I've covered this before, but the more exposure on this the better. (My bold):
The $10m Silent Guardian weapon is part of a family of Raytheon's directed energy weapons, which also includes the larger Vigilant Eagle System, a high-powered microwave antennae the size of an advertising hoarding designed to fry the electronics of incoming shoulder-launched surface-to-air missiles up to 60 miles away, and the vehicle-mounted Active Denial System, which operates beyond small arms range (about 500 metres).
All are in the business of handing out pain. The human effects were evaluated by Sandia Laboratories and the Air Force Research Laboratories. Their findings: "This technology is capable of rapidly heating a person's skin to achieve a pain threshold that has been demonstrated by AFRL human subject testing to be very effective at repelling people, without burning the skin or causing other secondary effects." The device, it adds, "is an alternative to lethal force."
The human testing showed that the beams will penetrate even tiny openings and cracks in any physical barrier, including clothes, walls and shields. It is as though it wraps around corners to affect any piece of exposed body - the fingers or face, say, of those trying to hide.
Silent Guardian works by projecting a beam of microwave energy at a frequency of 94GHz up to a range of 250 metres. Raytheon says there is no comparison with radiation from a microwave oven, with a much higher frequency, and that it only penetrates the first skin layer, the epidermis, to a depth of 0.4mm, no matter how close to the beam you are. That's deep enough to trigger the sensory nerves in the skin. However, Andrew Rice, a consultant in pain medicine at Chelsea and Westminster Hospital in London, told New Scientist last year that "even if the use of temporary severe pain can be justified as a restraining measure, which I do not believe it can, the long-term physical and psychological effects are unknown".
What is clear is that this weapon ushers in a new era of paralysing weapons for urban warfare and, potentially, a techno-politics of border exclusion and crowd control. Raytheon insists that although pain is produced instantaneously, it will cause no damage, apparently on the assumption that targets will move away at once.
[snip]
Then last month in an interview with the US press, the US secretary of the Air Force, Michael Wynne, offered an equivocal opinion about the use of non-lethal weapons. "Non-lethal weapons are still being reviewed by the medical group ... Basically my point to them was [that] we need to start using that here in the US on Americans. And if we start using that here on Americans ... the first thing they will do is cry out that you have hurt them medically in a way that is pejorative."
Crucially, the secretary added: "So I think we should use it, if we're not willing to use it here, against our fellow citizens, then we should not be willing to use it in a wartime situation." His statement was interpreted initially as recommending the use of non-lethal weapons. But a more careful reading suggests that he was may have been warning against their use.
If we have a weapon we will use it. Against our own citizens. This is too great a temptation for any government in power. It would even be clever to use against your opponent in a presidential debate, say, where you could turn it on at a crucial point and make the opponent sweat and leap away and look like a fool...think of all the voters changing their minds to vote for you! And those damned dirty hippie protesters, and those stupid people who hold up signs in front of the White House.....
Just think what you could do to silence free speech!
Update 1/26:
Phila of Bouphonia has an excellent post on this::
Yesterday's demonstration of the active denial system - a directed-energy weapon that heats the water in human skin to an uncomfortable temperature - seems to have gone nicely:During the first media demonstration of the weapon yesterday, airmen fired beams from a large dish antenna mounted atop a Humvee at people pretending to be rioters and acting out other scenarios that US troops might encounter in war zones....
Anyone hit by the beam immediately jumped out of its path because of the sudden blast of heat throughout the body. While the heat was not painful, it was intense enough to make the participants think their clothes were about to ignite….
"There should be no collateral damage to this," said Senior Airman Adam Navin, 22, of Green Bay, Wis., who has served several tours in Iraq.
This is the first time I've ever heard the ADS described as "not painful"; the whole point of the weapon is to produce a level of pain that people can't tolerate.
Beyond that, an angry mob whose members are simultaneously trying to get out of the path of a heat ray sounds to me like an unbeatable recipe for "collateral damage."
