Returns the speed of light c in vaccum, in meters per second (). This is a physical constant.

LIGHT(*accuracy*)

accuracy |
Optional. A Boolean expression, either TRUE or FALSE. Decides whether an accurate value should be returned by the function. Default is TRUE if omitted. |

Function |
Answer |
Explanation |

= LIGHT() | 299,792,458 | The speed
of light in vacuum is 2.99792458 ? 108 ms-1. This is an exact (accurate) value. By default, the value for the “accuracy” parameter is TRUE. Therefore, if omitted, the function returns an accurate value. |

= LIGHT(TRUE) | 299,792,458 | The answer is the same as above. |

= LIGHT(FALSE) | 3E+08 | . A
rough value is returned. This value is often used in text books. |