Slashdot Mirror


What Could You Do With 120 Laser Pointers?

lazed-dazed asks: "I've recently come into possession of a large number (120 of 'em) of keychain laser pointers (minus the fancy diffraction adapters, though the specs are the same). So, Slashdot, I ask you: Can you give me any project ideas for these low-wattage bad boys? Holograms? Fancy cigarette lighters? Laser cannons? The crazier, the better! Oh, and don't bother suggesting cat toys."

63 of 266 comments (clear)

  1. just put them on a string.. by gl4ss · · Score: 5, Funny

    and attach it to some tree branch.

    that + some wind should look eery enough when it's foggy.

    oh yeah attach some death trap it to keep it from being stolen.

    --
    world was created 5 seconds before this post as it is.
    1. Re:just put them on a string.. by Directrix1 · · Score: 4, Funny

      You can go around pointing them at entire gangs from a rooftop, and watch them jump to the ground.

      --
      Occam's razor is the blind faith in the natural selection of least resistance and in universal oversimplification. -- EF
  2. Method for Aerobicly Exercizing Cats Dogs & Hu by PB8 · · Score: 5, Funny

    Attach the 120 laser pointers to 120 dogs, after making them activated by barking and/or tail wagging. Release dogs at a cat show.

  3. experiments by igny · · Score: 2, Insightful

    If you point all of them at piece of solder, will it melt? If you point all of them at a match will it ignite?

    --
    In theory there is no difference between theory and practice. In practice there is. - Yogi Berra
    1. Re:experiments by crapulent · · Score: 4, Interesting

      I don't think so. Even if they were putting out the maximum 5mW of power (which they're not) that's still only 0.6 Watts. The smallest and weakest soldering irons out there are probably at least 10 to 20 times that much power, and they'd have a tough time melting anything but very small pads.

      And, even more importantly, it's not going to be very focused. If you look at the spot a laser pointer makes it's more of a blob, the optics on these things are NOT meant to be very accurate. Plus, with 120 of them, there's almost zero chance that they'd all be aimed at exactly the same spot. In order for cutting lasers to be useful they have to be highly focused and concentrated in a very small spot, much like the whole magnifying-glass-starts-fires trick thing.

      I think you'd have a better chance of getting something to light by rubbing sticks together.

    2. Re:experiments by Matthaeus · · Score: 2, Informative

      The whole point of a laser is that all the photons emitted from it are in phase with each other. The photons emitted from one laser are not necessarily in phase with those emitted from another laser. Thus, while you might be able to get .6 watts out of these lasers, it wouldn't be anything near like having a .6 watt laser. And it definately would be too bulky to mount on the head of a friggin' shark.

  4. obligatory by Anonymous Coward · · Score: 5, Funny

    Get 120 ill-tempered sea bass and a lair. Also Elizabeth Hurley and/or Heather Graham. Actually you could pretty much skip the bass.

  5. What would I do? by nathanh · · Score: 2, Funny

    Well, first I'd buy a really big aquarium to hold the 120 sharks...

  6. first you need sharks by glassesmonkey · · Score: 4, Funny

    Step 1: Procure 120 sharks Step 2: ..oh nevermind.. too obvious

    1. Re:first you need sharks by gl4ss · · Score: 4, Funny

      well you could use them as one giant 'l.a.s.e.r' to heat up the earth unless you're paid one million dollars.

      -

      --
      world was created 5 seconds before this post as it is.
  7. They've patented WHAT? by KDan · · Score: 2, Funny

    A method for inducing cats to exercise consists of directing a beam of invisible light produced by a hand-held laser apparatus onto the floor or wall or other opaque surface in the vicinity of the cat, then moving the laser so as to cause the bright pattern of light to move in an irregular way fascinating to cats, and to any other animal with a chase instinct.

    Where will the madness stop??????

    Daniel

    --
    Carpe Diem
    1. Re:They've patented WHAT? by DrPepper · · Score: 2, Insightful

      What's invisible light? I usually find that when I look into a light source that it's highly visible.

