swirled into an accretion disk, heats up and glows regardless of whether there is a light trap inside. Even quasars and neutron stars masquerade as black holes.
If the twin has a solid surface, its reflections are fainter than a whisper in a working reactor. The radiation predicted by Stephen Hawking would only confirm quantum effects, not the horizon. A falling object freezes forever as a red ghost at the boundary — due to light stretching and time dilation. But that frozen image doesn't yet mean the boundary is uncrossable.
If the Sun were compressed into a black hole of the same mass, all planets would stay in their orbits — gravity at a distance wouldn't change.
In science fiction, black holes are often depicted as gateways to other worlds: for example, in the movie Interstellar, the heroes travel through a wormhole near such a hole.