When people want to talk about something unpleasant, they often invent nicer-sounding phrases to disguise what's really going on. "Wake turbulence" is the kind of term that can bring to mind vague, ...

It's common to see line-shaped clouds in the sky, known as contrails, trailing behind the engines of a jet airplane. What's not always visible is a vortex coming off of the tip of each wing--like two ...