What Are Black Holes?

Imagine you are throwing a ball up into the air. Gravity pulls it back down. On Earth, if you throw it hard enough, it flies away forever. But what if gravity was super strong? What if nothing could fly away?

A black hole is like a cosmic vacuum cleaner that is so powerful, even light gets stuck. Light usually zips through space at the fastest speed possible. But near a black hole, the pull of gravity is stronger than that speed.

Think of a black hole as having an invisible line around it called the event horizon. If you cross this line, there is no turning back. It is like falling down a waterfall where the current gets too strong to swim against.

Light is not made of heavy stuff like rocks. It has no weight. But gravity bends space itself. When space curves tightly around a black hole, light has to travel through that curve. If the curve is steep enough, light goes round in circles or falls right in.

So, when we look up at the night sky and see stars, we are seeing light that escaped their stars and traveled across space. But if a star collapsed into a tiny, dense point, its gravity becomes a trapdoor for light. Once inside, light cannot escape to reach our eyes. That is why it looks black!