What If Our Reality Is Only One of Many?

Caleb: Welcome to the Human Element Podcast, where we explore what it means to be human one question at a time. I'm your host Caleb. Today we are asking a question that sits right on the razor's edge where cutting edge physics blurs into accident phlo ancient philosophy and where deep theology meets pure science fiction. What if our reality is only one of many? What if there are other realities out there? But before we leap into this sci fi nonsense that I'm sure a lot of you people are thinking of right now. What what is what is Caleb talking about? Well, before we dive into alternate timelines and parallel selves or hi the hidden dimensions, I want us to anchor ourselves first. Before we ask if there are other realities, let's take an honest look at the sheer and just vast magnitude of ours, what we can actually see, what we can touch and what we can measure. Because the truth is the baseline reality we inhabit is already so unfathomable that so unfathomably fathomably vast that our brains aren't genuinely wired to comprehend it. have you ever just looked up at the sky and realized that it just goes on forever? Even when you get into space, it just goes on forever. There's no ending to it. That's a big big question and big thought to sit with. So let's start with measuring our own universe. And by doing that, we have to measure it with light. Light is the fastest moving entity in the known universe. It races through our vacuum of space at roughly one hundred and eighty six thousand miles every single second. So to put that into a perspective, if you could travel at the speed of light, you could circle the earth seven and a half times in the blink of an eye. In one single year traveling nonstop at that blinding velocity, a beam of light covers about five point eight eight trillion miles. We call that distance one single light year. Now let's look out our own cosmic window here. Our absolute closest stellar neighbor is what's known as a red dwarf star, and it's named Proc Proxima, Proxima Centauria. It is sitting just down the street from us. Cosmically speaking, at a distance of four point two four light years. That is roughly twenty five trillion miles away from us. So if we built a spaceship today using our fastest current chemical rocket technology, it would take us somewhere in the neighborhood of seventy thousand years. just to reach that very first next star over from us, our neighbor. Seventy thousand years. Even if you were sitting on a beam of light, it would still take you more than four years of continuous travel just to get to the next star. Let that sink in. Just how big the universe is. It's unimaginably big. And it's Terrifying to think about. So let's zoom out farther. Proxima Centauria is just one star in our local neighborhood. Our home galaxy, which is known as the Milky Way, is a massive swirling spiral spiral structure that stretches roughly 100,000 light years from one edge to the other. So inside this single galactic structure, astronomers estimate that there are anywhere between one hundred billion and four hundred billion stars, billions of suns. And based on everything we've learned from modern exoplanet discoveries, nearly every single one of those stars likely plays host to its own family of planets, just like Earth is with the sun. And yet So if you step outside the boundaries of the Milky Way, our galaxy, you hit a vast gulf of intergalactic void, and then you reach our nearest major galactic neighbor, an Andromeda galaxy, or the Andromeda Galaxy. Andromeda is two point five million light years away. the light hitting your eye when you're looking through a telescope left that galaxy when early human ancestors were just beginning to walk the earth. And Andromeda is an absolute monster. It holds roughly one trillion stars of its own. So if we zoom out to the absolute limit of modern physics, we find the observable universe, the entire horizon of space that light has had time to travel since the Big Bang, that cosmic bubble is roughly ninety three billion light years across. So inside our observable bubble, our best empirical estimates suggest there are around two trillion distinct galaxies. Two trillion, each filled with hundreds of billions or trillions of stars. Each star is surrounded by worlds. Let that really reality just sit with you for a moment. We live our daily lives, we buy our groceries, stress over our deadlines and love our families all on one single planet, orbiting one regular star, tucked away in one arm of one galaxy in a universe that holds trillions of other galaxies just like ours. So here's the baseline question I want to open with today. So giving this staggering, terrifying scale that we've discussed, is it really crazy to assume that we are not alone? Notice what I'm not saying here. I'm not saying we've proven that there is life out there. I'm not claiming a spaceship has landed or that we've intercepted a signal from a distant civilization. I'm simply asking, given the mathematical mathematical architecture of our own universe, is it crazy to look up at the night sky and wonder? Is it wild? To suspect that in all that limitless space life might have found a way to spark somewhere else too. I don't think it is. In fact, I think harboring that wonder is one of the most deeply scientific impulses a person can have. Just walk outside and look at the sky tonight. And just that's just your own universe. That's your galaxy. Your scene. You can't see anything else. But it's also an impulse that brings up a lot of exential friction. Which