The Roman pes was a smidge shorter than our foot—it came in at around 11.6 inches—and similar Old English units based on the length of people’s feet were also a bit shorter than our 12-inch ...

The real length of a normal pendulum is almost unattainable, so limited is our knowledge of the force of gravity on land and at sea, A more certain basis for a natural unit has been found in the ...

Units of speed are always a unit of length per unit of time. Different units of length and time may be chosen depending on the situation. This makes it easier to read the measurements.

In a competing theory called loop quantum gravity, on the other hand, space and time are broken into discrete blocks, which gives rise to a smallest possible length (expressed in units of the ...

Japan’s traditional units of measurement for length and weight include the monme (3.75 grams), which has become an internationally recognized standard for weighing pearls.