
Just about complicated: black hole
(ORDO NEWS) — You can often hear that scientists somewhere there discovered another black hole or even received confirmation of their merger.
However, statistics show that few people know what a black hole really is. We will try to explain this difficult phenomenon to you as accessible as possible (well, it’s very, very simple).
Emptiness?
A black hole is not an empty place or a “funnel” in space. This is an area where a huge amount of matter is concentrated, which turned out to be closed in an extremely small space.
How is this possible? Imagine a star that is 10 times the size of the sun. Presented? And now try to compress it mentally in such a way that it fits, for example, in Moscow.
This will require incredible pressure, which means that the gravitational field will increase to such a strength that even light will not be able to leave the limits of the influence of the object.
Terminology
The term “black hole” was introduced in 1967 by John Wheeler. Although, archives make it clear that astronomers have been describing mysterious objects in space for several centuries that strike with density and massiveness. By the way, their existence was predicted by Albert Einstein in the General Theory of Relativity (GR).
According to GR, when a massive star dies, a small dense core remains. If the star is at least three times the size of the Sun, then after its death we will most likely get a black hole.
It is important to understand that it is impossible to observe a black hole through a telescope, but you can calculate its location and determine the size with high accuracy. This becomes possible due to the influence that black holes have on objects and matter around them.
For example, if a black hole rushes through a cloud of gas and dust, then scientists will be able to observe how matter will be drawn in and accelerated – the birth of an accretion disk.
Something similar can be observed in the case when a black hole passes near the star (this sometimes breaks the star). At the moment when the black hole begins to “absorb” the substance into itself, it begins to accelerate and heat up to critical temperatures. At this moment, a stream of x-rays is emitted into space, which astronomers fix on the Earth.
The death of a star – the birth of a black hole?
Black holes are most often formed after a supernova explosion, and smaller luminaries with insufficient mass turn into neutron stars. If the mass of a star is three times that of the Sun, then such an object becomes a candidate for the role of a black hole after its death.
When a massive star dies, incredible processes occur, but we will try to describe them simply: when a star collapses and begins to shrink, then its surface gradually approaches an imaginary boundary (event horizon). If at that moment you could be on the surface of a star, then time for you would begin to slow down relative to an outside observer.
When the surface of the star reaches the event horizon, time will stop completely, and the star will lose the ability to further destruction. As a result, a black hole is an infinitely destructible object for which time does not exist . Yes, friends, black holes are beyond our usual understanding of the world order.
The birth of larger black holes
In 2004, NASA astrophysicists noticed a source of short flashes of gamma radiation. Pointing the Chandra and Hubble telescopes to a point , scientists found that the source was a collision of a black hole with a neutron star. What was the result? A new black hole was born, but a larger one.
Black Hole Sizes
There are black holes that are remnants of massive stars. They are usually 10-24 times more massive than the sun . Scientists observe the influence of these objects on the surrounding space regularly.
However, there are isolated black holes . This is perhaps the most unpleasant in this phenomenon. The thing is that around them there is no gas, no dust, no stars. Therefore, it is very difficult to detect them, or impossible in principle. Computer simulation shows that there can be several trillion of these miniature objects in the Milky Way alone! Yes, they are much smaller than classical (if I may say so) black holes, since they have nothing to “eat” to grow, but the processes taking place in their bowels are similar to those of their larger “colleagues”.
Of course, we cannot ignore supermassive black holes, which are a million or even a billion times more massive than the Sun! Such monsters live in the center of almost every galaxy (even ours) and constantly “devour” everything that comes close to them. Such an abundance of matter has made it possible to gain enormous mass over millions of years.
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