Convert Square Pole (pole²) to Barn (b (area)) instantly.
About these units
Square Pole (pole²)
A square pole is yet another equivalent to the square rod and square perch. The triple terminology reflects different regional dialects and occupational vocabularies within the British Isles. The persistence of three names for the same unit illustrates the decentralized nature of early measurement standards, where local custom often outweighed national regulation. Although modern metrication has replaced these units, they remain historically important when examining rural land divisions and genealogical land records.
Barn (b (area))
The barn is an area unit used almost exclusively in nuclear and particle physics, equal to 10⁻²⁸ square meters. Despite its incredibly tiny size, the barn emerged from humorous origins: early nuclear physicists joked that certain atomic nuclei were "as big as a barn" compared to the particles trying to hit them. The barn quantifies interaction cross-sections—essentially probabilities of particles colliding or interacting with nuclei. Because fundamental forces operate at extremely small scales, typical cross-section values lie in the microbarn, nanobarn, or picobarn range. The barn is essential for describing reaction rates in particle accelerators, nuclear reactors, and astrophysical processes such as stellar fusion.