Quote (Black487 @ Mar 26 2013 05:48pm)

(This won't convince the nutters, but I find aviation and meteorology neat)

Contrail.  Short for Condensation Trail. 

There are two kinds I'm aware of, wingtip vortices and regular exhaust trails.

What happens when you take a icy cold drink, and leave it outside on a hot and humid day?  It develops condensation (as if by magic).  The icy beverage drops the surrounding air temperature to the dew point (point of saturation, where water turns from a gas to a liquid and becomes visible). 

http://www.koat.com/image/view/-/7242678/medRes/2/-/maxh/480/maxw/640/-/sbyn7z/-/bottles-of-beer-with-condensation.jpg

Contrails are kind-of similar in that they too produce condensation.  In Wing Vortices, air rolls off of the wings due to their shape, lift, etc and enter into a fast swirling motion like so:

http://i.imgur.com/yg4w53j.gif

In the center of the swirl (the part that looks like the eye) air pressure drops.  When pressure drops, temperature also drops (sometimes beyond the dew point).  Just like a cold bottle of beer dropping the air temperature and producing condensation, the cold core of the vortices can also produce visible condensation.  Like so:

http://images4.wikia.nocookie.net/__cb20121227140328/warthunder/images/f/f6/Wingtip_vortices.png

Since clean air is invisible to the eye, we can't really see the vortices without using some kind of way to dirty up the air (smoke, fog, clouds etc).  You can youtube demonstrations of this.  But we can occasionally see the condensation trails they produce. 



The other kind of contrail is through engine exhaust.  The two main products expelled by the engine are CO2 and water vapor. 

Anything above 24,000 feet will always freeze... and voila!

Quote (Aisu_aS @ Mar 26 2013 06:50pm)

Nah brah, all this makes too much sense. You are blind and it has to be chem trails.

Quote (doomchaser @ Mar 26 2013 09:54pm)

...there is a dif between con trails and chem trails..one does not effect the color of the whole sky and the other 1 can turn it a milky white...no other proof needed no other test needed people can see the truth ....wait I mean some people not all apparently...Now keep calling me a coco nut case you sad people

Quote (Black487 @ Mar 26 2013 07:56pm)

We have red contrails for precisely the same reason that we have red clouds... particularly near twilight.

What is more likely? That there is a global conspiracy happening in front of 7 billion witnesses every day or that there is some natural phenomenon with atmospheric processes which you don't aren't aware of?

You would literally have to dupe every scientist, university, aviator, skeptic. Worst of all, these things are all easily testable and provable yet here we are.

Quote (doomchaser @ Mar 26 2013 11:01pm)

listen young kid believe it or not the sky used to be blue not a milky white lmao  if you think con trails can do this  then yes you can argue about it i believe there is more then just con trails and I ask why chemicals there is a number of reason I for one like to think it is for savving us from the heat...some want to believe they want to kill us with it...Those like you just keep their eyes shut

Quote (doomchaser @ Mar 26 2013 06:54pm)

...there is a dif between con trails and chem trails..one does not effect the color of the whole sky and the other 1 can turn it a milky white...no other proof needed no other test needed people can see the truth ....

Quote (doomchaser @ Mar 27 2013 12:01am)

listen young kid

Quote (doomchaser @ Mar 27 2013 12:01am)

believe it or not the sky used to be blue not a milky white lmao  if you think con trails can do this  then yes you can argue about it i believe there is more then just con trails and I ask why chemicals there is a number of reason I for one like to think it is for savving us from the heat...some want to believe they want to kill us with it...Those like you just keep their eyes shut