what is black hole in space and how it generates? can we see inside it?

Answer 1

Any mass contained in a radius smaller than its schwarzschild radius, is a black hole. It does not have to form via the collapse of a star, though this is one astrophysical process that can do it.

r_s = (2GM/c^2) with

c= the speed of light, G = the gravitational constant and M is the mass of the object.

The schwarzschild radius scales linearally with mass (an object twice as massive will have twice the schwarzschild radius) and to get you started, an object the mass of the sun (2x10^30kg) has a Schwarzschild radius of 3 km. In otherwords, if you jammed the sun into a sphere 6km across, it would be a black hole. The schwarzschild radius indicates a volume of space where the escape velocity from the mass in question is the speed of light or greater. Using the linear scaling, an object the mass of the earth (6(?)x10^24 kg would have a schwarzschild radius of about 1/300,000 of 3km, or 1 cm.

It is called a black hole because no light that crosses the schwarzschild radius can completely escape the mass to an infinite distance. (This does mean that if you are just outside the schwarzschild radius yourself, you CAN see light that is emitted from within it, or passes within it as long as it is not too close; only an observer at d= infinity cannot.) Thus this volume of space appears "black." You can read more about black holes on wikipedia at http://en.wikipedia.org/wiki/black_hole....

The Schwarzschild radius is typically defined for an observer at infinite distance, however the event horizon (or Schwarzschild surface) corresponds to the Schwarzschild radius as seen at any distance. As an observer approaches the singularity, the event horizon contracts as seen from that observer's frame of reference.

This page illustrates this effect nicely.
http://casa.colorado.edu/~ajsh/approach.html#schwarzschild.surface

Answer 2

If the mass of any object of the space is very large then it will have too much of gravity. And thus, it's gravity makes the object compact and smaller in size, and this process continues. At one stage, it becomes black hole if the process doesn't stop. (The stopping of process depends upon the mass of the object because if the object is not very large then it doesn't have that much gravitational force that can make the object smaller) And thus its continues contraction in size due to gravitation leads to generation of the black hole. We cannot see inside it because it has one point called - "Singularity", where there exist no any kind of atomic (and molecular) movement. And thus there can not exist any kind of "reflection" of light, which makes us "see" the object. Time is stopped in that "singularity" point. Even light also cannot pass through it, with its hyper speed of 299792.458 km/sec.
Although scientist are still researching about Black holes. The most famous and popular topic regarding the black holes is "Time Travel" where any person performs a time-travel and reaches in either future or past. But it needs lot of research and development.

Answer 3

A black hole is an object predicted by general relativity with a gravitational field so strong that nothing can escape it — not even light. A black hole is defined to be a region of space-time where escape to the outside universe is impossible. The boundary of this region is a surface called the event horizon. This surface is not a physically tangible one, but merely a figurative concept of an imaginary boundary. Nothing can move from inside the event horizon to the outside, even briefly. 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.

General relativity (as well as most other metric theories of gravity) not only says that black holes can exist, but in fact predicts that they will be formed in nature whenever a sufficient amount of mass gets packed in a given region of space, through a process called gravitational collapse; as the mass inside the given region of space increases, its gravity becomes stronger and (in the language of relativity) increasingly deforms the space around it, ultimately until nothing (not even light) can escape the gravity; at this point an event horizon is formed, and matter and energy must inevitably collapse to a density beyond the limits of known physics. For example, if the Sun was compressed to a radius of roughly three kilometers (about 1/232,000 its present size), the resulting gravitational field would create an event horizon around it, and thus a black hole.

Answer 4

A black Hole is a object which has a huge hole travelling in the space It has the capacity of swallowing a Space Ship I heard of that a black Hole has swallowed a Big Russian Space Ship its not a tourist spot.

