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A simulation reveals the combining of 2 great voids. (Image credit: SXS (Simulating eXtreme Spacetimes) Project)
Researchers have discovered gravitational waves coming from a great void merger event that suggest the resultant great void settled into a stable, round shape. These waves also reveal the merging great void may be much larger than previously thought.
When initially detected on May 21, 2019, the gravitational wave event called GW190521 was believed to have originated from a merger between 2 great voids, one with a mass equivalent to just over 85 suns and the other with a mass equivalent to about 66 suns. Researchers believed the merger therefore produced an approximately 142 solar mass child great void.
Recently studied spacetime vibrations from the merger-created black hole, rippling outward as the space settled into an appropriate round shape, appear to suggest it’s more massive than initially predicted. Instead of have 142 solar masses, computations say it should have a mass equivalent to around 250 times that of the sun.
These results could ultimately help researchers better test general relativity, Albert Einstein’s 1915 theory of gravity, which first introduced the concept of gravitational waves and great voids. “We are truly exploring a new frontier here,” Steven Giddings, a theoretical physicist at the University of California,
Related: How dancing great voids get close enough to combine
General relativity predicts that objects with mass warp the very fabric of space and time– joined as a single, four-dimensional entity called “spacetime””– and that “gravity” as we perceive it arises from the curvature itself.
Simply as a bowling ball placed on an extended rubber sheet causes a more severe “dent” than a tennis ball would, a great void causes more curvature in spacetime than a star does, and a star causes more curvature than a planet does. A black hole, in general relativity, is a point of matter so dense it causes curvature of spacetime so severe that, at a barrier called the event horizon, not even light is fast enough to escape the inward dent.
This isn’t the only revolutionary prediction of general relativity. Einstein also predicted that when objects accelerate, they should set the very fabric of spacetime ringing with ripples called gravitational waves. And again, the more massive the objects involved, the more drastic the phenomenon. This means that when dense bodies like great voids spiral around one another, constantly accelerating due to their circular movement, spacetime rings around them like a struck bell, buzzing with gravitational waves.
These ripples in spacetime carry away angular momentum from the spiraling great voids, which, in turn, causes the great voids’ mutual orbits to tighten up, drawing them together and increasing the frequency of the gravitational waves produced. Spiraling closer and closer,