Where does escape collide?

In astrodynamics escape velocity is the minimum speed at which a body, given no further thrust, will coast away from a gravitating mass and never fall back, because its kinetic energy just equals the depth of the gravitational potential well. Bate, Mueller, and White's Fundamentals of astrodynamics derives it from conservation of energy, giving the familiar root-two-times-circular-speed result at a given radius. The referent is a threshold speed in a gravitational field, measured in kilometres per second, unrelated to a control character in text or a learned avoidance response.[1]

Unit

The threshold speed, in km/s, to coast free of a gravity well

Recovery means

Not applicable

Measured by

Computed from the gravitational parameter and radius via conservation of energy (v = sqrt(2 mu / r))

In the psychology of learning escape is a form of negative reinforcement in which an organism acquires a response that terminates an aversive stimulus already present, as a rat learns to cross a barrier that stops a shock. Domjan's The principles of learning and behavior distinguishes escape, where the response ends an ongoing aversive event, from avoidance, where it forestalls one. The referent is a learned instrumental response defined by its reinforcing removal of aversion, a construct unrelated to orbital speed or text encoding.[2]

Unit

A learned response whose reinforcer is the end of an aversive stimulus

Recovery means

Not applicable

Measured by

Indexed by acquisition and latency of the escape response and its resistance to extinction when aversion is removed