|
|
|
|
|
|
Symbol | Definition |
---|---|
≡ | exactly equal |
≈ | approximately equal to |
= | equal to |
digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |
The light-day is a unit of length useful in astronomy, telecommunications and relativistic physics. It is defined as the distance that light travels in free space in oneday, and is equal to exactly 2.59020683712×1013 metres.
A pace is a unit of length consisting either of one normal walking step (~0.75 m), or of a double step, returning to the same foot (~1.5 m). Like other traditional measurements, paces started as informal units but have since been standardized, often with the specific length set according to a typical brisk or military marching stride.