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Why Protesters In Cairo Use Laser Pointers
New submitter Ahmed Shaban writes "Why do protesters in Cairo use laser pointers? At the beginning, they were used to light up snipers on rooftops. Later, it just became fashionable to use them, and such things spread very fast among the youth of Cairo, who can find the high power laser pointers for sale on the sidewalks. The article contains amazing photos of a chopper lit up by green laser pointers."
No. Laser tag have fog machines.
Atmospheric effects like fog machines and hazers are why you can see them in Laser tag.
You can see the ones in the Egypt videos because they're just really powerful. Far more powerful that what is legally available in the USA without a variance.
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0 is the magic number.
With the Egyptian military completely on board with the protesters this time around, I guess the laser pointers dont have much actual purpose anymore.
Its actually quite remarkable what is happening there. More people were protesting than had voted for the president because the president decided that their constitution didnt apply to him, so the military takes down the president in response but remarkably doesnt assume power.
How many countries actually have a military that would do this sort of thing? I'm fairly certain that mine, with a military that runs an agency well known now for violating the constitution, would not.
"His name was James Damore."
...are the moronic A/Cs on /. who seem happy to denigrate the Egyptian people for celebrating the peaceful overthrow of a useless leader.
The fact that the army has removed these incompetants and are immediately handing power back to the people is un-precedented and incredible. The Egyptian people and army could teach some other nations a thing or two, I think, not to mention some of the ignorant bigots who plague /.
Smivs on the intertubes!
The military is on their side!...
Aren't these the same people that shoot live bullets in the air to celebrate? Maybe lasers are somewhat less dangerous...
Technically they did have democracy and got what they voted for, but what they didn't have were safeguards to ensure that a president couldn't just declare himself dictator for life after being elected. And so that's what he tried to do as early as possible. They need to adjust their system, institute checks and balances, constitutional changes requiring national referendums etc.
You use your cat to confuse riot police?
My understanding is that they didn't really have much of a choice in who to vote for. It was between a known bad guy and a probably bad guy, so they went with the latter due to lack of choices to begin with. Is it really a free and democratic election if you don't have choices?
Police and cats have much in common
1) They both enjoy stalking weaker prey
2) They both enjoy toying with their prey
3) They both have a love/hate relationship with lasers
4) There's tons of videos on YouTube of them both doing dumb things
If lasers are being sold for cheap on the street, odds are good that they're producing a wide range of wavelengths. The cheaper the laser, wider the range of wavelengths it emits. It's one of the reasons better lasers come with an IR filter to help reduce accidental blinding of observers.
Um, no. Not enough to say so, at least.
What makes a laser a laser is that it is a single wavelength. The light amplification process itself only works on a specific wavelength, and weeds out other light. You have to put extra circuitry into a laser to get it to produce a wider range.
Seems the same in US too..
I was in the dorms at college when Obama was elected for the first time. His supporters rioted and caused a bunch of property damage and ruffed up people.
There's also been cases of sports fans rioting when their team has won.
People do crazy shit to celebrate that just seems counterproductive to an outside observer.
If it were so easy, many South American countries would have become as prosperous and democratic as the US since their constitutions were basically copies of the US Constitution. Yet, somehow, it didn't really work.
You can see the same in many former British colonies. If you read their Constitution, you'll see that they're not much different from what you find in any modern democracy. Bill of rights, checks and balances, constitutional protections for both negative and positive rights. They also inherited the common law tradition and much of their legislation is copy-pasted from UK legislation circa 1960. It's so similar in theory that UK-trained lawyers can usually practice with minimum to nil extra training, as most of the legal education is done from UK textbooks and case books anyway.
Yet, in practice, it's quite different. Sure, you have the same theoretical protections, but they do little good when everyone is free to ignore them. It's nice to tell the courts that they have to be independent and fair, but how do you guarantee that?
"They need to adjust their system, institute checks and balances", etc. is all wishful thinking. It's about as useful as telling a developing country that all they need to do is grow. It's true but pretty useless as far as advice goes. The tricky part is knowing how to move from the equilibrium where the law is widely ignored, where formal checks and balances don't work, where the constitution is not worth the paper it's written on, to a better equilibrium. As far as I can tell, no-one has yet found a magic recipe for that because things are usually the way they are for a reason. It's not like bad institutions just spring up at random: they are usually people who have an interest in maintaining the status quo, and we were able to see times and times again that removing whoever happens to be in power doesn't do much to solve the structural problems and can even lead to worse outcomes (Iraq? Libya?).
If an aircraft is on auto-pilot, there's negligible risk.
If an aircraft is currently under human control while cruising, there's a slight risk.
If an aircraft is under human control while taking off, landing or performing any sort of maneuver, there's a reasonably significant risk.
