If the universe is a simulation, who’s running the server?

Is this the real life, or is it a simulation?

You're walking down the street and suddenly feel like you've been there before. A strange déjà vu. The same faces. The same breeze. The same billboard. You blink, and it passes. Coincidence? Maybe. Or maybe it's a small bug in a much bigger program - reality itself. It may sound like science fiction, but a growing number of scientists, philosophers, and even tech entrepreneurs believe we might be living inside a computer simulation; not a metaphorical one but a literal, coded simulation where everything from stars and galaxies to our thoughts and choices are governed by lines of logic, processed on a cosmic server. If this sounds absurd, consider this: some of the brightest minds on Earth are taking the question seriously.

The simulation hypothesis took a more formal shape in 2003, when philosopher Nick Bostrom at Oxford University proposed a startling idea: if advanced civilisations in the future can run highly realistic simulations of their ancestors, then statistically, it is far more likely that we are one of those simulations than the original biological beings. Think of it this way - if one "real" world spawns millions of simulations, the odds that you're living in the base reality shrink dramatically. Just like you're more likely to be watching a reboot or remake on TV than the original event.

At first, this sounds like pure fantasy. But here's where it gets strange: physics itself is starting to look… digital. We used to think the universe was continuous - like a smooth canvas. But quantum mechanics suggests the opposite: everything comes in chunks. Matter is made of atoms. Light comes in photons. Even time and space might be quantised - made of tiny, indivisible units. Like pixels on a screen. Physicists have even found that the laws of nature - gravity, electromagnetism, nuclear forces - are so neatly organised, they feel almost... programmed. The equations are elegant, consistent, and strangely clean. Why should the universe behave so perfectly, unless it's following a script?

Some of the brightest minds on Earth are taking seriously the idea that we may be in a simulation. Representational pics/iStock

One of the strangest features of quantum physics is that particles don't exist in a fixed state until they are measured. A particle like an electron doesn't sit quietly in a corner waiting for you to find it. Instead, it exists as a cloud of probabilities - and only decides its location the moment you look. This is called the observer effect.

Think of it like a video game. The landscape only renders when the player enters a new area - to save memory and processing power. Could the universe be doing the same? Is our reality only rendering itself when we're paying attention? It's a wild thought - but not an impossible one. And maybe this isn't such a new idea after all. Pop culture has long been fascinated by this possibility. The Matrix made us question whether reality itself is just a sophisticated illusion. In Inception, dream worlds folded into each other until even waking life felt uncertain. Westworld gave us artificial beings wondering if they were real, and Black Mirror routinely blurs digital fantasy and human consciousness. Even in video games like The Sims, Minecraft, or No Man's Sky, we create entire worlds - sandbox simulations with coded rules and evolving behaviors. But this isn't just a Hollywood obsession. Indian philosophy has hinted at it for centuries. The ancient concept of maya in vedanta describes the world as an illusion - not in the sense that it doesn't exist, but that it's not the ultimate reality.

What does artificial intelligence have to do with this? Here's where things get even more interesting. Today's artificial intelligence can already simulate human conversations, write poetry, create art, and generate entire virtual worlds. We are using AI to build tiny, convincing simulations all the time. If our generation can do this in 2025, imagine what a civilisation a million years ahead of us could build. Maybe we are inside their project. A science experiment. A simulation of how early 21st-century humans behaved during climate change, AI revolution, and geopolitical chaos. Perhaps somewhere out there, a 16-year-old alien coder is watching you right now, writing notes like: "Subject #493A feels sad on Sundays. Recommending more street food in algorithm."

There's no "proof" yet that we are in a simulation. But there are some weird hints.

Pixellated Space: Some physicists think the smallest possible length, the Planck length, could be the resolution of the universe. Below it, nothing makes sense. That's like a minimum pixel size.

Speed Limit: The speed of light is the fastest anything can travel. Is this a cosmic speed cap, like bandwidth limits in a network?

Cosmic Coincidences: The laws of physics seem just right for life to exist. If the universe were slightly different, we wouldn't be here. Is this evidence of a designed environment - like a video game level carefully adjusted for gameplay?

Glitches: People often report déjà vu, strange synchronicities, or repeating patterns. Are these software bugs? Maybe. Or maybe they're just the universe's way of keeping us curious.

Okay, but if this is a simulation… who's running it? Ah, the big question. If our world is a simulation, who created it? Some say it could be an advanced alien species - a kind of cosmic coder civilisation curious about their ancestors. Others say it could be a post-human AI - a superintelligence that evolved beyond humanity and now simulates its past for study. A few go further and suggest we may be just one layer in an endless chain of simulations. Our simulators are also simulated. And so on.

Actually, this idea isn't depressing. It can be strangely inspiring. If you are in a simulation, and yet you're aware enough to ask "Am I real?", that already makes you special. You are self-aware code. A thinking, feeling consciousness that questions its reality. That's a rare and beautiful thing, simulated or not. So go on. Enjoy your tea. Laugh with your friends. Fall in love. Do science. Make art. Because even if the universe is a simulation, the feelings you have inside it are as real as anything. And who knows - maybe the one running the server is watching and smiling.

Nishant Sahdev is a theoretical physicist at the University of North Carolina, United States. He is the author of the upcoming book Last Equation Before Silence. X: @NishantSahdev