Einstein's general relativity shows us that time is not absolute. Near massive objects like black holes, the fabric of spacetime becomes severely warped. This warping causes time to run slower in regions of stronger gravitational fields, an effect known as gravitational time dilation.
The mathematical relationship for gravitational time dilation shows that time slows down as we approach a massive object. The formula involves the gravitational constant G, the mass M of the black hole, the distance r from its center, and the speed of light c. As the distance decreases, the time dilation factor becomes more significant.
At the event horizon, the boundary beyond which nothing can escape a black hole, time dilation becomes extreme. From an outside observer's perspective, time appears to stop completely at this boundary. Light from objects falling toward the black hole becomes increasingly redshifted, eventually fading from view as the wavelength stretches to infinity.
Near a black hole, the gravitational field varies dramatically with distance. This creates powerful tidal forces that stretch objects vertically while compressing them horizontally. An astronaut falling into a black hole would experience spaghettification - being stretched like a piece of spaghetti due to the difference in gravitational pull between their head and feet.