Does there really exist something like white hole(opp. of black hole) ?

Science Channel You've probably heard of black holes, but what about a white hole? This hypothetical cosmic body acts in the exact opposite manner of a black hole. Instead of pulling in matter, a white hole expels it like a sort of cosmic exhaust valve, giving off serious amounts of energy. Some cosmologists theorize that a black hole in one universe might empty out through a white hole in another universe. In these theories, the black hole acts as a kind of tunnel -- instead of pulling in matter that collapses into a single point, the black hole shuttles the matter right through the tunnel and out the white hole on the other end [source: Than]. In other words, the matter that comes out of a white hole is the matter that fell into a black hole.

While some scientists do believe that white holes are theoretically possible, they've never actually been observed, so most believe that don't exist [source: NASA]. At one time, some scientists thought that quasars might actually be white holes, but in the end, they concluded that quasars are actually powered by very large black holes [source: Ptak].

Some scientists believe that a gamma ray burst that took place in 2006 might actually have been a white hole due to its unusual fierceness and long duration, but other explanations for this particular cosmological event are more likely [source: Wilkins]. Overall, white holes are still just a hypothetical concept, and they're a controversial subject in the scientific community.

You've heard of black holes: those rips in spacetime that suck up matter into oblivion. Now scientists are proposing that we've seen evidence for the opposite of black holes, or white holes, which spew out matter into our universe instead.

Our universe is a weird weird place, and black holes are some of the weirdest things around. But mathematically, a black hole should be able to be reversed, making something that spews matter out instead of swallowing it. These "white holes" would operate differently than black holes do; they'd spontaneously pop into existence for an infinitely small amount of time and barf out a bunch of crap expel a large amount of matter before collapsing in on themselves to form black holes, never to be seen again.

This sort of behavior is understandably tricky to observe, but scientists think that they may actually have spotted one. Back in 2005, a gamma ray burst was measured that didn't come along with the supernova that's typically associated with gamma ray bursts, and it's possible that the burst was instead caused by the collapse of a white hole.

What's especially interesting about white holes is that their spontaneous creation of matter is analogous to the Big Bang, to the point where they're also being referred to as "Small Bangs." They wouldn't have any fixed spacetime coordinates and wouldn't be detectable at all, but they could instantly appear literally anywhere, anytime and do their thing before collapsing again. There could even be one behind you right now.

So far this is all just conjecture, but the same was true about black holes up until just the last few decades. And as physicist Murray Gell-Mann famously said, "everything not forbidden is compulsory," so at least from a quantum mechanical perspective, white holes must definitely be out there.

Do white holes exist? Answer: Thank you for your interesting question about black holes. As you mentioned in your question, the gravitational pull of a black hole is so strong that anything that gets too close to it cannot escape. The "event horizon" is the closest you can get to the black hole and still escape (but it gets much more difficult to escape as you get close to the event horizon). If you get to the horizon or cross it you can't escape -- even if you travel at the speed of light (and that's the highest speed possible). Since nothing can escape from the event horizon we can never see what is going on inside -- a form of "cosmic censorship". If you were unlucky enough to fall into a very big black hole you might drift past the event horizon without too much trouble (although it would be impossible to go back), and you'd find yourself falling towards the "singularity" at the center. As you get closer to the singularity the strong gravity would try to stretch you out like spaghetti, and when you reached the singularity you'd be squashed. Unfortunately the laws of physics as we know them don't work at the singularity (when everything gets squashed to a point). There is a lot of ongoing research to figure out a new theory of gravity that explains what happens at the singularity. Things may not be so bad, however, if the black hole is spinning. There is a theory that a spinning black hole may have an "Einstein-Rosen" bridge at the center (a bit like a tunnel) that leads from the center of a black hole to the center of a "white hole" in another universe. So, with a very strong spaceship you might be able to enter a black hole here and emerge from a white hole in another universe. A "white hole" is the opposite of a black hole, and has no "event horizon" so you would be able to see the singularity at the center -- and we'd be able to view something that our physics theories cannot explain. If they do exist, white holes should be easy to detect, but they have never been seen. Most physicists think what white holes do not exist, and that something falling into a black hole gets squashed at the singularity and the black hole grows a little larger.

