For 10 points, name these seemingly contradictory situations.
One of these statements concerns the apparent ages of binary stars like Algol. One of these situations that concerns the apparent contraction of the radius of a rapidly rotating disc is named for Ehrenfest, while another concerns the apparent lack of information conservation at the event horizon of a black hole. One named for (*) Olbers concerns the darkness of the night sky despite the number of stars in the universe, while another concerns a pair of twins, one of whom boards a spaceship. For 10 points, name these seemingly contradictory situations.
One of these statements concerns the apparent ages of binary stars like Algol.
paradoxes