The angstrom equals 10⁻¹⁰ meters or 0.1 nanometers. It is used in chemistry and crystallography for atomic and molecular dimensions. The Bohr radius — the characteristic size of a hydrogen atom — is 0.529 Å. Covalent bond lengths are typically 1–2 Å.
Real-world: A water molecule is about 1 Å across. The covalent bond in H₂ is 0.74 Å. X-ray wavelengths are 0.1–100 Å.
Read full angstrom reference →The statute mile equals 1609.344 meters exactly since the 1959 international definition. It is the official road unit in the United States, United Kingdom and Myanmar. The name comes from the Latin "mille passuum" — one thousand Roman paces. The nautical mile (1852 m) is different and used only in marine and air navigation.
Real-world: London to Edinburgh is about 400 miles by road. A marathon is 26.22 miles. US highways typically post 65–75 mph speed limits.
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