Like black holes, white holes have properties like mass, charge, and angular momentum. They attract matter like any other mass, but objects falling towards a white hole would never actually reach the white hole's event horizon (though in the case of the maximally extended Schwarzschild solution, discussed below, the white hole event horizon in the past becomes a black hole event horizon in the future, so any object falling towards it will eventually reach the black hole horizon).

In quantum mechanics, the black hole emits Hawking radiation, and so can come to thermal equilibrium with a gas of radiation. Since a thermal equilibrium state is time reversal invariant, Stephen Hawking argued that the time reverse of a black hole in thermal equilibrium is again a black hole in thermal equilibrium. This implies that black holes and white holes are the same object[I DO NOT KNOW how?]. The Hawking radiation from an ordinary black hole is then identified with the white hole emission. Hawking's semi-classical argument is reproduced in a quantum mechanical AdS/CFT treatment, where a black hole in anti-de Sitter space is described by a thermal gas in a gauge theory, whose time reversal is the same as itself.

White holes are predicted as part of a solution to the Einstein field equations known as the maximally extended version of the Schwarzschild metric[clarification IS needed FOR ME AND FOR EVERYONE ] describing an eternal black hole with no charge and no rotation. Here, "maximally extended" refers to the idea that the spacetime should not have any "edges": for any possible trajectory of a free-falling particle (following a geodesic) in the spacetime, it should be possible to continue this path arbitrarily far into the particle's future, unless the trajectory hits a gravitational singularity like the one at the center of the black hole's interior. In order to satisfy this requirement, it turns out that in addition to the black hole interior region which particles enter when they fall through the event horizon from the outside, there must be a separate white hole interior region which allows us to extrapolate the trajectories of particles which an outside observer sees rising up away from the event horizon. For an observer outside using Schwarzschild coordinates, infalling particles take an infinite time to reach the black hole horizon infinitely far in the future, while outgoing particles which pass the observer have been traveling outward for an infinite time since crossing the white hole horizon infinitely far in the past (however, the particles or other objects experience only a finite proper time between crossing the horizon and passing the outside observer). The black hole/white hole appears "eternal" from the perspective of an outside observer, in the sense that particles traveling outward from the white hole interior region can pass the observer at any time, and particles traveling inward which will eventually reach the black hole interior region can also pass the observer at any time.

Recent speculations:::::::::::::::::::

A more recently proposed view of black holes might be interpreted as shedding some light on the nature of classical white holes. Some researchers have proposed that when a black hole forms, a big bang may occur at the core, which would create a new universe that expands outside of the parent universe.[8][9][10] See also Fecund universes. The Einstein–Cartan–Sciama–Kibble theory of gravity extends general relativity by removing a constraint of the symmetry of the affine connection and regarding its antisymmetric part, the torsion tensor, as a dynamical variable. Torsion naturally accounts for the quantum-mechanical, intrinsic angular momentum (spin) of matter. According to general relativity, the gravitational collapse of a sufficiently compact mass forms a singular black hole. In the Einstein–Cartan theory, however, the minimal coupling between torsion and Dirac spinors generates a repulsive spin–spin interaction which is significant in fermionic matter at extremely high densities. Such an interaction prevents the formation of a gravitational singularity. Instead, the collapsing matter on the other side of the event horizon reaches an enormous but finite density and rebounds, forming a regular Einstein–Rosen bridge.The other side of the bridge becomes a new, growing baby universe. For observers in the baby universe, the parent universe appears as the only white hole. Accordingly, the observable universe is the Einstein–Rosen interior of a black hole existing as one of possibly many inside a larger universe. The Big Bang was a nonsingular Big Bounce at which the observable universe had a finite, minimum scale factor. A recent paper argues that the Big Bang itself is a white hole. It further suggests that the emergence of a white hole, which was named a 'Small Bang', is spontaneous - all the matter is ejected at a single pulse. Thus, unlike black holes, white holes cannot be continuously observed rather their effect can only be detected around the event itself. The paper even proposed identifying a new group of γ-ray bursts with white holes.

