1. According to the standard model, what is the elementary constituent of nature?

2. How thick is a string?

3. What is the weakest force of nature?

4. Which fundamental forces does the standard model describe?

5. What does it mean to describe a particle as “elementary” or “fundamental”?

6. What are the problems with string theory today?

7. The equivalence principle refers to which phenomenon?

8. The uncertainty principle is a feature of which theoretical framework?

9. Has the universe always been the same size?

10. How did black holes get their name?

11. What is the messenger particle of electromagnetism?

12. How does the existence of quantum foam clash with Einstein’s general theory of relativity?

13. After the first superstring revolution, how many viable versions of string theory emerged?

14. How many dimensions of space does the current formulation of string theory require to be viable?

15. Why did the existence of a tachyon bring about the collapse of bosonic string theory?

16. Bosonic and fermionic vibrational patterns differ by how much?

17. What does the M in M-theory stand for?

18. How many dimensions does a Calabi-Yau space have?

19. Who was the first scientist to argue that light exhibits wave properties?

20. What is the basic principle underlying special relativity?

21. What do string theorists think that the extra dimensions of space will look like?

22. Supersymmetry predicts what about the elementary particles?

23. Which of the following particles is thought to be massless?

24. Which small-scale phenomenon creates the incompatibility between general relativity and quantum mechanics?

25. What is the term for the approximations string theorists much make in their calculations?