brings me to a second point I want to establish right at the top of this podcast. Even if we are not alone, even if life does exist elsewhere in this huge cosmos, or if reality turns out to be infinitely larger than this single universe, that does not mean we have to throw away our own theology, our religion, or our sense of profound spiritual meaning. If your worldview includes a belief in a creator, why should a larger creation be? threaten that. A bigger, more complex creation doesn't make a creator look smaller. It makes the concept of creation look infinitely more majestic. Human significance was never actually supposed to depend on us being the absolute only thing that exists in the cosmic vacuum. Our value doesn't rely on us being a lonely anomaly in a barren desert. True human significance As taught by almost every major philosophy, and faith tradition depends on being made, being conscious, and being known and loved within the specific reality we actually inhabit. Every faith tradition will naturally navigate the theological math of a vast universe or a potential multiverse differently. And those distinct conversations are worth having with total intellectual honesty. But scale alone is not an executioner for faith. For millions of people, staring into the deep field of space doesn't erode beliefs. It radically deepens them. It reminds us that reality is far more awe inspiring, far stranger, and far grander than our ancestors ever could have dreamed of. We aren't asking these questions today to tear down anyone else's sense of home or certainty. We're asking the we are asking them because we are curious, because we have driven, we are driven to explore, and because to be human is to look at a horizon and wonder what lies just beyond our sight. So let's step off the edge of the map. What if our reality is only one of many? Let's explore that together. Let's begin our journey with an exercise that is simple, immediate, and perhaps a little bit humbling. I want you to look around whatever room or space you are sitting in right now. Look at the walls, the light filtering through the window, the texture of service beneath your hands. Listen to the sound of my voice, the ambient hum of traffic outside, or the quiet rustle of a fan. It feels absolute, doesn't it? It feels like you are perceiving the definitive, unedited version of the world exactly as it is in the moment. But biology tells us completely different. Everything you and I experience from the moment we wake up to the moment we fall asleep is filtered through five basic physical senses. And those senses were never designed by evolution to show us the objective, unfiltered totality of the universe. They were built for one specific Utilitarian purpose is to help a fragile bipedal mammal survive on a savannah without getting eaten. Our biological sensory windows are incredibly narrow. Think about a dog. A dog moves through the exact same physical living room that you do, or your cat. But its reality is painted in an intricate, overwhelming tapestry of sense that you are completely blind to. A dog can hear high frequency acoustic vibrations that are entirely non existent to your ears. So your dog can hear things that you You are you're never gonna hear. Or let's consider a honey bee. A bee looks at a flower and sees brilliant glowing patterns of ultraviolet light that helps guide it to its nectar. To your eyes, that flower might just look flat uniform yellow. The bee is interacting with a visual landscape that is physically present right in front of your face, yet completely locked. Away from your own perception. So here's the first philosophical hurdle we have to clear. If other creatures on this very same planet live fundamentally different sensory worlds, how can we be so confident that our human version of reality is the complete final draft? The truth is we are already surrounded by invisible realities every second of the day. Right now, passing directly through your body are thousands of radio waves, cellular signals, Wi-Fi networks, and television broadcasts. If you don't have a phone or a receiver tuned to the exact right frequency, those waves are entirely entirely unprecip unpreceptible. You can't seem you can't see them, smell them, or touch them. They are carrying data, voices and videos across the room. Just invisibly. You can't see them. You don't see the invisible force of gravity pulling down on your shoulders right now, but it's actively pinning you to your chair or where you're standing. You don't see the magnetic field of the earth, but migratory birds use it like a highway in the sky. The simple biological truth reminds us that the unseen is not the same thing as the unreal. Now let's be intellectual intellectually rigorous here. The fact that your phone uses radio waves doesn't prove that an alternate timeline exists where you choose a different career or where history took a different turn. It doesn't provide concrete evidence of a parallel universe. But what it does do, with absolute certainty, is prove that our biological perception has strict, unyielding boundaries. It forces us to adopt a stance of deep intellectual humility. It proves that we are viewing reality through a tiny keyhole aperture. And that realization is the exact threshold where science begins to take the idea of multiple realities very seriously. So when you hear the word multiverse tossed around today, which likely that you probably will eventually hear the word multiverse, it's usually in the context of movies, stories about superheroes jumping between different