rare events

In active galactic nuclei, supermassive black holes are surrounded by a dense ring of dust that acts like a curtain: it hides everything happening at the center. If a star ventures too close to the black hole, tidal forces tear it apart, and the resulting flare is usually visible in optical and X-ray light.

Buried in Antarctic ice, there's a detector the size of a cubic kilometer. It doesn't catch light but ghostly particles — neutrinos. Yet sometimes, a different beast might flash through: a pair of muons born together and flying apart in a wide fan. No known particle of ordinary matter can paint that pattern.

Picking out a single faulty microchip from a million, without any clue what the fault looks like, is a classic needle-in-a-haystack problem. A classical computer would test each chip one by one.

Two stars circle each other like dancers in a slow waltz. This dance is not eternal: the partners gradually draw closer until they collide and merge into a single entity. At that very moment, a red nova is born — a flash that lights up the sky for a few weeks, then slowly fades, enveloped in a dense cloud of dust.

Imagine a tiny coin hidden inside a perfect safe, but the walls are so thin that the coin sometimes slips right through, leaving a barely audible sound. Axions are like those coins — except instead of metal, they're particles, and instead of a safe, they're ordinary matter. They barely notice obstacles, making them incredibly hard to catch directly.

A multitude of atoms can act like a synchronized orchestra: if each emits light in unison with the rest, the flash becomes many times brighter. This is superradiance — a phenomenon well studied in the lab, but almost never sought in space. Now astrophysicists suspect that such collective 'notes' also play out in interstellar space.

In the ocean, sometimes a huge solitary wave appears out of nowhere and then vanishes. Such rogue waves are rare but dangerous. Similar rare and intense spikes occur in other systems, from financial markets to lasers. The problem is that they are hard to predict, let alone trigger on demand.

In the center of galaxy J2344 five years ago, a black hole tore apart a star, and now scorching gas bubbles there — a cosmic “stew pot”. Every 12 hours, giant X-ray bubbles rise in it, and on their ascent, super-hot splashes lasting 5–30 minutes appear.

When a massive star runs out of fuel, it collapses and explodes as a supernova. An instant before the catastrophe, neutrinos — ghostly particles — burst from the core. They rush through the star and interstellar space like the smell of smoke, heralding a fire that will only ignite minutes or even days later.

Detecting a faint signal against a noise background is like trying to hear a distant bell in a storm. Ordinary amplification only makes the din more deafening. Quantum error correction solves the problem in an unexpected way.

In 1997, the Pacific Ocean warmed so much that corals bleached from Indonesia to the Galápagos, and floods and droughts swept across five continents. Such events, which climate scientists call extreme El Niños, occur every few decades, and to understand how often they will arrive in the future, we need thousands of years of observations.

The galaxy is like a city at night: most windows shine steadily, but sometimes a skyscraper lights up all its lights and then goes dark. Just like that, according to a new hypothesis about planets around alien stars (exoplanet), we might first notice another civilization — by a short but blinding flash that could mark its demise.

The ocean doesn't always stick to the same schedule. Sometimes the warm El Niño current strengthens, sometimes it weakens, and each regime dictates its own reaction speed to the past. These hidden regimes are like shifts in currents that remember their path with different depths.