Explore the concept of time's arrow in causal networks through this thought-provoking lecture by Sean Carroll from Caltech and Santa Fe Institute. Delve into the derivation of a macroscopic arrow of time from reversible and time-symmetric fundamental laws, considering coarse-graining and the Past Hypothesis of low entropy. Examine how familiar aspects of time's arrow, such as causes preceding effects, can be derived from this formalism. Discover how the causal arrow naturally emerges when describing macroscopic systems in terms of a causal network, and consider suggestions for incorporating prediction and memory into this framework. Gain insights into foundational questions in quantum mechanics, spacetime, cosmology, entropy, and complexity from this renowned theoretical physicist and author.