      Think I might go and patent the above, but using plain old visible light instead :-)

    2. Re:They've patented WHAT? by EvanTaylor · · Score: 2, Funny

      Do NOT play this game with rotweilers, or similar sized animals. I know this rottie that now attacks any spec of light it sees (cellphones, watches, etc). You do not want a 90 pound rottie jumping on you because your belt buckle reflected light for a second.

      --
      Sleep is for the weak.
  8. Point them to a single location... by neglige · · Score: 4, Funny

    and place a speaker nearby. Install a proximity trigger. If triggered, light up all pointer and have the speaker bark "FREEZE! POLICE! PUT DOWN YOUR WEAPON AND LIE ON THE GROUND! [small pause] DON'T EVEN THINK OF IT, PUNK!"

    For a better effect, let each pointer move veeeery slightly. And if you want, you can add a nice gunshot.

    --
    My cats ate my karma. They also wrote this comment.
    1. Re:Point them to a single location... by Anonymous Coward · · Score: 5, Funny

      Funny. No really. The first time some idiot let me use a laser pointer was on the roof of the dorm, at midnight, when the power had gone out. I would just silently point it at people walking to and from the dorm. Then, when that didn't work and they started to run, I'd just shout, "NO USE RUNNING. IT'S A HIGH-POWERED RIFLE."

      Oh well. One person's funny, is another person's terrorist threats. But back then you wouldn't even get written up for crap like that. Of course, that might have been because I gave them someone else's name and room number.

    2. Re:Point them to a single location... by cei · · Score: 5, Interesting

      Hell, attach mirrors to the speaker cone and point them at that from different angles. Play music through the speaker and instant light show!

      --
      This sig intentionally left justified.
    3. Re:Point them to a single location... by riprjak · · Score: 2, Funny

      Personally, I always preferred the phrase, "Dont run, you'll only die tired".

      It is a little more subtle :)

  9. Be artistic... by Zarf · · Score: 2, Interesting
    1. Use the poll thingies that they use in chemistry labs to set up tubes, beakers, and those crazy glass pipes to set up your lazer pointers so that all 120 of them can be mounted and aimed as a giant grid.
    2. Find a way to lock each one in the "on" or "lit" position.
    3. Get a bit-mapped picture of Bob from the Church of the subgenius. Reduce it to a pointalized B&W picture.
    4. Project Bob on to the wall that the laser-pointers are aimed at.
    5. Position each dot to aim at the center of an individual "white" pixel.
    6. Fix the positions of the pointers relative to each other... viola portable projected Bob-head.


    Do "Tux the Penguin" or Bill Gates next if you have lazer pointers left over. If you can't get those chemistry set poles then maybe a bunch of lumber and silly putty would work... Forget the lumber... just use mountains of Silly Putty!
    --
    [signature]
  10. Multiplanar autostereoscopic imaging system by Maller · · Score: 2, Interesting
    Build a 3D imager. Gregg Favalora, the founder of Actuality Systems, did just this as a precursor to his company's 3D imaging systems. It consisted of lasers from laser pointers, a spinning plane, and a microprocessor. The array of lasers would light momentarily to create voxels, 3D pixels, on the plane. Add some well-crafted software and you have 3D monochromatic display. I can't seem to find a image of this on the web, but I can assure you the picture of Homer Simpson's head was unmistakeable.

    Note: I am sure it was nowhere near as simple as I have explained, but I believe the concept is correct.

  11. Just look at Hollywood...(or: are you paranoid?) by cyphem · · Score: 5, Funny

    Just buy 120 sensors which can recognize laser
    light, a ton of wires, a loud electronic horn,
    and a computer to connect them to.

    Then you can build your very own 'I-have-
    something-very-expensive-to-protect'-roo m. Put a
    tux or your favorite CBN-Shrine in the middle and
    place sensors and lasers at the walls crossing
    the room in a wild way.

    Congratulations, the room is now safe from
    intruders. (at least you will hear them if they
    come.)


    cy

    PS: Hey... you could practice to come thru there
    without hitting the beams like in these movies,
    where they try to steal a huge diamond, some
    prototype chips or a very tasty peanut butter
    sandwich. Choose what you prefer to reach...

