wat is blackhole?

Question

the mass

Answer 1

There are many popular myths concerning black holes, many of them perpetuated by Hollywood. Television and movies have portrayed them as time-traveling tunnels to another dimension, cosmic vacuum cleaners sucking up everything in sight, and so on. It can be said that black holes are really just the evolutionary end point of massive stars. But somehow, this simple explanation makes them no easier to understand or less mysterious.
NOTE: This section is about what are called "stellar-mass black holes". For information about black holes with the mass of billions of Suns, see Active Galaxies & Quasars .


Black Holes: What Are They?
Black holes are the evolutionary endpoints of stars at least 10 to 15 times as massive as the Sun. If a star that massive or larger undergoes a supernova explosion, it may leave behind a fairly massive burned out stellar remnant. With no outward forces to oppose gravitational forces, the remnant will collapse in on itself. The star eventually collapses to the point of zero volume and infinite density, creating what is known as a " singularity ". As the density increases, the path of light rays emitted from the star are bent and eventually wrapped irrevocably around the star. Any emitted photons are trapped into an orbit by the intense gravitational field; they will never leave it. Because no light escapes after the star reaches this infinite density, it is called a black hole.
But contrary to popular myth, a black hole is not a cosmic vacuum cleaner. If our Sun was suddenly replaced with a black hole of the same mass, the earth's orbit around the sun would be unchanged. (Of course the Earth's temperature would change, and there would be no solar wind or solar magnetic storms affecting us.) To be "sucked" into a black hole, one has to cross inside the Schwarzschild radius. At this radius, the escape speed is equal to the speed of light, and once light passes through, even it cannot escape.

The Schwarzschild radius can be calculated using the equation for escape speed.


vesc = (2GM/R)1/2

For photons, or objects with no mass, we can substitute c (the speed of light) for Vesc and find the Schwarzschild radius, R, to be

R = 2GM/c2
If the sun was replaced with a black hole that had the same mass as the sun, the Schwarzschild radius would be 3 km (compared to the sun's radius of nearly 700,000 km). Hence the Earth would have to get very close to get sucked into a black hole at the center of our solar system.

Answer 2

A black hole is an extremely dense matter created when an extremely dense star collapses under its own huge gravity. The gravity of a blackhole approaches infinity. Nothing can escape the gravitational field of a blackhole, not even light. A blackhole cannot be identified and nothing can be known except its gravitational field. As it cannot be seen , the distance cannot be known and the mass of blackhole cannot be known even if the gravitational force is known.

Answer 3

If not to take the word "blackhole" literally, I would say that in physical science this may be meant as the mysterious place where a matter neither can exist and nor it occupies any space but the blackhole still makes a physical sense which is out of our normal perception on matter, energy and space.

Answer 4

Black holes are the evolutionary endpoints of stars at least 10 to 15 times as massive as the Sun. If a star that massive or larger undergoes a supernova explosion, it may leave behind a fairly massive burned out stellar remnant. With no outward forces to oppose gravitational forces, the remnant will collapse in on itself. The star eventually collapses to the point of zero volume and infinite density, creating what is known as a " singularity ". As the density increases, the path of light rays emitted from the star are bent and eventually wrapped irrevocably around the star. Any emitted photons are trapped into an orbit by the intense gravitational field; they will never leave it. Because no light escapes after the star reaches this infinite density, it is called a black hole.

Answer 5

Any material it has attracting force on things surrounding it. This attracting force is depending on the density or specific gravity of the matter. For example a stone thrown in the air is attracted by the earth's gravitational force. At the same time, the same stone also attracts the earth. Here, the gravitiation force by the earth is greater than that of the stone. So the stone falls on the earth. The specific gravity of water is one. That means, 1 ml or 1 cc of water weighs 1 gm. Thus the weight/volume is one. Some heavy metals are with specific gravity of more than 5. That means 1 cc of that metal will weigh more than 5 gm. The more the specific gravity, the more the attraction power. In nature, there are certain materials are existing in the universe with very very high specific gravity. Some times their specific gravity may be more than 10000000000000000000000000 g/cc. I can explain in other way. What will be weight of an apple? It may be 200-250 gm. Take apple sized stone. What will be weight of this stone? It may be 1 to 1.5 kg. Take apple sized iron ball. What will be its weight? Say 2-3 kg. Suppose, you imagine the weight of the same apple sized iron ball as 10000000000000000000000000 kg. In reality, this is not possible in this world. But such type of materials are existing in the universe. Such type of materials may possess very very high attracting power. This type of materials can attract even light also. That means, even light can not escape from this materials. Thus no light will be visible in and aroung this materials in the univers. This is simply a dark hole. This is called BLACK HOLE.

Answer 6

A black hole is a concentration of mass great enough that the force of gravity prevents anything past its event horizon from escaping it except through quantum tunnelling behaviour (known as Hawking Radiation). The gravitational field is so strong that the escape velocity past its event horizon exceeds the speed of light. This implies that nothing, not even light, inside the event horizon can escape its gravity. It is, however, theorized that wormholes can provide an exit path for energy or matter. The term "black hole" is widespread, even though it does not refer to a hole in the usual sense, but rather a region of space from which nothing can return.

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

Answer 7

A black hole is a concentration of mass great enough that the force of gravity prevents anything past its event horizon from escaping it except through quantum tunnelling behaviour (known as Hawking Radiation). The gravitational field is so strong that the escape velocity past its event horizon exceeds the speed of light. This implies that nothing, not even light, inside the event horizon can escape its gravity. It is, however, theorized that wormholes can provide an exit path for energy or matter. The term "black hole" is widespread, even though it does not refer to a hole in the usual sense, but rather a region of space from which nothing can return.

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.

Answer 8

"An object whose gravitational pull inside a certain radius is so strong that nothing, not even light can escape it. A black hole forms when the amount of matter in the core of a star undergoing a supernova is great enough to cause a runaway gravitational collapse."

Answer 9

Black holes are the places where stars used to exist.They were once occupied by a star.Due to the death of the star extremely dence matter is created there.As a result all object that pass by it are sucked by it.

It is said that even light cannot pass through a black hole.It is that powerful.

Some scientists claim that just 1cm cube of material from the black hole could weigh tonnes.

Bye Bye

Answer 10

i cant wait till eventually your questions are up for the day. I dont understand how you heard about the LHC yet I choose you've been smarter. the first attempt to bypass a beam by skill of the total LHC is scheduled for September 10, 2008,[9] and the first intense-power collisions are planned to ensue after the LHC is formally unveiled, on October 21, 2008.[10] so that you've till eventually october. so relax some my bruthuh.