Miles to Light-seconds (mi to ls)
1 mile equals 0.000005368193752 light-seconds (rounded).
How to convert miles to light-seconds
To convert miles to light-seconds, multiply the number of miles by 0.000005368193752. The factor is rounded to 10 significant digits. To go the other way, multiply light-seconds by 186,282.3971 (rounded).
light-seconds = miles × 0.000005368193752
Example: 10 miles = 0.00005368193752 light-seconds.
About these units
Mile (mi)
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
Light-second (ls)
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
Related conversions
- Light-seconds to miles (reverse)
- Miles to meters
- Miles to kilometers
- Miles to centimeters
- Miles to millimeters
- Miles to inches
- Miles to feet
- Miles to yards
- Miles to micrometers
- Miles to nanometers
- Miles to nautical miles
- Miles to pixels (CSS)
- Miles to light-years
- Meters to light-seconds
- Kilometers to light-seconds
- Centimeters to light-seconds
- Millimeters to light-seconds
- Inches to light-seconds
- Feet to light-seconds
- Yards to light-seconds
See all length units.