White holes are the opposite of black holes, objects into which nothing can enter but are constantly spewing out matter. They were thought to be completely hypothetical, more a mathematical oddity than a real thing...but we may have seen one.

We've talked about white holes before in some detail here and here, but the basic idea behind them is that the laws of physics aren't comfortable with things that happen in only one direction. In other words, if black holes exist, then it should be possible to reverse the equations governing them so that you get something that's reversed but otherwise identical. That's what a white hole is.

Of course, just because something can happen going both forwards and backwards in time doesn't mean that, in practice, we'll actually observe both of those phenomena. (The fact that entropy only increases when the laws of physics say it could just as easily decrease is a famous example of this, but we'll leave a discussion of that for another day.) At its most basic, white holes simply wouldn't be as stable as black holes are, and it seems that they would collapse almost immediately under the weight of its own gravity.

Here's where things get interesting. A gamma ray burst back in 2006 didn't fit with our understanding of where they come from - its long duration (102 seconds) meant that it had to be created in a supernova explosion, and yet there were no supernovas there for it to have come from. Its discoverers actually said that "this is brand new territory; we have no theories to guide us."

Now, five years later, it's being suggested that we might actually have caught sight of a white hole. The fierceness and duration of the explosion could well fit with a white hole briefly popping into existence, spewing out some matter, and then quickly collapsing into itself, resulting in this massive explosion. Although it's not the most likely explanation - after all, it invokes something that many astronomers have concluded is exceedingly unlikely, verging on impossible - it can't be immediately discounted.

The trouble is that we've found out all we're going to from this particular burst, so all we can do now is wait for another of these strange hybrid bursts and see how it behaves. If these hybrid bursts really are white holes, then the universe is about to get a lot stranger. HELLO I AM REFERRING SOME OTHER DISCUSSION FORUM OR WEBSITE......:))

HERE IS DIFFERENCE:::::::::::

A black hole is an astrophysical object that is so dense that it sucks everything, including light, into itself. According to general relativity, a white hole is the "opposite" of a black hole; i.e. instead of sucking everything into it from its event horizon, it pushes everything away, not allowing anything to enter it.

Before we start talking about the theoretically speculated white holes, we need to describe the nearly unarguably real astrophysical objects known as black holes. How do we know that black holes exist? Well, we have two sources of evidence supporting this claim.

Firstly, we have data collected from the images of telescopes that is basically inexplicable unless black holes exist. Through the analysis of these images, we have observed objects that are in an orbit around something both dark and extremely massive. These massively dark objects seem to be very small in size relative to other objects of similar or greater mass that we can observe. Based on the solutions to Kepler's equations of planetary motion for the objects orbiting these dark, massive objects, they can only be black holes if we are to assume that general relativity is correct.

Secondly, we have a very good, well-tested theory of gravity that predicts the existence of such objects in the universe.

So, where do white holes come in?

Well, our theory of gravity, better known as Einstein's theory of general relativity, predicts the existence of black holes, because they are a particular solution to a set of equations known as the Einstein field equations. Exact solutions to these equations can be positive and negative. This is not unusual; indeed we see this sort of thing all the time in mathematics. For example, the solutions to y2 = 9 are y = 3 and y = -3.

Depending on your choice of sign for a particular solution to the Einstein field equations, you can get a black hole, which grows by sucking in matter from far away, or you can get the "opposite," a white hole, which is like a black hole running backwards in time.

So, what would a white hole look like? Well, if you somehow had a camera that could record a black hole sucking in matter, and then you played the recording in reverse, you'd see a white hole. You'd see matter being blown away from the white hole's event horizon, and the hole would gradually decrease in size as it spat this matter out. We're pretty certain that black holes are real, but does that mean that white holes real too?

