ON 2 NOVEMBER 2012, an intense burst of radio waves flashed across the skies above the Caribbean island of Puerto Rico. There was no spectacular fireworks display visible to human eyes, but the signal was captured by the 305-metre-wide radio dish of the Arecibo Observatory, nestled among the island’s forest-covered peaks.
Radio astronomers had been waiting for one of these for a while: a fast radio burst. Lasting only a few thousandths of a second, these super-bright pulses are thought to come from deep space, and are extremely rare. The Arecibo burst was only the eleventh ever detected. There was a suspicion that all previous readings, from a single radio telescope in Australia, were down to a technical glitch.
They weren’t. But what these strange pulses are remains a mystery. Some think they come from super-dense stars orblack holes dancing with those stars. Some have even floated the idea – one few people are willing to buy – that they could be “hailing signals” from aliens.
“At stake are not only black holes and space-time, but the start of everything”
The latest idea is that they could encode something equally astonishing: a signal from black holes behaving in an entirely new way. If so, it would transform our understanding of these most enigmatic cosmic objects, and mark the beginning of the end of a quest to reconcile two fundamentally irreconcilable descriptions of the physical universe. It might even explain the beginning of it all.