Black Hole, White hole, Wormhole. Ew!! Seems like all these space terms are making us puzzled. So I’m back guys with an interesting topic today. Yes, it is about the difference between Black Hole, Wormhole and White Hole. So wasting no time, let us dive in to find out what these are and why they are of such immense interest to us.
A white hole is a hypothetical celestial object which expands outwards from a space-time singularity and emits energy, in the manner of a time-reversed black hole. These could make up a major part of the mysterious dark matter that’s thought to make up most of the matter in the universe.
Physicists describe a white hole as a black hole’s “time reversal,” a video of a black hole played backward. A simpler notation is like a bouncing ball is the time-reversal of a falling ball. While a black hole’s event horizon is a sphere of no return, a white hole’s event horizon is a boundary of no admission. No spacecraft will ever reach the region’s edge.
In 2014, Carlo Rovelli, a theoretical physicist at Aix-Marseille University in France, and his colleagues suggested black holes and white holes might be connected in another way: When black holes die, they could become white holes.
They added that once a black hole evaporated to a degree where it could not shrink any further because space-time could not be squeezed into anything smaller, the dying black hole would then rebound to form a white hole.
Rovelli and his colleagues estimated it would take a black hole with a mass equal to that of the sun about a quadrillion times the current age of the universe to convert into a white hole.
Scientists believe they may have witnessed a white hole when a sudden burst of white light appeared out of nowhere and then vanished. There have been no other similar events recorded to study.
One of the key reasons why white holes are not considered being real is the fact that white holes decrease entropy. The laws of thermodynamics tell us that the overall entropy of the universe is increasing.
A white hole spits out everything and nothing goes in. So while a black hole has an event horizon that, once you get close enough, you can never escape, a white hole has an event horizon that you can never even get close to.
While we know that black holes exist, so far, white holes (and wormholes) exist only in pages of physics papers.
So now let’s move on to find out what is a black hole. Well, most of us have heard about this.
A black hole is a region of space-time exhibiting gravitational attraction so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it. The theory of general relativity predicts that a sufficiently compact mass can deform space-time to form a black hole.
This is what Wikipedia’s definition says. But the part of the statement that makes a black hole interesting is that no particle even the fastest thing light can escape from it.
Black holes result from large, dying stars that collapse in on themselves. All the mass is squeezed into a tiny amount of space. Whilst the core of the star is imploding, the outer layers are flung out into space in the form of a supernova: a wonderful cosmic explosion.
When a star burns through the last of its fuel, the object may collapse, or fall into itself. For smaller stars (those up to about three times the sun’s mass), the new core will become a neutron star or a white dwarf. But when a larger star collapses, it continues to compress and creates a stellar black hole.
Small black holes populate the universe, but their cousins, supermassive black holes, dominate. These enormous black holes are millions or even billions of times as massive as the sun but are about the same size in diameter. Such black holes are thought to lie at the center of pretty much every galaxy, including the Milky Way.
Black holes have three “layers”: the outer and inner event horizon, and the singularity.
The event horizon of a black hole is the boundary around the mouth of the black hole, past which light cannot escape. Once a particle crosses the event horizon, it cannot leave. Gravity is constant across the event horizon.
The inner region of a black hole where the object’s mass lies is known as its singularity, the single point in space-time where the mass of the black hole is concentrated.
Black holes don’t suck. Suction is caused by pulling something into a vacuum that the massive black hole is not. Instead, objects fall into them just as they fall toward anything that exerts gravity, like the Earth.
Well, that’s it about black holes and white holes. Now let us see about wormholes.
Wormholes were first theorized in 1916, though that wasn’t what we called them at the time. While reviewing another physicist’s solution to the equations in Albert Einstein’s theory of general relativity, Austrian physicist Ludwig Flamm realized another solution was possible. He described a “white hole,” a theoretical time reversal of a black hole. Entrances to both black and white holes could be connected by a space-time conduit.
But if a black hole is at one end of a wormhole, what’s at the other end? A white hole. The same math that predicts the existence of a black hole also predicts the existence of its mirror opposite: a white hole. While anything that enters a black hole can never escape, anything that escapes a white hole can never return.
In 1935, Einstein and physicist Nathan Rosen used the theory of general relativity to elaborate on the idea, proposing the existence of “bridges” through space-time. These bridges connect two different points in space-time, theoretically creating a shortcut that could reduce travel time and distance. The shortcuts came to be called Einstein-Rosen bridges, or wormholes.
You can picture a wormhole as a kind of tunnel that connects two points in space-time. That tunnel could be a straight chute or take a more winding path. If the wormhole is “traversable” it acts as a shortcut through space-time, connecting two points that would otherwise be far apart. Wormholes could connect different spots within a single universe, or they can connect different universes.
Wormhole geometries are inherently unstable. The only material that can be used to stabilize them against pinching off is material having negative energy density, at least in some reference frames. No classical matter can do this, but it is possible that quantum fluctuations in various fields might be able to.
These aren’t still found but supposing they did exist, how would we even begin to go about finding them? According to a recent research paper, all you need is a black hole, stars orbiting it, and equipment for predicting and measuring those orbits. For more see.
At present, space-time wormholes are only theoretical constructs derived from general relativity; there is no experimental evidence for their existence.
Black holes are found to exist, and also there have been many movies regarding these. White holes and Wormholes are also yet to be found in case they are present. Last but not the least, their study always fascinates us and makes us awe.