You don’t have to be a science fiction fan or have a degree in astrophysics to be familiar with black holes. These objects have been observed all over our universe over the last several decades, capturing the imaginations of scientists and laypeople alike. Black holes and their theoretical counterparts, white holes, have been speculated to be everything from a means of traveling to distant parts of the universe to the key to time travel.
According to Astronomy magazine, the first black hole ever observed by astronomers was discovered in the form of an X-ray-emitting space object known as Cygnus X-1 in 1964. Because black holes had previously been theorized but never proven to exist, it took decades for Cygnus X-1 to be confirmed to be one. A decade after its discovery, Cygnus X-1 became the subject of a famous bet between Kip Thorne and Stephen Hawking, who settled the bet in 1990, the same year that the first major confirmation of its status as a black hole was published.
Multiple scientific studies confirmed Cygnus X-1’s official black hole status in 2011, highlighting the fact that the other side of the proverbial coin has yet to be proven. Why don’t we have proof of the other side of a hole in space if we have proof of one?
Black hole math led to the study of white holes
Albert Einstein published his theory of gravity in 1915. Not long after, physicist Karl Schwarzschild proposed one solution to Einstein’s theory, effectively resulting in the creation of a black hole. Ludwig Flamm, an Australian physicist, investigated Schwarzchild’s solution and realized a second solution to Einstein’s theory was possible, resulting in the creation of what would eventually be known as a white hole.
Ludwig Flamm expanded on his investigation, hypothesizing a link between Einstein’s two solutions. Flamm proposed the use of a spacetime conduit to connect one side of the hole to the other. In 1935, Einstein and Nathan Rosen proposed a (largely similar) theory for a conduit that would later be called an Einstein-Rosen bridge and a wormhole by physicist John Wheeler.
While black holes absorb light, white holes emit it. Objects cannot avoid being drawn to the center of a black hole, but cannot avoid being drawn to the center of a white hole no matter how hard they try. If the two were connected, we’d have a doorway — one way in, one way out.
The creation of a black hole in brief
When a massive star dies, a black hole has the potential to form. When a star uses up all of its thermonuclear fuel in its core, it destabilizes. As a result, the core rapidly collapses within itself, ejecting its outer parts into space. The collapsed core has the potential to form a black hole, which is an object with infinite density and a gravitational force so powerful that even light cannot escape it (via Britannica).
White holes, unlike black holes, have no gravitational pull or impact on nearby stellar objects that can be seen through a telescope. White holes are currently theoretical mathematical concepts that astrophysicists use to further study black holes in space.
Scientists investigate the area of space that surrounds a black hole mathematically. When they perform these mathematical calculations without taking into account the mass that exists within the event horizon of a black hole, they “create” a theoretical white hole.
What would a white hole look like?
A white hole observed by a nearby spacecraft may appear to be a black hole for the most part, including evidence of rotation and a ring of gasses and dust around its event horizon, according to Space. The distinction between the two would become clear only when the white hole began to belch out light rather than drawing all surrounding light inward.
A white hole is defined by physicists as a black hole that runs backward through time. They argue that objects inside a white hole are not trapped and are free to move outward and away. However, because nothing can enter the white hole, the remaining universe has no effect on its source.
Because of the white hole’s singularity, Science ABC’s John Staughton suggests that “some element of the infinite past could have an impact on our present, but we could have no effect on it, no matter how hard we tried.” For the time being, researchers have not publicly disclosed proof that a white hole exists in space — at least not beyond theoretical science. They might exist, but for the time being, they’re just an idea.