Black Holes

Most everyone has heard of black holes; science fiction books and movies use them as effective plot devices. However, does everybody know what they actually are? These real-life objects are scattered throughout the universe, particularly at the centers of galaxies. So, they're common, but nobody has really explored them. There's a good reason for that: once you get inside a black hole, there's no escape.

That makes them intriguing and frightening all at once. However, that hasn't stopped astronomers from studying them from the outside and using the laws of physics to understand them.

Black holes are objects in the universe with so much mass trapped inside their boundaries that they have incredibly strong gravitational fields. That gravity is so strong that nothing can escape a black hole once it has gone inside. Most black holes contain many times the mass of our Sun and the heaviest ones can have millions of solar masses.

Despite all that mass, the actual singularity that forms the core of the black hole has never been seen or imaged. The way astronomers know about them is by their effect on the material surrounding a black hole and the light that passes by.