Questions & Exercises on Relativity & Causality

1. What is ether? Why was its thought to exist?
    

2. What is an interferometer? How does Michelson's interferometer work?
    

3. Why does it take longer to fly from Europe to the States or Canada than vise versa?
    

4. What is a geodesic?
    

5. How did Michelson and Morely show that light traveled with the same speed independent of the ether wind velocity?
    

6. What was Einstein's approach to solving the ether dilemma?
    

7. Explain what are frames of reference. What are observables?
    

8. What are the transformation equations, in the context of Relativity Theory?
    

9. State Einstein's postulates.
    

10. What is the General Theory of Relativity?
     

11. Write down the transformation equations of Einstein's Special Theory of Relativity.
     

12. Using the above equations of question 11 Einstein showed that If an observer in frame F' measures the length, say of a stick, as L' and re-measures it as L once the stick is in relative motion to it, then these measurements are related according to: L = L'/γ. Consider a meter stick that is set to motion with a speed of 0.7c away from earth. What is its length as measured from earth?
     

13. Does the meter stick "really shrink" or does it appear shrunk?
     

14. Same as question 12, but now instead of length, the time interval: T = γT'. That is to say, a moving clock ticks less frequently. Two identical clocks are first synchronized and then set in relative motion by sending one off in a space ship traveling with a speed v = 0.7c. What time does the clock on the space ship register, as observed from earth, when the clock on earth registers one year?
     

15. What is a paradox? What is the Twin Paradox? Which twin eats more birthday cakes?
     

16. What is causality? How is it modified by Einstein's Theory of Relativity?
     

17. What is simultaneity? How is it modified by Einstein's Theory of Relativity?