Welcome to Bun Bang Fai, the festival where Laotians launch rockets at clouds to make them rain.
Laughing teenagers stop their mopeds in the dirt road. They’re watching five figures haul a thick, blue, two-meter-long tube up a huge bamboo frame. The figures descend and run towards you. Everyone starts counting down. Welcome to Bun Bang Fai, the festival where Laotians shoot rockets at clouds to make them rain.
Shooting at the sky may be a universal human instinct. Laotians have held their rocket festival every year for at least five centuries to provoke Phaya Thaen, the rain god, who makes his anger known through the medium of thunderstorms. In 19th-century France, Beaujolais winemakers would fire cannons at approaching hail storms until they went away, and for the 2008 Olympics, China tried to control rainfall by seeding clouds with silver iodide from 30 airplanes, 4,000 rocket launchers, and 7,000 anti-aircraft guns, with uncertain results.
If aggression fails†, there are gentler approaches to changing the weather. As well as praying for precipitation, 19th-century US farmers believed that the more land they cultivated, the more water would evaporate from irrigated fields, gather in clouds above and fall again as rain. The basic logic of this might be more convincing if farming didn’t often involve destroying some of the planet’s most efficient rainmakers: trees.
The leaves of a single tree in the rainforest canopy send 760 liters of water vapor into the atmosphere annually. It is estimated that the Amazon rainforest supplies over half its own rain in this way. Yet humans wipe out areas of foliage the size of Panama every year and most scientists don’t consider replanting trees to keep pace with such destruction a viable option. So they are increasingly focusing their research on mechanical means of influencing the global climate. Proposed geoengineering techniques range from installing giant mirrors in the desert to whitening clouds with seawater spray in order to reflect heat from the sun. British researchers have proposed pumping gases similar to those released by volcanoes into the upper atmosphere through a 19-kilometer-long pipe anchored to a boat and suspended from a balloon. The gases would block out sunlight, cooling the earth and temporarily reversing global warming.
Be careful when you choose your method of climate control, however, and don’t count on it working. Weather patterns are so chaotic, and forecasts so unreliable, that there’s no way to know for certain what actually makes a difference. Nevertheless, we continue looking for new things to fire at the sky, hoping one might turn out to be a silver bullet. “Sometimes they work,” says Uncle Bounkham, 56, of the rockets he makes for the festival in Baan Kern, Laos. “But sometimes they don’t.”
† During the Vietnam War, US planes seeded clouds over the Ho Chi Minh trail to mire Vietcong guerillas in mud. The artificial monsoons lasted 45 days; the results, according to the New York Times, were “inconclusive".
How to make a weather rocket
Cut down a large bamboo stem and boil it to remove the soft fibers inside. Bamboo is so tough the Indian army uses it for body armor, but be sure to get a thick stem, just to be safe.
Find a cave and collect the white crystals that crust the heaps of bat dung. This is saltpeter; grind it up with charcoal to make gunpowder, but don’t use metal implements – one spark would spell disaster.
If your village hasn’t already set up a launchpad, make a bamboo scaffold with friends. In the festival, position your rocket carefully, then launch it remotely using wires and a large battery.
The best rockets fly far and high, tracing white spirals of smoke in the sky; the worst kill spectators. Traditionally, rocketeers whose launches suffer even minor failures are thrown into a muddy pond by the crowd.
How to make rain
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Umbrella-shaped “ionizers” in the United Arab Emirates electrify the air, causing moisture to condense and form rain. They only work on days with at least 30 percent humidity, however. Days, that is, when it might well rain anyway.
The Chinese government’s weather-modification program has access to over 7,000 anti-aircraft guns and 4,500 rocket launchers, all primed for shooting at clouds. They fire special shells or rockets containing silver iodide to aid the formation of raindrops.
In 1953, psychoanalyst William Reich used his theory of a cosmic, libido-based energy called “orgone” to relieve drought-stricken blueberry farmers in Maine, USA. Reich set up his orgone-manipulating “cloudbuster” at 10am on July 6; it rained all night.
Bun Bang Fai, the annual Laotian fertility festival, is a chance for neighbors to get drunk, put on smutty shows and fire homemade rockets at the rain god in the sky, Phaya Thaen, in order to anger him into sending a thunderstorm.
In 1915, the council of San Diego, California, USA, hired “Moisture Accelerator” Charley Hatfield to relieve the city from drought. One month after Hatfield began releasing his secret cocktail of 23 chemicals into the air, heavy rain devastated the area, killing 20 people.
During a Bulgarian pagan Paparuda ritual, a young girl dressed in foliage dances through her village while her neighbors douse her with buckets of water. This attracts the weather god’s attention, who sends more rain for an encore performance.
Cement can “seed” clouds, but only if the powder stays dispersed and airborne. In 2008, a 25-kilogram sack of cement blasted a meter-wide hole in the roof of a Moscow building after a misguided attempt to seed clouds by the Russian Air Force.
Shooting infrared beams into the sky can create storm clouds by fusing sulfur and nitrogen gases into particles that attract moisture. Unfortunately, the Swiss researchers behind “rain lasers” have yet to find a way to make those clouds release any rain.