The birth of our universe is one of the most profound mysteries of existence. For centuries, scientists and philosophers have pondered whether the universe had a purpose, a creator, or a reason for existing at all. But modern physics proposes something even more mind-bending: What if the universe emerged not from a singular cause or a divine will—but from quantum possibilities? Did the universe choose to exist?
From Singularity to Quantum Beginnings
The standard Big Bang theory tells us that the universe began as a singularity—a point of infinite density and temperature. But the concept of a singularity raises many paradoxes. To address this, physicists have proposed quantum mechanical explanations that replace the singularity with something less contradictory: a probabilistic quantum origin.
One such approach is the Hartle-Hawking no-boundary proposal, developed by physicists James Hartle and Stephen Hawking. It suggests that the universe didn’t begin with a sharp bang, but rather emerged smoothly from a quantum state. According to this model, the universe is a quantum system governed by a wave function, much like particles in quantum mechanics.
The Wave Function of the Universe
In standard quantum mechanics, a wave function gives a probability distribution for all possible states of a system. It tells us where a particle might be found when measured. Extending this concept, the wave function of the universe describes the probabilities of different possible universes.
This wave function resides in Hilbert space, a mathematical space that holds all possible quantum states. Just as a particle can be in a superposition of locations or momenta, the early universe was in a superposition of all possible configurations—each with a different geometry, energy level, or even physical law.
From this cosmic superposition, our specific universe is just one of the many possible realities that emerged. In this view, the universe didn’t start with a single, fixed history. Instead, it began with many potential histories—and the one we inhabit is simply the one that decohered into classical reality.
A Timeless Beginning: Wheeler–DeWitt Equation
In trying to reconcile general relativity with quantum mechanics, physicists John Wheeler and Bryce DeWitt formulated the Wheeler–DeWitt equation. Unlike the Schrödinger equation, this equation contains no time variable. It implies that, at the most fundamental level, the universe might be timeless.
This seems paradoxical. How can a universe without time lead to the flow of time we experience? The key lies in the nature of quantum superpositions and entanglement.
Time as an Emergent Phenomenon: The Page–Wootters Mechanism
A possible resolution comes from the Page–Wootters mechanism, which proposes that time is not a background parameter but an emergent property arising from quantum entanglement.
Imagine a simple quantum universe with two parts: a “clock” (say, a qubit) and a “system” (such as an electron). When these are entangled, the system appears to evolve relative to the clock. The “flow of time” is not an absolute progression but a change in the relationship between the two entangled components. In this view, time = entanglement.
Thus, the illusion of time arises from within the universe itself—not from outside it.
Observation and Reality: Schrödinger’s Cat & The Observer Effect
Quantum mechanics is notorious for its strange predictions. Before measurement, particles exist in a superposition of all possible states. The classic thought experiment of Schrödinger’s cat illustrates this: A cat in a box is both dead and alive until someone opens the box. The act of observation collapses the superposition into a definite state—alive or dead.
This leads to the observer effect: The idea that measurement defines reality. According to the Copenhagen interpretation, the wave function collapses upon observation, selecting a single outcome from all the quantum possibilities.
The double-slit experiment supports this idea. When electrons are fired through two slits without being observed, they create an interference pattern, acting like waves. But when observed, they behave like particles. This suggests that observation itself changes the behavior of matter.
Wheeler’s “It from Bit”: Information as the Foundation of Reality
Physicist John Archibald Wheeler took this concept even further. He proposed that information is the most fundamental building block of reality—not matter, not energy. His famous phrase, “It from Bit,” suggests that every physical entity (“it”) comes from binary information (“bit”).
Wheeler argued that the universe doesn’t exist in a definite state until it is observed. Just as a video game renders a scene only when the player looks at it, reality “renders” when conscious beings observe it. Even more radically, Wheeler claimed that observation can bring the past into being.
When we observe a galaxy a billion light-years away, we’re seeing light that left it a billion years ago. According to Wheeler, our observation “creates” that past by collapsing the wave function of the universe to include that particular history. In this way, we are participators in the creation of reality—even the distant past. So, did the universe choose to exist? Or did we choose it?
But Do We Need a Conscious Observer? Enter Decoherence
Wheeler’s ideas are elegant, but they raise a serious question: Do we really need a conscious observer to make reality “real”? Or did the universe “choose” to exist itself?
The answer may lie in quantum decoherence—a phenomenon that explains how quantum systems begin to behave classically due to interaction with their environment.
In the real world, no system is perfectly isolated. Every quantum system interacts with its surroundings—light, particles, heat, radiation. These interactions effectively “observe” the system, causing it to lose its quantum superposition and settle into a specific state.
This process—quantum decoherence—does not require consciousness. It happens naturally when systems become entangled with their environment. In the early universe, as it expanded and cooled, quantum fluctuations interacted with radiation fields and matter. These interactions caused decoherence, effectively collapsing the wave function of the universe into a classical, observable cosmos.
Thus, while Wheeler emphasized conscious observation, decoherence tells us that the universe can “choose” a definite reality without needing minds to observe it.
So… Did the Universe Choose to Exist?
In a way, yes—but not in the way we typically understand “choice.” The universe didn’t consciously choose to exist. Instead, quantum mechanics suggests that all possible versions of the universe were once equally real, described by a vast superposition of quantum states.
From this sea of possibilities, our universe “chose” its path through quantum decoherence—a natural, physical process that selected specific classical outcomes from a set of quantum probabilities. There was no hand of God, no grand plan—just the raw mathematics of probability, interaction, and entanglement.
Yet, in a deeper philosophical sense, we are part of the universe’s unfolding story. Whether through conscious observation or natural decoherence, we participate in the making of reality. We are the products of a quantum beginning, and now, as conscious observers, we reflect upon the very process that gave rise to us.
Conclusion: A Universe Born from Possibility
The idea that the universe didn’t begin with a bang, but with a quantum wave function, reshapes how we understand existence itself. In this view, reality is not fixed or predetermined—it emerges through processes of probability, interaction, and observation.
Whether time is emergent, reality is informational, or decoherence collapses possibilities into a singular outcome, one thing is clear: The universe didn’t have to exist in this exact way—but here it is. And so are we.
We may never know if the universe truly “chose” to exist, but through quantum theory, we begin to understand how choice might arise without a chooser—and how reality can emerge from the rich, probabilistic fabric of quantum possibility.
Sources:
https://en.wikipedia.org/wiki/Wheeler%E2%80%93DeWitt_equation
https://en.wikipedia.org/wiki/Problem_of_time