 This is an odd situation indeed. An event in Bob’s future seems in some way to become fixed or inevitable by being in Alice’s past. But that is not the end of the oddness here. Imagine that at point \(\mathbf{A}\) (where Alice’s plane of simultaneity intersects the world line of Andromeda) there is an Andromedean, Carol, who is walking directly towards Earth at about 4 km/hour. Then Carol’s plane of simultaneity intersects Earth at some point \(\mathbf{C}\) which is about 11 ½ days after \(\mathbf{O}\), the meeting of Alice and Bob. If all events (like \(\mathbf{A})\) in Alice’s past or present at \(\mathbf{O}\) have happened, are fixed, or are real, then the principle of relativity (the second assumption of the special theory introduced above) suggests that we must also extend the same courtesy to Carol; and so simultaneous with the fixed and real event \(\mathbf{A}\) (Carol’s walking towards Earth at exactly the point at which Alice’s plane of simultaneity intersects the history of Andromeda) is the event \(\mathbf{C}\) (and so fixed and real), the intersection of Carol’s plane of simultaneity with Earth, which is in the future of both Alice and Bob. It is easy to see that, by adjusting the speeds of Alice and Carol, any event to the future of \(\mathbf{O}\) can be shown to be fixed or real or inevitable. But \(\mathbf{O}\) itself was just an arbitrarily chosen point in the spacetime. “It begins to seem that if anything is definite at all,” we might echo Penrose, “then the entire space-time must indeed be definite! There can be no ‘uncertain’ future.” (p. 304)