The Explosive Paintball Flak Cannon would be a portable rapid-fire upward facing gun. It would fire exploding powdered dye shells that would be set to detonate at a certain altitude (or time after leaving gun -- whatever's easier).

The elevation and direction of the barrel would be computer-controlled so that a raster of sky would be scanned firing a shell when necessary to produce dots in the appropriate places.

Being based on discrete shells rather than smoke nozzles, the shells could be of different colours, allowing colour pictures to be printed in the sky as well as text messages.

Mounted on a trailer (with feet that can be locked down for firing), the Explosive Paintball Flak Cannon could be easily towed behind a car and taken to outdoor events.

Bigger versions could feature multiple barrels to spell larger messages/ draw larger pictures and to give smaller messages a longer lifespan on a windy day by printing the message faster. Alternatively, multiple units could be hooked up to the same computer and used to create large messages.
-- st3f, May 10 2005

The Skytypers http://www.skytypers.com/
A group that type messages in the sky using smoke nozzles behind aircarft flying in formation. [st3f, May 10 2005]

No need for dye. Ordinary flack is quite visible. http://www.homestea...son/files/flack.jpg
[ldischler, May 11 2005]

This had darned-well better be biodegradable soy-based ink.

Other than that, it's great.
-- shapu, May 10 2005


You could do animation by having successive scans explode just a bit closer on each pass.
-- Soterios, May 10 2005


Animation....I like that. This is beginning, in scale, to resemble John Varley's storms as a form of art.
-- normzone, May 10 2005


Animation? Cute extension to the idea. It would need a massive parallel array of cannons to do that, though.
-- st3f, May 10 2005


Maybe a really fast, motorized gatling cannon would do.
-- Soterios, May 11 2005


Nice. I guess you'd just need really fine control over the ballistics... presumably, it wouldn't take much difference in charge size/composition for the shells to wander a little over the distances involved. Chaos theory and all that. [+]
-- Adze, May 11 2005


Interesting idea but I'm not getting the dye or ink part. Isn't smoke the best choice?
-- bristolz, May 11 2005


No ink (the word paintball is just my own inaccurate mental shorthand), just a finely powdered dye (with a small explosive charge at the centre). The finer the powder the better it would be at hanging in the air once the charge has detonated. Smoke might hang in the air better (depends how fine you can make the powder) but I can't think of a way of accurately delivering that out of a cannon.
-- st3f, May 11 2005


Just like a firework, I'd think. The burst charge is surrounded by a very finely ground flammable material that generates a lot of smoke.
-- bristolz, May 11 2005


Actually I was just thinking about launching flares with parachutes to spell messages at night, but that might get expensive (as well as being more difficult to deploy accurately).
-- st3f, May 11 2005


Neat, so [+]... in spite of the fact that the only practical use for this would be offensively invasive advertising (with air pollution). Still pretty neat.

Then again, the powdered dye could perhaps be made of fertilizer, and be shot out over a field? (Explosives & fertilizers share a lot of chemicals...)
-- sophocles, May 11 2005



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