Unfolding the Universe: A Personal Inquiry into Space, Time, and the End of Everything

There was a moment recently when I was flipping through my IB Chemistry book, just going back to basics for a bit of revision, when I came across something we all learn early on: atoms can neither be created nor destroyed. That line stopped me in my tracks. It felt so final. So absolute. But then I thought, wait—if they can’t be created or destroyed, where did they even come from in the first place?

That one thought opened a whole door in my mind. If atoms are always there, or at least the energy that forms them is always there, then what did the Big Bang actually do? Did it create matter? No—it couldn’t have, right? So maybe it didn’t create matter or energy. Maybe it just spread it out. That was the first moment I began to rethink what cosmic expansion might actually mean.

Where Does Matter Go When the Universe Expands?

Cosmic expansion is a well-accepted idea, especially following the discovery that galaxies are moving away from each other. Scientists say that space itself is expanding—not just matter flying through a fixed space. But I started to wonder—can space stretch like that? For anything to expand, doesn’t it need something to expand into? If you have a balloon, it expands into the air around it. So if our universe is expanding, there has to be something already there, some sort of background or canvas into which matter and energy are being stretched.

Here, I stumbled onto the concept of the metric expansion of space—the idea in general relativity that it's not objects flying away through space, but rather the distances between them growing because space itself is expanding. But that raised new questions for me: is it really space that’s expanding, or just the matter and energy within it? I began to feel that space—and time—already existed even before the Big Bang. Maybe the Big Bang wasn't the beginning of space and time, but rather the beginning of activity within it.

This echoes some speculative theories in cosmology, like eternal inflation or cyclic models, where our universe might be one phase or bubble in a larger multiverse. These aren't confirmed, but they share the idea that space and time may not have had a definite beginning.

The Density Question: Why Is the Universe Clumpy?

Then came another question. If everything started from the same point—the Big Bang—why isn’t matter evenly distributed? Why is the universe full of galaxies, stars, and empty voids, instead of a smooth soup?

The answer lies in quantum fluctuations—tiny differences in density that got stretched out during the inflationary period right after the Big Bang. Those small uneven spots became seeds for structure. Gravity then amplified them over time. This is supported by observations of the cosmic microwave background, which show those faint early imprints.

But I started to picture all this in my own way. I imagined gravity as forming valleys and dents in a flexible space. Over time, as matter spreads out, these valleys flatten. I even visualized a particle perched on a peak in the cosmic fabric, slowly rolling down into a valley. Maybe as the universe expands and becomes less dense, these valleys become shallower, and particles stop clumping altogether.

That image reminded me of gravitational lensing—the idea that massive objects bend space-time, creating curved paths for light and matter. It’s something Einstein predicted in his theory of general relativity, and we’ve observed it through telescopes. It gave more depth (literally) to my mental picture of the universe.

Could Atoms Unravel Too?

Thinking about density brought me to atoms. Inside them, there’s space between the nucleus and electrons. And inside protons and neutrons, there’s space between quarks. If space is expanding on a cosmic level, could it also affect the spaces inside particles?

At first, I thought maybe the structure of atoms could stretch and eventually break down. But then I learned that while cosmic expansion affects large-scale structures, it doesn’t affect bound systems like atoms, planets, or even galaxies. Their internal forces are much stronger than the influence of expansion—at least for now.

However, in the far future—far beyond our current era—if the expansion continues accelerating, there’s a theoretical scenario called the Big Rip. In it, the universe’s expansion rate becomes so extreme that even atoms and subatomic particles are torn apart. It’s just one hypothesis, but it matched closely with my intuition.

Thresholds and Dark Energy: Expansion in Phases

Another thing I started to sense was that the expansion wasn’t uniform over time. First, there was rapid inflation, then a long period of slower expansion, and now it’s accelerating again. Why this change in pace?

That led me to dark energy—a mysterious form of energy that seems to act opposite to gravity, pushing the universe apart. According to our best models, about 68% of the universe is made of dark energy, yet we don’t know what it is.

I began to think about thresholds. Maybe dark energy “activates” once matter spreads out past a certain point. When the universe was dense, gravity dominated. But once galaxies moved far enough apart, gravity weakened, and dark energy took over. This echoes the cosmological constant idea in Einstein's equations—a fixed energy density of space itself. But it could also be dynamic, like in quintessence theories.

What fascinated me was the rhythm: expansion, slowdown, acceleration—almost like breathing. Could this cycle repeat? Could there be other phases, each peeling away another layer of structure: galaxies, stars, atoms, particles—until only energy remains?

Time and Its Role

If space existed before the Big Bang, did time exist too? It feels logical to me that it did. Maybe the compressed mass-energy of the early universe simply sat in space and time for an unimaginable duration before it became unstable and expanded.

Some physicists suggest time began with the Big Bang. Others, like in the Hartle–Hawking no-boundary proposal, suggest time may have been in a different state before—more like space than time. I’m not sure, but in my imagination, time is like a silent observer. It doesn’t start or stop. It just is.

The Dimensional Dilemma

I’ve also heard of theories with extra dimensions—like string theory’s ten or eleven dimensions. But to me, that feels... disconnected. Everything we observe happens in three spatial dimensions and one of time. Shouldn’t theories be grounded in what we can measure?

Higher dimensions might help unify physics mathematically. They might even be “curled up” so small we can’t see them. But until they affect something observable, I find it easier to work within the 3D world. That’s where matter, energy, and gravity exist—the things I can reason about.

So instead of imagining a fourth spatial dimension into which space expands, I see expansion as matter and energy stretching into existing space. A space that’s always been there.

Where This Leads

So where does this all go? I imagine a future universe that becomes so spread out that gravity fades. Atoms fall apart. Particles unravel. Energy floats alone in an endless flat void. Nothing moves, because there's nothing left to pull or push. Just calm.

And yet, there’s a strange beauty in that. Because all the complexity—galaxies, stars, life, consciousness—came from that same energy. If it happened once, could it happen again? Maybe some threshold will reverse the spread. Maybe all that quiet energy will re-condense into something dense and unstable. A new Bang. A new beginning.

I’m not saying I know the answers. I’m not a physicist—I come from biochemistry. But I think wondering is a valid part of the scientific process. And what I’ve learned is that every big theory once began as a question. Even gravity, even relativity, even the Big Bang.

So I’ll keep wondering. I’ll keep imagining particles on peaks, valleys flattening, timelines stretching, thresholds breaking, and energy dissolving into silence.

Because maybe, just maybe, the universe doesn’t end with a bang or a whimper.

Maybe it ends with a question mark.

And maybe curiosity is the greatest force we’ve got.