It’s easy to think of ourselves as small, insignificant specks floating on a minor planet in an average galaxy. The universe is vast beyond comprehension, with billions of galaxies, each containing billions of stars and planets. Against this backdrop, we often feel microscopic. Yet, if we look in the opposite direction—within ourselves—we find another vastness. One that mirrors the universe in complexity and depth. This is the inner universe: our minds, our consciousness, and the microscopic and subatomic worlds that make us who we are.
What if we are not just in the universe, but the universe is also in us? What if we are, quite literally, a universe within a universe?
The Outer Universe: Immeasurable Vastness
When we look up at the night sky, what we see is a mere fraction of the observable universe. With an estimated diameter of 93 billion light-years, the universe stretches beyond the limits of human imagination. Galaxies swirl like cosmic pinwheels, stars are born and die in spectacular explosions, and black holes warp space and time in ways we are only beginning to understand.
We often say we are made of “star stuff,” a phrase made famous by Carl Sagan. It’s not poetic license—it’s scientific fact. The elements that make up your body—carbon, nitrogen, oxygen, and more—were forged in the hearts of dying stars. When those stars exploded as supernovae, they seeded the cosmos with the ingredients for life.
So, in a literal sense, the universe is in us. But what if we flip that perspective?
The Inner Universe: The Universe Within
Let’s shrink things down.
Your body contains around 37 trillion cells. Within each cell is a complex machinery of organelles, molecules, and atoms. Inside those atoms are subatomic particles like electrons, protons, and neutrons. And those particles are governed by the strange rules of quantum physics—a realm so counterintuitive, it challenges our very understanding of reality.
Some scientists speculate that the quantum realm might even contain extra dimensions, and possibly entire “hidden” realities we can’t yet detect. In that sense, each one of us might contain universes of possibility within the very atoms that make us.
Go a step further: your brain alone contains around 86 billion neurons, each forming thousands of connections to other neurons. The resulting neural network is more complex than the Milky Way. The patterns that form from these connections create thought, memory, identity, and consciousness.
In many ways, your mind is a universe. Not just metaphorically, but structurally. The complexity of the brain rivals, and perhaps even exceeds, the complexity of any known system in the cosmos.
Consciousness: The Inner Cosmos
One of the greatest mysteries in both science and philosophy is consciousness. What makes you you? How can matter—atoms and molecules—give rise to self-awareness? This question remains unanswered, but what’s clear is that the experience of consciousness is like a personal universe.
Think about dreams. Entire worlds are created while you sleep. People, places, events, sensations—all conjured by your mind. Some traditions in Eastern philosophy describe reality itself as a kind of dream or illusion—Maya—projected by the mind. In these perspectives, the universe we perceive may be shaped more by our inner faculties than by objective reality.
From this angle, we begin to understand the deep interplay between the outer and inner universes. The world we experience “outside” is filtered through perception, memory, and emotion. So, even if we share the same physical universe, each of us lives in a deeply personal and subjective universe within it.
Fractals, Patterns, and Cosmic Echoes
A fractal is a pattern that repeats itself at different scales. Zoom in or out, and the same design appears. Nature is full of fractals—from the branching of trees and rivers to the structure of lungs and blood vessels.
Interestingly, the large-scale structure of the universe resembles a web. Galaxies form along filaments, separated by vast voids, creating a cosmic web not unlike neural networks or fungal mycelium. Some scientists and philosophers have noted the eerie resemblance between the structure of the universe and the brain.
Could this be a coincidence, or is there a deeper truth? Are we seeing a kind of cosmic self-similarity? If the universe is fractal in nature, then perhaps we are not just in the universe—we are a reflection of it. A microcosm within a macrocosm.
We Create Meaning in the Universe
Existentially, the idea that we are a universe within a universe offers both comfort and challenge. It implies that even in the vast indifference of space, there is incredible meaning within each of us.
We are not just passive observers. We are active participants. We name the stars. We write poems about galaxies. We send spacecraft to explore other planets. We simulate entire universes in computer models. And, perhaps most importantly, we love, grieve, wonder, and imagine.
These are not trivial activities. They are how the universe becomes aware of itself. As physicist Brian Cox once put it, “We are the cosmos made conscious.” In that sense, the universe is not just “out there”—it is in here, in the seat of consciousness.
The Spiritual and Philosophical Echo
Ancient spiritual traditions have long hinted at this idea. In Hinduism, there’s the concept of Brahman—the infinite, eternal reality—and Atman—the inner self or soul. The Upanishads declare, Tat Tvam Asi—“Thou art that.” In other words, you are the universe.
In modern mystical or spiritual thought, this idea often re-emerges. Whether through meditation, psychedelics, or transcendental experiences, many report a sense of oneness with the cosmos. The boundary between the self and the universe blurs.
This suggests a kind of deep interconnectedness—where the inner and outer worlds are not separate, but different expressions of the same underlying reality.
Final Thoughts: Embracing the Mystery
We may never fully understand the universe—its origin, its purpose, or its ultimate fate. But perhaps that’s not the point. Maybe our role is not to conquer the mystery, but to live within it. To explore both outer space and inner space with equal curiosity.
The phrase “We are a universe within a universe” reminds us that we carry infinity within us just as much as we’re surrounded by it. Every heartbeat, every thought, every breath is part of a larger cosmic story—and a smaller, equally profound personal one.