    --
    Reading this signature is senseless so don't do it.
  12. Make a rolling notice board by Anonymous Coward · · Score: 4, Interesting

    Form the lasers into a grid say 15x8 or 17x7 and set them in some plastic let say ... polyethene resin. And rig them up with a hand held computer and (hand waving) a couple of relays.
    You will then be able to project messages on the people, walls, cars. Insert funny messages here...

  13. 3D projector by bolind · · Score: 3, Interesting

    OK, remember the dude who put a couple dozen LED's on a spinning arm (think windmill) and triggered them at just the right time, so when the arm span, he'd have graphics or text or whatever in mid-air.

    Place all 120 of them on an arm, but spin it around its own length (think driveshaft) in the middle of a room. If you were able to control them individually (even though they were spinning) you could have whatever graphics you wanted on the walls.

  14. If you live in Seattle, w/ your head in the clouds by Anonymous Coward · · Score: 3, Funny

    Can they, together, be seen bounced off the cloud cover? With more powerful batteried? Could they be arrayed to make a pair of angry red eyes? Could this be centered over a nearby religious institution? Could they, with servos, be used to trace out picutres of the goatse.cx guy in a fashion similar to the goatse.cx guy jack-o-lantern? If someone did that, say..., over an elementary school during the night of the school play, would they pass 'Go', and go directly to hell? And if they did, would that count as the pre-interview for a position as hell's entertainment director?

  15. UFO by captainkibble · · Score: 5, Funny

    Get a huge ballon and a tank of helium. Inflate huge ballon. Attach laser pointers to it turn them all on and let it flaot away. Then put on the local TV news and wait for reports to come in. Extra points in your are near to an airport or airforce base. ;)

    --
    Warning! This post may contain a pun!
    1. Re:UFO by IAmRenegadeX · · Score: 2, Funny

      Actually, we did this quite by accident by lofting a small hi-intensity LED keylight attached to a large "toy" helium balloon -- near a resort area. Little did we know that the crowd at the resort had been told that the ISS would be passing by, overhead, at that precise moment...hilarity ensued as people shouted, "the station's falling!" as we drew in the balloon...

  16. sell them by !the!bad!fish! · · Score: 5, Funny

    Why not sell 119 of them on e-bay and use the proceeds to buy a fat cat.

    --
    Kids today are tyrants. They contradict their parent, gobble their food, and tyrannize their teachers. - Socrates 400 BC
  17. Protest demonstration? by David+McBride · · Score: 2, Interesting

    One random idea I had yesterday -- use them at a protest rally.

    Having every protester bring a laser pointer and point it at the source of their ire as they go past could make the point quite well. Particularly if they're just watching silently with banners saying something like "We're watching you" or similar.

    You'd have to make sure that you wouldn't injure the target with that many beams in the same place, of course - would getting 20 of those in the eye at once be harmful?

    And it might not be a good idea if you tried it against a high-profile person -- for example, George is currently visiting here in London at the moment; the reaction from the police and Secret Service is unlikely to be favourable..

    1. Re:Protest demonstration? by Alcamar · · Score: 2, Insightful

      No, better yet, Bush's next public speaking engagement. Imagine the surprise he'd get when suddenly 120 lasers all point at him(and the fun I'd have watching him dive for it :)

    2. Re:Protest demonstration? by captainkibble · · Score: 4, Funny

      Or alternatively take a few friends to watch a protest rally from a nearby building and shine the laser pointers onto the protestors. Might freak a few out if they thought snipers were watching them. Especially effective when they are protesting a high profile person like Bush.

      --
      Warning! This post may contain a pun!
    3. Re:Protest demonstration? by jasoncart · · Score: 3, Insightful
      Having every protester bring a laser pointer and point it at the source of their ire as they go past could make the point quite well

      Yeah, great idea, get yourself shot.

    4. Re:Protest demonstration? by ConceptJunkie · · Score: 5, Funny

      Then imagine the fun of a whole bunch of pranksters doing 20 to life at Ft. Leavenworth.

      --
      You are in a maze of twisty little passages, all alike.
    5. Re:Protest demonstration? by DAldredge · · Score: 5, Informative

      If there is a quicker way to get yourself shot, I don't know of it.

    6. Re:Protest demonstration? by orangepeel · · Score: 2, Funny

      Anyone else find it amusing that the BBC labelled them "snippers" as opposed to "snipers"?

