zero point

Meanings

1. The location of the center of a burst of a nuclear weapon at the instant of detonation. The zero point may be in the air, or on or beneath the surface of land or water, depending upon the type of burst, and it is thus to be distinguished from ground zero.
2. Ground zero.

1. A children's game involving jumping over a chain of linked elastic bands.

Etymology

From early restandardization, possibly under influence of established US military terms such as zero hour, of the prior term point zero, which was coined during the Trinity Project, as point + zero, with zero being the code name for the Trinity test location. The original sense was that of ground zero and referred to only latitude and longitude, without regard to altitude, until the latter term's coinage in 1946.