Science fiction has often relied on the concept of black holes as a plot device, painting them as portals to other universes or as vehicles for time travel. But what happens when we take the fiction out of it? What is really going on inside these terrifying remote entities? In short, black holes are massive gravitational craters that bend space-time due to their incredibly dense centers, or singularities. As it collapses, the star explodes in a supernova – a catastrophic ejection of its outer material. A dying star continues to collapse until it becomes a singularity—an object with zero volume and infinite density. It is this seemingly impossible paradox that causes a black hole to form.

At the edge, or event horizon, of a black hole, time begins to slow down astronomically. The farther you go into a black hole, the more time becomes distorted. Some theories even suggest that if you could survive the initial entry into a black hole, images of the future and the past would be created simultaneously from within. While this is an interesting concept—and no doubt the origin of many sci-fi buffs—due to the inaccessibility of black holes, there is no known way to test it. What is generally accepted, however, is that due to the black hole’s distortion of the space-time continuum, time at the base of its event horizon passes much more slowly than Earth’s time.

The extreme density of the new singularity pulls everything in, including spacetime. Spacetime, in a very basic sense, is the unity of space and time as a four-dimensional continuum. So, what happens if you bend it? Well, if you were to experience a black hole up close, time would certainly be very different on Earth than it is here. If you imagine spacetime as a suspended flat plane of Silly Putty, creating a singularity would be like putting a marble in the middle. The marble will bend the plane dramatically downward, lengthening any interaction the marble has with the plane. The same goes for black holes, although the distortion you’ll experience will be somewhat more severe than what Silly Putty can produce.Black holes are hard to find, but if you’ve not only found one, but actually been inside one, you know it’s deadly. Depending on the location relative to the center, the strong gravitational force from the singularity pulls at different rates, which can create a “spigatification” effect on any object unfortunate enough to be trapped inside. As the word suggests, spaghettification lengthens the object in question so that it resembles spaghetti.

We may never be able to prove exactly what happens inside black holes, although many scientists are making the connection between the singularity and the Big Bang theory, which suggests that our universe is made of matter. What could have been a singularity came into being.