Download Measuring Distance in our Universe. Due Tue 1 Dec 2009 Imagine

Measuring Distance in our Universe.
Due Tue 1 Dec 2009
Imagine that you could travel to the stars at the speed of light. It would take 8
minutes to get to the Sun from Earth. To get to the next nearest star, Proxima
Centauri, it would take 4.2 years traveling at the speed of light.
Distances on earth are often measured in kilometers but distances to the stars are so
large that kilometers aren’t very practical units. Astronomers use the unit called a
light-year to measure distances between stars and across the universe. A light-year
is the distance that light travels in one year, about 9.5 million million kilometers.
Make sure you realize a light-year is a unit of distance, not time.
Light-year: 9.4605284 × 1015 meters, or 9,460,528,400,000 kilometers
The bright star Spica is 262 light-years from our solar system. How many
kilometers is this?
If you were able to sit on top of a light wave and travel at the speed of light, how
many years would it take you to get to the Andromeda Galaxy, which is 9 X 1023 m
away?