Our intrepid hero works in an open office, within a short stone's throw of the IT Support Desk. They fool around every Friday (and most days between Friday and the following Thursday). The inane chatter and laughter is annoying and disruptive.

How can our intrepid hero create a hand-thrown silence grenade over the weekend?


  • Area of effect should be 10 m$^2$
  • Despite calling it a grenade it need not explode in the traditional sense
  • Should incapacitate those in the blast radius for ~ 8 hours
  • Fits in the palm of the hand and can be easily activated and thrown
  • Should have a delay mechanism...I don't want to knock myself out
  • Cannot be fatal/cause long term damage (I hear prison is pretty loud too)
  • Should not require any ridiculous future tech or military grade components
  • Works.

Desired Effect: Silence until 4:30pm at least.

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    $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$ – Monica Cellio Mar 14 '17 at 1:53

10 Answers 10


Creating silence is a tough ask. I think the best way to approach this is to fill the space in your office with something sound dampening.

In that case, what better approach than expanding, sticky, riot foam?

enter image description here

Evidently the stuff isn't that expensive, and if you can build grenades in your garage over the weekend, you are probably mad-genius enough to pack that aerosol into a tighter space.

Toss a few of those babies in the corridors in each direction from you to dissuade nuisances, and then pop a few more on top of the nearby cubicles. Wait and listen as the noises die down...after a brief bout of shouting and confusion. As an added bonus, if you gum up your boss he can't hassle you any more for the rest of the day. As a downside, the SWAT team probably will.

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    $\begingroup$ This photo looks like an alien hatchling ripping out of the white guy's chest. That you call it a "baby" doesn't help. $\endgroup$ – John Dvorak Mar 10 '17 at 21:10
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    $\begingroup$ Is the riot foam the suit or that terrifying mass that looks like snakes stuck to the guy? o_o $\endgroup$ – jpmc26 Mar 11 '17 at 0:08
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    $\begingroup$ I would assume it's the tentacles $\endgroup$ – user16973 Mar 11 '17 at 0:08
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    $\begingroup$ Ah, the beautifully Lovecraftian riot foam. Good idea. $\endgroup$ – Papayaman1000 Mar 11 '17 at 22:58

Sorry gents! Simply knocking people out won't work because that fat ba***rd, Ted, at the accounting desk snores like an elephant in heat. What we really need is active noise cancellation. Thankfully, this already exists: http://id2studio.at/content/noise/. Tossing one of these on each office window would/should effectively cancel everyone's sounds. It won't knock the loud mouthed goof-offs out, but your stated goal is silence, not jail-time.

ps - Here's a video demonstration: https://player.vimeo.com/video/71085920 And Sono isn't the only one. There's also Muzo and Whisper.

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    $\begingroup$ Do the Sono, Muzo, or Whisper actually exist? To me those videos look like art projects or concepts looking for investors. $\endgroup$ – Carl Kevinson Mar 10 '17 at 20:27
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    $\begingroup$ Sono was a concept that won a James Dyson Award. Whisper had a Kickstarter, but it failed. Muzo had a KickStarter campaign and is (I think) currently available for purchase. This is NOT an endorsement. I have never tried any of these. Like Kingledion, my door closes (plus, I'm usually the instigator of office shenanigans). $\endgroup$ – Tim Mar 10 '17 at 21:09
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    $\begingroup$ Sorry, it is just another case of industrial designers who decided to play engineers. This device cannot work, and does not exist (except in concept pictures). $\endgroup$ – Anpu Mar 11 '17 at 4:31
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    $\begingroup$ +1 to @Anpu's comment. A point source emitter cannot cancel a field, only a point. If you had four orthogonally positioned emitters and zero-latency tracking of a subject then maybe you could cancel all noise for that subject, but it would definitely require future / military tech. id2studio aside, the noise canceling grenade is not your answer. $\endgroup$ – MooseBoys Mar 11 '17 at 5:30
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    $\begingroup$ @SargeBorsch yes, you've caught up to exactly the point I was making. $\endgroup$ – hobbs Mar 11 '17 at 8:56

Sound can be cancelled by applying additional sound waves that cancel out existing sound waves and cause the vibrations that carry sound to flatten out. This is how sound-cancelling headphones work. However, there is a kickstarter campaign I heard about for something called the "Muzo", which is essentially a sound-cancelling speaker that operates on the same principle. You can stick it to your window to silence the street, to your desk to keep coworkers from hearing your computer activities, or stick it in the middle of your table at a restaurant to keep your conversations more private. I imagine that discretely placing a few of these around where you would expect the offending coworkers to be when they are making a ruckus could potentially effectively silence them and cause all sorts of hilarious disruption as you wirelessly activate and deactivate them at your pleasure.

