Body language Body language Body language is a type of nonverbal communication in which physical behaviors, as opposed to words, are used to express or convey information. Such behavior includes facial expressions, body posture, gestures, eye movement, touch and the use of space. Body language exists in both animals and humans, but this article focuses on interpretations of human body language. It is also known as kinesics. Body language must not be confused with sign language, as sign languages are full languages like spoken languages and have their own complex grammar systems, as well as being able to exhibit the fundamental properties
Wide-body aircraft wake turbulence is generally related to the weight of an aircraft, these categories are based on one of four weight categories: light, medium, heavy, and super. Due to their weight, all current wide-body aircraft are categorized as "heavy", or in the case of the A380 in U.S. airspace, "super". The wake-turbulence category also is used to guide the separation of aircraft. Super- and heavy-category aircraft require greater separation behind them than those in other categories. In some countries, such as the United States, it is a requirement to suffix the aircraft's call sign with the word "heavy" (or "super") when