for their existence today. The conservation laws that are integrability conditions for equations of motion guarantee they existed in the past, which is why they exist today. Further, Ellis believes the physics models that omit an objective present and treat the universe as a purely static, four-dimensional block--where the "flow" of time is merely an illusion--fail to account for the reality of human experience and cause-and-effect.

Bernard Carr, English physicist, cosmologist, and protegee of Stephen Hawking, proposes an evolving block