Einstein’s equations hint gravity can break, reconnect like magnetic fields: US study

Key TakeawaysAccording to Einstein, gravity is not just a pulling force but a curvature of space-time caused by mass and energy.Einstein's famous equations that explain gravity are being rewritten using new variables and explain other phenomenon in physics like plasma behavior.Researchers suggest that gravitational fields can break and reconnect just like magnetic fields do and release large amounts of energy. A collaborative study between researchers at the University of Columbia in the US and the Universidad Adolfo Ibáñez in Chile has found that, under the right conditions, gravitational fields can break and reconnect, while releasing large amounts of energy. Interestingly, researchers made the discovery while re-examining Einstein’s equations, devised more than a century ago. Einstein’s field equations are a set of 10 interrelated differential equations that the physicist used to describe gravity. According to Einstein, gravity is not just a pulling force but a curvature of space-time caused by mass and energy. Over the past few years, physicists have been developing new formulations of these equations. While the equations remain mathematically the same, they are expressed in different variables. Luca Comisso, an associate research scientist at the Department of Astronomy and Physics at Columbia University, studies plasma and found that Einstein’s rewritten equation resembles one that could describe plasma. Gravitational field connections Cossimo’s previous work also involved Felipe A. Asenjo at the Universidad Adolfo Ibáñez and, for the first time, identified a set of rules that explained limits on how space-time could bend, stretch, and evolve. In their recent work, the researchers show how gravitational field connections can change when ideal conditions to break them down exist. These are called gravitational reconnection. “Einstein’s equations contain constraints on how space-time can evolve that are not immediately apparent,” said Asenjo in a press release. “By revealing these hidden new properties, we can begin to understand the fundamental rules governing how this gravitational reconnection process behaves.” Works like magnetism To simplify how gravitational reconnection works, the researchers took help from a similar phenomenon seen in magnetism called magnetic reconnection. “Magnetic reconnection is when these field lines, in some specific configuration, break and reattach in a different configuration,” Comisso said. “When they break and reconnect, they release energy.” In their study, the researchers argue that gravity can do the same. However, the geometry is different because Einstein’s space-time has four dimensions, instead of three. To make sense of this, the researchers suggest that gravity be considered as field sheets, instead of field lines. “Adding one dimension to a line gives you a plane. You can think of it as putting many lines together to form a ‘sheet,” explained Comisso. These sheets then stretch, move and reconnect, releasing energy, and although they are not physical objects, the reconnection is a mathematical process that describes how energy is transferred to matter. “It helps us predict some patterns of the space-time,” added Comisso in the press release. “Even without doing the full calculation, we know that space-time needs to behave in a certain way, that it needs to satisfy those constraints.” For now, gravitational reconnection is just a theoretical discovery. The researchers have to investigate how the process works in specific astrophysical events like a merging black holes. In these situations, the gravity can distort spacetime, making it difficult to calculate. Nevertheless, it will help scientists predict how much energy is released during these events and what signatures could be seen in gravitational waves. The researchers published their findings in the journal Physical Review D. Get the latest in engineering, tech, space & science - delivered daily to your inbox.Ameya is a science writer based in Hyderabad, India. A Molecular Biologist at heart, he traded the micropipette to write about science during the pandemic and does not want to go back. He likes to write about genetics, microbes, technology, and public policy.