Physicist Sabine Hossenfelder explores the scientific concept of the block universe, which suggests that the past, present, and future all exist simultaneously as a single entity. Drawing on Einstein’s theory of relativity, she explains that because simultaneity is relative to an observer's motion, there is no universal "now," meaning every moment is equally real. The source argues that our perception of time flowing is a sensory illusion similar to the mistaken belief that the Earth is flat. While acknowledging that quantum mechanics introduces unpredictability, Hossenfelder maintains that this indeterminism still fits within a model where all points in time are permanently present. Ultimately, the text posits that the future is already established in the fabric of spacetime, yet our individual choices remain the essential links that determine its specific structure.