Source: Discovery News
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Spawning Conspiracy Theories
There are several conspiracy theories that involve aviation. The most famous of these involve the aliens of Roswell and the tragic events of September 11th. However, there is one conspiracy theory that has a measurable amount of believers that is easily refuted with the simple laws of science and statistics. This is, of course, chemtrails.
Those who subscribe to the Chemtrail theory believe that the entire aviation industry, military and civilian, are tasked by the U.S. government to spray artificial clouds high above the ground in our atmosphere with the intent of altering our climate or inoculating the population with inhalable drugs. This theory is based on the visible identification of the common aircraft contrail, and a reliance on the fallacy that it can be identified as something else.
So in a final sweeping motion, what do you say we explain-away this whole chemtrail thing after all, shall we?
The Science & History
When an organic material is burned, it will produce different compounds: soot, smoke, and various oxides. What is produced will vary depending on the material that was burned and the process in which it was burned. However there are two things that are generally universal in the burning of organics; water and carbon dioxide.
Generally, neither of these can be seen with the naked eye unless temperatures are cold and the steam condenses into visible water vapor. This is common from smoke stacks, the tailpipes of automobiles, or even your breath in the winter months.
The gasoline engine creates about one gallon of water for each gallon of gasoline consumed. When the engine is shut down, the remaining water oxidizes (or rusts) the exhaust and the engine’s cylinders. This limits the life of the exhaust system and the engine, but is not a major problem and is accepted as part of the normal process and life cycle of the internal combustion engine.
This water, seemingly innocuous, became lethal in the Second World War for the crews of the Boeing B-17 bomber. The four Wright turbocharged engines in the B-17 allowed it to climb above 30,000 feet. The humid exhaust of the engines quickly froze in the minus 40 degree air (temperatures become significantly colder at higher altitudes) leaving long white clouds behind the bombers indicating their presence and precise location to the German fighters. The safety of being at altitude was compromised by these telltale condensation trails, or contrails.
The military worked to find a solution and discovered that certain acidic compounds injected into the exhaust eliminated contrails. This solution became available after the conclusion of the war and was immediately obsolete with the advent of radar, which allowed airplanes to be “seen” regardless of the time of day or weather. This idea was later briefly resurrected with the Northrop B-2 stealth bomber, though ultimately not incorporated into the design.
The Commercial Jet Age
The post-war, high altitude commercial airliners typically operated around 25,000 feet. Only the low production Boeing 377, though still propeller-driven, could climb above 30,000 feet and was most commonly operated as an intercontinental airliner. Because of this, contrails were rarely seen in the United States prior to the 1960s.
The year 1958 was a watershed year in commercial aviation. Boeing introduced the 707 and Douglas the DC-8, while a year later Convair debuted the 880. The turbojet engines on these airliners thrived in the cold thin air found above 30,000 feet and they were routinely operated in these flight levels. In the 1960′s, contrails became commonplace across the United States, especially along designated jet airways between ground based navigation aids. When the temperature is low enough and the humidity high enough, the 1,500 gallons of water produced every hour by these jetliners was transformed into four cirrus clouds.
When the humidity is very high, the contrails will remain for hours. In moderate humidity the contrails may last . . .