A new model predicts a naked singularity yields a saddle-like space known as anti-de Sitter space. Photo by University of Cambridge/Wikimedia Commons
May 22 (UPI) -- A new computer model predicts the possibility of naked singularities in four-dimensional space, challenging Einstein's general theory of relativity.
The theory of relativity describes gravity -- a product of matter's effect on spacetime -- and its relations to the other laws of physics. A singularity is a point in space where gravity is so strong that the laws of physics break down. The theory of relativity predicts all black holes are located in the center of black holes, surrounded by an event horizon, rendering them unobservable.
Some scientists believe singularities could exist outside of an event horizon, exposed. The theoretical phenomena are known as naked singularities. If they exist, they would contradict Einstein's theory of relativity.
Researchers have previously designed models predicting naked singularities, but until now, all such models relied upon five dimensions. For the first time, physicists have created a model predicting naked singularities in four-dimensional space -- three spatial dimensions, plus time.
The model shows a naked singularity can yield what's called anti-de Sitter space, a curved, saddle-shaped space. Light doesn't travel linearly in anti-de Sitter space. Instead, it's curved inward toward a boundary and reflected back.
"It's a bit like having a spacetime in a box," Toby Crisford, a theoretical physicist at the University of Cambridge, said in a news release. "At the boundary, the walls of the box, we have the freedom to specify what the various fields are doing, and we use this freedom to add energy to the system and eventually force the formation of a singularity."
The new paper -- published in the journal Physical Review Letters -- doesn't offer proof of the existence of naked singularities. But it does showcase the shortcomings of relativity theory and provides an opening for new gravitational theories like quantum gravity.
"The naked singularity we see is likely to disappear if we were to include charged particles in our simulation -- this is something we are currently investigating," said Cambridge researcher Jorge Santos. "If true, it could imply a connection between the cosmic censorship conjecture and the weak gravity conjecture, which says that any consistent theory of quantum gravity must contain sufficiently charged particles. In anti-de Sitter space, the cosmic censorship conjecture might be saved by the weak gravity conjecture."