The study of the universe can create many theories, prepositions and new findings. It is where we live and what surrounds us and it is full of mysteries. One of the most commonly theorised and mentioned parts of space are Black Holes. They are a gravitational field so strong that no matter,light or radiation can escape it. Hence the term black hole as they are solid black and everything in them “disappears”. There are two common types of black holes, these are Supermassive black holes, and Stellar mass black holes, the Supermassive black holes are at the center of galaxies they often contains the mass of millions of stars whereas Stellar mass black holes are created when large stars explode.
Some interesting facts about a black hole include that as you get closer to a black hole and its event horizon it distorts space and time and as a result time gets slower.
There are two parts to a black hole, the event horizon and the singularity, the event horizon is the part we can see it is black. It acts as a curtain to the singularity and therefore we do not know what the singularity actually is, it is just there, and we cannot see it as entering a black hole would result in a very fast death, as if the black hole was small you would be very close to the singularity and hit a fire wall which will instantly annihilate you, or if the black hole was large enough you would be pulled apart each cell stretched until you were a string one atom thick of plasma until you reached the singularity. Either way not a fun way to go.
Light matter and radiation cannot leave a black hole, whereas for a white hole it is the opposite.
White holes are theoretical, however likely they are they have not been proven to exist, only in mathematical equations.
White holes first appeared in mathematical theories when black holes were theorised. This was only a few months after Albert Einstein published his general theory of relativity a scientist called Schwarzschild, the Schwarzschild metric describes a black hole, but this is an eternal black hole (meaning it has always been there and will always be there) without spin, charge or change. However this is impossible as no black hole could last forever or have lasted forever.
Every black hole has an event horizon, as do white holes, In general relativity, an event horizon is a boundary in spacetime beyond which events cannot affect an outside observer. It is often described at the point of no return. From the perspective of an outsider anything happening on or past the event horizon, happens infinitely far in the future.
According to Stephen Hawking, there is an electromagnetic type of radiation that should emit from a black hole. It is called Hawking Radiation and is created near the event horizon by quantum effects, or reasons that cannot be explained simply by regular classic physics. This sort of radiation is the reason black holes do not gain mass. This is because in space particle pairs of a +/- particle or a particle and antiparticle are appearing from the void simultaneously and then meeting and annihilating each other, and this is happening in space all the time everywhere. So Hawking thought, “what happens when this is next to a black hole?”. The antiparticle that has negative charge and negative mass doesn’t have enough energy to avoid the event horizon and is sucked into the black hole, this overall decreases the mass of the black hole. Whereas the positive particle with positive mass is able to escape the event horizon and the pair is separated therefore the black hole has a subatomic sort of glow that is barely visible and emits this thermal radiation which is the positive particles.
This means that although we say it is totally black because there is nothing, it is not fully true, as the black hole is constantly emitting thermal radiation. And this has a devastating effect as the mass keeps on decreasing, the thermal energy keeps increasing making it hotter and hotter until it is so small and so hot it effectively explodes.
So you may ask, “If there is an end to a black hole, then when is the start”, The start is when a star collapses. To understand this we have to understand the makeup of a star. A star is mostly a huge collection of hydrogen atoms that collapse under their own gravity. In the core nuclear fusion crushes these hydrogen atoms into helium atoms releasing huge amounts of energy. This energy is radiation and it pushes against the gravity to create a balance between the two forces and this makes the star stable. As long as the nuclear fusion is happening the star will remain stable however larger stars than our sun have a much bigger mass allowing much heavier atoms to be fused, and so more elements are able to be created at the core and it produces even more radiation to stabilize the star until it reaches iron. The fusion of iron does not create any energy. This means that the mass and gravity of the star keeps increasing and the radiation given off cannot support this and the star collapses. This is called a supernova explosion and from this the entire mass is pushed into a small dense area. The results from this could either be a black hole or a neutron star. Neutron stars are a tiny area around 30 km where the densely packed neutrons give the star a huge mass and the neutron stars are only created if the previous star was not massive enough to create a black hole. However black holes are the next step up and are created is the previous star was massive enough.
Black holes will actually not suck everything up like a vacuum as we believe. If we were to swap our sun for a black hole nothing would actually change, apart from we wouldn’t get the heat from the sun and ultimately freeze. This is the reason we can have a black hole at the center of every galaxy and the galaxy will still exist without being sucked in and never coming out. As well as galaxies there are things called quasars, they have a center which is a
White Hole Theories.
White holes are a theory they are mathematical opposites of black holes there were discovered in the Schwarzschild metric in the 1970s and have not got any evidence besides the evidence written within the mathematical equations. Because of this there is no certainty as to if they really do exist, but this doesn’t stop physicists becoming interested in them. Being exact opposites of each other it means white holes will eject and almost infinite stream of matter, light and radiation.GRB 060614 was the first real sign of a white hole it was a Gamma Ray Burst that was picked up in 2006 and is said to have come from the constellation Indus which is 1.6 billion light years away. It lasted 102 seconds and since it happened many telescopes have been investigating it including the Hubble telescope. This was enough to spark many theories such as ones like white holes are the aftermath of a black hole and once the black hole dies it turns into a white hole spewing out everything it once engulfed. Or even Black holes are joined to white holes via a wormhole which means if you could get past the black hole, you would go through a wormhole and be ejected out of the white hole sort of like teleportation across the universe. But one issue with this is it is just a theory, we don’t know where the white hole would be and it is a one way ticket, as well as the obvious ” you get torn up and annihilated by black holes.” and so why theoretically possible it is unlikely.