The Product Requirements Document or PRD describes all aspects of a new idea required or desired to make its realization a success. The PRD is the bridge between the often vague project briefing and the highly detailed engineering implementation plan. It is also known as the Program Of Requirements (POR), …

Synchronizing modern electronic systems such as the Internet and GPS navigation is currently done using microwave atomic clocks that measure time based on the frequency of natural vibrations of cesium atoms. Those vibrations occur at microwave frequencies that can easily be used in electronic systems.   Optical atomic clocks will …