Today, the light signals work on an electrical timing system.

今天，光信号在电子计时系统上工作。

All sorts of machines, from heating and cooling systems to assembly lines, rely on super-accurate satellite-based timing systems, and many have little-to-no backup options.

各种各样的机器，从加热和冷却系统到装配线，都依赖于超精确的基于卫星的计时系统，而且许多机器几乎没有备份选项。