What is a white hole? opposite of black hole ?

Question

Black holes, white holes, worm holes

Answer 1

In astrophysics, a white hole is a postulated celestial body that is the time reversal of a black hole. While a black hole acts as a point mass that attracts and absorbs any nearby matter, a white hole acts as a point mass that repels or even (perhaps) ejects matter.

White holes appear as part of the vacuum solution to the Einstein field equations describing a Schwarzschild wormhole. One end of this type of wormhole is a black hole, drawing in matter, and the other is a white hole, emitting matter. While this gives the impression that black holes in this universe may connect to white holes elsewhere, this turns out not to be the case for two reasons. First, Schwarzschild wormholes are unstable, disconnecting as soon as they form. Second, Schwarzschild wormholes are only a solution to the Einstein field equations in vacuum (when no matter interacts with the hole). Real black holes are formed by the collapse of stars. When the infalling stellar matter is added to a diagram of a black hole's history, it removes the part of the diagram corresponding to the white hole [1].

The existence of white holes that are not part of a wormhole is doubtful, as they appear to violate the second law of thermodynamics.

Quasars and active galactic nuclei are observed to spew out jets of matter. This is now believed to be the result of polar jets formed when matter falls into supermassive black holes at the centers of these objects. Prior to this model, white holes emitting matter were one possible explanation proposed.
A black hole is a concentration of mass whose gravitational field is so strong that nothing can escape. Black holes are predicted by general relativity. Under the description provided by general relativity, as an object moves closer to a black hole, the energy required for it to escape continues to increase until it becomes infinite at the event horizon, the surface beyond which escape is impossible. Inside the event horizon, the geometry of spacetime is distorted in a way that makes moving closer to the central singularity inevitable no matter how the infalling object moves.

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 been hypothesised that black holes radiate energy due to quantum mechanical effects known as Hawking radiation.
physics, a wormhole (also known as Abbreviated Space) is a hypothetical topological feature of spacetime that is essentially a "shortcut" or "abbreviation" through space and time. A wormhole has at least two mouths which are connected to a single throat. If the wormhole is traversable, matter can 'travel' from one mouth to the other by passing through the throat.

The name "wormhole" comes from an analogy used to explain the phenomenon. If a worm is travelling over the skin of an apple, then the worm could take a shortcut to the opposite side of the apple's skin by burrowing through its center, rather than travelling the entire distance around, just as a wormhole traveller could take a shortcut to the opposite side of the universe through a hole in higher-dimensional space.

Answer 2

A so-called "white hole" is purely theoretical and not supported by any evidence that they actually exist, nor by any law of physics. The concept, though, is that a white hole would be the other side of a black hole, sort of like a drain for all the stuff sucked into a black hole.

Answer 3

The white hole is an hypothetical concept in physics. It is presumed to be the other side of black hole through which all the things drained into the black hole are flushed out.

Answer 4

a new type of hole :D