A white hole is a bizarre cosmic object which is intensely bright, and from which matter gushes rather than disappears. In other words, it's the exact opposite of a black hole. But unlike black holes, there's no consensus about whether white holes exist, or how they'd be formed.
The short answer, unfortunately, is no. White holes are really just something scientists have imagined — they could exist, but we've never seen one, or even seen clues that one may exist. For now, they are an idea. To put it simply, you can imagine a white hole as being a black hole in reverse.
Just as nothing can escape a black hole, nothing can enter a white hole. White holes were long thought to be a figment of general relativity born from the same equations as their collapsed star brethren, black holes.
In general relativity, a white hole is a hypothetical region of spacetime and singularity that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the reverse of a black hole, from which energy-matter, light and information cannot escape.
Grey holes are a combination of white and black hole properties (Zel'dovich and Novikov, 1971). Black, white, and grey holes belong to the more wide class of theoretical relativistic objects, otons, possessing event horizons (Zel'dovich and Novikov, 1971).
Theoretically, if you were to approach a white hole in a spacecraft, you would be inundated by a colossal amount of energy, which would most likely destroy your ship. Even if your spaceship could withstand gamma rays, light itself would start slowing you down like air resistance slowing down a moving vehicle on Earth.
While researchers have never found a wormhole in our universe, scientists often see wormholes described in the solutions to important physics equations. Most prominently, the solutions to the equations behind Einstein's theory of space-time and general relativity include wormholes.
Red holes, as these objects are called, have unbounded but not infinite redshifts. Small ones can be denser and more massive than neutron stars; large red holes may lie at the centers of AGNs. The red-hole model fits some AGN phenomena better than the black-hole model.
So then what's a white hole? White holes are created when astrophysicists mathematically explore the environment around black holes, but pretend there's no mass within the event horizon. What happens when you have a black hole singularity with no mass? White holes are completely theoretical mathematical concepts.
A Q-star, also known as a grey hole, is a hypothetical type of a compact, heavy neutron star with an exotic state of matter. Such a star can be smaller than the progenitor star's Schwarzschild radius and have a gravitational pull so strong that some light, but not all light, cannot escape.
White holes cannot exist, since they violate the second law of thermodynamics. General Relativity is time symmetric. It does not know about the second law of thermodynamics, and it does not know about which way cause and effect go.
A white hole is a bizarre cosmic object which is intensely bright, and from which matter gushes rather than disappears. In other words, it's the exact opposite of a black hole. But unlike black holes, there's no consensus about whether white holes exist, or how they'd be formed.
Since nothing can escape from the gravitational force of a black hole, it was long thought that black holes are impossible to destroy. But we now know that black holes actually evaporate, slowly returning their energy to the Universe.
The possibility that a black hole could actually impact Earth may seem straight out of science fiction, but the reality is that microscopic primordial black holes could actually hit Earth. If one did, it wouldn't just impact like an asteroid, it'd pass straight through the entire Earth and exit the other side.
Occasionally, two black holes will slam into each other—an event so powerful that it literally creates a ripple in space-time that travels across the universe.
Rather than a devil or a trickster then, black holes could be the nurturing childhood pals of their galaxies – growing up alongside them and maybe even helping them to form stars. Sagittarius A*. Credit: Event Horizon Telescope collaboration et al.
The nearest known black hole is Gaia BH1, which was discovered in September 2022 by a team led by Kareem El-Badry. Gaia BH1 is 1,560 light-years away from Earth in the direction of the constellation Ophiuchus.
The most powerful supernova yet recorded (ASSASN-15lh) was 22 trillion times more explosive than a black hole will be in its final moments. It doesn't matter how small or how massive a black hole is, their closing fireworks are exactly the same. The only difference is how long it will take a black hole to explode.
In astrophysics, spaghettification is the tidal effect caused by strong gravitational fields. When falling towards a black hole, for example, an object is stretched in the direction of the black hole (and compressed perpendicular to it as it falls).
The polar-opposite of a Black Hole — where nothing can “escape” the event horizon of a Black Hole, and anything that gets too close is pulled into the ominous dark void with tremendous force — nothing can “enter” the event horizon of a White Hole, and anything that gets close is pushed away with equal force.
A wormhole is a hypothetical structure connecting disparate points in spacetime, and is based on a special solution of the Einstein field equations. A wormhole can be visualized as a tunnel with two ends at separate points in spacetime (i.e., different locations, different points in time, or both).