1. Light and Telescopes

2. Imagine that you throw a ball directly upward
Imagine that you throw a ball directly upward. Which of the following statements best describes how Newton’s second law accounts for the motion of the ball when it reaches its maximum height?
The ball has a velocity that is zero and an acceleration that is zero.
The ball has a velocity that is upward and an acceleration that is downward.
The ball has a net force that is downward and a velocity that is downward.
The ball has a net force that is downward and an acceleration of zero.
The ball has a net force that is downward and an acceleration that is downward.

3. Light and Telescopes
Did you get the Newton’s Laws and Gravitation Tutorial handout?
Did you get the practice ranking tasks on gravity?

4. A Telescopes is a tool used to gather light from objects in the universe

5. Tool
Websters: Tool- something (as an instrument or apparatus) used in performing an operation or necessary in the practice of a vocation or profession
From the “Learn while Cold Chillin’!” Slang Flashcards: Tool -

6. There are two different types of telescopes
A refracting telescope uses a glass lens to concentrate incoming light
A reflecting telescope uses mirrors to concentrate incoming starlight

7. A refracting telescope uses a lens to concentrate incoming light

8. Reflecting telescopes use mirrors to concentrate incoming starlight

9. Three main functions of a telescope
Most important!!
Gather More Light – (bigger Is better) making objects appear brighter
followed by
to see fine detail
(called resolution)
and least important,
magnify
magnification = (objective lens focal length / eyepiece lens focal length)

10. A larger objective lens provides a brighter (not bigger) image

11. If you pass white light through a prism, it separates into its component colors.
long wavelengths
ROY G B I V
short wavelengths
spectrum

12. But visible light is only one type of electromagnetic radiation (light) emitted by stars
Astronomers are truly interested in the entire spectrum of Light!

13. Consider This Class as Seen in Different Wavelengths of Light!

14. Consider Orion as Seen in Different Wavelengths of Light!

15. Observations at other wavelengths are revealing previously invisible sightsUV
infrared
Map of Orion region
Ordinary visible

16. Hubble Space Telescope Views of Orion Nebula showing stars hidden in clouds

17. TODAY’S Sun as seen in visible light from Earth and from space in X-rays by satellites

18. Radio wavelength observations are possible from Earth’s surface

19. The Very Large Array (VLA) in New Mexico

20. Differences in the temperature and density of small portions of Earth’s atmosphere cause passing starlight to quickly change direction, making stars appear to twinkle.

21. Earth’s atmosphere hinders astronomical research
Image of stars taken with a telescope on the Earth’s surface
Same picture taken with Hubble Space Telescope high above Earth’s blurring atmosphere

22. High above Earth’s atmosphere, the Hubble Space Telescope provides stunning details about the universe

23. But visible light is only one type of electromagnetic radiation (light) emitted by stars
Astronomers are truly interested in the entire spectrum of Light!

24. Astronomers use different instruments to look at light of different wavelengths - sometimes, we even have to go above Earth’s atmosphere.

25. Not all EM radiation can penetrate Earth’s atmosphere.

26. Tutorial: Telescopes and Earth’s Atmosphere pg. 43
Work with a partner!
Read the instructions and questions carefully.
Discuss the concepts and your answers with one another. Take time to understand it now!!!!
Come to a consensus answer you both agree on.
If you get stuck or are not sure of your answer, ask another group.

27. Which is the correct reasoning for why a gamma ray telescope located in Antarctica that is to be used to look for evidence of black holes in the centers of galaxies would not get funded?
There is no way to detect the presence of a black hole.
Gamma rays are too energetic to detect with a telescope.
You can’t build a functioning telescope in Antarctica.
Gamma rays don’t penetrate Earth’s atmosphere.

28. Imagine you’re the head of a funding agency that can afford to build only one telescope. Which of the three proposed telescopes below would be best to support?
A gamma ray telescope in Antarctica
A radio telescope in orbit above the Earth
A visible telescope located high on a mountain in Peru
An ultraviolet telescope located in the Mojave desert