Fall into a black hole and time explodes: you see galaxies age to heat death in minutes while your friend watches you freeze at the event horizon.
Small stellar-mass ones shred you before you cross—spaghettification; supermassive beasts like Sagittarius A* (4 million Suns) give you hours.
We’ve photographed their shadows (M87 in 2019, our own in 2022), yet Hawking radiation and the black hole information paradox are still unsolved.