G-Man (Half-Life) refers to simply as his "employers". His mysterious nature has made him an icon of the "Half-Life" series, with his identity and motives remaining almost completely unexplained. The G-Man's name comes from "G-Man", an American colloquialism meaning "Government Man". However, within the "Half-Life" games, he is identified by this name only in the program code and the multiplayer profile menu as a default name option, not within the story itself; his name is derived from his "Half-Life" model and entity name and has since been reused in subsequent games of the series. His name has been confirmed and he has
G-force produce g-forces on the rocket and passengers. The unit of measure of acceleration in the International System of Units (SI) is m/s. However, to distinguish acceleration relative to free fall from simple acceleration (rate of change of velocity), the unit g (or g) is often used. One "g" is the acceleration due to gravity at the Earth's surface and is the standard gravity (symbol: "g"), defined as metres per second squared, or equivalently newtons of force per kilogram of mass. Note that the "unit definition" does not vary with location—the g-force when standing on the moon is about 0.181 g.