“The fastest that human spacecraft are likely to achieve in the twenty-first century, I think, is 300 kilometres per second.” HumanSpacecraft Book:The Science of Interstellar Source: The Science of Interstellar
“Why are black holes so different from all other objects in the macroscopic Universe? Why are they, and they alone, so elegantly simple? If I knew the answer, it would probably tell me something very deep about the nature of physical laws. But I don’t know.” UniversePhysicsBlack HolesTheoretical Physics Book:Black Holes & Time Warps: Einstein's Outrageous Legacy Source: Black Holes & Time Warps: Einstein's Outrageous Legacy
“Can you identify in your own life speculations that became educated guesses and then truth? Have you ever seen your established truths upended, with a resulting revolution in your life?” TruthsRevolutionary WarEducated Guesses Book:The Science of Interstellar Source: The Science of Interstellar
“Yes, that’s what I meant to say. If this seems a bit circular to you, well, it is, but it has deep meaning.” Circularity Author:Kip S. Thorne