This doesn't incapacitate anyone and can't be thrown, but it can be discretely planted in key locations where it would be unlikely to be found. Note that some people are driven nuts by complete silence and they need a little background sound in order to function normally. With a collection of a high-powered version of these speakers placed strategically around a target area, you may even be able to prevent your offenders from even hearing themselves, driving them mad and causing all sorts of hilarity.

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    $\begingroup$ I know that this idea works in theory, but is there any evidence of someone getting it to work? $\endgroup$ – Kevin Wells Mar 10 '17 at 21:06
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    $\begingroup$ @KevinWells only in a misunderstanding of theory, not in actual theory $\endgroup$ – Display Name Mar 11 '17 at 8:50
  • $\begingroup$ This seems to lack the important quality of being a grenade that can be thrown at or at least in the general direction of offenders. I think that is an implied desired quality of the solution being requested. After all no one creates a comic book out of the hero with the device that makes bad guys not act badly. $\endgroup$ – Chad Aug 25 '17 at 15:38

Organize an off-site meeting without going to the meeting.

  • You may need to obtain official-looking letterhead from the boss, CEO, or someone higher-up who isn't going to be in close contact with this group; if he intercepts the grenade, it's a dud. The stack of physical invitations may require two hands (breaking your constraint), but I think you'll manage. Depending on the number of interns available to you, "throwing" this grenade can take some time, but people will most likely believe a distributed letter over an email.
  • Speaking of which, you can go the digital route. Deployment logistics are reduced significantly and you can even schedule an automated delivery, but the interception vulnerability is greater due to the ease and immediacy of replying to an email. Plus, you can add an "emergency" constraint to throw this grenade whenever you want, which simplifies the location selection process.
  • And this brings us to picking the location. If the meeting is scheduled during work hours, the location should be at least 4 hours away (if people are to leave from the office) or 8 hours away (if people are leaving from home) from the office. This will ensure that everyone will get to the location and not be able to get back to the office by 4:30.
  • Luckily, having the grenade working more than once was not in your constraints. If word gets back to the scapegoat planner, this could be a one-time use only. However, it could also be everyone's little secret to take a scheduled day off at a Chuck E. Cheese's each year.
  • $\begingroup$ Not to be a downer, but if I got an email saying there was a meeting 4 hours away, I would definitely ask someone before blindly going for it. In fact, if there was a meeting 4 hours away, I wouldn't go even if it was confirmed to be real $\endgroup$ – Kevin Wells Mar 10 '17 at 21:09
  • $\begingroup$ @KevinWells I personally wouldn't be able to resist the allure of an expedition to Chuck E. Cheese's. Your coworkers may vary. $\endgroup$ – Bret Mar 10 '17 at 21:21
  • $\begingroup$ I wouldn't drive 4 hours for Chuck E. Cheese's, if I wanted to go to one, there are closer places, and I would go with my personal friends, not my co-workers. I think this would be a better suggestion if it was an invite to a fake company retreat, say to a ski resort or similar. Then people would be more likely to drive for it $\endgroup$ – Kevin Wells Mar 10 '17 at 21:36

Sleeping gas grenade

Sleeping gases can be nasty but basically take the stuff the dentist or doctor use to render patients unconscious for surgery and add it to an air tight container.

You will probably need to add quite a bit since the people in question won't have a mask over their face forcing them to inhale.

For the delay you could go with a timed trigger with a mechanical opening or if you don't feel the need to be fancy it could be a wax sealed container with a wick like a smoke bomb, wick melts the wax, the gas under pressure escapes.

Drawbacks of this plan.

  • Controlling the radius is going to be difficult (ideally you would use this in a closed room)
  • I am not sure what concentration of gas is required to knock someone out (and I am not googling that at work)
  • They will only be unconscious for a while, not the whole day, but when they come to they will feel like crap which should keep the shenanigans to a minimum
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    $\begingroup$ This sounds like a really bad idea. The concentration of gas required to knock someone out depends on body size and probably some other factors. There's a good chance you'd kill or permanently injure someone in your attempt. Also, gases spread out - having enough gas to knock out IT for more than just a minute or two would mean it would spread and knock out you as well. $\endgroup$ – Rob Watts Mar 10 '17 at 18:51
  • $\begingroup$ The other big problem with this (and any other inhaled solution) is that if there is enough in the space to knowck them out, then when they fall asleep, they will keep inhaling it until they die, particularly because these gases tend to be heavier than air and therefore pool near the ground $\endgroup$ – Kevin Wells Mar 10 '17 at 21:06
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    $\begingroup$ Wait, are you suggesting to administer gases that normally require a licensed profession in a controlled situation to avoid somebody dying? $\endgroup$ – Michael Mar 10 '17 at 21:23
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    $\begingroup$ @Michael when compared to explosives...yes. $\endgroup$ – James Mar 10 '17 at 21:24

You don't need a grenade. A grenade goes BOOM. What you need is carefully designed architecture.

