"I have emphasized what I consider the two most remarkable features that I have learned in my research on space and time: (1) that gravity curls up space-time so that it has a beginning and an end; (2) that there is a deep connection between gravity and thermodynamics that arises because gravity itself determines the topology of the manifold on which it acts".
In “The Nature of Space and Time by Stephen Hawking and Roger Penrose” by Stephen Hawking in the lecture "Quantum Cosmology"
"We should think of twistor space as the space in terms of which we should describe physics."
In “The Nature of Space and Time" by Stephen Hawking and Roger Penrose by Roger Penrose in the lecture "The Twistor View of Spacetime"
"These lectures have shown very clearly the difference between Roger and me. He's a Platonist and a positivist. He's worried that Schrödinger's cat is in a quantum state, where it is held alive and held dead. He feels that can't correspond to reality. But that doesn't bother me. I don't demand that a theory correspond to reality because I don't know what it is. Reality is not a quality you can test with litmus pap. All I'm concerned with is that the theory should predict the results of measurements. Quantum theory does this very successfully. It predicts that the result of an observation is either that the cat is alive or that it is dead. It is like you can't be slightly pregnant: you either are or you aren't."
In “The Nature of Space and Time" by Stephen Hawking and Roger Penrose by Stephen Hawking in the lecture "The Debate"
Can I write a review on such a book? Hawking and Penrose... It's staggering...I don't even know what day the mailman comes...After having re-read this oldie after Hawking's passing, I'd say it depends on where you are in the universe, whether you're on/near some sizeable object (of mass), its rotation, distance from other masses, or whether you live in my neck of the woods...
If you're into Physics, and Quantum Mechanics in particular, read on.