![]() As such, it is an unsurpassed method of dramatic instantaneous retributive destruction: thunderbolts as divine weapons can be found in many mythologies. Lightning plays a role in many mythologies, often as the weapon of a sky god and weather god. Neo-Attic bas-relief sculpture of Jupiter, holding a thunderbolt in his right hand detail from the Moncloa Puteal (Roman, 2nd century), National Archaeological Museum, Madrid Drawing from this powerful association, the thunderbolt is often found in military symbolism and semiotic representations of electricity. As a divine manifestation the thunderbolt has been a powerful symbol throughout history, and has appeared in many mythologies. In its original usage the word may also have been a description of the consequences of a close approach between two planetary cosmic bodies, as Plato suggested in Timaeus, or, according to Victor Clube, meteors, though this is not currently the case. It may have been a symbol of cosmic order, as expressed in the fragment from Heraclitus describing "the Thunderbolt that steers the course of all things". In Indo-European mythology, the thunderbolt was identified with the 'Sky Father' this association is also found in later Hellenic representations of Zeus and Vedic descriptions of the vajra wielded by the god Indra. “It’s important to consider this aspect of safety,” said Houard.Ptolemaic coin showing the Eagle of Zeus, holding a thunderboltĪ thunderbolt or lightning bolt is a symbolic representation of lightning when accompanied by a loud thunderclap. But the scientists believe the technology could still be useful, as launchpads and airports often have designated areas where no-fly restrictions apply. The laser is powerful enough to be a risk to the eyes of overflying pilots, and during the experiments air traffic was closed over the test site. These channels, which last for milliseconds, are more electrically conductive than the surrounding air, and so form an easier path for the lightning to follow. This leads to a long chain of what the researchers call filaments in the sky, where air molecules rapidly heat up and race away at supersonic speeds, leaving a channel of low density, ionised air. When laser pulses are fired into the sky, a change in the refractive index of the air makes them shrink and become so intense that they ionise air molecules around them. The laser diverts lightning bolts by creating an easier path for the electrical discharge to flow along. The footage shows that the lightning bolt followed the laser path for about 50 metres, suggesting that the pulses helped steer the strike. Only one strike, on 21 July, happened in clear enough conditions for the researchers to film the path of the lightning from two directions using high speed cameras several kilometres away. Instruments set up to record lightning strikes showed that the laser diverted the course of four upward lightning discharges over the course of the experiments. The scientists waited for storms to gather and between July and September last year, fired rapid laser pulses at thunderclouds for a total of more than six hours. Writing in the journal Nature Photonics, Houard and colleagues in Switzerland describe how they carted a powerful laser to the top of the Säntis mountain in north-eastern Switzerland and parked it near a 124m-high telecoms tower that is struck by lightning about 100 times a year. But in more recent times, scientists have looked for other ways to protect buildings and objects from damaging strikes. Traditional lightning rods date back to Benjamin Franklin who used to chase thunderstorms on horseback before his famous kite experiment in 1752. More than a billion bolts strike Earth each year, causing thousands of deaths, 10 times as many injuries, and damage that runs into tens of billions of dollars. The charge carried in a bolt is so intense that it reaches 30,000C, about five times hotter than the surface of the sun. Lightning bolts are huge electrical discharges that typically spark over two to three miles. “The hope is to extend that protection to a few hundred metres if we have enough energy in the laser.” “Metal rods are used almost everywhere to protect from lightning, but the area they can protect is limited to a few metres or tens of metres,” said Aurélien Houard, a physicist at École Polytechnique in Palaiseau.
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