Besides the supernatural comic that turned into a Syfy science fiction series, dark matter is the ghostly electromagnetic-radiation-resistant stuff most of the universe is made of. Now astronomers are on the brink of proving that what we’re actually floating around in could be an infinite graveyard of primordial black holes.
Black holes are obviously nothing new. We’ve been fascinated by the mysteries of these galactic points of no return (not to mention using them to scare the living daylights out of sci-fi moviegoers) since we knew they existed. It’s the possibility that our universe could be littered with them that has astronomers so eager prove it. Primordial black holes differ from the space-horror standard in that they are not vortices left behind by dead stars, but the relics of sound waves that echoed through space during Big Bang — and collapsed soon after.
NASA astrophysicist Alexander Kashlinksy believes the evidence of gravitational waves recently detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO) can shed light on the dark matter theory. "If this is correct, then all galaxies, including our own, are embedded within a vast sphere of black holes,” Kashlinsky says. Spooky.
Gravitational waves are ripples in spacetime, the cosmic tapestry of inextricably linked space and time that is also one of the more obscure things Einstein predicted in his now-immortal theory of relativity. They are also evidence of a collision between primordial black holes whose attempts to orbit each other were an epic fail. LIGO detects them by extending two arms that experience a microscopic warp if one happens to bend the fabric of spacetime by passing through them. Gravitational waves also give an advantage to probing telescopes, because while light waves shooting through space are easily warped by satellites and any other kind of matter, gravitational waves that surge through the blackness have the superpower of being unalterable. This has NASA even more excited because it means the ancient information encrypted in these waves will also stay intact in the face of a telescope lens. Exactly how ancient? Try 13 billion years.
Proof that dark matter was formed by primordial black holes could drastically change theories about the emergence of our nascent universe. Kashlinsky’s previous observations of infrared light in space gave a glimpse into what the far reaches of the cosmos looked like billions of years ago. Using NASA’s Spitzer Space Telescope, he was able to study celestial objects so many light-years away that by the time the image embedded in that light reached us earthlings, it was a glowing fossil of what those objects looked like before our planet even existed. There were just too many galaxies in the way. The luminous background that remained when light from every known galaxy was removed was the eerie phosphorescence of sound wave remnants.
NASA also used its Chandra X-Ray Observatory to observe the primeval glow from somewhere else in the electromagnetic spectrum. It would be telling if both experiments produced the same patterns of light. Sure enough, the excess cosmic X-ray background was identical to the excess cosmic infrared background, and the only phenomena in the universe (literally) which can pull this off are primordial black holes.
Dark matter began to spawn stars and planets in the first 500 million years of the universe’s existence when it collapsed into blobs they named halos, which sounds much more sci-fi than it actually is. Kashlinsky theorized that there would have been infinitely more halos if dark matter was made of primordial black holes. It would also prove that the similarity between the infrared and X-ray experiments was more than a cosmic coincidence. Early stars would not have been able to generate such an intense infrared glow as what he and his colleagues observed, and generating enough heat to spark X-rays would have been impossible unless black holes had contact with the gases that created those stars.
“It won’t be long before we’ll know if the [black hole] scenario … is either supported or ruled out,” says an optimistic Kashlinsky . While we still need more research to prove dark matter is made of even darker materials, it’s both creepy and mind-blowing to think that we could be suspended in a vast sound wave necropolis.