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).
up vote 5 down vote. We don't directly measure distances to anything light years away by timing light. Light year is just a unit of distance like a mile or kilometer. We know how fast light goes in 1 second, we know how many seconds in a year and so we know how many meters (or miles) are in a light year.