Well, just because an equation that mathematically describes the universe has a negative solution as well as a positive one, doesn't necessarily mean that both of those solutions can describe actual events. For example, if I tell you that the square of the number of baseball tickets that I have is 9, then, mathematically, I could have either 3 tickets or -3 tickets. However, -3 baseball tickets doesn't make any physical sense; there's no such thing. Additionally, there are plenty of examples of equations in dynamics where there are both positive and negative solutions with respect to time, but only one can describe the real world. This is because that, as we can see just by looking around us, time moves in one direction; time never reverses itself.

The white hole solution to Einstein's field equations is one of these types of solutions that doesn't apply to the real world. It's like having -3 baseball tickets; it just doesn't happen.

Probably white holes, as the opposite of black holes, do not exist. The reason is an unsurpassable singularity from the black hole to the white hole region. The reason why people believed in white holes was because the complete extended solution to the black hole space time was unknown. There was a time when physicist believed that AGN were actually white holes instead of supermassive BHs. I said probably, because this are all theoretical models that, although have supporting evidence, are still speculative. So, in GR there is nothing today that we can call a white hole. Wormholes are not white holes, and are hypothetical objects that violate the strong energy principle in GR. I have learned not to say that something doesn't exist because the accepted theories say so. Maybe white holes do exist in quantum gravity, because this theory may eliminate singularities. At present we don't know. If they do exists, in some theory not yet realized, their collision and or creation with respect to BHs will be a very interesting problem.

No,Hawking did not prove a white hole and a black hole are one of the same nor could he or anybody ever do . We can only prove the existence of what we can make actual observations of, but i will give a challenge to who is willing to accept, a gravitational field in of space-time itself nothing! escapes a black hole if anybody believes the universe is finite then explain me why it is expanding rather than contracting.?

As I can only think of very complicated scenarios which none of which make much sense. But i don't believe the universe to be finite, the universe is full of weird contradiction even at the most fundamental level this is why many scientists are beginning to think the universe is holographic. If that being the case we can't really say what created the projector because our brains cannot outgrow the confines of the computers program. But i personally don't believe this scenario even though its much more logical than a fairy waving a wound and saying let there be light.

Another amateur answer: the energy of a White Hole is convex and the energy of a Black Hole is concave, so they cannot approach each other. Two black holes can approach one another; two white holes can approach one another. But white holes and black holes are kept apart magically, in much the same ways that matter and antimatter are kept apart.

The White Hole and the Black Hole are the same, just at different stages of their life -- the White Hole is the Expansive Stage; the Black Hole is the Recessive or Withdrawn Stage. White Holes become Black Holes become White Holes become Black Holes over and over again during their life cycle.

A Black Hole in one dimension is effectively a White Hole in an Opposite Dimension. A Black Hole in this dimension is effectively building an anti-Universe in an Opposite Dimension.

Technically you would say that a black hole is a causal region which is not in the past of any point in the external universe. Similarly a white hole must be causally before any point in the external universe. That is a perfect description of the Big Bang. Mathematically a singularity exists inside a black hole, where matter becomes infinitely compressed. I don't believe there is more than one singularity in the universe, however. All black holes are from our viewpoint frozen portions of time and space, and the singularity within all of them is only going to "occur" - in a sense - at the end of the universe. Therefore a black hole could never meet a white hole, except in one sense: as both the singularity at the beginning and end of the universe are both "beyond time" they may well be the same singularity, it would certainly resolve the question of where everything came from! So black holes and the Big Bang are two sides of one coin. In another sense you can't collide them, they are eternally linked to each other.

A black hole pretty much is the same as a white hole.

Hawking's result proves they're essentially the same object, so the result will be a black hole with a radius larger than the sum of the radius of the black hole and the "white hole".

I'm just an undergraduate so possibly one of the other members can give a more detailed answer.

edit: I implied but did not directly say that due to a white hole being the same as a black hole your question becomes "what is the result of the collision between two black holes" so the answer is what I said above. I put white hole in quotations because it's really just another (possibly smaller or larger) black hole.

