Scientists have come up with yet another way the Earth could get destroyed by cosmic objects way beyond the planet's reach.
This time, it involves gravitational waves colliding to create a black hole that could lay waste to Earth. Fortunately, this appears to be an unlikely way for the apocalypse to occur.
The Two Types Of Gravitational Waves
Gravitational waves are ripples in space that are produced in a disturbance or movement in massive cosmic objects.
Most gravitational waves, New Scientist explains, are spherical and move outward the way ripples do in a pond. However, it can also be plane-fronted and move forward like a tidal wave. This type of gravitational wave is produced when the object or particle is moving at the speed of light.
According to Science Alert, the collision of two plane-fronted gravitational waves would result in a singularity that's the same kind found at the core of a black hole. While this sounds quite ominous, it's not a cause for concern, as the singularity usually just disappears quickly.
However, there is a specific sequence of events that may not be as harmless as what usually happens.
An Unlikely But Deadly Collision
New research, published in the pre-peer review website arXiv, reveals how a different type of collision involving gravitational waves could spell doom for the planet.
Physicists Frans Pretorius and William E. East calculated the effect of a collision between one point of a spherical gravitational wave and a plane-fronted gravitational wave — and it's not a very comforting hypothetical scenario.
If enough energy is expelled, space-time could actually envelop the singularity and create a black hole around it. This would absorb the powerful energy from the wave.
Science Alert points out that there's nothing in the universe that's known to expel the necessary amount of energy to form a black hole from gravitational waves.
However, if it does happen and it happens close enough to Earth, destruction would be certain for the planet. After all, gravitational waves that are strong enough to create a black hole would definitely obliterate all traces of nearby life.
"You wouldn't want it to be nearby, and if it were it would stretch Earth by thousands of kilometers and everything would be destroyed," astrophysicist Vitor Cardoso, an astrophysicist from the University of Lisbon, says in a New Scientist report by Leah Crane. "As soon as we learned about it, we would die."