It has been argued bymany experts in quantumcosmology that time is nota fundamental concept,but an approximate andemergent one

摘要

To understand why, it is helpful to distinguish be-tween the notion of a fundamental law and an effectivelaw. A fundamental law is posited to hold "meta-uni-versally" from first principles and must be unique.String theory, for instance, is an attempt at discoveringsuch fundamental laws of nature. Effective laws, at theother extreme, govern experiments at scales that weobserve directly within one universe, down to the smallscales probed by the Large Hadron Collider and up tothe scales probed by observations of the cosmic micro-wave background. We can only observe the effectivelaws, but we hope that it should be possible to derivethem from fundamental laws - otherwise the latter hasno connection with what we observe. The question iswhether that indirect connection provides enoughground for experimentally testing the fundamentallaws so that they are relevant for our scientific under-standing of the world.