Carl Sagan - "The illegality of cannabis is outrageous, an impediment to full utilization of a drug which helps produce the serenity and insight, sensitivity and fellowship so desperately needed in this increasingly mad and dangerous world.
Holy smoke: Incredible images of vapour trails and cones created by planes in the sky
Humans sometimes make cloud formations without realizing it. High-flying military planes and low-flying commercial planes cause disturbances in clouds. By doing so, they create their own formations. These aren't "real" cloud formations, of course,