Talk:Main Page

I can't get through at the moment <a href=" http://bridgesventures.com/cheap-tadalafil/ ">generic tadalis</a> Patrick Smith, a pilot, also dismisses the theory in his book about air travel, Cockpit Confidential. “Contrails are formed when humid jet exhaust condenses into ice crystals in the cold, dry, upper-level air ­ it’s not unlike the fog that results when you exhale on a cold day,” he says. “Contrails are clouds, you could say. Water vapor, strange as it might sound, is a byproduct of the combustion within jet engines, which is where the humidity comes from. Whether a contrail forms is contingent on altitude and the ambient atmospheric makeup - mainly temperature and something known as vapour pressure.”