Chapter 12 – Is Anyone Out There? |
| Activity Summaries |
Physics Principles |
Activity 1: Lenses and Ray Optics
Observing images formed with convex lenses introduce students to how telescopes work. They also observe that real images are not formed nor magnified by concave lenses. Comparing measurements helps students understand the importance of focal length in the making of a telescope. |
- Convex Lenses
- Concave Lenses
- Real and Virtual Images
|
Activity 2: The Telescope
Students make refracting telescopes, using convex lenses. Their observations lead to discussion about why a telescope requires two lenses with specific positioning and different focal lengths. |
- Telescope Construction
- Convex Lenses
- Concave Lenses
- Real and Virtual Images
|
Activity 3: Digital Imaging
This activity introduces students to the use of pixels in electronic images and
relationship between the number of pixels and detail in the image. This leads to understanding of the differences between analog and digital images. |
- Pixels
- Digital and Analog Images
|
Activity 4: The Electromagnetic Spectrum
In this activity, students first estimate Earth – moon distance from a NASA video clip that highlights time delay in communication between Apollo astronauts and Houston. Reading about the speed of light introduces students to wavelengths in
the electromagnetic spectrum. |
- Electromagnetic Waves
- Speed of Light
- Wavelength and Frequency
of Light
|
Activity 5: Interference and Spectra
Viewing a light through a diffraction grating enables students to observe separation of white light into its colors. They read about how scientists use this process and characteristic spectra of gases to identify the presence of gases on stars. Students consider how the light spectrum could be used to communicate with advanced beings. |
- Diffraction
- Light Interference
- Light Spectra
|
Activity 6: Send Them a Recording
Students measure the number of grooves per centimeter to observe differences in long-playing records and CDs. From this they are able to infer the differences in how information is stored on analog and digital recordings. Students then apply this information to their plans for communication with extraterrestrial beings. |
- Speed of Electromagnetic Waves
- Digital vs. Analog
- Diffraction and Interference
|
Activity 7: The Size of Space
After reading about how parallax is used to measure distance to nearby stars, students apply this concept to find distances between objects. Learning the
extreme distances between stars engages students in discussion and consideration of the challenges inherent in attempts to travel to, or communicate with, life on distant stars. |
- Parallax
- Speed of Sound
- Measuring Distances in Space
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