- Globally hyperbolic(as used in physics and cosmology)
- A mathematical property of spacetime (the fabric of space and time combined) that ensures cause and effect work in a predictable, well-behaved way throughout the entire universe.
- Physically realistic(as used in physics)
- Consistent with how the actual universe actually behaves, based on observation and experiments rather than pure mathematical possibility.
- Roger Penrose(as the originator of the gravitational entropy arguments being discussed)
- A renowned British physicist and mathematician who has written extensively about consciousness, cosmology, and the nature of time; he's known for proposing unconventional ideas about how the universe began.
- Singularity theorems(as used in cosmology and general relativity)
- Mathematical proofs developed by Penrose and Hawking showing that under certain conditions, the universe must contain points where the laws of physics break down (like at the center of a black hole).
- Spacetime(as one criterion for whether something is physically real)
- A physics concept combining space (location) and time into one continuous system—basically, every physical object exists somewhere at some moment in time.
- Stephen Hawking(as a key figure in modern physics)
- A legendary British theoretical physicist famous for discovering that black holes emit radiation and for his work on the nature of time, space, and the universe.
- Strong causality conditions(as used in relativity and cosmology)
- Mathematical requirements ensuring that cause and effect follow a strict, logical order with no weird time-travel-like loops or violations of cause coming before effect.
- counterexample([IHT] arg. 2)
- A possible obligational situation (casus possibilis positus) that verifies the antecedent and falsifies the consequent of an inference