Black holes are formed when massive stars collapse at the end of their lives. As the star collapses, its gravity becomes so strong that it crushes the atoms together, creating a singularity. A singularity is a point in space where gravity is infinitely strong and the laws of physics as we know them break down.
Inside a black hole, space and time are warped so much that they become meaningless. This means that it is impossible to predict what happens to anything that falls into a black hole. However, scientists believe that anything that crosses the event horizon, the boundary around a black hole from which nothing can escape, is stretched out infinitely long and thin in a process called spaghettification.
Once something crosses the event horizon, it is trapped inside the black hole forever. Even light cannot escape, so black holes are invisible to the naked eye. However, scientists can indirectly observe black holes by studying the effects they have on the objects around them.
Black holes can grow by absorbing mass from their surroundings. This can happen when a black hole merges with another black hole or when it swallows up a star or other object. As a black hole grows, its event horizon also grows.
Black holes are not dangerous unless you get too close to one. The gravitational pull of a black hole can be so strong that it can tear apart anything that gets too close. However, the nearest black hole to Earth is millions of light-years away, so we are not in any danger of being sucked into one.