dimensions, meeting alternate versions of themselves, fixing broken timelines. But in theoretical physics, the concept isn't a single uniform idea. When serious scientists use the term, they are generally referring to three entirely distinct models of reality, and it is absolutely vital that we separate them so we can look at them clearly. so level one. It's like the patchwork universe, the infinite inflation, we'll call it. The first model is perhaps the easiest to conceptualize, because it doesn't require any strange magic. It's j it just requires a lot of space. It is the idea of an infinite or internally inflating universe. When we talk about the universe, we usually mean the observable universe, what we see, the universe that we know. That ninety three billion light year bubble we discussed earlier, the Milky Way. But cosmologists, cosmo cosmologists, have no reason to believe that space simply stops at our own visual horizon. If you were to travel to the very edge of our own observable bubble, you would see just as much universe stretching out ahead of you as you left behind. If the cosmos is truly infinite, if space goes on forever and ever without an end, then a fascinating mathematical consequence emerges. There are only so many ways you can arrange subatomic particles within a given volume of space before those configurations must begin to repeat. In a genuinely infinite universe, if you travel far enough out, You will eventually encounter another region of space where particles have assembled in the exact same configuration as our own neighborhood has. You would find another galaxy just like the Milky Way, another solar system, probably another Earth, and perhaps another version of you listening to another version of this podcast. These wouldn't be alternate dimensions, they would just be incredibly distant patches of the exact same physical space. Separated by distances so vast that light will never have time to cross the gulf between us. So the easiest way for me to understand that is so kind of think bubbles and the kind of like the fizz in a soda, right? universes. That's kind of the multiverse in that sense. Then we have level two, which is the quantum branching, which is the mini worlds interpretation. The second model takes us out of the macroscopic space and plummets us directly into the bizarre counterintuitive world of quantum mechanics. This is known as the Mini Worlds interpretation, originally proposed by physicist Hugh Everett III in nineteen fifty seven. At the subatomic level, matter behaves in ways that seem utterly nonsensical to our daily experience. Before a particle is observed or measured, it doesn't exist in one definitive location. Instead it exists in a cloud of probabilities, a state known as superposition. It is essentially doing multiple things at the exact same time, but when a scientist measures that particle, the superposition collapses and it suddenly chooses a single definite state. So for decades, physicists wrestled with this massive riddle. Where do the other probabilities go when the wave function collapses? The mini world's interpretation offers a staggering answer. They don't go away. Instead, every single time a quantum event occurs, Every time a particle faces a choice, reality splits, the universe branches. In our branch, the particle landed here, in another branch it landed there. So if this interpretation of quantum math is correct, then branching events are happening trillions of times every millisecond, at the subatomic level across the entire cosmos. Every possible outcome of every quantum interaction actually occurs in its own distinct branch. of an ever growing infinite tree of reality. It means that there's an astronomical number of coexisting timelines running parallel to our own, decoupled from our own sensory access. So this level level two, the quantum branching, is one that I it's hard for me to kind of get behind. it's kind of the thought process of essentially where maybe you made a different decision in life and now that is playing out in some different universe that is parallel to ours, maybe. So I d I don't know. I kinda that one's kinda hard for me. But it is a theory. Then we have level three, which is also the string theory landscape. This third major scientific concept emerged from the complex mathematics of what's known as the string theory and and theory. This model suggests that our entire four dimensional universe, so three dimensions of space and one dimension of time, might just be a three dimensional membrane or brain floating inside a much higher dimensional hyperspace. But the string theory is kind of like imagining a giant sheet of paper representing our universe. And then there's two dimensional drawings trapped on that sheet of paper, entirely unaware that right next to us, separated by a fraction of a millimeter in a direction we cannot perceive, floats another sheet of paper. Another distinct universe. Entirely. So it's kinda like two universes that are like side by side, right? That but we have no idea. So in this landscape, these separate universes could have emerged from different pockets or broader multiverses, and they wouldn't necessarily look anything like ours. They could have inherited entirely different fundamental constants. They might have different strengths of gravity, different subatomic forces, or completely different laws or physics altogether. So some might be dead, cold expanses where atoms can't even form, others might hold types of matter and energy that we Can't begin to even conceptualize. Hope you're still with