1. Redshift
Ms. Griswold
5/14/2014

2. AIM: How does the REDSHIFT of SPECTRAL LINES provide evidence that the universe is expanding?
Do Now:
Describe what is being shown in the picture.

3. 1: What happens to the sound that a fire truck makes as it approaches and then passes you?
DOPPLER EFFECT

4. SHORTER LONGER THE DOPPPLER EFFECT Wavelength gets
when source is moving towards observer
Wavelength (of sound or light) gets
when source is moving away from observer
SHORTER
LONGER
THE DOPPPLER EFFECT

5. COLOR: light at a specific wavelength
**Electromagnetic Spectrum is on pg 14 of ESRT**
2: Based on the Electromagnetic Spectrum, does red light or blue light have a LONGER wavelength?

6. 1 2 3:
List your observations of one similarity and one difference between Diagram 1 and Diagram 2.

7. 1 2
REDSHIFT: THE LIGHT FROM THE STAR IS SHIFTED TOWARDS THE RED END OF THE SPECTRUM
4: If the spectral lines are moving towards the RED end of the spectrum, are their wavelengths getting longer or shorter?

8. REDSHIFT: THE LIGHT FROM THE STAR IS SHIFTED TOWARDS THE RED END OF THE SPECTRUM
because the star is moving away – doppler effect means that the wavelengths are getting l o n g e r

9. Check for Understanding
When viewed from Earth, the light from very distant galaxies shows a red shift. This is evidence that these distant galaxies are
(1) revolving around the Sun
(2) revolving around the Milky Way
(3) moving away from Earth
(4) moving toward Earth
Check for Understanding

10. Check for Understanding
When viewed from Earth, the light from very distant galaxies shows a red shift. This is evidence that these distant galaxies are
(1) revolving around the Sun
(2) revolving around the Milky Way
(3) moving away from Earth
(4) moving toward Earth
Check for Understanding

11. Check for Understanding
2. The diagram below shows the spectral lines for an element.
Which diagram best represents the spectral lines of this element when its light is observed coming from a star that is _________ from Earth ?
Moving TOWARDS Earth? ______
Moving AWAY from Earth? ______
Check for Understanding

12. Check for Understanding
2. The diagram below shows the spectral lines for an element.
Which diagram best represents the spectral lines of this element when its light is observed coming from a star that is _________ from Earth ?
Moving TOWARDS Earth? ______
Moving AWAY from Earth? ______ B. A.
Check for Understanding

13. -Independent – can you figure this out without anyone helping you
-Independent – can you figure this out without anyone helping you? What resources can you use?
-Quiet – respect your classmates’ intellectual space to think
-On task – can you show perseverance by completing 100% of your classwork?
You’re On Your Own

14. Spectral Lines The light that passes through the gas
Q: What gases are in stars?