The colloquial term 'nanosecond' is pervasive in our vernacular speech. Even elementary school kids use it in their banter. Here's NSF spelled out in molecules by scientists and engineers at the University of Illinois. Nano means a billionth. A nanometer is to an inch what an inch is to 400 miles.
Light travels just over a foot in a nanosecond.
Although we have only recently been able to see things at this nano level, they have occurred in nature and in humans since the beginning of time. It was not until 20 years ago that we could see a cluster of molecules on a surface. But to see was just the first step. Nanoscale is three orders of magnitude smaller than most of today's human-made devices. One nanometer is one billionth of a meter.