Black holes and their hidden structures: in the footsteps of Einstein and Hawking

“I don’t spend my day peering through a telescope. I study black holes from a theoretical standpoint,” says physicist Bert Vercnocke, who wrote his dissertation on black holes and their hidden structure.

A black hole is an area of outer space from which nothing can escape, not even light. Why would this interest a physicist? “Black holes lend themselves well to the study of gravity. Even today, gravity remains one of the least understood natural forces, despite Newton’s laws and Einstein’s theory of relativity. Describing gravity on a very small scale is particularly challenging. Currently we do not have a ‘quantum gravity theory’ that is able to reconcile gravity with quantum mechanics, the theory of the matter at nanoscopic scales.”

A possible candidate to fill this gap is string theory, explains Vercnocke: “String theory posits that the many small particles that make up matter – such as neutrons and protons – are derived from a single type of tiny building block: vibrating strings. Depending on the energy with which they vibrate, these strings take the form of tiny particles, including gravitons, or gravity particles. This hypothetic elementary particle is what allows string theory to bridge the gap between nanoparticles and gravity. The problem with string theory is that it cannot – because of its extremely small scale – be tested using today’s technology. Black holes give us an opportunity to test it in a theoretical way.”

In his doctoral research, Vercnocke built on Stephen Hawking’s work on quantum gravity: “He discovered that a black hole is not ‘black’ at all. Rather, black holes emit heat and thus have a temperature. This radiation and temperature suggest an inner structure, but such an inner structure cannot be described using Einstein’s theory.”

String theory can, but there is still much work to be done, explains Vercnocke: “At this point, string theory only offers an explanation for super-symmetrical black holes – black holes with a huge amount of electrical charge. These holes are mathematically simple. But in reality, black holes have no charge. In my research, I am trying to open string theory up to black holes with less charge. The ultimate goal is to arrive a theory for zero-charge black holes.”

Ilse Frederickx

Bert Vercnocke currently works as a postdoctoral research at the University of Amsterdam. On 9 September 2014, he received the Academische Stichting Leuven Prize for Science and Technology. Click here for interviews with the other laureates