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).
In metric terms, the speed of light is a tad less than 300,000 km/sec. 1 light year is approximately 5.9 trillion miles, 20.5 light years would therefore be 20.5 times 5.9 trillion miles or about 120 trillion miles.