You’re probably thinking about the "Mirror Universe" or the CPT Symmetric Universe.
It’s a wild idea. Honestly, most people hear "two universes" and immediately think of Doctor Strange or some high-budget Marvel flick where everyone has a goatee and bad intentions. But in the world of actual, literal physics—the kind involving chalkboards and massive particle accelerators—the theory about 2 universes is much more grounded in the math of how time and matter actually behave.
It’s not just sci-fi fluff.
Physicists like Latham Boyle, Kieran Finn, and Neil Turok from the Perimeter Institute for Theoretical Physics in Canada have been shaking things up with a model that suggests our Big Bang wasn't just a beginning for us. Instead, it might have been a "double-sided" event. Imagine a mirror held up to the moment of creation. On our side, time moves forward and matter dominates. On the other side? Time moves backward (from our perspective), and the whole thing is made of antimatter.
It sounds like a headache. It kinda is.
What is the CPT Symmetric Universe?
To understand the theory about 2 universes, we have to talk about "CPT." This stands for Charge, Parity, and Time. Scientists have known for a long time that there are certain symmetries in nature. Basically, if you swap all the charges (plus to minus), flip the spatial coordinates (like looking in a mirror), and reverse time, the laws of physics still work exactly the same.
Physics doesn't care which way the clock runs.
The problem is that our specific universe seems to break these rules. We see way more matter than antimatter. Time only flows one way—toward the heat death of the universe and gray hair. So, Boyle and his team proposed a solution: what if the "symmetry" isn't found within our universe alone, but in a pair of universes?
One universe is "C-negative" (mostly antimatter), "P-flipped" (a mirror image), and "T-reversed" (moving backward in time).
✨ Don't miss: The Portable Monitor Extender for Laptop: Why Most People Choose the Wrong One
We are the other half.
Together, the two universes satisfy the CPT symmetry perfectly. It’s a clean, elegant way to fix some of the biggest "bugs" in the standard model of cosmology without having to invent a bunch of new, invisible particles that we can't find.
The Problem with Inflation
For decades, the "standard" way to explain why the universe looks the way it does was a theory called Inflation. This theory says that right after the Big Bang, the universe expanded faster than the speed of light. It’s a bit of a "fudge factor." It fixes the math, but it requires us to believe in a field (the inflaton field) that we've never actually seen.
The theory about 2 universes—specifically the CPT-symmetric version—actually throws Inflation out the window.
Turok and Boyle argue that we don’t need it. If you have a twin universe moving backward in time, the math naturally explains why our universe is so flat and uniform. You don't need a magical burst of expansion. It’s a much more minimalist approach to reality.
I like that. It feels less like we're making stuff up to cover our tracks.
Dark Matter and the "Right-Handed" Neutrino
Here is where it gets really interesting for the space nerds. One of the biggest mysteries in science is dark matter. We know it’s there because we can see its gravity pulling on galaxies, but we have no clue what it's made of.
The theory about 2 universes offers a shockingly simple answer.
🔗 Read more: Silicon Valley on US Map: Where the Tech Magic Actually Happens
In our world, we’ve only ever seen "left-handed" neutrinos. These are ghost-like particles that pass through your body by the trillions every second. Physics suggests there should be "right-handed" ones too, but we’ve never caught one.
The CPT model predicts that one of these right-handed neutrinos is actually the dark matter we've been looking for. It doesn't require a whole new "Dark Sector" of physics or exotic particles that sound like they were named by a toddler. It just requires one heavy, invisible neutrino that exists because the math of a twin universe demands it.
Is this the same as the "Multiverse"?
Not really.
When people talk about the "Multiverse," they usually mean the Many-Worlds Interpretation of quantum mechanics or the "Eternal Inflation" idea where billions of bubble universes are constantly popping into existence. Those theories are messy. They imply that there's a version of you who ate a bagel for breakfast instead of cereal, and another version where you're a professional unicyclist.
The theory about 2 universes is much more constrained. It’s just two. A pair. A cosmic binary.
It’s a "Big Bang" that created a "before" and an "after" that are mirror images of each other. If you were in that other universe, you wouldn't feel like you were moving backward. Your brain would process "backward" as "forward." You’d think we were the weird ones moving in reverse.
Why it's gaining steam right now
Science moves in cycles. For a long time, the "Two Universe" idea was seen as a fringe curiosity. But lately, our big experiments—like the Large Hadron Collider—haven't found the "supersymmetric" particles that many physicists expected.
We’re hitting a wall.
💡 You might also like: Finding the Best Wallpaper 4k for PC Without Getting Scammed
When you hit a wall, you go back to the basics. You look at the simplest possible explanations. The CPT Symmetric Universe is about as basic as it gets. It uses the laws of physics we already have and just applies them more broadly.
There's also the ANITA experiment. A few years ago, a NASA-funded balloon over Antarctica detected high-energy particles (neutrinos) seemingly coming up out of the Earth. This shouldn't happen. Some researchers joked—or half-joked—that these could be particles from a "reverse" universe leaking into ours. While most scientists think there's a more mundane explanation involving ice reflections, it put the theory about 2 universes back into the headlines.
What this means for our understanding of reality
If this theory is true, it changes the "vibe" of the cosmos.
- The Big Bang wasn't the beginning. It was a point of symmetry. There was "something" before it—it just happened to be a mirror image of everything we know.
- Fate and Determinism. If the two universes are linked by symmetry, does that mean every action here is mirrored there? Probably not in a "destiny" sense, but the physical constraints are much tighter than we thought.
- Antimatter. We’ve always wondered why there isn't more antimatter in our universe. If there were, we’d all explode the moment we touched anything. This theory says the antimatter isn't "missing"—it's just on the other side of the mirror.
It's a weirdly comforting thought.
The universe isn't a chaotic accident that just happened once. It’s a balanced system. It’s symmetrical.
How to track this theory as it develops
If you want to dive deeper into the theory about 2 universes, you should keep an eye on the work coming out of the Perimeter Institute. Look for papers by Neil Turok. He’s one of the heavy hitters in this field and he’s remarkably good at explaining these mind-bending concepts without using too much jargon.
You should also look into "Cosmological CPT Symmetry." That's the technical term you'll need if you're searching through academic databases like arXiv.
We are also waiting for more data from neutrino observatories like IceCube in the South Pole. If they find evidence of that specific "right-handed" neutrino, the CPT Symmetric Universe goes from a "cool idea" to the "leading explanation" almost overnight.
Actionable steps for the curious
- Read the source material: Check out the paper "CPT-Symmetric Universe" by Boyle, Finn, and Turok. It’s technical, but the introduction and conclusion are surprisingly readable for non-physicists.
- Watch the lectures: Neil Turok has several public lectures on YouTube from the Perimeter Institute. Search for "Neil Turok CPT Universe" to see him map this out on a literal chalkboard.
- Follow the ANITA updates: Keep an eye on NASA's balloon-based neutrino research. Any "upward-pointing" events are huge news for the mirror-universe crowd.
- Differentiate your terms: When talking about this, remember to distinguish between the "Multiverse" (infinite copies) and the "CPT Symmetric Universe" (one specific mirror twin). Using the right terms will help you find better info.
The universe is a lot stranger than we give it credit for. Sometimes the wildest explanation—that we have a backward-running, antimatter twin out there—is actually the simplest one the math allows.
Keep looking up, but maybe start looking "behind" the Big Bang too.