What does a black hole look like inside
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Understanding the Interior of Black Holes
Theoretical Models of Black Hole Interiors
Two-Dimensional Semiclassical Black Holes
The inner structure of two-dimensional dilatonic evaporating black holes reveals two types of spacelike singularities. These singularities are critical in understanding the evolution of spacetime from the event horizon to the singularity itself1.
Quantum Gravity and Black Hole Interiors
In the realm of quantum gravity, black holes form and evaporate unitarily. The interior spacetime appears due to the special features of microscopic degrees of freedom when viewed from a semiclassical standpoint. This relationship between quantum mechanics and the equivalence principle remains consistent, albeit subtle2.
Charged and Distorted Black Holes
For charged, nonrotating distorted black holes, the Cauchy horizon remains regular if the distortion at the event horizon is regular. The inner geometry of both the outer and inner horizons shows a duality in their properties. The curvature within the inner domain between the horizons is also studied, revealing simple relations between 4D curvature invariants and the Gaussian curvature of the horizon surfaces3.
Singularities and Spacetime Geometry
Singularities in Spherical and Rotating Black Holes
The singularities inside spherical, charged black holes are well understood, featuring a null singularity along the Cauchy horizon followed by a spacelike central singularity. In rotating black holes, the Cauchy horizon singularity is characterized by the divergence of curvature dominated by gravitational field modes, resembling a singular shock wave6.
Regular Black Holes
Regular black holes, which do not have singularities, are proposed to contain regions of matter or false vacuum configurations. These solutions within general relativity coupled with Maxwell's electromagnetism and charged matter show that the interior region can be de Sitter, while the exterior is Reissner-Nordström, separated by an electrically charged boundary8.
Probing Black Hole Interiors
Quantum Probing of Singularities
The cosmic censorship conjecture suggests that singularities are hidden by an event horizon, making them unobservable classically. However, quantum analogues, such as the transition rates of an Unruh–DeWitt detector, indicate that it is possible to probe the structure of the singularity from outside the horizon7.
Gravitational Diagram and Quantized Space-Time
Black holes exist within quantized space-time, and their state can be described by equations for the quantum density of the medium and gravitational potentials. Inside a black hole, the quantum density doubles due to gravitational compression, and cosmic bodies break into quarks at the surface. These quarks can penetrate and potentially restore matter inside, suggesting that a giant black hole might resemble a new universe with star systems and planets9.
Visualizing Black Hole Interiors
Double Images and Shadows
Simulations of black holes, including those with octupole distortions, show that a local observer can see two shadows or images of a single black hole. This eyebrow-like structure, previously thought unique to multi-black hole systems, is now observed in single black holes as well10.
Conclusion
The interior of black holes is a complex and multifaceted subject, involving various theoretical models and quantum mechanics. From the nature of singularities to the potential for regular black holes and the ability to probe these interiors, our understanding continues to evolve. The visualization of black hole interiors, including the intriguing double images, adds another layer to this fascinating cosmic phenomenon.
Sources and full results
Most relevant research papers on this topic
Interior design of a two-dimensional semiclassical black hole
Two-dimensional semiclassical black holes exhibit two types of spacelike singularities, and their structure and evolution are studied using the homogenous approximation.
Black Hole Interior in Quantum Gravity.
Quantum gravity allows black holes to form and evaporate unitarily, with special features revealed by microscopic degrees of freedom.
Interior of a charged distorted black hole
The Cauchy horizon of a charged, nonrotating distorted black hole remains regular, with a duality between the properties of the horizons and a proper time for a test particle to move along the symmetry axis.
Black Holes
Black holes are the most terrifying phenomenon in the universe, as they consume information and can trap individuals, making them potentially fatal if they enter them.
Black Holes
What are black holes? Composed? And how do they look? What happens to the information inside it? More importantly, what happens to you if you enter the black hole? Believe me the most terrifying thing you can hear about the universe, is having something like black holes. Worse, it falls into one.
The Internal Structure of Black Holes
Black hole interiors are well understood, with a null singularity along the Cauchy horizon preceding a spacelike central singularity, and the Cauchy horizon singularity being a singular shock wave propagating along the Cauchy horizon.
Looking inside a black hole
We can probe the structure of a black hole's singularity from outside its event horizon, despite its event horizon being hidden by a cosmic censorship conjecture.
Regular black holes: Electrically charged solutions, Reissner-Nordstr\'om outside a de Sitter core
Regular black hole solutions can be found in general relativity, with various types of solutions based on matter boundaries, and their physical and geometrical properties are analyzed.
Highly CitedGravitational Diagram of an Ideal Black Hole
Ideal black holes are completely invisible, while non-ideal black holes have visible glows due to photon reflections from their surface, and may contain weak gravity planets like Earth where life is possible.
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