3. What paradox does time travel generate?
(a) The snooze button paradox.
(b) The grandfather paradox.
(c) The light year paradox.
(d) The grandmother paradox.

4. What does Hawking say extraterrestrials might be like?
(a) Like humans.
(b) Easy to get along with.
(c) Not very bright.
(d) Very primitive or very advanced.

5. How could this energy density be created?
(a) By separating virtual particles from real particles.
(b) By taking out virtual particles in a closed loop.
(c) By creating new weights for each energy density.
(d) By dividing the molecules into fragments and then reassembling them.

6. What barrier could wormholes break?
(a) The light barrier.
(b) The no-boundary barrier.
(c) The sound barrier.
(d) The weight barrier.

7. What popular sci-fi show does Hawking refer to when discussing its differences with humanity in a millennium?
(a) Torchwood.
(b) Star Wars.
(c) Star Trek.
(d) Doctor Who.

8. For nearly all of history, what has moved forward?
(a) Energy.
(b) Spacetime.
(c) The Earth.
(d) Humanity.

9. What kind of explanation does Hawking give for how it might be possible to travel through time?
(a) Blanket statement.
(b) Complex.
(c) General.
(d) Superficial.

10. What equation will be able to determine the wave function for information?
(a) Schrodinger.
(b) Popper.
(c) Heisenberg.
(d) Rossinger.

11. What are cosmic strings?
(a) Points between which waves connect.
(b) Sections of space divided into tiny lines.
(c) Objects with length but tiny cross sections.
(d) Planes with narrowly etched furrows.

12. What is the name of Hawking's conjecture about the laws of physics and macroscopic time travel?
(a) The Chronological Spacetime Conjecture.
(b) The Timeline Protection Conjecture.
(c) The Chronology Protection Conjecture.
(d) The Theoretical Projection Conjecture.

13. What kind of advanced development does Hawking predict for humanity?
(a) Social development.
(b) Weapon development.
(c) Biological and electronic development.
(d) Religious development.

14. How can one find black holes?
(a) By finding the mass of everything invisible.
(b) By finding matter that orbits around a seemingly invisible object.
(c) By seeking out the matter that revolves around finite space.
(d) By seeking out the matter that orbits around a visible object.

15. What do black holes absorb?
(a) Mass.
(b) Energy.
(c) Heat.
(d) Weight.