critical mass

• 指实现某种显著效果、进程或连锁反应所需的最低数量或规模。最初为核物理术语，现广泛用于商业、科技和社会领域。

The minimum amount or size of something required to start or sustain a significant effect, process, or chain reaction. Originally a nuclear physics term, now widely used in business, technology, and social contexts.

1. Nuclear physicsC1formal

   The minimum amount of fissile material needed to sustain a nuclear chain reaction.

   临界质量

   • The scientists carefully calculated the critical mass for the reactor.
   • Reaching critical mass is essential for a nuclear explosion.
   • The experiment required a precise amount of uranium to achieve critical mass.

2. Sufficient quantityB2formal

   The minimum amount or number of something required to start or sustain a process or movement.

   临界质量

   • The campaign needs to reach a critical mass of supporters to be effective.
   • Once the company achieved critical mass, its growth accelerated rapidly.
   • The movement gained critical mass after the public protest.