The original version of This story appeared in Quanta Magazine.

At the beginning of time and the center of each black hole lies a point of infinite density called a singular. To explore this mystery, we take what we know about space, time, gravity and quantum mechanics and apply it to a place where all these things simply break down. There is perhaps nothing in the universe that challenges the imagination more. Physicists still believe that if they can come up with a coherent explanation for what actually happens in and around singles, something revelatory will arise, perhaps a new understanding of space and time from it.

In the late 1960s, some physics speculated that single -foldingness could be surrounded by a region of chaos, where space and time grow randomly and shrink. Charles Misner of the University of Maryland calls it a ‘Mixmaster Heelal’, after which was a popular series of kitchen appliances at the time. If an astronaut was to fall into a black hole, “one might imagine mixing the astronaut’s body parts in the way that a mixmaster or eggbeat mixes the yolk and white of an egg,” wrote Kip Thorne, a Nobel Prize award -winning physicist.

Einstein’s general theory of relativity, which is used to describe the gravity of black holes, uses a single field comparison to explain how space curves and matter are moving. But that comparison uses a mathematical short -hand that is called a tensor to hide 16 clear, intertwined comparisons. Several scientists, including Misner, have devised useful simplified assumptions to explore their scenarios such as the Mixmaster universe.

Without these assumptions, Einstein’s equation could not be analytically resolved, and even with them it was too complicated for the numerical simulations of the time. Like the device they are named after, these ideas fell out of the style. These ‘dynamics are supposed to be a very common phenomenon in gravity,’ said Gerben Oling, a postdoctoral researcher at the University of Edinburgh. “But it’s something that has fallen off the map.”

Over the past few years, physicists have revised the chaos around single mathematical instruments. Their goals are twofold. One hope is to show that approaches that Misner and others have made are valid approaches of Einsteineian gravity. The other is to push closer to singles in the hope that their extremes will help to reconcile general relativity with quantum mechanics in a theory of quantum gravity, which has been a goal of physicists for more than a century. As Sean Hartnoll of the University of Cambridge put it: “The time is now ripe for these ideas to be fully developed.”

The birth of mixmaster chaos

Thorne described the late 60s as a ‘golden era’ for blackgat research. The term “black hole” only used widespread. In September 1969, during a visit to Moscow, Thorne received a manuscript by Evgeny Lifshitz, a prominent Ukrainian physicist. Along with Vladimir Belinski and Isaak Khalatnikov, Lifschitz found a new solution for Einstein’s gravity equations near a singular, using assumptions that the three of them devised. Lifshitz was afraid that Soviet sensors would delay the publication of the result because it contradicted earlier evidence that he co -authored, and he asked Thorne to share it in the West.

Earlier, black -hole models accepted the perfect symmetrys that were not found in nature, and said, for example, that a star was a perfect sphere before collapsing in a black hole, or had no net electrical load. (These assumptions resolved the equations of Einstein in the simplest form by Karl Schwarzschild shortly after Einstein published them.) The solution found by Belinski, Khalatnikov and Lifschitz found that the BKL solution was called after their initials, which could occur in a mess. The result was not a smooth stretch of space and time within, but a rowing sea of ​​space and time that stretched and compressed in various directions.

Thorne smuggled the newspaper back to the United States and sent a copy to Misner, which he knew, according to similar lines. It appeared that Misner and the Soviet group looked independently on the same ideas with similar assumptions and different techniques. In addition, the BKL group “used it to solve the greatest unresolved problem of that era in mathematical relativity,” Thorne said of the existence of a ‘generic’ singular. Belinski, the last surviving member of the BKL trio, recently said in ‘Ne -mail that Misner’s vivid descriptions in turn helped him visualize the chaotic situation near the singles they both revealed.