It would be amazing and terrifying if true – a ‘laser AK-47’ that can set fire to targets and clothing from 800 metres (half a mile) away.
According to South China Morning Post, that’s exactly what researchers at a Chinese company called ZKZM Laser have developed.
The newspaper claims that the rifle beam cannot be seen by the naked eye, but can cause “instant carbonisation” of human skin and tissue.
According to the report, the weapon, called ZKZM-500 laser assault rifle, can light clothes on fire up to 800 metres away, even through windows.
The weapon apparently weighs 3 kilograms (6.6 pounds), is powered by a rechargeable lithium-ion battery, and can fire approximately 1,000 ‘shots’ lasting around 2 seconds.
“The pain will be beyond endurance,” allegedly said one of the researchers, who was not named in the SCMP article.
But alas, even the small amount of information given is raising some pretty big issues here – mostly due to a little something called the laws of physics.
Okay, so we all know that even low-powered lasers can damage eyes, but that’s because our eyes are an especially sensitive body part, and it’s the retina’s incredible ability to bounce light and heat around that causes the damage.
And yes, lasers can definitely heat stuff up. Proposed laser models have been created that could heat materials to temperatures hotter than the centre of the Sun in just 20 quadrillionths of a second.
But you have to put in a lot of energy to make it worthwhile. A small lithium-ion battery doesn’t quite cut it.
To create a portable laser that can heat up high enough to cook something in less than two seconds, you’d be looking at something much heavier than three kilograms.
Devin Coldewey, from Tech Crunch, ran some numbers, and even in imaginarily perfect circumstances, you’d be looking at something closer to the size and heaviness of a 90 kilogram (200 pound) Tesla Powerwall, as opposed to a relatively small gun.
According to Coldewey, you couldn’t even get a laser powered by a lithium-ion battery, which a person could actually lug around, to produce enough heat to hurt someone 1,000 times, even at point blank range.
When you look at producing that much power at the 800 metre limit the report mentions, even more issues come into play.
Lasers suffer from something called attenuation. When light goes through a medium (such as air or water), the laser will begin to lose its intensity. And this isn’t a small amount of loss, even at a much shorter distance than 800 metres.
While a laser beam can easily travel 800 metres and more, once it hit the target it would only be a fraction of the power it had at the beginning. Definitely not enough to fry a human or even their clothes.
So, what’s going on here? Well, right now we just don’t know why such crazy claims are circulating, although there is speculation this is all just government propaganda.
Perhaps the researchers have indeed found a way around all these issues, but we’re certainly not holding our breath. Until there’s a credible demonstration of this fanciful laser rifle, such guns are still only to be found in Star Wars, not real life.
Source : sciencealert.com