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).
One light year is the distance which the light will travel in one year (speed of light in 299,752,458 m/s))). Distance is also measured in parsec (1 parsec = 3.26 light years: the distance at which one astronomical unit subtends an angle of one second of arc).