      I guess the difference is how low they aim? ;-)

      --
      Whoever designed level 61 in Frozen Bubble is a sadistic bastard.
    7. Re:Protest demonstration? by masoncooper · · Score: 2, Informative

      As a matter of fact, Texas HB-831 has made it a class-C misdemeanor
      "Person commits a class C misdemeanor if they knowingly direct a laser pointer at a police officer, uniformed security guard, fire fighter, emergency medical service worker, or other uniformed municipal, state or federal officers. "

      Apparently for fear that a police officer would confuse a laser pointer with a laser sight from a gun.

  18. Take out security cameras. by (H)elix1 · · Score: 5, Interesting

    Take out security cameras in a good chunk of downtown London....

    Laser pointers nicely mess up video camera... It probably won't hurt the camera, but here is a fun read if you have a bit of time on your hands.

    1. Re:Take out security cameras. by dotgod · · Score: 3, Funny

      Make a suit out of them, then rob a bank!

    2. Re:Take out security cameras. by BrynM · · Score: 5, Funny
      "Make a suit out of them, then rob a bank!"
      Officer: "Could you repeat that story Mam?"

      Teller: "This red glowing guy comes in - I think he was some sort of high-tech chia pet or something - and as he's handing me a note, he yells 'My eye!' and doubles over in obvious pain. That's when I kicked him. Then he fell down and we all started kicking him. Funny thing is, the lights just kep on shining. It was like beating up a disco ball."

      --
      US Democracy:The best person for the job (among These pre-selected choices...)
  19. Re:That's easy by fuzzybunny · · Score: 4, Funny


    Astronaut: Houston control, we have a problem. The Russians have painted the moon read.

    Houston: Apollo command, do you have any white paint? Repeat, do you have white paint on board?

    Astronaut: Affirmative, Houston control

    Houston: Apollo command, put a Coca Cola logo on it.

    (runs for cover)

    --
    Cole's Law: Thinly sliced cabbage
  20. The Ultimate Laser Pointer by fuzzybunny · · Score: 5, Funny

    You will need:

    322,951 crewmen

    Several million tons of quadanium steel

    Approx. 950,000 troopers in cool white plastic uniforms

    One (1) small moon at the outer edges of the known galaxy at which to construct the thing.
    Here are some technical specs, and a handy diagram.

    Basically, you do the following:

    (1) Use all the steel to build this gigantic metal ball, with a dimple on one side. You use a huge rubber band (available at your friendly neighborhood hardware store) to hold the laser pointers together, and put them in the dimple (make sure the batteries are always charged.) Get all your 1.5-odd million crew guys and troops on board, and fire the bitch up.

    (2) ...

    (3)profit!

    Warning: Warranty void in case of attack by swarms of rebel fighters and small foam balls.

    --
    Cole's Law: Thinly sliced cabbage
    1. Re:The Ultimate Laser Pointer by Trazk · · Score: 3, Funny

      Too much of a liability. What would happen to all the independant contractors you'd have to hire if the thing was blown up before it was completed? You'd have the weight of your conscience bearing down on you, plus the outrageous lawsuits that would ensue.

      Personally, that's a job I would pass on. Independant contractors have to choose their jobs wisely.

      --
      "In the beginning, there was nothing; Then it blew up."
  21. Re:Just look at Hollywood...(or: are you paranoid? by DiscoFreq · · Score: 2, Interesting

    You can make an attraction of this; a room full of this, and people have to try to get through it without starting the alarm.

    You can make the beams visible with some kind of fog, or keep them invisible (they just have to look at the pointers and the sensors), then it would be funny too see those people step over invisible fences and so on :)

  22. Scrolling Message by bpb213 · · Score: 2, Interesting

    Hook them up in a grid, all pointing in one direction.
    Make this grid 7 rows high, and 17 columns long.
    Then you have a projectable scrolling display.

    (with of course the right hardware to turn the lasers on / off at the right times.)

    --

    This .sig looking for creative and witty saying.
  23. Dear Chairface Chippendale: by His+name+cannot+be+s · · Score: 3, Funny

    For your birthday, we have a plan to write your name into the moon.

