“Could a Black Hole Contain a Universe? What Theories Suggest”

The Mind-Bending Discovery That Changes Everything

In early 2025, the James Webb Space Telescope made a discovery that sent shockwaves through the scientific community. The $10 billion telescope found that the vast majority of deep space galaxies it observed are rotating in the same direction, with around two-thirds spinning clockwise while only one-third rotates counter-clockwise. In a random universe, scientists would expect to find 50% of galaxies rotating one way, while the other 50% rotate the other way. This observation has profound implications that could rewrite our understanding of cosmic origins. The uncovered preferred direction for galaxies supports the idea that the universe was born in a black hole, and could tell us something profound about the birth of the universe by possibly hinting that everything we see around us is sealed within a black hole. The discovery suggests our cosmos might have an inherent spin inherited from a parent black hole, making us unwitting passengers in the ultimate cosmic journey.

Einstein-Cartan Theory: The Revolutionary Framework

While Einstein's general relativity describes gravity through spacetime curvature, there's a more sophisticated theory that could explain how universes birth within black holes. Einstein-Cartan theory, also known as the Einstein-Cartan-Sciama-Kibble theory, is a classical theory of gravitation proposed by Élie Cartan in 1922 that differs from general relativity by incorporating Riemann-Cartan geometry with locally gauged Lorentz symmetry and additional equations relating torsion to spin. Think of spacetime not as a smooth fabric, but as a twisted rope where the "twist" represents torsion. The minimal coupling between torsion and Dirac spinors generates an effective nonlinear spin-spin self-interaction, which becomes significant inside fermionic matter at extremely high densities and is conjectured to replace the singular Big Bang with a cusp-like Big Bounce at a minimum but finite scale factor. This theory doesn't just modify gravity—it revolutionizes our entire concept of cosmic birth and death.

The Big Bounce: When Black Holes Give Birth

Imagine a cosmic recycling program where destruction becomes creation. In Einstein-Cartan theory, the minimal coupling between torsion and Dirac spinors generates a repulsive spin-spin interaction significant in fermionic matter at extremely high densities, preventing the formation of a gravitational singularity. Instead, the collapsing matter reaches an enormous but finite density and rebounds, forming the other side of an Einstein-Rosen bridge, which grows as a new universe. Accordingly, the Big Bang was a nonsingular Big Bounce at which the universe had a finite, minimum scale factor, or the Big Bang was a supermassive white hole that was the result of a supermassive black hole at the heart of a galaxy in our parent universe. Picture matter compressed to unimaginable densities, then suddenly springing back like a cosmic trampoline, creating not destruction but an entirely new realm of existence.

Nikodem Popławski: The Pioneer of Black Hole Universes

Nikodem Janusz Popławski, a Polish theoretical physicist born March 1, 1975, is most widely noted for the hypothesis that every black hole could be a doorway to another universe and that the universe was formed within a black hole existing in a larger universe—a hypothesis listed by National Geographic and Science magazines among their top ten discoveries of 2010. Popławski theorizes that torsion manifests itself as a repulsive force which causes fermions to be spatially extended and prevents the formation of a gravitational singularity within the black hole's event horizon, causing the collapsing matter to reach an enormous but finite density, explode and rebound, forming an Einstein-Rosen bridge (wormhole) to a new, closed, expanding universe. His work transforms black holes from cosmic destroyers into cosmic creators. The rotation of a black hole could influence the spacetime on the other side of its event horizon and result in a preferred direction in the new universe, with Popławski suggesting that the observed fluctuations in the cosmic microwave background might provide evidence for his hypothesis.

Torsion: The Hidden Force That Changes Everything

In the standard model of physics, particles are treated as point-like objects, but reality might be far more complex. Torsion allows fermions to be spatially extended instead of "pointlike," which helps to avoid the formation of singularities such as black holes, removes the ultraviolet divergence in quantum field theory, and leads to the toroidal ring model of electrons. Think of elementary particles not as tiny dots, but as microscopic spinning tops with actual physical extent. In Einstein-Cartan Theory, the torsion of spacetime affects the dynamics of fermions significantly, and this coupling can lead to modifications in our understanding of particle interactions under extreme conditions, such as in the early universe or inside neutron stars. The coupling between the spin of elementary particles and torsion in the Einstein-Cartan theory of gravity generates gravitational repulsion at extremely high densities in fermionic matter, approximated as a spin fluid, and thus avoids the formation of singularities in black holes. This repulsive force acts like a cosmic safety valve, preventing infinite collapse and enabling cosmic rebirth.

