Anatomy of a Black Hole
May 31, 2024
As currently understood by basic definition, black holes suck in space-time. Once the event horizon is crossed, space-time travels inward at the speed of light and only accelerates/moves faster than the speed of light until it reaches the singularity. Schwarzchild’s success at untangling and solving one of Einstein’s equations helped lay the foundation for the framework of a singularity of a black hole–where space-time moves at an infinite rate and all mass is compressed into a single point. This explains how light cannot escape a black hole, due to the fact that anything that cannot travel faster than the speed of light will be contained inside the event horizon. In comparison, a white hole is if a black hole was mirrored and is a theoretical concept that represents the inverse of a black hole. Essentially, the white hole is expelling space-time at the speed of light at the event horizon which prohibits anything, including light, from ever entering a white hole unless its speed was greater than the speed of light. Like a black hole, space-time will be moving faster than the speed of light inside the event horizon but a white hole is basically just a “reflected” black hole so it would be traveling in the opposite direction (away from the center).
Image Courtesy of NASA via Medium
Image Courtesy of Astronomy Magazine
While there is a basic understanding of a black hole’s insides, it becomes entirely theoretical after matter reaches and enters the singularity. After building upon the theory of general relativity, Albert Einstein and Nathan Rosen developed a theoretical concept called the Einstein-Rosen bridge, which is more commonly referred to as a wormhole. These entrances would allow matter to start from a point in space-time and travel through to an exit (another point in space-time) at potentially faster speeds than normal travel, acting as a shortcut to different points in the universe, or even from universe to universe. The entrance would resemble somewhat of a black hole with the singularity acting as a tube to allow passage to a mirrored version of itself.
This wormhole concept is now utilized through an abundance of science-fiction films, where characters enter from one setting to jump across the galaxy/galaxies in a matter of seconds. One example of this is in Guardians of the Galaxy Vol 2., in which the characters jump around various star systems through brightly lit key ports in the sky (are circular or hexagonal shaped, according to my memory).
There are also many theories surrounding the idea that a black hole does not have a singularity, but rather something else inside. The Loop Quantum Gravity Theory suggests instead of a single and infinitely dense point, a Planck star would be formed in a black hole instead of a singularity where matter would only be capable of pushing down until a very small point (space repulsive forces stops complete collapse when star transforms into black hole). This theory would additionally help resolve some contradictions in the information paradox, as there the paradox highlights the contradicting ideas of information loss with traditional behaviors of black holes. Another theory about the inside of black holes revolves around String theory, a proposed design that suggests everything in the universe, including particles, are vibrating strings and the foundation of elementary particles, and what makes up our world is just that. One theory describing the inside of a black hole can be tied to this concept, as there could be no singularity at all but instead, a giant ball of strings that grows as more particles–which are made up of these vibrating strings–fall into the black hole and are engulfed by this giant sphere.
Some theories surrounding black holes are less technical and more interesting to think about. What would happen if a human fell into a black hole? Well, a person could experience a concept known as spaghettification, which is determined by the gravitational gradient of a black hole. Essentially, when a person falls through a black hole, forces begin to compress and stretch the body into a noodle shape as it reaches the singularity. However, Stephen Hawking's idea in 1970 that black holes evaporate due to their emission of Hawking Radiation proves the spaghettification proposal false, as this concept wouldn't be possible as black holes would eventually give out.