On the Origin of Time

We tend to think of the Big Bang as a singular, explosive event—a cosmic firework that lit up the darkness and set in motion a pre-written script for the universe. In this story, the laws of physics were fixed from the very first moment, existing like divine commandments before time and space even had meaning. We, as inhabitants of this universe, are merely actors discovering the lines of a play that was written billions of years ago. Our scientific quest is to find this master script, to read the mind of God. But what if this entire picture is profoundly wrong? What if the laws of physics aren’t a fixed blueprint, but rather evolving participants in the cosmic story? This suggests a far stranger reality: one where the universe developed its rules as it developed itself, with the past taking shape only as it is observed from the future.

This radical perspective emerged from two decades of intimate collaboration between Thomas Hertog and the late Stephen Hawking. As one of Hawking’s closest colleagues, Hertog worked side-by-side with him on a new quantum theory of the cosmos, a project they pursued until Hawking’s final days. Their goal was to solve a puzzle that had haunted Hawking for years: his own famous theory of black holes, when applied to the universe as a whole, predicted an infinity of universes, rendering our own existence a statistical impossibility. To resolve this, they had to abandon the idea of a single, objective history of the universe. Instead, they proposed a 'top-down' cosmology, a new story where we, as observers, play a central role in shaping the reality of the cosmic past. This book is Hertog's account of that final, revolutionary theory—a journey to the very origin of time itself.

Module 1: The God's-Eye View is Dead

For centuries, physics has tried to find a "God's-eye view" of reality. This is the idea that we can describe the universe from an external, objective standpoint. Think of Newton's absolute space and time, or Einstein's search for timeless mathematical laws. This approach works for predicting a solar eclipse. But it fails spectacularly when applied to the whole cosmos. Why? Because we can't step outside the universe to measure its starting conditions.

This leads to a paradox. The traditional "bottom-up" view of cosmology, where fixed laws dictate everything from a single beginning, creates unresolvable problems. A bottom-up approach starts at the big bang and moves forward. It assumes a set of eternal laws and initial conditions. But what determined those laws? And what set those conditions? This path leads to two unsatisfying answers. The first is that our universe is a mathematical necessity, making life a mere lucky coincidence. The second is the multiverse.

Here's the problem with the multiverse. Theories like eternal inflation suggest our universe is just one bubble in an infinite cosmic foam. Each bubble has different laws. We just happen to live in one that supports life. This is the anthropic principle. Hawking initially explored this idea. But he came to see it as a "negation of our hopes of understanding." It is metaphysics, not testable science. If your theory predicts everything, it predicts nothing. It becomes untestable. So, Hawking and Hertog realized they needed a new approach. To solve the puzzle of our origins, we must abandon the external perspective and build a theory from within. This means acknowledging our role as observers inside the system. We aren't just watching the show; we are part of it. This shift is the foundation for everything that follows.