The Mathematical Beauty of Cosmic Recycling

The mathematics underlying black hole universes reveals nature's elegant recycling system. The coupling between the spin of elementary particles and torsion in the Einstein-Cartan theory of gravity generates gravitational repulsion at extremely high densities in fermionic matter, approximated as a spin fluid, and thus avoids the formation of singularities in black holes. This scenario can explain inflation without a scalar field and reheating, and depending on the particle production rate, such a universe may undergo several nonsingular bounces until it has enough matter to reach a size at which the cosmological constant starts cosmic acceleration, with the last bounce regarded as the big bang of this universe. Each bounce creates a slightly larger universe, like nested Russian dolls of cosmic proportions. The resulting closed universe on the other side of the event horizon may have several bounces, creating an oscillatory universe with each cycle larger than the preceding cycle, until it reaches a size at which dark energy dominates and expands indefinitely, suggesting our universe might have originated from a black hole existing in another universe.

White Holes: The Exit Gates to New Realities

If black holes are cosmic entry points, white holes serve as the exit doors to new universes. In the new universe, according to this theory, the parent universe appears as the other side of the new universe's only white hole, a region of space that cannot be entered from the outside and which can be thought of as the reverse of a black hole. While black holes are often described as sucking everything, including time, into a point of nothingness, white holes are theorized to act in reverse, ejecting matter, energy and time back into the universe. Picture a cosmic fountain where instead of water flowing down, spacetime, matter, and energy cascade outward in an eternal gush of creation. Shockwave cosmology, proposed by Joel Smoller and Blake Temple in 2003, has the "big bang" as an explosion inside a black hole, producing the expanding volume of space and matter that includes the observable universe, with this black hole eventually becoming a white hole as the matter density reduces with the expansion.

The Cosmic Microwave Background: Evidence from the Beginning

The cosmic microwave background radiation might be our universe's birth certificate, containing hidden signatures of its black hole origin. According to the black hole universe model, the observed cosmic microwave background radiation can be explained as the black body radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole to the present universe, with results showing the radiation temperature of the present universe can be approximately 2.725 K if the universe originated from a hot star-like black hole. When a hot and dense star-like black hole accretes its ambient materials and merges with other black holes, it expands and cools down, with a governing equation derived from the Planck law of black body radiation and radiation energy conservation expressing the possible thermal history of the black hole universe. This suggests the universe's temperature evolution follows the same cooling pattern expected from an expanding black hole interior.

The Arrow of Time: Inherited from Another Universe

One of physics' greatest mysteries is why time moves forward instead of backward, but black hole cosmology offers a startling answer. The motion of matter through the black hole's boundary, called an event horizon, can only happen in one direction, providing a past-future asymmetry at the horizon and, thus, everywhere in the baby universe, with the arrow of time in such a universe inherited, through torsion, from the parent universe. Think of time as a river flowing from the parent universe through a black hole waterfall into our cosmic basin. This arrow is also entropic: although black holes are states of maximum entropy in the frame of reference of outside observers, new universes expanding inside black holes continue to increase entropy. This elegant solution suggests that time's direction isn't fundamental to our universe but borrowed from our cosmic parent, making every moment we experience a legacy from another realm of existence.

Quantum Gravity and the Ultimate Computer

Our universe might be more than just a cosmic accident—it could be nature's most sophisticated computational system. Basically, we live inside a gigantic quantum gravity computer known as the Hubble sphere, and we even are quantum gravity computers, with the observable universe essentially a quantum gravity computer that calculates approximately 10^104 bits per second. All quantum gravity and quantum gravity computers are directly linked to the Planck scale and the Compton frequency in matter, and quantum gravity computers are in many ways nature's own designed computers with enormous capacity to 3D "print" real time. This perspective transforms our understanding of reality itself—we're not just observers in the universe, we're participants in its cosmic computation. The coupling between spin and torsion generates gravitational repulsion at extremely high densities, causing collapsing matter in a black hole to bounce at a finite density and expand into a new region of space on the other side of the event horizon, while quantum particle production caused by extremely high curvature near a bounce can create enormous amounts of matter, produce entropy, and generate a finite period of exponential expansion of this universe.

