dufus Posted July 2, 2018 Share Posted July 2, 2018 Humans have dreamed of weaponised lasers since HG Wells first mooted them. Should we be careful what we wish for? You can thank HG Wells for the idea of a ray gun. Weaponised lasers, microwave beams, particle beams and so on ... Wells’s Martian death rays in 1897’s War of the Worlds sparked the concept. Twenty years later one Albert Einstein offered a proof of concept in 1917, and then Charles Townes finally made one (OK, a laser) in 1951. Star Trek injected further vim to the fantasy of handheld zappers with its phasers, followed by the blasters of Star Wars – enough appetite to stimulate real military research – remember Ronald “Ray gun” and his Star Warsprogramme? Charles Townes with his maser, the forerunner to the laser. Photograph: AP Military research into so-called directed energy weapons (Dew), continues to this day. So why, in the 21st century, are we still hurling bits of hot metal about? Where’s my ray gun? Compared with conventional weapons, a laser could be deadly accurate, silent, light speed, cheap to use and would never run out of ammo. But so far, the chemical reactions in guns and artillery are just heaps more efficient. Bang bang rather than pew pew, still To pack the same kinetic punch as a bullet, you need a lot of energy to deliver the mass. For a laser beam, say, made of (massless) photons, that’s around 2,000 joules of sharply focused energy – at least 30,000 watts per zap. At present, that entails a colossal power pack – a battery the size of a bedstead is fine on a large vessel such as a boat or a plane (and don’t worry, they’re working on them), but problematic for a handgun. Compounding this is the fact that lasers are notoriously inefficient. Air is an awful medium for a laser beam to travel through, made worse by rain, fog or smoke – the sort of conditions you’d find on a battlefield. It’ll have to be as powerful as possible, so wave goodbye to those rapid-fire rods of glowing death you see in Star Wars because visible light scatters energy, so isn’t efficient enough (and besides, photons can’t be persuaded to do that). And with all that power comes the problem of overheating so your gun might melt before you could hit anything. However, a new technology called adaptive optics, which was developed for telescopes to compensate for atmospheric noise and concentrates the beams, aims to overcome some of these challenges. Naturally, the world’s various militaries are still developing these types of weapons, but the US has the only one known to be in use – a lower-energy laser system that can zap landmines, called Zeus. Nearly all research programmes seem to become defunct, the funding withdrawn, only for a successor project to pop up like a space-age Whac-A-Mole. And these are just the ones they’ve told us about. Star Wars, or the Strategic Defense Initiative, envisioned satellite-borne x-ray lasers zapping intercontinental ballistic missiles (ICBMs) out of the sky. The US army’s tactical high energy laser (Thel) was a sort of son of Star Wars. It could shoot down incoming missiles travelling at Mach 1 from more than six miles. Discontinued in 2005, Thel begat the US Air Force’s Airborne Laser,nicknamed YAL-1, which can destroy a ground target 60 miles away from a jumbo jet cruising at 12,192 metres (40,000 ft). The US Navy’s version, the Free Electron Laser, looked promising but funding ceased with the introduction of Northrop Grumman’s Firestrike array in 2008. Costing just 59 cents (44p) a shot, and being powerful and accurate enough to disable airborne ICBMs, rockets and even flying shells, it’s easy to see why Firestrike proved popular. An infrared image of the Missile Defense Agency’s Airborne Laser destroying a target missile. Photograph: AP A frightening (and for now unlikely) future Plasma weapons might trump lasers. These fire a beam of plasma – basically what lightning and the sun is made of. As far back as 1993, the US was working on the mysterious Marauder project, designed to hurl doughnut-shaped plasma projectiles at near the speed of light. It proved remarkably successful but suddenly the lab fell silent after 1995. The latest effort, the BBC reports, is a laser-guided lightning weapon developed by the US Army called the Laser-Induced Plasma Channel. It uses a laser beam so intense it creates plasma along its beam – if that works it will be scary. The US air force also developed a microwave weapon used for riot control. The Active Denial System causes debilitating pain by heating the water in your skin but is still being tested for long-term side effects.Naturally, police forces in the US and China are holding out for a handheld version. These microwaves – such as the ones given off by your mobile phone signal – might also be used to zap missile and plane electronics remotely. Likewise, EMP strikes could be potentially catastrophic – enough to fry an entire city’s electrical infrastructure. Experts at the University of Michigan are looking at those to direct at airborne threats. The idea of particle beam weapons, which emit a high-energy beam of subatomic particles that can turn a target’s atomic structure into scrambled eggs, has even been mooted. The downside of this idea is, while they would work fine in a vacuum, those particles scatter and bounce around in an atmosphere, bathing the assailant in a lethal dose of radiation. Hoist by your own atomic petard. Adaptive optics may soon make dogfights, or even missiles, a thing of the past but are we any closer to our handheld ray gun? Perhaps the closest we have is the US Army’s PHASR, designed simply to temporarily blind and disorient targets. And engineer Pete Bitar, whose company develops non-lethal directed energy weapon tech to fry the electronics of potential truck bombs, is just one expert among many who say his tech could easily be adapted for handheld devices – even smartphones – within years. You may have to wait for your ray gun – but anyway, haven’t we got more pressing things to worry about? https://www.theguardian.com/technology/2018/jun/26/ray-guns-will-they-ever-be-more-than-cool-toys Link to comment Share on other sites More sharing options...
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