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a.ratnaparkhi
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How we can prove the existence of black holes?
And how they are located in in the space as they can absorb light too?
And how they are located in in the space as they can absorb light too?
94JZA80 said:some would say that, b/c we have yet to literally "see" the shadow of a BH (the event horizon) against the backdrop of stars and illuminated gas and dust, we do not have definitive proof of the existence of black holes.
abhishek k said:i was reading a brief history of time and i answers very clearly the very question you asked. Though black holes absorb all light(one way to detect anything) it does have a observable gravitational effect through which the have been proved to exist. they also release x-rays which they don't suck in(this i couldn't understand why) which is another way to detect them
94JZA80 said:You've got a bit of a contradiction in your statement - X-rays are a form of light/electromagnetic radiation, so a BH can't absorb all light and still emit X-rays. I'm actually currently reading Hawking's "A Brief of Time," and while I don't recall the exact part you're referrencing, i'd have to imagine that the X-ray emission you'rereferring to is coming from the radiation given off by the accretion disk of material orbiting and falling into the BH, and not from the BH itself...
keep in mind that other forms of radiation will escape in the same manner. the accretion disk emits less and less energetic radiation as as you make your way from the inner edge of the disk to the outer edge, that is, as you progressively get further away from the event horizon. i don't know enough about high-energy astrophysics to say for sure, but if X-rays are being emitted by the accretion disk very close to the event horizon, then i would imagine that UV and visible light are emitted further from the event horizon, and so on and so forth all the way down through radio emission. perhaps even gamma rays are being produced in a region closer to the event horizon than where the X-rays are being produced. now whether we can see all this radiation being emitted is another story, since often times vast amounts of interstellar dust blocks our direct line of sight with the BH. again, i don't specialize in this kind of thing at all, so I'm merely postulating, but i would also imagine that its tough for us to see UV and visible light due to their range of wavelengths being similar in size to the dust particles they're trying to penetrate as they travel to us. infrared, microwave, and radio emission however i would think is easier to see b/c the range of wavelengths that these energies correspond to are much larger than the diameters of the dust particles they're traversing through. so keep in mind that it isn't just X-rays that are emitted from the general vicinity of a BH, regardless of whether that's all we can see or not...abhishek k said:yup! you are right i read the part again after writing the previous reply. The x-rays are not emmited by the black hole itself but the matter at the event horizon. This is the reason why x-rays aren't absorbed by the black hole
i don't know if its correct to view one particle of a spontaneous pair as exceeding the speed of light, as I've never heard of that approach before. perhaps that is the violation of relativity? that being said, there is an explanation for it. Hawking Radiation makes the black hole "appear" as though its emitting radiation. but as we know, mass and energy can only cross the event horizon in one direction, and can never cross back over. from what I've read, the energy that "appears" to be coming directly from the black hole is actually coming from the energy in the BH's magnetic field exterior to its event horizon. minor fluctuations in these fields lead to the quantum uncertainty and the brief existence of particle-particle pairs. if one crosses over the event horizon before the pair disappears altogether, then the other particle of the pair appears to have been emitted by the BH itself b/c the creation of the pair happened so close to the event horizon in the first place. but again, the source of energy that creates the pair in the first place comes from the BH's magnetic field exterior to the event horizon.Driftwood1 said:Quantum uncertainty allows for one of the particle pairs to escape at the event horizon boundary
You can view it as Quantum mechanics allowing the speed of one of the particle pairs to exceed the speed of light and therefore escape
Some Big Relativistic Rule seems to be violated here
Chimps said:I am not convinced by the mathematics of Hawking radiation. I believe it may be flawed.
Chimps said:I am not convinced by the mathematics of Hawking radiation. I believe it may be flawed.
a.ratnaparkhi said:How we can prove the existence of black holes?
And how they are located in in the space as they can absorb light too?
a.ratnaparkhi said:How we can prove the existence of black holes?
And how they are located in in the space as they can absorb light too?
nabeshin said:..But strictly speaking, a black hole is the mathematical solution to Einstein's Equations corresponding to a delta-function mass distribution.
A black hole is a region of space with a gravitational pull so strong that nothing, including light, can escape from it. It is formed when a massive star dies and collapses in on itself.
Scientists use a variety of methods to prove the existence of black holes. One way is by studying the effects of their strong gravitational pull on nearby objects, such as stars or gas clouds. Another way is by observing the intense radiation emitted from the edge of a black hole, known as the event horizon.
Black holes are located in space through a few different methods. One way is by using telescopes to observe the effects of their gravity on nearby objects. Another method is by detecting the X-rays emitted from the accretion disks (a disk of hot gas and dust) around black holes. Scientists can also use gravitational lensing, where the gravity of a black hole bends and magnifies light from objects behind it, to locate black holes in space.
As of now, it is not possible for humans to travel to a black hole due to the immense gravitational forces and extreme conditions. However, scientists are studying ways to potentially send spacecrafts to study black holes from a safe distance.
Yes, there are three main types of black holes: stellar black holes, intermediate-mass black holes, and supermassive black holes. Stellar black holes are formed from the collapse of a single massive star, while intermediate-mass black holes are believed to form from the merging of smaller black holes. Supermassive black holes are found at the center of galaxies and are significantly larger than other types of black holes.