Recent Discoveries Challenge Our Cosmic Perspective

The year 2024 brought groundbreaking discoveries that support black hole universe theories. The James Webb Space Telescope spotted a black hole as it appeared just 1.5 billion years after the Big Bang, gobbling material 40 times faster than its theoretical feeding limit called the Eddington limit, and the discovery could explain why so many giant black holes appear so early in the universe's history. Astronomers have discovered a supermassive black hole at the center of a galaxy just 1.5 billion years after the Big Bang that is consuming matter at a phenomenal rate—over 40 times the theoretical limit—and while short lived, this black hole's 'feast' could help astronomers explain how supermassive black holes grew so quickly in the early Universe. These observations suggest that black holes in the early universe behaved very differently than expected, possibly indicating fundamental processes we don't yet understand about cosmic birth and growth.

The Schwarzschild Radius Connection

The mathematics of black hole universes reveals an astonishing coincidence that might not be coincidental at all. Any such model requires that the Hubble radius of the observable universe be equal to its Schwarzschild radius, that is, the product of its mass and the Schwarzschild proportionality constant. This means our observable universe's size matches exactly what we'd expect if we were living inside a black hole of equivalent mass. A black hole cosmology is a cosmological model in which the observable universe is the interior of a black hole, originally proposed by theoretical physicist Raj Kumar Pathria and mathematician I. J. Good, with the observable universe being the interior of a black hole existing as one of possibly many inside a larger parent universe, or multiverse. The numerical match between these cosmic scales isn't just remarkable—it's so precise that it demands explanation, possibly pointing to the most fundamental truth about our cosmic home.

Solving the Singularity Problem

Traditional physics breaks down at singularities, but Einstein-Cartan theory offers an elegant solution to this cosmic crisis. According to Einstein's Theory of General Relativity, anyone trapped inside a black hole would fall towards its centre and be destroyed by immense gravitational forces at a singularity, the point where matter is believed to have collapsed and been crushed down into an infinitesimally tiny point where our understanding of physics and time breaks down. Using the laws of quantum mechanics, a new study proposes a radically different theoretical standpoint where, rather than a singularity signifying the end, it could represent a new beginning, as illustrated in a paper entitled 'Black Hole Singularity Resolution in Unimodular Gravity from Unitarity' published in Physical Review Letters. This breakthrough suggests that what we've long considered the universe's ultimate dead ends are actually cosmic maternity wards, birthing new realities beyond our wildest imagination.

Experimental Challenges and Future Possibilities

Testing black hole universe theories presents extraordinary challenges, but recent technological advances offer new hope. While the Einstein-Cartan Theory provides intriguing theoretical insights, its physical consequences are difficult to observe directly, with the effects of torsion generally very small under ordinary conditions, though in environments with extremely high density and spin concentration, such as near black holes or in the early universe, the effects might become significant. Einstein-Cartan theory is not the minimal theory that explains the effects of general relativity, partly because it equals general relativity in spin-vacuum, making it mandatory to look for additional effects and how we can observe them, though some of the proposed effects lie far from our current scope. Future gravitational wave detectors and advanced telescopes might finally provide the evidence needed to confirm or refute these mind-bending possibilities.

The Multiverse Connection

If our universe exists within a black hole, the implications extend far beyond our cosmic boundaries into an infinite multiverse. In the version as originally proposed by Pathria and Good, and studied more recently by Nikodem Popławski among others, the observable universe is the interior of a black hole existing as one of possibly many inside a larger parent universe, or multiverse. Accordingly, our own universe could be the interior of a black hole existing in another universe, Popławski continued. This creates a mind-boggling hierarchy where every black hole in our universe might contain entire universes with their own galaxies, stars, and potentially life. Conversely, our entire cosmos might be just one of countless universes nested within black holes throughout a vast parent reality. The scale becomes incomprehensible: trillions of universes within universes, each containing billions of galaxies, in an infinite fractal of cosmic creation.

Cosmic Inflation Without Inflation Fields

Traditional cosmic inflation theory requires mysterious scalar fields, but black hole universe models offer a more elegant explanation. Torsion may prevent a singularity and replace it with a nonsingular bounce if particle production dominates over shear, with particle production after the last bounce generating a finite period of inflation, during which the universe expands and isotropizes to the currently observed state. This scenario generates cosmic inflation, which explains why the present Universe at largest scales appears spatially flat, homogeneous and isotropic. Instead of needing exotic fields that we've never detected, cosmic expansion emerges naturally from the physics of spinning matter rebounding from near-infinite density. The collapse reaches a bounce and forms a regular Einstein-Rosen bridge (w