When we use moment or jiffy, as in “I’ll be back in a moment” or “She’ll be with you in a jiffy,” we usually mean in an undefined but brief period of time, but in fact, both have a precise length.
Although lost through time, a moment was originally an English reference for ninety seconds.
While a jiffy is from science and is one one-hundredth of a second, the time it takes light in a vacuum to travel one centimeter.
