Convert Long Reed (long reed) to A.U. of Length (a.u.) instantly.
About these units
Long Reed (long reed)
The long reed is a traditional unit of length used in Egypt and other ancient cultures, roughly equivalent to 2 cubits. It was employed in surveying, architecture, and the measurement of agricultural fields. The unit's length made it suitable for laying out longer distances with relatively few measurements, especially in river valley contexts where precision at large scales was important for irrigation and crop management. Historical records show the long reed in use for temple construction, pyramidal measurements, and land division, illustrating the practical integration of human-based units into early engineering practices.
A.U. of Length (a.u.)
The atomic unit of length, also known as the Bohr radius unit in atomic units, is approximately 5.29177 × 10⁻¹¹ meters. It is defined as the radius of the lowest-energy orbital of the hydrogen atom, providing a natural scale for describing atomic and quantum mechanical systems. Atomic units were devised to simplify equations in quantum chemistry and atomic physics by normalizing fundamental constants such as electron charge, Planck's constant, and electron mass to 1. In this system, many equations become dimensionless and far easier to manipulate mathematically. The atomic unit of length is essential in molecular orbital calculations, quantum simulations, and the study of electron behavior in atoms and molecules. Its use reflects an approach to physics in which units are chosen to match the natural scales of the systems being studied.