Geoastronomy

Dan O'Brien, 2021/06/11

Learning activities to understand some of the spatiotemporal effects of the Sun's rays on the Earth - suitable for Project-Based Learning.

目次

  1. Frames of Reference
    1. Earth-Sun Model with Allocentric Perspective
    2. Sun Always to the Left
    3. Sun Always to the Right
    4. On the Plane of the Ecliptic, Sun Always to the Right
    5. Always Looking South
    6. Polar Axis Frames
    7. Transforming between Surface Cartesian Coordinate Axes
    8. Earth-Sun Model for Smartphone/Tablet - Allocentric & Egocentric Perspectives
  2. 3D Simulations
    1. Interactive Planet Earth with Map
    2. Earth 3D Simulation (Using 3D Equations)
    3. Earth 3D Simulation (Using 2D Equations)
    4. Earth 3D Simulation with only One Time Measure
  3. Trigonometry Problems
    1. Finding the Polar Tilt in the Sun's Direction
    2. Finding the Length of the Day
    3. Finding the Length of the Day (Older Version)
    4. Understanding Compound Rotations
    5. Where and When is the Sun Directly Overhead?
    6. Angle between the Sun and the Zenith
    7. Horizontal Sundial with Hour Lines
  4. Sun Hours
    1. Sun Hours (Best Fit)
  5. Map Projection
    1. Terminator Line - Equirectangular Projection
  6. Make Your Own Sundial!
    1. Where Should the Hour Lines be on a Sundial?
    2. Horizontal/Vertical vs Equatorial Dial Plates
    3. Horizontal or Vertical Dial Plate
    4. Card Stand for Equatorial Sundial
    5. Equatorial Sundial - Dial Plate Parallel to Equator
  7. Photos
    1. Equatorial and Horizontal Sundials in Action - AM
    2. Equatorial and Horizontal Sundials - Setup
    3. Vertical Sundial in Action - AM Only (Shaded After)
    4. Horizontal Sundial (Roughly) Zeroed at 12:16pm Local Time
    5. Equatorial Sundial (Roughly) Zeroed at 12:18pm Local Time
    6. Horizontal & Equatorial Sundials in Action - PM
  8. Worksheets, Lesson Plan & Slide Deck PDFs
    1. Lessons 1-3 Wksht May 2021
    2. Lessons 4-6 Wksht May 2021
    3. Copy of Slide Decks
    4. Lessons 1-3 Lesson Plan

1.

Frames of Reference

  • 1. Earth-Sun Model with Allocentric Perspective
  • 2. Sun Always to the Left
  • 3. Sun Always to the Right
  • 4. On the Plane of the Ecliptic, Sun Always to the Right
  • 5. Always Looking South
  • 6. Polar Axis Frames
  • 7. Transforming between Surface Cartesian Coordinate Axes
  • 8. Earth-Sun Model for Smartphone/Tablet - Allocentric & Egocentric Perspectives

1.1.

Earth-Sun Model with Allocentric Perspective

– Dan O'Brien

1.2.

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1.3.

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1.4.

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1.5.

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1.6.

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1.7.

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1.8.

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2.

3D Simulations

  • 1. Interactive Planet Earth with Map
  • 2. Earth 3D Simulation (Using 3D Equations)
  • 3. Earth 3D Simulation (Using 2D Equations)
  • 4. Earth 3D Simulation with only One Time Measure

2.1.

Interactive Planet Earth with Map

– Dan O'Brien

2.2.

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2.3.

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2.4.

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3.

Trigonometry Problems

  • 1. Finding the Polar Tilt in the Sun's Direction
  • 2. Finding the Length of the Day
  • 3. Finding the Length of the Day (Older Version)
  • 4. Understanding Compound Rotations
  • 5. Where and When is the Sun Directly Overhead?
  • 6. Angle between the Sun and the Zenith
  • 7. Horizontal Sundial with Hour Lines

3.1.

Finding the Polar Tilt in the Sun's Direction

Write down an expression for the tilt of the polar axis, θ(T), resolved in the Sun's direction. You can drag the North Pole around the blue circle.
– Dan O'Brien

3.2.

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3.3.

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3.4.

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3.5.

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3.6.

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3.7.

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4.

Sun Hours

  • 1. Sun Hours (Best Fit)

4.1.

Sun Hours (Best Fit)

The city data has been imported from Excel...make sure you can do this yourself first.
– Dan O'Brien

5.

Map Projection

  • 1. Terminator Line - Equirectangular Projection

5.1.

Terminator Line - Equirectangular Projection

– Dan O'Brien

6.

Make Your Own Sundial!

  • 1. Where Should the Hour Lines be on a Sundial?
  • 2. Horizontal/Vertical vs Equatorial Dial Plates
  • 3. Horizontal or Vertical Dial Plate
  • 4. Card Stand for Equatorial Sundial
  • 5. Equatorial Sundial - Dial Plate Parallel to Equator

6.1.

Where Should the Hour Lines be on a Sundial?

– Dan O'Brien

6.2.

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6.3.

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6.4.

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6.5.

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7.

Photos

  • 1. Equatorial and Horizontal Sundials in Action - AM
  • 2. Equatorial and Horizontal Sundials - Setup
  • 3. Vertical Sundial in Action - AM Only (Shaded After)
  • 4. Horizontal Sundial (Roughly) Zeroed at 12:16pm Local Time
  • 5. Equatorial Sundial (Roughly) Zeroed at 12:18pm Local Time
  • 6. Horizontal & Equatorial Sundials in Action - PM

7.1.

Equatorial and Horizontal Sundials in Action - AM

10:59am local time on phone; 14-min delay based on longitude and Greenwich meridian data so sundials should read 10:45
– Dan O'Brien

7.2.

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7.3.

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7.4.

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7.5.

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7.6.

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8.

Worksheets, Lesson Plan & Slide Deck PDFs

  • 1. Lessons 1-3 Wksht May 2021
  • 2. Lessons 4-6 Wksht May 2021
  • 3. Copy of Slide Decks
  • 4. Lessons 1-3 Lesson Plan

8.1.

Lessons 1-3 Wksht May 2021

Lessons 1-3 Wksht May 2021
– Dan O'Brien

8.2.

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8.3.

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8.4.

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情報