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 light year is defined as the distance that light travels in one Earth year. Light moves extremely fast: 300,000 km/s or 180,000 miles/second. In one second light can travel around Earth almost four times. Nothing travels faster, establishing light as the ultimate speed limit.