Have you ever had someone shine a bright flashlight in your face? It's a lot like that. It causes you to jerk away, confuses you, and partially blinds you for anywhere from a few seconds to several minutes. Any of those can be deadly given that the person with the laser probably doesn't know if the aircraft is on autopilot or is preparing to land.
It's one of those laws where, sure, 98% of the time nothing bad will happen if you do it. But that last little bit of a time, something *really* bad could happen. So it's a felony.
Nope, just mail order that mofo. These guys sell 1W+ blue lasers:
Wicked Lasers -- any colour, any power, get em before they're gone.
---
ECHELON is a government program to find words like bomb, jihad, plutonium, assassinate, and anarchy.
Some laser pointers do put out IR wavelengths as a byproduct of the way they're built. Low-power laser pointers aren't a problem, the IR simply isn't powerful enough to do anything. But with 100mW+ laser being sold to ordinary people, there is a very real IR hazard from cheaply-made badly-filtered (or not filtered at all) laser pointers, especially green laser pointers.
The reason it's so dangerous is that unless you have special dual-wavelength safety glasses, they'll only filter out the visible light, leaving the IR output to wreck havok on your eyes.
http://en.wikipedia.org/wiki/Laser_pointer#Infrared_hazards_of_DPSS_laser_pointers
Eat the rich.
"The pilot should have bailed out and let the damned thing crash into the crowd."
Pilot bailing out....of a conventional helicopter.
And to think /. was once a techy site.
"This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
It's one of the big errors that scifi movies have with lasers in space combat (the other error being that laser pulses move slow enough to be seen).
If you had asked me, I would have said that it was lasers makes pew-pew noises in space.
When information is power, privacy is freedom.
It's all fun and games, 'til someone loses an eye.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Egyptians revere cats.
So obviously they are fascinated with laser pointers as well.
Troll is not a replacement for I disagree.
Is that not the textbook definition of a coup d'etat?
Just because a government is democratically elected doesn't mean it's a democracy. History is full of democratically elected governments that then turn into totalitarian regimes.
If Obama woke up tomorrow and ordered that all Tea Party members be arrested, I would expect our military to essentially remove him from office - in the immediate case by ignoring him, and in the longer case by Congress impeaching him and removing him from office - which would still require the cooperation of the military (they'd have to decide to listen to Congress and not the President.)
In Egypt, there isn't really a constitutional mechanism to get rid of a leader who, while democratically elected, isn't fulfilling his responsibilities as a democratic leader, so the best thing they have is the Army takes care of it.
So while this may technically be a coup in that the elected leader is being removed from office through a non-elective means, it's not necessarily undemocratic, if you believe the elected leader is abusing the freedoms of the people and the coup is to create the opportunity for someone who does respect the rights of the people to be elected.
paintball
I am sorry but you are plain wrong! "Enough energy to vapourize a ship" can be achieved with an infrared laser (photons of energy below 1 eV). Even if you allow for multiphoton interactions it is orders of magnitude below the threshold for the pair creation (1.02 MeV for electron-positron) . There aro no lasers that produce photons in MeV range. Also, the annihilation of electron and positron, which is the lowest energy particle-antiparticle anihilation, produces gama photons ~.51 MeV which are quite invisible to humans.
Although atmosphere does reduce the power, it's columnated light and in a vacuum anyway it would not lose any of its power. Dust, fog, humidity in the air will lower the power, but also cause you to be able to see the beam in the air. If you can't see the beam of a laser, it's likely delivering very close to 100% of its output power on target.
Years ago, when laser pointers were expensive, I had a 5mw red laser that we tested at 1/4 mile. It lit up an entire dumpster very nicely. (lenses weren't that good back then, it wouldn't hold a point for more than 25 feet or so, and TONS of scatter)
But on the other issue of power, just because it's a laser doesn't make it any more destructive than something else of the same power. A 100w lightbulb puts out 100x the power of a 1w laser pointer. And you don't see lightbulbs catching helicopters on fire. (even if focused in a spotlight) The only reason 1w lasers catch paper on fire is they're concentrating 1w of power into a 2mm x 2mm area. That would probably feel like a match at 1/2", enough to light paper. That's not going to melt metal obviously, at any range. The laser just lets you project that "half inch from a match" out several hundred yards. It doesn't make it more (or less) intense.
Somewhat back on topic though... wow.... that flight had to SUCK for those helicopter pilots. Someone hits one 727 with a laser pointer and the whole city loses their mind and the swat team rolls. That heli looks like it had 3-4 dozen green and at least two blue pointed at it. They would have to be out of their minds to look down except through cameras, and imagine the refractions going on inside the cockpit, with greens and blues scattering off all the shiny things. I bet that is an incredibly effective deterrent for the pilots.
Ironic, they sent in the helicopters as a show of force, and got driven off by the demonstrators using cheap, commonly available tech. Sort of like making the water canon truck leave by throwing rocks at it. Embarrassing.
I work for the Department of Redundancy Department.