Black holes, the densest objects in the universe, eat up anything that comes too close, even light. Is there anything left inside these behemoths that could reveal what they devoured in the first place? String theory, an attempt to merge gravity with quantum physics, says yes. A new study suggests that within black holes lie tangled pathways of strings called supermazes, which hold that information in multiple dimensions.
What Are Black Hole Supermazes?
Supermazes come from M-theory, an umbrella idea that includes multiple versions of string theory, in which our universe contains 11 dimensions—not just the four that physicists know to exist. In M-theory, the universe is made of multidimensional vibrating strings called branes. Supermazes are a kind of map of how various two-dimensional and five-dimensional branes intersect within the confines of black holes. The mazes are a way to picture a black hole’s microstructure—its minuscule quantum makeup.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
“The maze is a very intricate, complex structure with lots of rooms and chambers and intersections of walls, with all sorts of layering on those walls,” says study co-author Nicholas Warner of the University of Southern California. The walls are the branes, and “the intersections are where the two-dimensional things meet the five-dimensional things. When they meet, they pull on each other and bend.”
Supermazes would inhabit black holes that weren’t truly black holes. Instead they’d be fuzzballs: fuzzy balls of vibrating branes that lack the traditional features of black holes—an event horizon (outer boundary) and a singularity (a single point containing all the mass). “There are a huge amount of problems associated with black holes and their horizons,” Warner says. Fuzzballs are “a state of matter that looks like a black hole and behaves like a black hole but differs at the horizon scale.”
Warner and his co-authors, Iosif Bena and Dimitrios Toulikas, both at the Institute of Theoretical Physics in France, and Anthony Houppe of the Swiss Federal Institute of Technology Zurich, described supermazes in a paper published on March 14 in the Journal of High Energy Physics.
What the Experts Say
Supermazes are a “nice” new way to create families of fuzzballs, says Samir Mathur, a theoretical physicist at the Ohio State University, who originally proposed fuzzballs. The authors of the new study “have done a lot of hard work in making more families,” he adds. “I find all these constructions very interesting, and this latest one is very interesting as well.”
One question that’s still unresolved is whether the supermaze versions of fuzzballs fully satisfy all the requirements scientists have for black holes—or theoretical objects that replace them. “The solutions constructed by Dr. Bena and his collaborators are very interesting, and they are certainly close to being black holes,” says University of California, Santa Barbara, physicist Don Marolf. “However, while it has been shown that these solutions have masses and charges that agree with what we expect for certain black holes, the authors have not yet shown that these solutions are in fact what we typically call black holes.”
For instance, cutting out event horizons from black holes makes it difficult to account for their entropy, a measure of their randomness or disorder. The researchers “have succeeded in writing many interesting and intricate solutions,” says physicist Juan Maldacena of the Institute for Advanced Study in Princeton, N.J., “but not yet a full set of solutions that can account for the entropy of these black holes, which is computed by a solution with a horizon.”
Why This Matters
Fuzzballs and string theory are just one way that physicists are trying to bridge the gap between Einstein’s general theory of relativity and quantum mechanics, which don’t get along. Scientists would like an ultimate theory that can describe both the very tiny machinations of particles and the grand movements of galaxies. The insides of black holes, which are extremely small and extremely massive, are the ideal testing grounds for trying out such a theory.
More specifically, fuzzballs and stringy supermazes have emerged as a way to solve a puzzle called the black hole information paradox. This quandary arose when physicists realized black holes seem to break a sacred law of physics: that information can never be destroyed. In 1974 Stephen Hawking realized that black holes must slowly evaporate by emitting particles that eventually deplete the black hole down to nothing. In the traditional picture of a black hole, this process destroys all the information contained in it. Fuzzballs, however, would be able to transmit some of this information through the evaporating particles. “The supermaze has a huge capacity to store information,” Warner says. “That solves the information paradox.”