Welcome Assignment August 9 & 10, 2011

1. Welcome AssignmentAugust 9 & 10, 2011 Planner: Wear covered shoes for rest of week Type up lab report as the information comes Get Science Notebook: The Universe Make a circle map – brainstorm all the things you can think of in the universe (space). In your lab group categorize the items you put down into a KWL Chart.

3. How do scientist know what’s out there? • Write some questions you have about the universe. • KWL • Complete the W part of the KWL Chart.

4. Welcome Assignment:Get Science Notebook – Write title:How Far is that Star? WEAR Covered Shoes August 10 – 12 TYPED Lab Report due August 17 = Period 1 TYPED Lab Report due August 18 = Period 2, 4, 5, 6

5. Science Investigation: • Research Question/Purpose • Background Information/Equations • Hypothesis • Materials • Procedure • Data/Observations • Data Analysis & Calculations • Conclusion

6. Research Question/Purpose • How can parallax be used to determine distances from earth to nearby stars? • Skills • Measure distances between two points • Calculate the distance to an object using ratios of measured values; • Compare the calculated value to the measured value; • Predict the parallax of an object at different distances.

7. Background Information/Equations • Write from your past experience: • What do you notice when you view a fast moving object up close, and a fast moving object from far away? (think about an airplane in the sky) • Distance = Diameter X Focal Length Parallax Shift

8. Hypothesis • If…Then…Because….

9. Materials • Masking tape • Black and red pencils • Extension cord • Lamp, 100 watt Lightbulb • Copier Paper Box (no lid) • Flat Table • Paper Clips • Metric Ruler • Meter Stick • Pen • Paper • Calculator

10. Procedure – Part 1 • Place the lamp on a table in the middle of the classroom • Make a small hole in the middle of the box • Place the box on a flat table so the hole points toward the light • Line the left side of the box with the table • Put a small piece of tape on the table below the hole. Use the pen to make a mark on the tape directly below the hole.

11. Procedure - Part 2 • Label sheet of copy paper “Star 1” • Place it inside the box • Turn off the classroom lights and turn on the lamp • RED Pen – Mark the paper where you see a dot of light. • Move the box so the right edge of the box lines up with the right edge of the table • Put another small piece of tape under the new location of the hole, and make a mark to record the specific position (telescope 6 months later) • Regular Pencil – mark the second dot B. Dot B represents the image of the star as seen 6 months later from the other side of Earth’s orbit. • Remove the paper.

12. Measurements • Measure and record the distance in millimeters between dots A and B. This distance represents the parallax shift for Star 1 • Measure and record the distance from the hole (lens) to the paper (film) at the back of the box in millimeters. This distance represents the focal length of our telescope. • Measure and record the distance in millimeters between the marks on the two pieces of masking tape. This distance represents the diameter of Earth’s orbit. • Use a meter stick to measure the actual distance from the box to the bulb. How did your calculations for Star compare with the actual distance

13. Data/Observations

14. Data Analysis & Calculations • Use the following formula to calculate the distance from the telescope to Star 1. • Distance = Diameter X Focal Length Parallax Shift • What happened to the dot of light for each star when you moved to your model telescope from one side of Earth’s orbit to the other? • What caused the apparent change in position of the dots of light for each star? Explain.

15. Conclusion • Is the parallax shift greater or smaller the farther away the star is? Relate each star’s parallax shift to its distance from Earth. Use data to support your statement. • Validate or Refute your Hypothesis. Use data to support your statement. • Identify any errors in calculations, measurement, etc. • Think about your experience (fast moving objects) explain how it relates to this lab? • How can parallax be used to determine distances from earth to nearby stars? Explain how this method works. • Would this method work for objects very close? • Would this method work for objects very far? • Would this method work for all objects in the universe?