ASTRONOMY Chapter 10 Sections 6-10

PART III: The Sun’s Interior

1. In the 1800ds geologists proposed that the earth is millions of years old. Astrophysics had a problem with this because of their belief about the sun. What was this understanding of the sun held by astrophysics that conflicted with the geologist’s ideas about the age of the earth?

2. How do we know that the energy from the sun does not come from its surface gas or its intense magnetic fields?

3. From what part of the sun does its enormous quantity of energy come?

10-7: Thermonuclear reactions in the core of the Sun produce its energy

4. What did Einstein’s special theory of relativity reveal about the amount of energy contained in matter?

5. What is the equation that provided the proof of your answer to #39?

6. What happens deep within the sun that, it turns out, is the source of the energy of the sun?

7. What is thermonuclear fusion?

8. What is the significance of thermonuclear fusion to the sun?

9. What ‘kind’ of thermonuclear fusion takes place in the core of the sun?

10. Sometimes hydrogen fusion is called hydrogen burning. What is the huge and very significant difference between hydrogen burning and hydrogen fusion?

11. Wow! Did you read the last paragraph on page 302?! What radical statement does the author make in the second sentence?

12. So, what is actually true about the ‘conservation’ of matter and the ‘conservation’ of energy?

10-8: Solar models describe how energy escapes from the Sun’s core

13. Read the first paragraph on page 305. What are the two forces that are in balance keeping the sun from neither shrinking nor expanding?

14. In what form is the energy created by the conversion of matter into energy that happens in hydrogen fusion?

15. Essentially what is the mechanism of the outward force that counteracts the inward force of gravity?
16. So, the sun pushes in and pushes out; what is the state of constancy called?
17. As the photons collide what happens to their energy?

18. All this colliding, even though it occurs at high speeds, slows down the photons. How long does it take the energy of a single gamma ray photon to reach the surface of the sun? BTW, is it the same photon that began the journey that eventually reaches the top? Explain how you know.

19. The region wherein the photons created by hydrogen fusion occurs does not extend to the surface of the sun. How much of the distance between the core and the surface is dominated by these emerging photons? What is the name given to this region?

20. Consider the part of the sun above the region described in the previous question. What is the mechanism by which energy is transported through this last portion of the sun? What is the name given to this region?

21. How do we know that the gamma rays generated at the sun’s core are not exactly alike?

22. When you hear the word ‘model’ you think of a 3D representation; but what is an astronomer’s model of the sun?

23. What are some of the characteristics ((list 5) the astronomers’ model of the sun reveal?

24. Take a close look at the graphs on page 306. What portion of the sun contains nearly all of its mass? Where is the sun hottest? At what portion of the sun’s radii does its density fall below 40,000 kg/m³?

25. Here is an interesting point: How many times more dense is earth’s atmosphere than the lowest part of the sun’s atmosphere?

10-9: The mystery of the missing neutrinos inspired research into the fundamental nature of matter

26. When hydrogen fusion occurs a gamma-ray photon and something else is created. What is the second particle? Describe the nature of this particle in terms of its charge and mass.

27. What does the author mean when he says that the sun (and the earth) is transparent to neutrinos?

28. How many solar neutrinos are produced every second? How many pass through each square centimeter of your body every second?

29. Why are astronomers so interested in building a neutrino telescope?

30. A neutrino detector was built in the mid 1960’s, and every three days or so it detected a neutrino. What was the problem with this rate of detection?

31. What were the three possible explanations for the low rate of solar neutrinos detected?

32. Describe how two of the three possibilities listed in the previous question were eliminated.

33. Which came first, the neutrino or the necessity that it must exist?

34. What is the origin of the name electron neutrino? Are there other ‘kinds’ of neutrinos? If so, name them.

35. Protons and electrons have ‘charge; what do neutrino’s have?

36. So, the neutrino detectors detected only one third of the neutrinos that theory predicted they should detect. What did scientists discover about the nature of neutrinos that explained why only a third of the predicted amount were detected?

10-10: Frontiers yet to be discovered

Many, many questions about the nature of our nearest star remain unanswered. A careful reading of 10-10 reveals 8 such questions. Choose the three that most interest you and list them here.