Black holes have long attracted attention as celestial bodies from which nothing, not even light, can escape. However, theoretical physicists propose a less understood but equally fascinating counterpart: white hole.
Unlike black holes that attracted matter, white holes repelled it.
What are White Holes?
In astrophysics, a white hole represents a theoretical phenomenon in which matter and light emerge from a specific area in space rather than being drawn into it. It is the exact opposite of a black hole.
You may already know that a black hole is an area in space where gravity is so strong that the escape velocity exceeds the speed of light, making it impossible for light to escape.
Escape velocity refers to the speed at which something must travel in order to escape the gravitational field of a planet such as Earth and instead travel into space.
Theoretical Foundations of White Holes
The idea of a white hole has its roots in the Schwarzschild black hole solution, named after German physicist and astronomer Karl Schwarzschild, who formulated it in response to Einstein’s theory of general relativity.
While formulating the equations that describe black holes, Schwarzschild found that white holes could exist according to the same laws of physics that govern black holes.
Extending black hole solutions with a time-reversal-invariant method transformed the black hole singularity into a white hole singularity; A field that expels matter rather than drawing it in.
In the context of physics, time reversal means imagining a scenario in which time flows backwards, reversing the order of events.
Schwarzschild’s solution to Einstein’s equations describes a point singularity surrounded by an event horizon.
Einstein’s Theory of General Relativity
Einstein’s theory of general relativity is a theory that describes gravity not as a force between objects like Newton’s theory, but as the curvature of space and time caused by mass and energy.
According to this theory of general relativity, planets, stars, and other massive objects bend the space around them, and this bending of space is what we perceive as gravity.
Essentially, objects move along these curves in space; For example, this is why the Earth revolves around the Sun.
What is Point Singularity?
A point singularity is a location in space where certain quantities (such as density or gravity) are infinitely large.
In simpler terms, it’s like a point in the entire universe where everything we can imagine (including the laws of physics) breaks down because everything is squeezed into an unimaginably small space.
Physicists often use this concept to describe the core of a black hole, where all its mass is concentrated in a single point.
What is Event Horizon?
The event horizon is actually a boundary around a black hole from which nothing, not even light, can escape.
Think of this as a point of no return; When anything crosses this boundary, it gets sucked into the black hole with no chance of getting out. This makes the event horizon the outermost layer of a black hole and defines the limit where the gravitational pull becomes so strong that nothing can escape.
As Schwarzschild theorized, in a strange case of time reversal, such as a white hole, this event horizon becomes a boundary along which matter and light can move. Only to escape, not to be absorbed.
Quantum Issues of White Holes
These ideas expand even further when you think of white holes as concepts in the fields of classical and quantum gravity.
Quantum mechanics, as well as theories of quantum gravity, predict phenomena such as Hawking radiation, in which black holes emit radiation due to quantum effects near the event horizon.
By applying time reversal to these processes, some scientists suggest that white holes may emit matter and light in a similar way as a physical process reflecting Hawking radiation.
Are There White Holes?
The question of whether white holes exist is fraught with difficulties. There is no observational evidence that directly supports the existence of such objects in the observable universe.
However, theoretical physics offers scenarios in which white holes could theoretically arise. One possibility is during the cosmic inflation, or “big bang,” of the early universe, when hyper-expansion might have stretched regions of space-time to form white holes.
Another interesting idea is the big bounce theory, which proposes that our universe began as a white hole formed from the remnants of the collapsing parent universe.
Loop Quantum Gravity Theory
Astrophysicist Andrew Hamilton suggests that if white holes exist, they may be the remnants of supermassive black holes that have undergone a quantum gravitational transformation, changing their role from absorbing mass and energy to expelling them. This theory is called loop quantum gravity.
This transformation could potentially occur under the influence of dark energy, or dark matter, which is known to influence the universe. But physicists still don’t have a clear understanding of how dark matter interacts with fundamental particles.
Links to Other Theoretical Frameworks
Exploring the concept of a white hole touches many other areas of physics. For example, gravitational lensing, the phenomenon of light bending around massive objects such as black holes, could similarly apply to white holes and alter our perception of the space behind them.
Moreover, the idea of a baby universe potentially arising from the outer layers of the parent universe via a white hole is deeply connected to multiverse theory, suggesting that our universe may be just one of many.
White holes also challenge our understanding of thermal balance in the universe.
Because they emit rather than absorb energy and matter, they can theoretically serve as cosmic seeds, distributing energy density and elementary particles throughout the universe, thus influencing the formation and evolution of galaxies in fundamentally different ways than black holes.
We created this article with AI technology, then had it fact-checked and edited by a HowStuffWorks editor.
Original article: What is a White Hole? Is There a Cosmic Event?
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