Black holes and White holes: Do we really know anything?

We’ve all heard of black holes. That mysterious object that is at the center of galaxies in which neither light nor matter can escape it. Black holes have even been found to rotate and roam around in space. Yikes! Hope one doesn’t roam into the Milky Way galaxy anywhere near Earth, or we will be toast.

Wikipedia defines a white hole as a hypothetical region of space-time which cannot be entered from the outside, but matter and light can escape. So a white hole is basically the opposite of a black hole. And to go farther, a black hole region represents time in the future, while a white hole region represents time in the past.

So, to me, that means that if someone (who has the capability of course) wants to travel in time to the future, they would have to be in the region of a white hole. So to go to the future, they would travel through the wormhole from the white hole end through to the black hole end which is in the future. Sounds cool to me. And the opposite if you want to travel in the past. Go from black hole through to the white hole, which is in the past. When do we start?

I’ve always been fascinated by time travel. Hence my love of Star Trek, The Time Machine, and Star Wars. I just know that time travel is possible. It must be! But only if time and space are actually spliced together as Einstein states. I’m still not convinced that time and space are tied together as one fabric. Hell, I don’t even know if time exists at all. It may well be just something that we use to be able to “measure” our existence. And that’s all there is to time. Nothing more.

But, lets say that time and space are one and we’re talking about space-time. Even though my favorite physicist, Stephen Hawking, argues that black holes and white holes are one in the same (that is one object), I believe that there are two distinct separate objects that we call black holes and white holes. And some describe a black hole as just a single point in space, with no “other” side. How can that be? Can you have something that has only one side?

But we do know that black holes exist. We’ve taken pictures of them, many of them. One is at the center of our very own Milky Way galaxy. Some are super massive, being hundreds of thousands of times larger than our own black hole. That’s really big. And we can’t even imagine how really big that is. Since scientists have been puzzled by the amount of energy coming from distant quasars and black holes in the center of galaxies, there seems to be more energy than can be accounted for. Where is it coming from?

Well, it is possible that black holes and white holes are probably connected, via wormhole. The black hole is in one universe, and that black hole is sucking matter and energy into it and spewing matter into the white hole that lies in another universe. Then matter is spewing into the other universe from the white hole. That’s the most probable scenario for all the huge amounts of extra energy being generated in our universe. There is a white hole that is spitting out energy and matter.

At the same time, our black holes are sucking up matter and transporting it to its connected white hole somewhere else. This process of give and take by both the black holes and white holes keeps the matter in balance, in all universes. Seems like a simple solution. And it sounds simple and plausible. Doesn’t it to you?

So I say we can travel time, and we can go through a black hole and come out the other end and vice-versa with a white hole. It would be so cool to be able to do that. I can’t wait for us to invent time travel. I know, I know. It won’t happen in my lifetime–but I can dream. Out scientists think they have it all figured out–but what do they really know? Nothing. Maybe a few pictures proves the existence of black holes–but come on. That’s all they know. They can’t fly up to a black hole and study it. We will never be able to do that. All they can do is speculate about a black hole. Until they go through one, they should shut up until then. Hate to be blunt, but it’s true.

But you know, black holes and white holes are NOT the only way to travel through time. Let’s say that time and space are actually separate. Independent of each other. Then what we think we know about them, being reverses of time, is all wrong. Then traveling through a black hole or white hole just puts us into another point in space, not time. But I’ll let that be for another post.

Scientists say that the laws of physics break down beyond the event horizon of a black hole or white hole. How do they know this? Again, speculation on their part.