me. I think it gets a little better. So hold on. Now let's take a deep breath and step back from the blackboard, okay? it is vital and critical that we face the truth about all three of these models. And none of this is settled by science. That's why it's called a theory. They're not proven facts, but they are highly serious, mathematically rigorous hypothesis proposed by some of the most brilliant physicists on the planet. So this stuff isn't just made up by conspiracy theorists. There is a mathematical formula that points to this hypothesis potentially being true. And some of the greatest minds on the planet. Study this. But it's also controversial. Why? Because they run headfirst into a foundational crisis regarding how we define science itself. So to be considered true science, a theory must be testable and falsifiable. Science hinges on that. You have to be able to design an experiment that could potentially prove it wrong, but if these other universes exist outside our observable horizon or in a parallel parallel quantum branch that are completely physical physically decoupled from our own, that we can't possibly see, how can we ever design an experiment that can test that? How can we collect data from a reality we are fundament fundamentally barred from interacting with? So a major debate is fracturing in the s within the scientific community. If a theory is beautiful and mathematically elegant, but completely untestable, even in principle, does it still count as science? Or has it crossed the boundary to become what is now philosophy? And that's not a dismissal of the theoretical physics. It's an incredibly profound challenge. It forces us to ask deep epistemic questions. What actually counts as true knowledge? How far can pure human reason and mathematics carry us before we hit an absolute wall where we simply cannot see any further? So if we accept that science leads us right up to that conceptual wall. Then the only way to go deeper is to pass the torch over to philosophy and the mystery of the human conscious. So for thousands of years, long before we wrote down the equations of quantum mechanics or the string theory, philosophers. Have been asking fundamental questions about the nature of existence. As far back as Plato, Socrates. They would ask the questions is reality something that exists entirely independent of us? Or is it actively shaped and constructed by the mind that experiences it? So think about that. So is reality something that exists independent of who we are, or is it just shaped and constructed by our own minds and how our minds experience? our existence. So if you build a sophisticated computer simulation, the virtual reality inside this program only exists because there is underlining code running it. In a similar vein, our internal conscious experience is the ultimate canvas upon which reality is painted. So if consciousness is nothing more than a mechanical byproduct of our brain chemistry, or just a collection of neurons firing in a specific sequence. inside the skull, then we are just as passive observers in a cold accidental universe. But what if conscious is something more fundamental? What if awareness isn't a late stage accident of evolution, but a core, foundational ingredient of the universe's fabric? So if this is true, then our rich inner life, our capacity for deep introspection, might actually be a clue the nature of existence itself, rather than just this evolutionary by product. We if humans come a long way from Learning to build fire to artificial intelligence. It's truly astounding how fast we've we've gotten to where we are. So when I sit with these multiverse theories late at night. There's only one highly specific question that I always find myself returning to. And it's not the equation it's definitely not a question about equations, or the dimensions or quantum states. It's a question about the living beings that might inhabit those spaces. If there really are other realities out there, whether they are separated by billions of light years of void or nestled inside parallel quantum branches, well the conscious mind inside them asks the same question we do. Would an intelligent being in another dimension look up at their own sky? Whatever color that sky might be, use your imagination. Do they feel small and yet inexplicably significant like you might? all at the exact same time that we are. Would they feel that identical ache of curiosity that we do? That same quiet longing to know if they are not alone? Once again, go outside at night, look up at the sky. And you're only seeing your only the universe you live in, not the tons of others that exist just like ours. because to me, that is the true human element in this entire cosmic conversation we're having. When we debate parallel worlds, we aren't really talking about cold abstract geometry or physical equations. We're talking about us. We're using the vast landscape of the multiverse as a mirror. To look back at our own reflections, trying desperately to understand our place in the grand design. We want to know, are we the absolute center of everything? Is it just us? Are we that important? Or are we just this cosmic accident, this random spark of biological lighting in this dark world? Or are we a party something much bigger, far more interconnected than our limited minds can even comprehend? Something operating with deep ultimate purpose, or perhaps something entirely without it. Different intellectual and historical traditions answer these questions in vastly different ways. Faith points us towards a deliberate intent