Convert X-unit (X) to Rod (rd) instantly.
About these units
X-unit (X)
The X-unit is an extremely small length, approximately 1.002 × 10⁻¹³ meters, historically used to express X-ray and gamma-ray wavelengths. The unit was invented before modern standards for measuring electromagnetic wavelengths existed, allowing scientists to describe extremely short wavelengths without resorting to scientific notation. X-units were valuable in crystallography and atomic physics in the early 20th century, enabling precise description of spectral lines emitted by X-ray sources. Although modern practice has largely replaced the X-unit with the nanometer or picometer, it continues to appear in historical literature. The unit's existence highlights how scientific progress shapes measuring conventions. Once essential, the X-unit now serves as a bridge to the history of early atomic research.
Rod (rd)
A rod, equal to 16½ feet (or 5.0292 meters), is a historic English unit that dates back to agricultural practices and land surveying in medieval Europe. Originally based on the length of a stiff pole used by farmers to control oxen, the rod became standardized and deeply embedded in systems of land division. Surveyors valued rods because they integrate neatly with other land-measurement units: 4 rods make a chain, and 160 square rods make an acre. These relationships simplified calculations when establishing property boundaries or mapping rural land parcels. Although no longer widely used for modern surveying—supplanted by meters or feet—the rod lives on in historical land deeds, mining claims, and older legal documents. Understanding rods can be essential for interpreting pre-modern land descriptions that still influence property law today.