They don’t know anything. Our laws of physics may break down and that should be a red flag right there. A red flag telling you that our laws of physics are so primitive and so young, that we really don’t know a whole lot of anything. But, hopefully one day we will. I just won’t get to see it. We’ll probably all be dead in 2012, and we’ll never learn how dumb we really are when it comes to the universe

white dwarf is the son of white hole :) lol

Did Aditya get his answer?? ;P

HELLO, I AM REFERRING WIKIPEDIA ......KEEP IN TOUCH...:))

A white hole, in general relativity, is a hypothetical region of spacetime which cannot be entered from the outside, but from which matter and light have the ability to escape. In this sense, it is the reverse of a black hole, which can be entered from the outside, but from which nothing, including light, has the ability to escape. White holes appear in the theory of eternal black holes. In addition to a black hole region in the future, such a solution of the Einstein field equations has a white hole region in its past. However, this region does not exist for black holes that have formed through gravitational collapse, nor are there any known physical processes through which a white hole could be formed.

Just as there are two separate interior regions of the maximally extended spacetime, there are also two separate exterior regions, sometimes called two different "universes", with the second universe allowing us to extrapolate some possible particle trajectories in the two interior regions. This means that the interior black-hole region can contain a mix of particles that fell in from either universe (and thus an observer who fell in from one universe might be able to see light that fell in from the other one), and likewise particles from the interior white-hole region can escape into either universe. All four regions can be seen in a spacetime diagram which uses Kruskal–Szekeres coordinates. see figure. In this spacetime, it is possible to come up with coordinate systems such that if you pick a hypersurface of constant time (a set of points that all have the same time coordinate, such that every point on the surface has a space-like separation, giving what is called a 'space-like surface') and draw an "embedding diagram" depicting the curvature of space at that time, the embedding diagram will look like a tube connecting the two exterior regions, known as an "Einstein-Rosen bridge" or Schwarzschild wormhole. Depending on where the space-like hypersurface is chosen, the Einstein-Rosen bridge can either connect two black hole event horizons in each universe (with points in the interior of the bridge being part of the black hole region of the spacetime), or two white hole event horizons in each universe (with points in the interior of the bridge being part of the white hole region). It is impossible to use the bridge to cross from one universe to the other, however, because it is impossible to enter a white hole event horizon from the outside, and anyone entering a black hole horizon from either universe will inevitably hit the black hole singularity.

I'd have to say no. (I'm no expert on the subject, so I'm just using logic here)

If a white hole hurls matter out, where did it come from? I think this is the most important question to ask. Even if the matter came from 'somewhere else', the excretion of such high volumes of matter would simply cause the excreted matter to implode on itself to form a black hole, which would then suck in all the matter this white hole can spew out, up until the black hole simply swallows the entire white hole.The ultimate 'energy drink'

In an entirely time symmetric situation, and assuming the universe does not contain any other fields besides the two B&W holes, the only way to determine what is the preferred time direction is by looking which of the two holes have the bigger entropy.

Each hole has an entropy proportional to the square of its mass. if Mbh≫Mwh, then we can consider the white hole a "temporary fluctuation" in a background of forward-oriented thermodynamic increase (using the convention that black-holes increase their entropy "forward" in time), in the case where Mbh≪Mwh is the other way around: The preferred thermodynamic arrow is backward and the black hole is a temporary fluctuation going forward.

In the case where Mbh≈Mwh there is no preferred thermodynamic time direction. If thermodynamic time is considered a flow, this would be a fixed point.

here is the link http://curiosity.discovery.com/question/white-hole

the links are:::::::::
http://www.astro.umd.edu/~miller/teaching/questions/blackholes.html

here is another link::::::::
http://en.wikipedia.org/wiki/White_hole

another link could be useful:::::::::: http://curious.astro.cornell.edu/question.php?number=108

another link:::::::: http://io9.com/5805202/mysterious-cosmic-explosion-might-be-first-ever-proof-of-white-holes

another link::::::::::::: http://wiki.answers.com/Q/Whatisthedifferencebetweenablackholeandawhite_hole

another link::::::::::::::: http://www.quora.com/Black-Holes/Is-there-an-opposite-of-a-Black-Hole-i-e-A-White-hole

i wanted to ask how much MB this discussion took.. ;P