in a relational archite with relational architecture. Philosophy focuses on the construction of meaning with moral responsibility. Science demands empirical evidence and systemic mechanisms. They don't always agree on the final answer. In fact As we know, they all clash pretty violently sometimes. But it's beautiful to realize that they all originate from the exact same human seed. Pure unadultered wonder. They all begin with a mind looking out at the dark, refusing to look away. Let's take all these dizzying cosmic ethics. things that we have talked about. The light years, these quantum splits, the higher dimensions, the philosophical systems. Let's bring it all back down to where we are here on Earth. Let's pull them into the room where you're sitting right now. And if you're still with me. Really listen and think about these things. I if reality is indeed infinitely larger than we know, what does that change about how you and I live our lives today? There are two very distinct psychological paths a person can take when faced with the concept of a multiverse, and they lead to completely opposite destinations. The first path leads us straight into a heavy paralyzing nihilism or nothing. You could look at the idea of infinite parallel realities and think if every single choice I could possibly make is already being carried out by another version of you in a different reality, Then the choices here don't really matter at all. If everything happens somewhere, then nothing I do here has any real value anyways. It can make you feel completely lost, like a drop of water erased in a vast, uncarrying ocean. That version's depressing. But I think a lot of us probably given the state of humanity and the evil that exists, we're probably more apt to see it that way. But there's a second path. And that is the one that I choose to lean into. And the one I want you to think about. I believe that the existence of multiple realities doesn't make our choices matter any less. It makes them matter probably infinitely more. And why is this? Well, because whatever versions of reality might theoretically exist out there in our cosmic neighborhoods or background, this specific reality is the only one that we're actually awake in, that we're in tune with. This is the reality where you are conscious. This is the landscape where you have to look. people in the eye, where you love your family, where you make the difficult moral decisions, where you face real consequences, and where you have and where you leave a permanent mark on the lives of the people you interact with on a daily daily basis. The existence of Of a billion other universes doesn't dilute the reality of the the child whose scraped knee you're abandoning right now. It doesn't minimize the weight of a kind word spoken to a stranger, or a promise kept when it would have been easier to break it. Your life doesn't get smaller just because the grand theater of creation gets bigger. maybe when we get right down to it, that is the real gift of this entire thought experiment. The multiverse, alternate timelines, unseen dimensions, they don't need to serve as an anchor that drags us down into this despair. Instead, they can serve us as a powerful reminder of just how much we still do not know. And how far we've came and how far we have still to go. They can provide us with this profound, beautiful dose of intellectual and spiritual humility towards one another. That we're all in this together. We all live this life every day and think how important it is or how much it controls us, but yet how small it is compared to the universe. We spend so much of our daily lives locked in arguments convinced that our specific view of the world is absolute, that it's definitive. We draw hard lines in the sand over politics today, culture, beliefs, entirely certain that we have this whole picture figured out. But realizing that we are viewing the universe through a tiny biological keyhole. Can remind us that our personal versions of reality is definitely incomplete. It reminds us to open our hands, to listen, and extend grace to each other. So as we bring this journey to a close today, I want to leave you with the very same question that we started with. But hopefully maybe it's a little more sharper and a little deeper now. Because you listen to it this far in, then you probably have a different grasp on the universe itself and our finite role within it. Are we truly alone in the familiar reality we know? Or is existence far bigger, far stranger, and far more meaningful than our minds could ever comprehend? We may never find the definitive empirical answers to these questions within our lifetimes. We may never build the telescope or write the equation that proves a parallel world exists. But perhaps the answers aren't the most important part of this equation. Perhaps the act of asking the right questions, honestly, humbly, with open minds and together is exactly where the real journey of being human really begins. So in this converse if this conversation got your mind moving today. Let me know. If you like this podcast, let me know. So I can do more maybe like this in between our guests. I think it's absolutely crazy to think that we're the only life form in all these different universes. It's the mathematical chances, the probability of us being the only thing out there is so small. It's so small. Thank you so much for listening to the Human Element podcast. This is where we explore what it means to be human, one question at a time. Take care of each other out there. And I hope to see you next time, okay?