Physics from information

This is an ongoing review on the idea that the phase space information loss at causal horizons is the key ingredient of major physical laws. Assuming that information is fundamental and the information propagates with finite velocity, one can find that basic physical laws such as Newton's second law and Einstein's equation simply describe the energy-information relation dE=TdS for matter or space time crossing causal horizons. Quantum mechanics is related to the phase space information loss of matter crossing the Rindler horizon, which explains why superluminal communication is impossible even with quantum entanglement. This approach also explains the origin of Jacobson's thermodynamic formalism of Einstein gravity and Verlinde's entropic gravity. When applied to a cosmic causal horizon, the conjecture can reproduce the observed dark energy and the zero cosmological constant. Quantum entanglement, path integral, and holography are also natural consequences of this theory.