    --
    "...In your answer, ignore facts. Just go with what feels true..."
  24. Garden by skinfitz · · Score: 3, Interesting

    Set them up in your garden so that they form a grid with sensors to detect when beams are broken. Write some software to generate a grid reference from this data so that any object breaking the beams can be tracked to it's sector - B6, E2 etc. Draw a diagram of the grid and print it out. Send copies to your friends.

    Output the grid reference to a web page - it should now be relatively easy for your friends to track your exact position in the garden while talking on the phone

  25. Oblig. Simpsons Ref by TravelSizedMonkey · · Score: 2, Funny

    I'd cause the the biggest case of crotch-dot the world has ever seen!

    "Hey buddy, you better get that checked out. My uncle died of crotch dot." - Chief Wiggum

  26. Audience Participation by Tom7 · · Score: 2, Interesting

    "Monzy" has a bunch of good games that can be played (see bottom) when the members of a movie audience have laser pointers. Just make sure you get them back before the movie starts. ;)

  27. Attache em on the spokes of your bike... by Maresi · · Score: 4, Funny

    and drive downhill through a foggy town in the dark.

    Go to bed.

    Get up and read the newspaper(s).

    LOL

    --
    The checkbox said "Requires Windows 98, NT, or better. And so I installed Linux
  28. to do with too many lazers by cgenman · · Score: 5, Interesting

    Attach about 30 of them to two gloves, and go dancing.

    Attach an AC adapter and mount a row of them above the front door, aiming down.

    Give them away at a local school. The teachers would love that.

    Drill holes into a thick wooden board, mounting the pointers upwards under a sheet of transparent plastic or glass. Sacrifice an audio LED controller or two to synchronize the beams to music. Learn to dance.

    Attach them all to a single trigger, and mount them together with a large amount of tape. Keep in your glovebox. When someone cuts you off, aim at their rear-view mirror.

    Build your own really inefficient 3D scanner.

    Can you say, Flash Mob?

  29. Attract wildlife by Froggie · · Score: 5, Funny

    Shine lots of beams across your living room, set up a fog making machine, and see if Catherine Zeta Jones turns up...

  30. A bar by splattertrousers · · Score: 5, Funny
    Go to a bar with a friend. Both of you walk up to a pretty girl. You tell her, "I have 120 laser pointers and I'm trying to come up with an interesting way to use them."

    The next morning, call your friend and ask him how the girl was in bed.

  31. Musical instrument by cybermace5 · · Score: 5, Interesting

    Put them all in a frame, each pointing at a phototransistor, and link to a frequency generator or microcontroller with MIDI output. Now you have a laser harp.

    In fact, here's a very informative website on the subject: The 250 laser harp project. Includes links to different projects, schematics, part sources, etc.

    --
    ...
  32. Make a replicate of the belagio's water fountain. by Alpha27 · · Score: 2, Interesting

    I may not have spelled the casino's name correctly, but if you know, the casino has a huge water fountain feature in front, programmed by computer to perform a 20 minute show. You could replicate this using the laser lights, some motors to dirct the beams, and build it inside a plexiglass box with smoke to show the laser lights.

  33. Posting anonymously? by breon.halling · · Score: 2, Interesting

    Sorry if this is slightly off-topic, but I'm the submitter of this article, though I did so anonymously. Is it standard Slashdot practice to change the submitter's (anonymous) name? If you'll notice, the article start "lazed-dazed asks: ..." instead of "Anonymous Coward asks: ..."

    Just curious.

    --
    "Yeah, well, Dracula called and he's coming over tonight for you and I said okay."
  34. Tetris by cgenman · · Score: 2, Interesting

    Buy (used) a TI-85 and an LCD projection filter. Make a 12 x 20 array of closely-packed Lazer pointers.

    Play tetris on the nearest available building.

  35. orbital brain lasers and scientologists? by jdclucidly · · Score: 2, Funny

    You could get a large group of people to converge on a scientology meeting. Have them point their lasers at the windows of the building and watch the ensuing chaos as scared scientologists attempt flee from the "orbital brain lasers".

