A comprehensive resource for safe and responsible laser use
From mid-July 2016 to late August 2016, more than 570 persons have gone to the main government hospital in Srinagar, Kashmir for treatment of eyes that have been damaged by “birdshot” (lead pellets) fired from shotguns into crowds by Indian security forces trying to break up protests and crowds.
An August 28 2016 New York Times article describes some of the lead pellet-caused eye injuries:
“The patients have mutilated retinas, severed optic nerves, irises seeping out like puddles of ink.”
“[A] patient’s eyelids have been stretched back with a metal clamp, so his eyeball bulges out of glistening pink tissue. The surgeon sits with his back very straight, cutting with tiny movements of his fingers. Every now and then, a thread of blood appears in the patient’s eye socket. The patient is 8 years old…. Slowly, as residents stood around him in hushed silence, the surgeon flattened out the boy’s retina, as thin and delicate as a lace doily, and used a laser to reattach it to the back of his eye.
“In most cases, it became clear, the pellets had burst into through the cornea and out through the retina, leaving little hope of fully restoring vision…. ‘Once it goes in the eye, it rotates like this, and destroys everything there inside,’ Dr. Qureshi said. ‘It’s physics. This is a high-velocity body. It releases a high amount of energy inside. The lens, the iris, the retina get matted up.’”
The author, Ellen Barry, notes that “….most countries do not use them on unarmed civilians, as the pellets spray widely and cannot be aimed…. This year, the use of pellets on Kashmiri protesters increased sharply, with the police firing more than 3,000 canisters, or upward of 1.2 million pellets, in the first 32 days of the protests, the Central Reserve Police Force has said.”
From the New York Times
The prohibition lasts from July 18 through July 22. The list of items was first published by the city of Cleveland as part of regulations issued May 25 2016.
In the list, some items have specific descriptions, such as a restriction on “Lumber larger than 2” in width and 1⁄4” thick, including supports for signs” or “Umbrellas with metal tips.” For lasers, the list simply bans “Lasers;” there is no additional description such as allowing lasers under a certain size or power output.
The general public can possess a banned item if it is used in a workplace or at a home within the restricted zone, and if the item is used within the business or home.
The public is allowed to have guns in the event zone due to an Ohio state law allowing open carry by licensed gun owners. The event zone covers most of downtown Cleveland.
A much smaller security zone inside the convention arena, under the jurisdiction of the Secret Service, has banned guns.
From Wired and Q13 Fox. The city of Cleveland regulations are here. Click the “Read More…” link for a map of the event zone and the complete list of 72 banned items.
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One speaker noted “…we have had kinetic weapons for 500 years and laser weapons for 10-15 years…. The soldier wants a reliable, easy-to-handle, clear to understand system that has the reliability of a normal M16 rifle, or whatever, therefore the superiority is on the kinetic side.”
Author John Wills notes that laser sights are not as effective beyond 20 feet, and they do not substitute for marksmanship techniques such as grip and stance.
Glock Model 23 with M6 Tactical Laser Illuminator (xenon light plus red laser pointer < 5 mW).
Image from nukeit1 at Flickr, CC by 2.0 license.
Green laser sights are now available; they are more easily seen than an equivalent-power red laser. Infrared laser sights are made for use with night vision goggles. The beam cannot be seen by the naked eye, so a bad guy does not even know he is being targeted.
Wills concludes by saying “like any other tool there is a right way and a wrong way to use” lasers.
This differs from most pointers and handheld lasers, which use lasers that emit continuous light. This one emits a single, strong pulse each time the trigger is pulled. It is “enough to punch holes in plastic sheets, scorch wood, and pop balloons from several feet away” according to Dvice.com.
The maker, Patrick Priebe, posted a YouTube video showing the gun in action. He also was offering it for sale. According to Priebe, the gun uses a Q-switched Nd:YAG laser. It takes four seconds to charge the capacitor; the gun then fires a 100 nanosecond, 1 megawatt burst of infrared 1064 nanometer light. The gun took Priebe about 70 hours to build. His YouTube page offers to help others wanting to build their own laser gun.
SAFETY NOTE: Because the laser emits an invisible pulse, it would not be a visual interference hazard to aircraft (e.g., it could not cause glare or flashblindness). At close range the Q-switched pulse would definitely be an eye hazard, causing an explosive steam “pop” on the retina rather than the relatively slow burn of a continuous-wave laser. LaserPointerSafety.com has not done an analysis to determine the “safe” distance, beyond which it would not pose an eye hazard to pilots or others.
From Dvice.com and Hacked Gadgets forum