From Citizendium, the Citizens' Compendium
- See also changes related to Kilometre, or pages that link to Kilometre or to this page or whose text .
- Unit : Please do not use this term in your topic list, because there is no single article for it. Please substitute a more precise term. See Unit (disambiguation) for a list of available, more precise, topics. Please add a new usage if needed.
- Length : Add brief definition or description
- Metre (unit) : Unit of length; one of the seven SI base units.
- International System of Units : Metric unit system based on the metre, kilogram, second, ampere, kelvin, mole and candela.
- Mile : A non-SI unit of length, equal to 1.609 kilometres, and equivalent to 5,280 feet.
- Nautical mile : Unit of distance approximately equal to one minute of arc of latitude, now defined as being exactly 1852 metres.
- Light year : Distance that light travels in vacuum in one year; 9,460,730,472,580.800 km = 9.4607304 * 1012 km.
- Astronomical unit : Add brief definition or description
- Speed of light : A physical constant c describing the speed of electromagnetic radiation in vacuum. In the International System of Units the metre is the distance light travels in classical vacuum in 1/c seconds, using the defined value c = c0 ≡ 299 792 458 m/s (exact).