The storm that never quite ends, the stones that warn the unborn, and the machine that only pretended to think

The numbers are the reason it has a reputation. The storm fires on something like 140 to 160 nights a year, can run for nine hours at a stretch, and in its busiest spells flashes dozens of times a minute.[5] Sailors once used it as a natural lighthouse, the beacon of Maracaibo, steering by its glow long before anyone measured it,[2] and the lightning still marks the flag and coat of arms of Zulia state.[7]

For a long time the claim rested on eyewitness awe rather than measurement. That changed when a NASA instrument settled it. A satellite-borne sensor that counts lightning from orbit, watching for sixteen years between 1998 and 2013, found that Lake Maracaibo outflashed every other place on the planet, at about 232.52 strikes per square kilometre each year.[1][3] The lake edged out the Congo Basin, long assumed to be the record holder, because the newer study looked at the ground in finer squares and caught a local peak that coarser maps had smoothed away.[2] The record keepers at Guinness had already recognised the site in 2013 as the greatest concentration of lightning anywhere.[4]

What keeps the storm pinned in one place is geography, not anything exotic. The lake stays warm, and by day the tropical sun sets the local winds converging. Moist air off the Caribbean meets cooler air sliding down the mountains that wall in the basin, and the collision shoves the warm air upward into towering storm clouds, night after night over the same water.[2] Thunderstorms build there on close to three hundred days a year.[2] Older guesses that some gas rising from the swamps or the bedrock made the lightning special never fit the seasons the storm actually follows.[5]

It is not, despite the nickname, eternal. In early 2010 a severe drought starved the storm of the moisture it feeds on, and for several weeks the lake went dark at night before the rains returned and the lightning came back to its old address.[6]

Hundreds of these markers, some more than six centuries old, line the Sanriku coast. Many went up after the great tsunamis of 1896 and 1933, telling those who came later to run uphill, or recording how far the water had once reached.[1][5] A few even survive as place names, so that a valley or a stretch of shore carries its own warning to anyone who reads it.[1]

The most quoted of them stands above Aneyoshi, a hamlet in the city of Miyako in Iwate prefecture.[6] Its message, in the reporting that made it known abroad, runs roughly like this.[1]

High dwellings are the peace and harmony of our descendants.
Remember the calamity of the great tsunamis.
Do not build any homes below this point.

Inscription on the Aneyoshi tsunami stone, as translated in 2011 reporting[1]

The stone earned its place. When the wave of 1896 came through, only two of the hamlet’s residents lived; when another struck in 1933, the survivors again numbered a handful.[3][1] The village gave up on the shoreline, moved its houses to high ground, and planted the marker at the line the water must not be allowed to cross.[3]

In March 2011, the largest tsunami in living memory climbed the same valley. It rose and rose, and then it stopped just short of the stone. Researchers who mapped the flood put the water’s reach at 38.9 metres, halting only about half a metre below the marker, and every house above it came through undamaged.[3][1]

Elsewhere the lesson had faded. As towns grew and tall concrete seawalls promised safety, many old markers were built past or forgotten, and disaster scholars note that it takes only about three generations for a community to lose the memory.[4] A few places held the line by other means. The village of Fudai owed its survival to a former mayor who had seen the earlier waves and forced through a floodgate more than fifteen metres high, over complaints that it was a waste; in 2011 the barrier held and the village was largely spared.[2]

The stones are a piece of low technology aimed at a hard problem, which is how to make a warning outlast the people who received it. They work only when the living still read them.[4]

Its maker was Wolfgang von Kempelen, a civil servant in the Habsburg court with a gift for engineering. He built the automaton to impress Empress Maria Theresa after watching a conjuror perform, promising something more astonishing and returning a few months later with a life-sized player dressed in Ottoman robes, seated behind a cabinet.[1][5]

The performance was built to disarm suspicion. Before a game the showman would swing open the cabinet doors and pull out a drawer, revealing a dense tangle of gears and levers, apparently proving that nothing human could be folded inside.[3] Then the figure would raise its arm and play, and usually beat whoever sat across from it.[2]

There was, of course, a person inside. A strong chess player crouched within the cabinet and slid along a rolling seat, shifting from compartment to compartment to stay behind whichever door the showman happened to open.[3][1] Magnets set into the underside of each piece let the hidden player read the moves on the board above, and a system of levers carried his own moves up into the figure’s arm.[3]

Because a capable human ran it, the Turk played real chess against real opponents. In Paris around 1783 it faced Benjamin Franklin, then the American envoy and a devoted player of the game.[2] The finest player of the age, François-André Philidor, managed to beat it, but is said to have called the match one of the most tiring of his life.[3] The story that Napoleon played it at a palace near Vienna in 1809 and tried to cheat is often told, though the vivid versions contradict one another and are best treated as legend.[3]

After Kempelen died in 1804, the machine passed to Johann Nepomuk Maelzel, the showman who did much to popularise the metronome, and he toured it through Europe and across America.[3] In 1836 the writer Edgar Allan Poe examined it and argued in a widely read essay that a mind, not clockwork, had to be steering the moves. He was right about that, and wrong about several of the particulars.[3][2] The Turk’s run ended in a Philadelphia fire in 1854, and the full method was set down in print only a few years later.[4]

For all its brass and clockwork, the Turk never held a single idea about chess. Its real machinery was the sliding seat and the magnets that kept a living player hidden, game after game, in front of crowds who had come hoping to be fooled.[1]