What you need is an instant anechoic chamber - self assembling nanobots, that hopefully will cover the walls in spikes of soft, sound absorbing material, without, hopefully covering the co-workers in said material, resulting in a slow, quiet, painful death,

Or a less instant one with sound absorbing spikes on the walls.

Since the room's topology is known, you could, in theory back this up with active noise cancelling systems.

If you felt particularly evil (and didn't want to accidentally kill a few noisy co-workers , or add foam spikes to the walls manually), there's directional speakers on the market that you can use to beam the sound of people in the room to themselves... with a slight delay, which supposedly confuses people so they can't talk. They will go quiet eventually.


Hmm ... I think perhaps you're approaching the problem from the wrong angle. Instead of building something exotic to cancel sound waves, you need to build something simple to cancel your coworkers' desire to chatter all the time.

First thought. One of these:

hand grenade

Remove the pin, put it up on a cubicle wall, and warn co-workers that excessive vibrations in the air might set it off. You might ... acquire a reputation for being psychotically volatile, but hey. Peace and quiet is important too, why can't those fools see that?

Second thought. Get one of those bullhorns-in-a-can. Rig it to a volume-sensing machine. When it gets too noisy, it releases an annoying blare. Over time, Pavlovian (well, we're edging up on Skinnerian) conditioning will induce lovely silence in your coworkers.

Third thought. Set up one of those parabolic listening antennas. Live-stream their chatter to the Internet. This should have an inhibiting effect. (Warning: if there are amateur thespians in the crew, this could backfire, badly)

Final thought. This may seem trite and silly, but you could, like, ask them to pipe down...?


Making The Grenade If you must create a grenade for your purpose, then here is one. It will help you a lot in silencing down people, but you will have to use some sabotage and social networking skills to put it into action.

First, go to a hypno-therapist (perhaps without the dashes) and get a recording of his/her session for persuading the subject to go on a riot. Next, go to a electronic store and get several simple mp3 players in the shape of a grenade. Copy the hypno-therapist's session audio into your grenades and take them to your office.

Fire In The Hole!

At the desired time, quietly slip one into the waste bin of the desks where most of the noise is coming from. Now barricade yourself in the bathroom with the most attractive coworker of the opposite gender for the next 2 hours as the magic happens and all the noise escalates into an office-wide riot. Your boss will quickly fire all those noisy, rioting folk the next day. Make sure to remove your grenades the same day. If the new folk continue to be noisy, rinse and repeat until you get a batch of really quiet IT guys!

  • $\begingroup$ These sound bluetooth speakers grenades. Which are banned in my office :( Even the non-grenade bluetooth speakers! $\endgroup$ – kingledion Mar 10 '17 at 15:58
  • $\begingroup$ What about non-bluetooth grenades? The M40 military type? ;) @kingledion $\endgroup$ – Youstay Igo Mar 10 '17 at 17:11
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    $\begingroup$ This isn't science-based... Hypnotism doesn't actually work like that. $\endgroup$ – Rob Watts Mar 10 '17 at 18:56
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    $\begingroup$ Make sure to remove your grenades the same day, or else the janitor(s) will riot in the evening. $\endgroup$ – Peregrine Rook Mar 11 '17 at 1:51
  • $\begingroup$ Reading some books written by hypnotherapists tells me it does ;) @RobWatts For reference, read The Complete Idiot's Guide to Hypnosis by Roberta Temes $\endgroup$ – Youstay Igo Mar 11 '17 at 17:51

Etymotic Research ER20 ETYPlughttp://amzn.to/2cBbkmp

"Constructed of comfortable soft plastic, these earplugs are capable of much more. With a hearing attenuation of up to 20dB, they are perfect for industrial workers or anyone who regularly experiences high degrees of noise"

The product description says it all. They fit in your palm, and once you "throw" these silencers on, the sound canceling "incapacitation" begins immediately. They operate under fully time-controlled use at your whim, however, you WILL also be affected in that your own noise production will be within the"blast" zone. No special tech or military grade materials required.

They work.


Grenade plays simulacrum of the office's fire alarm. Protagonist locks doors once everyone leaves.

Grenade releases horrifically foul smelling odour.

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    $\begingroup$ Why would you release a foul odor after the building has been evacuated? And if you mean that as a separate suggestion, why would the OP want to keep working in a foul smelling office? $\endgroup$ – Kevin Wells Mar 10 '17 at 21:10
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    $\begingroup$ I'm sorry, but I laughed out loud at the foul smelling odor after getting everyone out of the building. That sounds like one of Pinky's plans from Pinky and the Brain. "Well its quiet in here finally, but it smells like farts" $\endgroup$ – kingledion Mar 10 '17 at 21:39
  • $\begingroup$ @KevinWells - I would guess that there should be an "or", not an "and" assumed. If so these are alternate versions of grenades - perhaps for use on different days. After all, the fire alarm will be looked into, or ignored, if used too often - being able to switch it up may let both be effective more times. $\endgroup$ – Megha Mar 12 '17 at 4:45

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