Black holes generate enormous gravitational forces that can present great danger to passing starships.
The black hole is one of the most mysterious of all the space phenomena found in the universe. It is an incredibly dense ball of matter that possesses such a large gravitational field that anything straying too close will be pulled into it. Every celestial object has a gravitational field. This means that to escape from its pull a starship must accelerate away from the surface with enough speed to overcome the force of gravity pulling it back.
In 1795, the mathematician Pierre-Simon Leplace wondered what would happen if a start were so massive that it had an escape velocity equal to the speed of light. In such a case, the light the star produced would not be able to escape from its surface, and so the start would appear to be completely dark. The concept was termed a black sun.
Early in the 20th century, Albert Einstein theorized that nothing could travel faster than the velocity of light, and so nothing could ever escape from a black sun. Einstein went on to develop his General Theory of Relativity, in which the concept of a black sun was further refined into what became known, in his time, as a black hole. Zefram Cochrane's development of warp propulsion in the 21st century used subspace technology to overcome the velocity restrictions Einstein had theorized.
If the Earth could be squeezed into a tiny sphere of about the diameter of a small coin, its density would be sufficient for its escape velocity to surpass the speed of light. It would then become a black hole.
A different way of thinking about a black hole is to imagine what it does to the space-time continuum. Space-time can be thought of as an imaginary rubber sheet, supporting all of the celestial objects whose mass deforms the rubber sheet, creating gravitational wells. The energy needed to escape a gravitational well depends on how steeply the rubber sheet is curved and a black hole curves space into a tiny bottleneck that spirals infinitely down. It was once thought that black holes might be corridors to other parts of the universe, but this idea is no longer seriously considered.
There are three different types of black holes. The most common is the heart of a dead star. Any star with a mass eight times greater than the Earth's sun will end its life in a cataclysmic explosion of a supernova. A supernova begins to occur when the heart of a massive start comes inert and collapses under its own weight, often leading to a black hole.
The second type are the tiny, primordial black holes that were created in the first 10 to 35 seconds after the Big Bang. They are much smaller than stellar black holes and can still be found in relative abundance; they are known as quantum singularities.
One hundred thousand years ago, an unknown race of beings harvested some of these black holes and used them as power sources for a network of relay stations that covered almost half the Galaxy. The USS Voyager NCC-74656 discovered one of these relay stations, which used a one-centimeter quantum singularity to generate four terawatts of power. In one minute, the relay extracted as much energy as a typical star gives out in one year.
The final type of black hole is incredibly massive; some are in excess of one billion times the mass of Earth's sun. These form naturally at the center of most galaxies. StarFleet ships avoid the center of the Milky Way galaxy, as a black hole of this type is widely believed to be located there.
There is a specific anatomy to a black hole. The event horizon is a spherical surface that marks the point beyond which it is impossible to escape from its gravitational pull, unless subspace techniques are used.
In 2371, the Voyager was caught within the event horizon of a type-4 quantum singularity. The gravimetric fluctuations and spatial distortions in this region of space affected the crew with headaches, muscles spasms, and dizziness. Voyager escaped by flooding the surrounding space first with warp particles and then with dekyon particles, lighting up the event horizon and highlighting the fracture caused when they entered.
At the very heart of a spherical event horizon is the singularity itself. This is a point of infinite density but minimal spatial dimensions, a place where the laws of physics break down. Any starship that encounters such a singularity will be crushed instantly.
Most black holes rotate because the stars that formed them were rotating, and a rotating black hole drags the space-time continuum just outside the event horizon around with it. This spinning, twisting motion produces large spatial distortions and is responsible for the gravimetric fluctuations that are felt in the vicinity of black holes. The affected region is known as the ergosphere.
In 2266, the USS Enterprise NCC-1701 collided unexpectedly with a black star and was thrown back in time to the 20th century. An analysis of the accident led to the discovery of the so-called slingshot maneuver, in which a starship flies toward the heart of a star's gravitation field, just skimming the surface. This is highly dangerous, but under appropriate conditions this procedure permits the vessel to enter a time warp.This article comes from Star Trek Magazine, v. 1, i. 12.