The smallest size of a fissionable material that may sustain a nuclear sequence effect at a continuing level.
The amount of matter necessary to generate adequate gravitational power to prevent the present development of this universe.
An amount or degree needed for a specific result or brand-new action to happen: "The abrupt national uproar over medications and drug abuse has reached politically crucial mass in Washington” ( Tom Morganthau).
the quantity of fissile product which needed to support a self-sustaining nuclear chain effect
A quantity or amount expected to trigger a phenomenon.
the minimal size of fissionable product that will maintain a chain reaction
the minimum quantity (of some thing) needed to start or keep a venture