Chemtrails = complete bullshit. No science behind it, nothing to support it aside from nut jobs. Con trails are just condensed water vapor from engine exhaust. Sometimes they fade immediately, sometimes they hang in the air for hours. Has to do with temp, pressure and relative humidity of the air. Look up old film of ww2 bomber formations over europe, huge con trails...those guys didn't bring one ounce of gear that wasn't necessary, let alone barrels of chemicals.