As stated in the syllabus: From time to time I will ask the class to submit childish questions, and I will select the most relevant of them and post them [here]. Every student is free to do some research, and to submit electronically a one-page answer to any of the posted questions. If your answer is acceptable and the best one received on the topic at the time of submission, I will post it on the website and grant you 10 extra-credit Final Exam points! Since there is a limit of two submissions per semester per student, you should make sure that you only submit answers when you are convinced that you have a good one! You are encouraged to come and talk with me about the question and answer before submission! Below are some of the most relevant questions I received on our first try. In many cases, I rewrote the questions, or combined several similar questions asked by different students. If you don't see your question here, don't be surprised. It may turn up later in the semester, when it is more relevant to current in-class discussions. 1. Why is the sky blue? 2. Why is the Moon following our car? 3. What is really at the end of a rainbow? 4. Why is it dark at night? 5. How can you tell a planet from a star? 6. What causes the seasons of the year? 7. Why don't the stars move? (That is, why do the constellations always look the same?) 8. What makes the tides? 9. How far does space go? 10. Are there other planets like Earth? 11. Why did dinosaurs become extinct? Student Answer 12. What is light? 13. Why are stars white? 14. What is the temperature on the Moon? and how do we know? 15. Why is the Earth round? 16. Why does the Moon seem bigger when it is lower in the sky/ near the horizon? 17. Why aren't telescopes made with dual eyepieces, like binoculars? 18. Why do stars "shoot"? 19. How does the number of stars in the Universe compare with number of grains of sand at the beach? 20. What is the deepest hole that people can dig, and how do they do it? All in all, a pretty good bunch of questions! Some of them are even FAMOUS QUESTIONS that scientists have spent a lot of time trying to answer. Care to try your hand at one? Come and see me if you need help!