Light-seconds to Miles (ls to mi)

1 light-second equals 186,282.3971 miles (rounded).

1 light-second = 186,282.3971 miles

How to convert light-seconds to miles

To convert light-seconds to miles, multiply the number of light-seconds by 186,282.3971. The factor is rounded to 10 significant digits. To go the other way, multiply miles by 0.000005368193752 (rounded).

miles = light-seconds × 186,282.3971

Example: 10 light-seconds = 1,862,823.971 miles.

About these units

Light-second (ls)

AstronomicalCurrent unit

The distance light travels in a vacuum in one second: 299,792,458 meters. The Moon is about 1.28 light-seconds from Earth.

Because the speed of light is now fixed at 299,792,458 meters per second, a light-second is exactly that many meters, with no uncertainty at all. Astronomers and radio engineers treat it as a convenient yardstick for distances that are small on the scale of the solar system but large on the scale of a laboratory. The abbreviation ls appears in tables of astronomical units, and it is not an official SI unit.

The Moon is the standard example: its average distance from Earth is about 1.282 light-seconds, which is why a radio exchange with a lunar mission has a noticeable round-trip lag of roughly two and a half seconds. The Earth's mean diameter is only about 0.0425 light-seconds, while the Sun's diameter is about 4.643. One astronomical unit is about 499 light-seconds. Sixty light-seconds make a light-minute, 3,600 make a light-hour, and 31,557,600 make a light-year, based on the Julian year.

1 light-second = 299,792,458 meters (exactly).

Sources: Wikipedia: Light-second; Wikipedia: Light-minute

Mile (mi)

US & ImperialCurrent unit

5,280 feet or 1,760 yards, exactly 1,609.344 meters. This is the statute (international) mile used on US and UK roads.

A thousand paces gave the mile its name. It descends from the Latin mille passus, the Roman mile, by way of Old English mil and Middle English myle. For centuries after Rome, miles of many lengths coexisted; a sixteenth-century Mercator map, for example, shows small, medium and large Flemish miles on a single scale bar. The English statute mile was fixed by an Act of Parliament under Elizabeth I in 1593, which declared that a mile contains eight furlongs, or 5,280 feet.

The 1959 international yard and pound agreement made that mile exactly 1,609.344 meters. A slightly longer US survey mile, about 1,609.347 meters, lingered in American land surveys and was slated for retirement from 1 January 2023. Today the mile is the road unit of the United Kingdom, the United States, Liberia and Myanmar, along with several territories such as the Bahamas, Belize, Guam and the US Virgin Islands. In Canada it survives chiefly in rail transport and horse racing.

1 mile = 1,609.344 meters (exactly).

Sources: Wikipedia: Mile; Wikipedia: Foot (unit); NIST Guide to the SI, Appendix B.8: conversion factors

Related conversions

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