It would appear to slow down, fade away, and get redder in color. It would speed up towards the event horizon, remaining the same color, and then something strange would happen.
![falling into a black hole simulation falling into a black hole simulation](https://flannelhead.github.io/images/lensing-disk-bloomed-960.png)
If you were to start off a large distance away from this black hole, at rest, and allowed an object to fall into it, what would you see?Īssuming you were able to remain stationary, you'd see this infalling object slowly accelerate away from you, towards this black hole. Space is curved by the presence of this mass, which causes every object within the Universe to experience an acceleration towards the central singularity. Outside of the event horizon, gravity behaves just like you'd conventionally expect. to a singularity that is, at most, one-dimensional. Once you cross the threshold to form a black hole, everything inside the event horizon crunches down. This is an simplified version of a realistic black hole, but a good place to start thinking about the physics that occurs in two distinct places: outside the event horizon and inside the event horizon. The event horizon is located a specific distance (the Schwarzschild radius) away from the singularity in all directions equally. That region is perfectly spherical, and has a boundary separating the regions where light can escape from the region where it cannot: the event horizon.
![falling into a black hole simulation falling into a black hole simulation](https://jila.colorado.edu/~ajsh/insidebh/schwplain_626.jpg)
It has an event horizon that surrounds a single point, and a region surrounding that point from which light cannot escape. When we typically think of a black hole, we imagine the much simpler kind: one described by its mass only. When the black hole rotates, the space both outside and inside the event horizon rotates, too: this is the effect of frame-dragging, which can be enormous for black holes. can form, with an event horizon proportional to its mass and an accretion disk of infalling matter surrounding it. When a massive enough star ends its life, or two massive enough stellar remnants merge, a black hole.