A "microinch" is a unit of length used to measure extremely small distances or dimensions. It is equal to one millionth of an inch or 0.000001 inches. In scientific notation, it can be represented as 1 µin (pronounced as "one microinch").
Microinches are typically used in precision engineering, manufacturing, and industries where very fine tolerances and high levels of accuracy are required. This unit allows for the measurement of surface finishes, material thicknesses, and other minute details with extreme precision.
To put it into perspective, a microinch is much smaller than a human hair, which is typically several thousand micrometers (µm) or microns in diameter.
A "handbreadth" is a unit of length that is approximately equal to the width of an adult human hand, excluding the fingers. It is often used in various historical and cultural contexts as a convenient way to estimate small lengths or distances. The actual measurement of a handbreadth can vary somewhat depending on the size of an individual's hand, but it is typically around 3 to 4 inches (about 7.6 to 10.2 centimeters).
In some historical systems of measurement, particularly in the ancient Near East and the Bible, the handbreadth was used as a standardized unit for measuring length. It was one of the smaller units within a larger system of measurement, often used for small-scale applications like measuring cloth, the dimensions of objects, or architectural details.
While the handbreadth is not a commonly used unit of measurement in modern times, it remains a useful and intuitive way to approximate small lengths informally, especially when a quick estimate is needed.