This article was automatically translated from the original Turkish version.
Have you ever wondered, “What if I had chosen the other path that day?” What if you had accepted that job offer, missed that train, or never met that person…?
In our reality, these questions remain mere “what ifs.” But according to one of modern physics’ most daring and controversial ideas—the Multiverse Theory—these alternatives may all be real, unfolding somewhere else.
For centuries, we assumed the universe was a single, all-encompassing entity made up of the stars, galaxies, and ourselves. But what if, like the cosmic bubbles in our cover image, our universe is just one of countless islands in an infinite ocean?
Today, we dive into the captivating realm of the Multiverse—a space where the boundaries of physics blur and science fiction dances with science.
In its simplest form, the Multiverse theory argues that the universe we inhabit—the one we believe began 13.8 billion years ago with the Big Bang—is not the only one that exists.
According to this theory, there could be countless other universes. Some may be nearly identical to ours (perhaps even containing a version of you reading this sentence right now), while others might operate under completely different physical laws—where gravity works in reverse or time flows backward.
This is not merely the invention of screenwriters or dreamers. The concept of the multiverse emerges as a natural consequence from the equations of two of modern physics’ most successful theories:
Quantum Mechanics and Cosmic Inflation.
Here are the two main scenarios supporting the existence of multiple universes:
Immediately after the Big Bang, the birth of our universe, an extraordinarily rapid expansion phase known as “inflation” occurred. Space expanded faster than the speed of light.
Most physicists believe this expansion ended in our region, allowing stars and galaxies to form. But according to the “Eternal Inflation” model, space itself never fully stopped expanding. It only paused in certain pockets—like our own universe.
Imagine boiling water. Bubbles constantly form. Our universe is just one of those bubbles. As our cover image suggests, new “universe bubbles” may be continuously forming in the cosmic void. Each bubble is an isolated universe with its own Big Bang and its own set of physical laws.
When quantum mechanics—the strange world of subatomic particles—enters the picture, things become even stranger. In the quantum realm, a particle can exist in multiple states simultaneously (for example, both left and right) until observed. This is called “superposition.”
So what happens to the other possibilities when we make a measurement? According to the Many-Worlds Interpretation, reality splits at every decision point.
Imagine flipping a coin. It lands heads. But according to this theory, another universe branched off at that exact moment where it landed tails. At every quantum event, the universe splits trillions of times. In this scenario, the bubbles in our cover image are not distant locations but overlapping, invisible alternate realities existing in the same space.
If there are infinite universes—especially under the cosmic foam model—the mathematics of probability tells us something unsettling: Eventually, patterns must repeat. If you travel far enough, you will inevitably encounter another universe where the arrangement of atoms is identical to ours.
There is a universe where another “you” is reading this sentence right now. There is another where a version of you put the article down and went for coffee. There may even be a universe where dinosaurs never went extinct and you could see a T-Rex outside your window.
The multiverse theory takes our existential loneliness and transforms it into an infinite crowd.
While the multiverse theory is exhilarating, there is a major problem in the scientific community: testability.
By definition, these other universes lie beyond our “observable universe.” We cannot communicate with them, travel to them, or observe them—at least not yet. If you cannot test something, is it science or philosophy?
For now, the multiverse remains a compelling possibility suggested by our best physical theories, yet unproven. Perhaps we will never reach those other bubbles in our cover image. But even the idea that they might exist is powerful enough to make us question our place in the cosmos.
What Is the Multiverse?
Why Do Scientists Believe in Such a Radical Idea?
Cosmic Foam Bath (Inflation Theory)
Quantum Branching Paths (Many-Worlds Interpretation)
Brain-Bending Consequences: Infinite Versions of “You”
Conclusion: Science or Philosophy?
