How do we detect black hole if even light can not come out and how can we dertermine its shape?

Answer 1

a "black hole" still has a gravitational signature, and it also emits some xrays or cosmic rays

a black hole is spherical, just like a planet or a star. it is not a hole, like the name suggests, it is a spherical body, just like a star, but much more dense

Answer 2

Black holes and neutron stars don’t give off light, so we can’t just look for them. However, astronomers can find black holes and neutron stars by observing the gravitational effects on other objects nearby.

Astronomers can discover some black holes and neutron stars because they are sources of x-rays. The intense gravity from a black hole or a neutron star will pull in dust particles from a surrounding cloud of dust or a nearby star. As the particles speed up and heat up, they emit x-rays. So the x-rays don’t come directly from the black hole or neutron star, but from its effect on the dust around it. Although x-rays don’t penetrate our atmosphere, astronomers use satellites to observe x-ray sources in the sky.

Many stars rotate around each other, much as the planets orbit our Sun. When astronomers see a star circling around something, but they cannot see what that something is, they suspect a black hole or a neutron star.

Astronomers use a technique called gravity lensing to search for black holes and neutron stars. When a very massive object passes between a star and the earth, the object acts like a lens and focuses light rays from the star on the Earth. This causes the star to brighten.

Answer 3

In theory, no object within the event horizon of a black hole can ever escape, including light. However, black holes can be inductively detected from observation of phenomena near them, such as gravitational lensing, galactic jets, and stars that appear to be in orbit around space where there is no visible matter.

The most conspicuous effects are believed to come from matter accreting onto a black hole, which is predicted to collect into an extremely hot and fast-spinning accretion disk. The internal viscosity of the disk causes it to become extremely hot, and emit large amounts of X-ray and ultraviolet radiation. This process is extremely efficient and can convert about 10% of the rest mass energy of an object into radiation, as opposed to nuclear fusion which can only convert a few percent of the mass to energy. Other observed effects are narrow jets of particles at relativistic speeds heading along the disk's axis.

However, accretion disks, jets, and orbiting objects are found not only around black holes, but also around other objects such as neutron stars and white dwarfs; and the dynamics of bodies near these non-black hole attractors is largely similar to that of bodies around black holes. It is currently a very complex and active field of research involving magnetic fields and plasma physics to disentangle what is going on. Hence, for the most part, observations of accretion disks and orbital motions merely indicate that there is a compact object of a certain mass, and says very little about the nature of that object. The identification of an object as a black hole requires the further assumption that no other object (or bound system of objects) could be so massive and compact. Most astrophysicists accept that this is the case, since according to general relativity, any concentration of matter of sufficient density must necessarily collapse into a black hole.

One important observable difference between black holes and other compact massive objects is that any infalling matter will eventually collide with the latter at relativistic speeds, leading to emission as the kinetic energy of the matter is thermalized. In addition thermonuclear "burning" may occur on the surface as material builds up. These processes produce irregular intense flares of X-rays and other hard radiation. Thus the lack of such flare-ups around a compact concentration of mass is taken as evidence that the object is a black hole, with no surface onto which matter can collect.

Answer 4

The existence of black holes in the universe is well supported by astronomical observation, particularly from studying X-ray emission from X-ray binaries and active galactic nuclei. It has also been hypothesized that black holes radiate energy due to quantum mechanical effects known as Hawking radiation.

Answer 5

We detect black hole by analysing the activities of matter surrounding it,if the matter tends to fall in and is revolving than it is a black hole,

In primordial and heavier black holes one more significant feature arrives that is streams of matter from 2 opposite sides.

Answer 6

Matter spiralling into a black hole emits thermal radiation - very hot light, in the x-ray spectrum. This light is emitted by the matter falling in, not the black hole itself, but we can see the results.

Answer 7

Black hole are detected looking light-ray's deviation caused to great attraction power exercited.

Answer 8

A black hollow is considered a "darkish remember" merchandise. you could not see it because of the fact that is darkish; using a telescope to look straight away on the black hollow, in spite of in case you knew precisely the place to look, does not show you how to work out something. observing its effects is the only thank you to be attentive to that a black hollow exists interior of reach.

Answer 9

So far no one has come up with any proof that black holes exist!

Answer 10

please visit nasa's website for correct information.

i recently saw an video about this.

though we cant see still we can know it by careful study of its presence and effect - when it engulfing a object or pulling that object towards it.