Convert Earth's Polar Radius (R⊕ (p)) to Bohr Radius (a₀) instantly.
About these units
Earth's Polar Radius (R⊕ (p))
The Earth's polar radius is approximately 6,356.8 km, slightly shorter than the equatorial radius due to the Earth's flattening at the poles. This measurement is critical in modeling Earth's shape, gravity field, and rotation. It impacts satellite orbits, geodetic surveys, and global positioning systems (GPS). The difference between the equatorial and polar radii also explains phenomena such as centrifugal force variations, equatorial bulges, and sea level differences across latitudes. Understanding R⊕ (p) is essential for precision navigation, Earth science, and astronomy.
Bohr Radius (a₀)
The Bohr radius, equal to approximately 5.29177 × 10⁻¹¹ meters, is the most probable distance between the electron and nucleus in the ground state of hydrogen according to the Bohr model. While modern quantum mechanics has evolved far beyond the Bohr model, the radius remains a remarkably accurate approximation for average atomic dimensions. The Bohr radius acts as a natural "yardstick" for the size of atoms and is frequently used in atomic physics and quantum chemistry. Many atomic properties — orbital sizes, electron probability distributions, and energy levels — are conveniently expressed in multiples of the Bohr radius. Because it reflects fundamental constants, including Planck's constant and the electron charge, the Bohr radius also appears in theoretical analyses of physical systems and helps unify atomic physics concepts across different contexts.