Ich habe bemerkt. Meine Zeit an der Universität Heidelberg ist schon lange her. Seitdem verlore ich mein Deutsch.

Cool, I get to practice German and Bitcoin. What a combo!

Warm stable air masses with high with moisture (high pressure systems) that make cirrus clouds, will generate the long condensation trails. When a cold air masses moves through an area, it is dry air. There will be very short trails if none at all.

I do not. It’s normal combustion of fuel at very cold temperatures.

Yes 100% true and that is done with small, typically twin engine piston airplanes. Not jetliners. A sim instructor at my company used to spray.

Hate to be the bearer of bad news but as a pro pilot flying 747s. High altitude cirrus clouds are associated with warm fronts. Burning Jet A or any hydrocarbon fuels like gasoline dos produce water vapor. Just like your car in winter, you see the cloud in the exhaust. Warm front over CO. When is it super cold like -15F, we boil water and throw it into the air right? What happens?

Good question and I doubt it.

One of these days I will shake your hand.

That’s awesome that you picked it up.

I’m looking forward to going to Breckenridge!

Love it!