Does Observation Create Reality? Schrödinger’s Cat, Quantum Mechanics, and the Case for the Multiverse

What if reality doesn’t truly exist, until you look at it?

That may sound like science fiction, but it’s a real question posed by some of the most brilliant minds in physics. At the heart of it lies a strange but undeniable fact: simply observing something appears to change it. And that leads to an even stranger possibility, that every potential outcome of every event could actually happen… in parallel universes.

Welcome to the multiverse. Let’s unpack what science really tells us about observation, possibility, and the nature of reality.

The Experiment That Shattered Our Intuition--> The Double-Slit Paradox

The now-famous double-slit experiment reveals something unsettling about the quantum world.

Imagine firing particles (like photons or electrons) at a barrier with two slits, and measuring where they land on a screen behind it.

• If you don’t observe which slit the particle goes through, it behaves like a wave, as if it passed through both slits at once, producing an interference pattern.

• But if you do observe which slit it travels through, the interference disappears. The particle behaves like a particle, passing through only one slit.

Let that sink in:

The act of observation changes the outcome.

Something about the physical reality of the particle, or wave, changes simply because it’s being watched.

Schrödinger’s Cat--> Dead, Alive, or Both?

To push this logic to the extreme, physicist Erwin Schrödinger proposed a now-famous thought experiment:

A cat is placed in a sealed box with a radioactive atom, a Geiger counter, and a vial of poison. If the atom decays, the poison is released and the cat dies. If it doesn’t, the cat lives.

According to quantum mechanics, until the box is opened and observed:

• The atom is in a superposition of decayed and not decayed.

• The cat is in a superposition of dead and alive.

As absurd as that sounds, it's the logical result of quantum theory.

But instead of dismissing it, some physicists asked a deeper question: What if both outcomes actually happen?

Enter the Multiverse... Many Worlds, All at Once

In 1957, physicist Hugh Everett introduced what’s now called the Many-Worlds Interpretation (MWI) of quantum mechanics.

Rather than saying the wave function “collapses” when you observe it, Everett proposed something radical:

Every possible outcome of a quantum event actually occurs, but in separate, parallel universes.

So-->

• In one universe, the atom decays, and the cat dies.

• In another, the atom doesn’t, and the cat lives.

• In each reality, an observer sees only one outcome... but both outcomes exist in their respective branches.

This isn’t just science fiction. The mathematics that governs quantum behavior (specifically Schrödinger’s equation) remains cleaner and more consistent under this interpretation than in others.

The Mathematical Backbone... Why the Multiverse Isn’t Just a Fantasy

While the multiverse remains unproven, it’s not just a speculative fantasy. It’s a direct consequence of the mathematics behind quantum mechanics.

Schrödinger’s Equation and the Wave Function

Quantum systems are governed by a wave function, a mathematical description of all possible states. The wave function evolves smoothly and predictably until a measurement is made.

In the standard interpretation (Copenhagen), we say the wave function collapses into a single outcome when observed. But there’s no rule in the equation that says this must happen. It’s an add-on assumption.

Everett’s Many-Worlds removes the collapse entirely. The math continues uninterrupted, and every possible outcome simply unfolds in a new branch of the universe.

Linearity and Unitary Evolution

The evolution of quantum systems is linear and unitary, meaning all components of a superposition evolve simultaneously without interference.

If a particle can be in state A or B, the math says both states evolve, unless we forcibly delete one (collapse). Many-Worlds doesn't require that deletion. It honors the math without needing special rules.

Hilbert Space... Room for Infinite Possibility

Quantum states exist within an abstract mathematical space called Hilbert space, a structure that holds all possible configurations of particles, fields, and states.

If something can exist within Hilbert space, the multiverse idea suggests it does, even if we only perceive one strand.

Decoherence... The Bridge Between Math and Experience

Decoherence explains why we don’t experience all branches of the multiverse. It’s a mathematical process where quantum superpositions lose coherence due to interactions with their environment.

This is not wave function collapse, it’s more like quantum separation. Each outcome becomes isolated, unable to interfere with others, forming independent branches of reality.

The String Theory Landscape

In string theory, the number of possible vacuum states, different ways to “build” a universe, is estimated at ~10¹⁰⁰⁰. That’s not a guess... it's derived mathematically based on how extra dimensions can be compactified.

The anthropic principle then suggests:

We live in one of the rare universes where conditions allow life, because we’re here to ask the question.

This lends probability weight to the idea that countless other universes exist, each with different physical laws and constants.

What If "The Upside Down" Isn't Just Fiction?

In the hit series Stranger Things, “The Upside Down” is portrayed as a dark, parallel dimension, a shadowy mirror of our world that exists alongside us, invisible but ever-present. While the show is fiction, the concept it’s built on isn’t so far-fetched. In fact, modern quantum physics, especially the Many-Worlds interpretation, proposes that parallel universes could be real, existing just beyond our ability to perceive or measure them. What if “The Upside Down” is more than a sci-fi trope? What if it's an artistic reflection of a mathematically grounded multiverse, where every possibility plays out somewhere else? If the laws of physics already suggest that unseen versions of reality may exist, maybe Stranger Things is tapping into something deeper, not fantasy, but foreshadowing.Observation, Consciousness, and Reality

So who, or what, is the observer?

This brings us to one of the most controversial ideas in physics and philosophy... does consciousness collapse the wave function?

Some interpretations suggest that conscious awareness plays a unique role in defining reality, that our observation doesn’t just measure reality, it manifests it.

Others say observers don’t need to be conscious, a camera or photon detector is enough. But the fact remains: the presence of a measurement apparatus alters the outcome.

And that leads to uncomfortable questions:

• Are we creating our reality by observing it?

• Are we just passengers riding one branch of an infinite multiverse?

• Or are we co-creators, collapsing possibility into form?

Why This Matters

I work in cybersecurity and infrastructure, where systems behave differently when watched, and data only becomes useful when observed and interpreted. That parallels the quantum world more than most people realize.

In physics, as in IT and security, observation defines outcome.

The implications stretch far beyond science fiction:

• Could AI systems eventually act as observers in quantum systems?

• Are there unseen consequences to every decision in our digital world, much like the many-worlds of quantum theory?

Whether or not the multiverse is real, it remains one of the most fascinating, mathematically elegant, and logically consistent interpretations of our universe.

We may never observe these parallel worlds directly, but every time we make a choice, take a measurement, or observe a system, we narrow an ocean of possibility into the single path we call now.

And just maybe, the other paths still exist... branching off into unseen realities where anything that can happen, does.