When you get sucked into a black hole, you don’t appear like you are getting sucked. You become slower and slower until you stop, slowly turn red, and disappear. Why is that? Time Dilation.

Time Dilation is where time would be slightly slower or faster due to the gravitational field surrounding it. Here’s an example: Time is like a spring. In some places it flows quickly, and in others it flows slowly. Gravity is like a giant rock placed in that spring—it slows the flow of time nearby.

This comes into play with black holes if you go inside one. Near a black hole, time runs slower compared to far away. If you watch someone fall in, they appear to slow down. They appear to freeze at the edge. They fade away.
But for the person falling, time feels normal.

Credits: Think Academy