Chapter 1: Delayed Choice

In the prologue, we established the geometric structure of the causal loop: time is not a unidirectional arrow but a snake biting its own tail. Now, we push this abstract theory to the experimental bench to witness how quantum mechanics rewrites history in the laboratory.

The Delayed Choice Experiment is one of the most perplexing experiments in quantum mechanics. It shows us that present observations can not only determine the present but can even flow backward to define history from billions of years ago.

This chapter will delve into the physical mechanisms and philosophical implications of this experiment, revealing how observers shape past history through present choices.