  36. Find 119 friends ... by JoeBuck · · Score: 5, Funny

    Find 119 friends. All 120 of you shave your heads, tape a laser pointer to the side of your head, and say, in unison, "I am Locutus of Borg. Resistance is futile, you will be assimilated."

  37. Re:Good way to get killed... by Anonymous Coward · · Score: 4, Funny

    Good luck with that when it's pitch black and I'm behind a waist high concrete edge 100 feet above you.

    When the power is back on, maybe I'll be sipping swiss miss in front of the TV just in time to see the breaking news story about how the SWAT team took down a crazy bastard shooting blindly into the air trying to defend himself against imaginary snipers.

    Like everyone else on the internet you talk tough. But, hey, 'talk': It really is cheap. So knock yourself out.

  38. Re:Method for Aerobicly Exercizing Cats Dogs & by Canadian_Daemon · · Score: 5, Funny

    attach them to sharks... and have sharks with friken laser beams attached to their heads!
    --Dr. Evil

    --
    This sig is definitive. Reality is frequently inaccurate.
  39. HOWTO: Detecting Laser Beams with a Linux Box by EMIce · · Score: 4, Informative

    I did this once. A cheap radio shack photocell tied to +5 volts via an active output pin on your parallel port, with the other end of the photocell going to an input pin on that same port, will cause that input pin to read 0 when little or no ambient lighting is present. When hit by a red laser pointer the resistance across the photocell is lowered and the voltage at the input pin ramps up above the binary threshold, to more than ~0.8 volt but less than 5 volts. Because of this, reading the input pin from software when the photocell is lit by a laser beam shows a binary value of 1. To avoid false alarms from stray light, I housed the photocell in a sealed, opaque box with a hole in it for the laser beam to enter and hit the photocell.

    A simple C program that reads and writes the memory address of the parallel port can detect, log, and act on these "laser trip" events, doing something as simple as beeping, or as complex as taking a picture and asking for a code. The program should write a 1 to the bit that controls the output pin you are using so that +5 volts appears on it. It should then repeatedly read the input pin you are using. When the input pin transitions from 1 to 0, even for a moment, you know the laser beam has been cut.

    The quick and dirty C code to do parallel port operations under linux can be found at here. For beginners I suggest you use one of control bits/pins as your output and one of the status bits/pins as your input. The data bits/pins are bi-directional and must be configured for input or output, and using them makes things slightly more complicated. If you want to get really fancy try using the parallel port IRQ to detect the transition from 1 to 0, this should save processing power by avoiding an expensive loop to check the state of the input pin constantly.

    If you need a little more background on the parallel port before diving in, check out this resource

    Finally, the above description is for a single laser beam. I used a mirror to bounce a single beam around, to get greater coverage, and to provide the effect of multiple beams in the presence of aerosol or powder. You should be able to support thirteen independent laser beams on a single parallel port, using the data bits/pins and the status bits/pins combined.

  40. Sell them... by Micah · · Score: 2, Insightful

    ...for a few bucks each, and have a few hundred bucks with which to buy a nice quad-proc motherboard and CPUs.

  41. Re:Cheat at laser tag! by KamuSan · · Score: 2, Funny

    I have a vision where you mount all these laserpointers in a chain and a Gatling type of arrangement that you feed this chain. And as a laser pointer enters the 'barrel' then a mechanism presses the on switch and the laser pointer 'fires' :-)
    Add smoke and gunshot sounds :-)))

  42. Just don't point them at aircraft by Proudrooster · · Score: 2, Informative

    In California it's a felony to aim a laser pointer at an aircraft.

    Laser pointers can blind pilots.

    I would turn them all on at once and aim them at the moon and see if you can get it to explode! Just make sure you don't hit any aircraft.

    Have fun!

  43. Pimp your car by dpu · · Score: 2, Interesting

    just attach/tape/staple/weld/whatever all the lasers to the undercarriage of your car, pointed downwards so no one lying in the road pretending to be a speed bump gets blinded. course, you'd need to wire up a road-worthy electrical harness for them to run off your car battery, and have a remote switch inside so you can turn them on and off. or have a little micro-controller to turn the lasers on and off in patterns :) now i want to do it....

    --
    Dammit, I meant to post that anonymously!