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).
Thatâs very fast. If you could travel at the speed of light, you would be able to circle the Earthâs equator about 7.5 times in just one second! A light-second is the distance light travels in one second, or 7.5 times the distance around Earthâs equator. A light-year is the distance light travels in one year. How far is that? Multiply the number of seconds in one year by the number of miles or kilometers that light travels in one second, and there you have it: one light-year.