What's next after black hole?
After a black hole has formed, it can grow by absorbing mass from its surroundings. Supermassive black holes of millions of solar masses ( M ☉) may form by absorbing other stars and merging with other black holes.
At the center of a black hole the gravity is so strong that, according to general relativity, space-time becomes so extremely curved that ultimately the curvature becomes infinite. This results in space-time having a jagged edge, beyond which physics no longer exists -- the singularity.
"Hawking said a black hole doesn't last forever," Finkbeiner said. Hawking calculated that the radiation would cause a black hole to lose energy, shrink and disappear, as described in his 1976 paper published (opens in new tab) in Physical Review D.
Black holes are also not particularly strong emitters of energy unless one counts the quasars sometimes produced by matter falling into them which can emit energy billions or trillions of times that of the sun.
Wormholes are shortcuts in spacetime, popular with science fiction authors and movie directors. They've never been seen, but according to Einstein's general theory of relativity, they might exist.
Despite their abundance, there is no reason to panic: black holes will not devour Earth nor the Universe. It is incredibly unlikely that Earth would ever fall into a black hole. This is because, at a distance, their gravitational pull is no more compelling than a star of the same mass.
As black holes evaporate, they get smaller and smaller and their event horizons get uncomfortably close to the central singularities. In the final moments of black holes' lives, the gravity becomes too strong, and the black holes become too small, for us to properly describe them with our current knowledge.
Astronomers believe that supermassive black holes lie at the center of virtually all large galaxies, even our own Milky Way. Astronomers can detect them by watching for their effects on nearby stars and gas. This chart shows the relative masses of super-dense cosmic objects.
Singularities are predicted to exist in black holes by Einstein's theory of general relativity, which is a theory that has done remarkably well at matching experimental results. The problem is that infinities never exist in the real world.
Gravitational waves are generated by the actual merger of two black holes, like ripples from a rock dropped into a pond. But they're also generated by the binary inspiral, and the intense gravitational interaction sends out weaker ripples as two black holes move inexorably closer.
How do you destroy a black hole?
The inequality suggests that to destroy a black hole, all you need to do is to feed it angular momentum and charge. But that hides a multitude of problems. For a start, things with angular momentum and charge also tend to have mass. And in any case, the equation above describes a steady state.
Black holes are dark, dense regions in space where the pull of gravity is so strong that nothing can escape. Not even light can get out of these regions. That is why we cannot see black holes—they are invisible to our eyes. Because nothing can get out of black holes, physicists struggle understanding these objects.
These explosions generate beams of high-energy radiation, called gamma-ray bursts (GRBs), which are considered by astronomers to be the most powerful thing in the universe.
For example, a black hole of 1 solar mass takes 1067 years to evaporate (much longer than the current age of the Universe), while a black hole of only 1011 kg will evaporate within 3 billion years. Black holes are detected by observing high-energy phenomena and the motions of nearby objects.
It is thought that the matter that goes into a black hole gets crushed into a tiny point at the center called a "singularity". That's the only place that matter is, so if you were to fall into a black hole you wouldn't hit a surface as you would with a normal star. Once it's there, it's there.
Even though certain features of the universe seem to require the existence of a multiverse, nothing has been directly observed that suggests it actually exists. So far, the evidence supporting the idea of a multiverse is purely theoretical, and in some cases, philosophical.
The world as we know it has three dimensions of space—length, width and depth—and one dimension of time. But there's the mind-bending possibility that many more dimensions exist out there. According to string theory, one of the leading physics model of the last half century, the universe operates with 10 dimensions.
Black holes themselves cannot be seen: their gravitational fields are so strong that nothing can escape them—including light. That is why their edges are called event horizons, because, much like with normal horizons, seeing beyond them is impossible.
Light-year is the distance light travels in one year. Light zips through interstellar space at 186,000 miles (300,000 kilometers) per second and 5.88 trillion miles (9.46 trillion kilometers) per year.
Is it possible for a black hole to "eat" an entire galaxy? No. There is no way a black hole would eat an entire galaxy. The gravitational reach of supermassive black holes contained in the middle of galaxies is large, but not nearly large enough for eating the whole galaxy.
Can humans create a black hole?
The creation of black holes at the Large Hadron Collider is very unlikely. However, some theories suggest that the formation of tiny 'quantum' black holes may be possible. The observation of such an event would be thrilling in terms of our understanding of the Universe; it would also be perfectly safe.
In turn, all the black holes found so far in our universe—from the microscopic to the supermassive—may be doorways into alternate realities. According to a mind-bending new theory, a black hole is actually a tunnel between universes—a type of wormhole.
A black hole is a region where spacetime is so curved that every possible path which light could take eventually curves and leads back inside the black hole. As a result, once a ray of light enters a black hole, it can never exit. For this reason, a black hole is truly black and never emits light.
So in our region of the Universe, there are some 100 billion supermassive black holes. The nearest one resides in the center of our Milky Way galaxy, 28 thousand lightyears away. The most distant we know of lives in a quasar galaxy billions of lightyears away.
The singularity at the center of a black hole is the ultimate no man's land: a place where matter is compressed down to an infinitely tiny point, and all conceptions of time and space completely break down. And it doesn't really exist. Something has to replace the singularity, but we're not exactly sure what.
In pure general relativity, with no other modifications or considerations of other physics, they remain black for eternity. Once one forms, it will just hang out there, being a black hole, forever.
It is possible for two black holes to collide. Once they come so close that they cannot escape each other's gravity, they will merge to become one bigger black hole.
