I paid my way. I never borrowed a shilling in my life. Can you feel that? I owe nothing.
Natural lightning is caused by the build-up of electric charge in thunderstorms. Florida, lying out as a prong between the Gulf of Mexico and the Atlantic Ocean, is especially prone to these. Sea breezes from the two warm bodies of water head inland and collide over the centre of the state. The warm air rushes upwards and then condenses into rain, ice, hail and something called graupel (a mixture of all three). As those particles collide and rub against each other, positive and negative electrical charges build up and separate in the clouds. Lightning occurs when those charges become so great that the air breaks down and conducts electricity between the two – mostly from cloud to cloud, but also down to the ground. “Triggered” lightning works by firing a rocket into the storm at around this moment. A copper wire attached to the rocket offers the charge an easy route to the ground and, about 70 per cent of the time, it takes it. (…)
The resulting wave of research, much of it funded by Nasa, laid the basis for current lightning safety. Many of lightning’s physical characteristics – its speed, temperature and current – were ascertained. Triggered lightning was used to test aircraft parts, runways, houses and power lines, and detection systems for lightning strikes were built across the world. Lightning still kills about 25,000 people a year (overwhelmingly in the developing world) and causes $1bn of damage annually in the US, but in terms of protection at least, a truce was declared.
In terms of how we understand it, however, lightning has only got stranger. The past 20 years have seen a series of confounding discoveries. In 1989, a group of scientists from the University of Minnesota were testing a video camera when they accidentally recorded an odd blossom of lightning rising out of the top of a storm. Over the next decade, other unexplained luminous phenomena (dubbed “Red Sprites”, “Blue Jets” and “Elves”) were also identified, billowing up from thunderstorms in columns and rings as high as 100km above Earth. Complicating matters further, in 2001 lightning was found to emit radiation. Not in odd or meagre quantities either. At every single stagger and step, lightning channels are now known to generate enough X-rays for a chest X-ray, despite having no obvious physical means to do so. Sometimes they also manage to blast off huge quantities of gamma rays, more often associated with collapsing stars – a process that may pose an as-yet poorly understood risk to aircraft.
image { Pierre Huyghe, No Ghost, Just a Shell, 2001 | More: video }
