# EXPLAIN THE DISTANCE OF LIGHT YEARS

Light year is how to measure the distance. Devinisi actually strange because the light makes the word that is usually used for a unit of time. However, the light is used to measure the distance. We usually use the size inch / foot / mile or cm / m / km to measure distances.

Astronomers used the telescope to view the stars, the issue becomes lainkarena very far away. For example, Earth's nearest star (other than our sun) approximately 24,000,000,000,000 nearby. Several other stars billions of times farther. When we talk about long distance certainly nobody wants to write or talk about numbers consisting of 20 digits because we liked most practical.

So, to measure very long distances, use a unit called a light year. Light at the speed of 186,000 miles per second (300,000 km per second). Light year is the distance light travels in one year or 186,000 miles per second X 60 seconds per minute X 60 minutes per hour x 24 hours per day X 365 days per year = 5,865,696,000,000 miles (9.460.800.000.000 km).

Using one year as a distance measuring light has another advantage, namely to help determine the age. For example, one star one million light years away means the light from the star has been running at the speed of light to reach us. To that end, the light requires one million light years to get here and the light we see is created a million years ago. So, the star that we are seeing at the moment is the form of star one year lalubukan star shape at this time. In the same way, about 8 light minutes away. If the sun suddenly burst out at this time, we will not know for 8 minutes because that is the time it takes light to blast up here.

Nanosecond the light is the distance light travels during a billionth of a second, which is approximately one foot (30 cm). Radar used this method to mengkur how far away an object like a plane. Vibration transmitted radio radar antenna is short, then wait for the echo of the aircraft or other object. While waiting, radar menguhitung number of nanoseconds passing. Radio waves running at the speed of light. Thus, the number of nanoseconds divided by 2 notify the radar unit how far an object.