1. Space Technology

2. Question of the Day: 3-20 Why is today special in the calendar year?
WWBAT: describe light, the spectrums, and the importance of both

3. Light and Knowledge
Almost everything we know about the universe comes by studying light from distant sources
Light come from:
Stars, planets, nebulas, etc

4. Electromagnetic Radiation
Visible light is a type of electromagnetic radiation
Other types include: X-rays, gamma rays, ultra violet, etc.
Electromagnetic spectrum: the arrangement of these waves according to their wavelengths and frequencies

5. Nature of Light Light can be described in two ways
Waves or particles
Waves are the most common form of light
Think of this like ocean waves, characterized by the wavelength
Photons are small packets of light energy that act like streams of particles moving very quickly
Wave form is where the spectrum comes from
Each photon has a specific amount of energy, which is related to its wavelength. Shorter wavelength=more energy

6. Visible Light Visible light is the light we can see
The wavelengths and energy of the light is the reason for the colors
Longer wavelengths (700 nm) = less energy
Redder in color
Shorter wavelengths (400 nm) = more energy
Bluer in color

7. Electromagnetic Spectrum

8. Light Spectrum
Spectrum: different types of light give off different bands of color
The spectrums are seen when passing the light through a prism
3 types of spectrum
Continuous, absorption, and emission
Each element has a distinct spectrum
Pg 676 example of each spectrum

9. Continuous Spectrum
Produced by an incandescent solid, liquid, or gas under high pressure
Produces an uninterrupted band of color

10. Absorption Spectrum Produced by a cool gas under low pressure
The missing colors were absorbed by the gas
Appears continuous with series of dark lines running through it
Cool and low pressures

11. Emission Spectrum Produced by a hot gas under low pressure
Is a series of few lines that are bright

12. Why study spectrums?
The type of spectrum tells us the types of elements that are in the object that is producing the light
Most stars produce light in the absorption spectrum
Therefore, we can figure out what the objects are made of!
End of day one

13. Question of the Day: 3-21 What are the three types of spectrums?
WWBAT:

14. Doppler Effect
When thinking of a train horn or ambulance siren, does the noise sound the same based on the direction is is traveling? Why?
The siren or horn sounds higher in pitch as it comes toward you. It sounds lower as it moves away.
We perceive the sound’s wavelength to be either shorter or longer than actuality

15. Doppler Effect

16. Doppler Effect…Why? The Doppler effect also occurs with light waves
We use that knowledge to determine if an object in space is moving toward or away from earth.

17. Tools for Studying Space
Telescopes (4 types)
Optical
Radio
Space
Special purpose

18. Optical Telescopes
Contain mirrors, lenses, or both to collect as much light as possible
There are two types
Refracting
Reflecting

19. Optical: Refracting
Refracting telescopes: uses lenses to focus light on a specific spot and then magnify the image
One issue that arrises is the chromatic aberration (chroma=color, aberrare= to go astray). When one color is in focus (like red) then there will be a halo around of a different color

20. Optical: Reflecting
Reflecting telescopes: use lenses and mirrors to focus and magnify light

21. Optical Advantages Both versions help astronomers by
Helping gather light from far away objects
Helping make objects more clear (resolve power)
Helping magnify objects (make them appear bigger)
*Think about when you used a telescope or binoculars

22. Radio Telescopes Used to detect radio waves from space objects
Have recorded events such as two galaxies colliding!
Radio waves are long waves that do not need a smooth surface to bounce off of. However, the signals are weak so large dishes are needed.

23. Space Telescopes
Telescopes are placed in space to avoid the distortion of Earth’s atmosphere on the image.
This produces clearer images than the Earth based optical telescopes.

24. Space Telescopes
Hubble Telescope: 24 meters long, 10 billion times more light-gathering power than human eye
Has produced spectacular images of planets, stars, galaxies and deep space

25. Special Purpose Telescopes
Telescopes that detect energy outside visible light such as X-rays and Gamma rays
These are used to detect black holes
Black hole: objects whose gravity is so strong that visible light cannot escape them