The Milky Way is about light-years in diameter. 1 light-year is equal to . What is the diameter of the Milky Way in meters?
A laser beam was fired off into space from an observatory on Earth’s surface. The beam was fired into an empty region of space, so it would not interact with anything. How far, in light-years, has the beam traveled 3 years later?
The speed of light is approximately . How far does a beam of light travel in 1 day? Give your answer to 2 significant figures.