Gravity Can Create Light, All on Its Own

As far as we know, our universe kicked off a long time ago by the Big Bang. One giant explosion set everything into motion and scattered the first material out into space.
Over time, the universe has changed and evolved in huge ways, forming generations of stars and planets, black holes, electromagnetic fields—you name it. But throughout all of this change, we can still see evidence of some of the earliest states of the universe.
Some of the most mysterious signatures from the beginning of time are gravitational waves. These waves, often referred to as ripples in spacetime, radiate through the universe and carry the effects of gravity out and away from the generating body. The strongest ones come from cataclysmic events like black hole mergers and supernovae—of the rapid expansion of the universe immediately following the Big Bang.
And, according to a new paper, some of the waves from that last category are strong enough that they can spontaneously generate light.
This Is Extraordinary: Gravity Can Create Light, All on Its Own