Add pigment dispensers to the wings of jet aircraft just above each engine exhaust cowling. Finely powdered hydrophilic pigment would mix with the turbulent jet exhaust and as the water in the exhaust cooled the pigment would be incorporated, adding brilliant color to the resulting ice crystals. The pigments I imagine using would be powerful dyes similar to crystal violet, safranin, and malachite green--a little goes a *very* long way. Of course the dyes actually selected must be harmless to man and the environment, and subject to biodegradation.
<preemptive PeterSealy-Deflection statement>No, don't even think it, this is not the same as conventional skywriting. Skywriters spray a type of paraffin/oil from onboard tanks into the hot exhaust to make a cloud of hydrocarbon vapor. I want to dye the water-ice crystals in a contrail.</preemptive PeterSealy-Deflection statement>
Visualize fluffy lines of color stretching across the entire sky at 30,000 feet...as if painted by a heavenly watercolorist...like a gigantic decorated Easter egg...a Teletubby kind of sky...I'll go take my lithium now.-- Dog Ed, May 04 2001 Sky Art https://www.atlasob...ht-path-art-contest [Klaatu, Jun 29 2019] Flight Aware https://flightaware...e/aircrafttype/RV10Track by airport, airline or aircraft type . [Klaatu, Jun 29 2019] If they were only used above cities where the atmospheric ecology is already wrecked and the smog is no fun to look at then it wouldn't hurt as much. Can they please be luminous?-- sirrobin, May 04 2001 I suppose you could write a pattern with an airliner, but it would have to be a very big pattern. I imagine a 747 has a turning circle of several miles.-- CasaLoco, May 04 2001 But, there are already all sorts of various, interesting colors inside you. I mean, you've got many different shades of pink, green, dark grey... haven't you ever been witness to a drive-by defenestration? ... oh, wait. I thought you said 'colored ENtrails'... nevermind!-- absterge, May 04 2001 Thpbtttt. Thpoilthportth. Reminds me of something Carl Sagan (I think) wrote, to the effect that even if NASA scientists found a way to dye the Moon pink in the name of science we certainly should not let them do it. Ok, give the kitty a fishbone...-- Dog Ed, May 04 2001 I think that this is cool. Cooler still if the dye used could change colors over time. It could start out really black to freak people out and then change to a pastel color. Airforce One could have red, white, white and blue.
FYI: The oil sky writers use is Texaco Canopus 13 (which used to be called Corvus oil and is used to help release concrete from wooden forms) it is supposedly non-toxic.-- gen1000, May 04 2001 gen1000: Thanks for the FYI. I looked for the info on aerobatic fliers' "smoke" but came up blank. I've seen it colored a murky red at an exhibition by the Canadian fighter-jocks, I don't remember their team moniker--not the Tumbling Maple Leaves? ;) I also saw the non-toxic notation several places, and that's good to remember next time you see an airshow. Isn't another trade name for the oil "Skywrite 19?"-- Dog Ed, May 04 2001 Oh, god no! FtLoGNO!! It perturbs me to see even my Google page marred with some kind of holiday cheer... black and orange, red and green... it's all part of the alien's scheme! alternating protein/sugar holidays! Please, please, please, no! I do not want to see halloween-easter-valentines-christmas-st patty's-4th-colored trails, inducing a sense of holiday through mass commercialization! Ack, ack, ack!! (forgive the blubbering, but this idea just struck a very sour chord with me)-- absterge, May 10 2001 Perhaps the colors could have a more pragmatic role. Blue contrails, for example, could denote jet aircraft, while red contrails would denote enemy ICBMs reentering the earth's atmosphere. This way you could take a look at the summer sky and know whether you should start panicking or not.-- RobGraham, May 10 2001 I'm surprised that this hasn't been a pride parade thing already.-- 2 fries shy of a happy meal, Jun 22 2019 // Of course the dyes actually selected must be harmless to man and the environment //
So endocrine disruptors that only affect women are still on the table…-- notexactly, Jun 23 2019 More easily done with flightaware.com <link> and without putting more cagada into our atmosphere.-- Klaatu, Jun 29 2019 Klaatu, oh my God, how the hell are you. Been a long time since Cali. Where you living?
Oh yeah, the idea, I remember Waugs loving it so it must be good.-- blissmiss, Jun 29 2019 What's more easily done?
(Though that reminds me that I need to diagnose and fix that PiAware that's been down for a couple of weeks…)-- notexactly, Jul 21 2019 random, halfbakery