A stationary black hole refers to a black hole that is not in motion with respect to an external observer. It doesn't necessarily mean that the black hole itself is not rotating, but rather that its motion through space is negligible. An orbiting black hole, on the other hand, is a black hole that is in motion around a central object or within a system of multiple objects, such as a binary black hole system.
Regardless of whether a black hole is stationary or orbiting, its fundamental properties remain the same. Black holes are regions of spacetime with extremely strong gravitational forces, formed when a massive star collapses under its own gravity. The key properties of a black hole are its mass, spin (angular momentum), and electric charge. These properties are characterized by the no-hair theorem, which states that a black hole's gravitational effects are determined solely by these three parameters.
If you were to approach a black hole, regardless of whether it is stationary or orbiting, the gravitational pull would become increasingly stronger as you get closer. This effect is known as gravitational time dilation, meaning time would appear to pass slower for an observer near the black hole compared to someone farther away. As you approach the event horizon, which is the boundary beyond which nothing can escape the black hole's gravitational pull, the gravitational forces become infinitely strong and spacetime becomes extremely distorted.
Entering inside a black hole, known as crossing the event horizon, is widely believed to be a one-way journey. Once inside the event horizon, all paths lead toward the central singularity, which is a point of infinite density at the core of a black hole. The extreme tidal forces near the singularity would result in a process called spaghettification, where you would be stretched and torn apart due to the intense gravitational gradients. Our current understanding of physics breaks down at the singularity, and it is not known what exactly happens beyond that point.
It is important to note that this description is based on our current understanding of black holes and the laws of physics. The study of black holes is an active area of research, and there is ongoing scientific exploration to deepen our understanding of these fascinating objects.