Answer 5

A black hole is a collapsing star with the gravity of thousends of our sun the gravity is so strong not even light can escape and no we can't see inside because it is called a 'black' hole so it's dark and there are some theories that say if you go inside a black hole you might go into different place or dimention so no you can't because everything inside must have been teleported

Answer 6

According to current astrophysics, a black hole is a void in space caused by the collapsing of a star. The gravity well created by it is so massive that not even light can escape from it, so even if we could probe it, we wouldn't get any data back from it.

Answer 7

The Most Distant Black Hole


Artist impression of a quasar with a black hole in a brown and yellow disk of gas and dust, which swirls as it is drawn in by the gravitational pull of the black hole, creating friction, heating the gas, and making it shine. Credit: NASA Education and Public Outreach at Sonoma State University - Aurore Simonnet


The black hole farthest away from Earth is at the heart of a quasar known to astronomers as SDSS J1148+5251.

The huge black hole is 13 billion lightyears away from Earth at the centre of the quasar. That distance places it near the very edge of the known Universe. lightyears

Quasars are extraordinarily luminous objects. Astronomers think they may be humongous galaxies containing gigantic black holes. SDSS J1148+5251 is such a quasar, which happens to have the most distant black hole at its core.

How much does it weigh? Astronomers have been trying to figure out the mass, or weight, of the black hole inside SDSS J1148+5251. They calculate that it is equal to three billion of our Suns.

The astronomers believe it weighs one quadrillion times the mass of Earth. One quadrillion can be expressed as a one with 15 zeros. That is 1,000,000,000,000,000.

In smaller units of measure, it weighs some 6x1039 kilograms, which could be written out as a 6 followed by 39 zeroes. That would be more than 13x1039 lbs. Now that's big!

QUASARS ARE...


Very bright, very distant objects that are seen frequently when we look back at the early Universe


Radiators of a huge amount of energy, up to 10,000 times the energy emitted by our entire Milky Way galaxy


One of the many kinds of active galaxies now visible to observers on Earth

Surprisingly early. Typical black holes are a few billion times the mass of our Sun, so the mass of SDSS J1148+5251 is not unusual. However, the astronomers found it interesting that such a big structure was able to form so early in the history of the Universe. The finding suggests that huge black holes existed when the Universe was only six percent of its current age, which may be 13-15 billion years.

While the black hole formed eight billion years before the Earth, it appears to be as massive as most black holes known anywhere in the Universe, including those formed much more recently. That surprised astronomers.

A team of astronomers from the United Kingdom and Canada used the United Kingdom Infrared Telescope (UKIRT) atop Mauna Kea in Hawaii to compute the mass of the SDSS J1148+5251 black hole by comparing its infrared light spectrum with closer quasars.

The telescope. The 3.8-metre UKIRT is the largest infrared astronomy telescope. It is near the summit of Mauna Kea at an altitude of 13,759 feet above sea level. The telescope is operated by the Joint Astronomy Centre in Hilo, Hawaii, on behalf of the UK Particle Physics and Astronomy Research Council (PPARC).

UKIRT's Imaging Spectrometer (UIST) — designed at the UK Astronomy Technology Centre (UK ATC) in Edinburgh, Scotland — detects infrared light at wavelengths between 1 and 5 microns with a 1024 x 1024 pixel Indium Antimonide detector array. It can be used for imaging, spectroscopy, integral field spectroscopy, and polarimetry.

The astronomy team used UIST to look at near-infrared light from the quasar SDSS J1148+5251. The expansion of the Universe since that light left the quasar had caused its wavelength to increase, which left little optical light to be seen.

To learn more:
What is a quasar?
Where are we in the Universe?
What is in a black hole?
What is a lightyear?


Joint Astronomy Centre
Joint Astronomy Centre public outreach site
Joint Astronomy Centre press release
Article abstract Astrophysical Journal, 587:L15-L18, 2003 April 10
American Astronomical Society
The Astrophysical Journal Letters at Harvard
The Astrophysical Journal Letters University of Chicago publisher
Oxford Astrophysics
Durham Physics