1 Massage the twitch muscle with your finger for 15 seconds. 2  Usually there are other muscles that twitch like leg cramps, so take 500mg of magnesium citrate capsule daily. 3  If you have headaches, massage the knot at the back of your neck for release.
Â­So to measure really long distances, people use a unit called a light year. Light travels at 186,000 miles per second (300,000 kilometers per second). Therefore, a light second is 186,000 miles (300,000 kilometers).
A year is a measure of time - 31557600 seconds. A light year is a measure of distance - the distance traveled by light in one year - 9.461e+12 km. A light-year (or light year, abbreviation: ly[3]) is a unit of length used informally to express astronomical distances.