Light-Year

In the PennySystem scale, 1 meter represents about 39.53 light-years, that is, the distance that light would travel in 39.53 years. The term light-year is often misunderstood. A light-year is a measurement of distance, not of time.

It is the distance light travels in one year. Light is used to measure distance since it is the fastest thing in the Universe and its speed is constant and very well known by accurate measurements.

Light travels at about 300 million meters per second. It takes light about 5½ hours to travel across the solar system, so a light-year is much bigger than this. The nearest star to us (apart from the Sun) is Proxima Centauri, which is about 4¼ light-years away.

We live inside a disc of stars (the Milky Way Galaxy) which measures about 100,000 light-years across and around 2000 light-years thick.

A light-year equals about 9.46053 x 10¹² km (or 5.878 x 10¹² miles).

That is, almost 10¹⁶ meters.