Cosmology+Lesson+4

The Universe is Really Big! (And Really Small!)

(How Big and Small Is It?) See [|this simulation] !

Try [|this quiz] as you watch [|this classic video] !

Starlight (including sunlight) takes time to travel. At the moment you were born, many rays of sunlight left the surface of our sun. Where are those rays now? At the moment you were born, many rays of starlight left billions of stars in our Milky Way. Are any of those rays reaching us now? If so, you could see what was happening in that star at the moment you were born! Find a chart of stellar distances (in light years) to allow us to find such a star. Choose some other stars on the list. What was happening on the Earth when that starlight first left that star?