Light Year And Doppler Effect
- 1. Light Year A measure of distance Distance light travels in one year What is it? So are we looking at the past? 5.86 x 10 12 miles
- 2. We are! Imagine looking at a star 30 LY’s away. What does that number mean? For an object 30 LY’s away it takes light 30 years to travel to your eye. How old would you be? For an object 130 LY’s away it takes light 130 years to travel to your eye. How old would you be? For an object 457630 LY’s away it takes light 457630 years to travel to your eye. How old would you be? 43 or 44 years 143 or 144 years 457643 or 457644 years
- 3. Light Years If a star is 30 LY’s away and the light left that star today it would not arrive at your eye for 30 years. (So, what you are looking at is 30 years in the past!!)
- 4. Doppler Effect Objects moving toward you appear blue or blue shifted Objects moving away from you appear red or red shifted
- 5. Doppler Effect in Action
- 6. What is a star made of?