The event horizon is a boundary in space-time that can only be passed through one way. Once light or matter passes through, it cannot pass back through the opposite way. The ergo sphere is a region located just outside the black hole, such as where the poles touch the event horizon. Since it is just outside the event horizon one could still escape from the black hole. The accretion disk is a spiral like disk of matter that rotates around the black hole, slowly falling into it. As long as the black hole has a continuous source of matter, the accretion disk is visible. The photon sphere is a region where photons are forced to rotate in orbits around the black hole due to its gravity. The orbits are very unstable, and even slight disturbances can cause the photons to fall in the black hole or escape from it. Last major part of a black hole is the singularity. This is the center of the black hole where space-time is infinitely curved. The laws of physics are broken when matter reaches this point. Non-rotating black holes form singularities in a single point, whereas rotating black holes form a ring singularity, (Oza, N. 2011, July 26). There is a lot that has not been discovered about black holes, and people are even unsure of their existence. The following paragraphs are just a brief overview of black holes, and there is a lot more …show more content…
Scientists soon set out to find if this was true or not. Soon the results came in but they didn‘t make sense. According to the results, the universe was not only expanding, but it was constantly accelerating apart. Scientists named this force dark energy. Dark energy makes up roughly 68% of the universe, yet scientists are unsure not only what it is but also how it operates. Because of this, a lot new theories about dark energy have sprung up over the years. There are three main theories about what dark energy is. One of these is that a very old and discarded version of Einstein’s theory of gravity, one that held what Einstein called a “cosmological constant”, could possibly be true. Another is some strange kind of energy-fluid that fills space could be the cause for dark energy. The last one is maybe there is something wrong with Einstein’s current theory of gravity and a new theory could be proposed to include some kind of field that creates this cosmic acceleration. Theorists still do not know what the correct explanation is, and all of these theories could be the cause. The world just has to keep looking (NASA,