[0:00]I like the freedom I feel outside the limitations of the real world. But computers are also mirrors, reflecting back who and what we are in the choices we make. The world we build. Imagine a world where the line between reality and digital world blurs, where the images and videos you see are so lifelike, you can't tell if they're real or generated by artificial intelligence. This is not a distant future. It's happening right now. This person looks real, doesn't she, but she's completely computer generated.
[0:40]In today's rapidly evolving technological landscape, innovations that would have seemed like science fiction just a decade ago are becoming a reality. Over 20 years ago, I first played the character of Thomas Anderson in the Matrix trilogy. This blurring of the digital and real worlds extends far beyond static images and videos. Picture yourself immersed in a hyper realistic virtual reality game, or even an entire simulated world so detailed that it becomes nearly indistinguishable from our own. As we approach a future where technology and AI transform our world, a profound question arises. What if our reality itself is a simulation? The simulation hypothesis proposes that the reality we know might be an artificial simulation, similar to a highly advanced video game or computer program. Imagine if our universe was created by a superior civilization, running on a powerful computer. While this idea has gained prominence in recent years, it has roots in ancient philosophical questions about the nature of reality.
[1:50]Plato's allegory of the cave is a powerful metaphor that illuminates the concept of the simulation hypothesis. Imagine a group of prisoners chained inside a dark cave from birth, only able to see shadows cast on the wall in front of them. They believe these shadows to be the entirety of reality. In a sense, they were living in a simulation of reality. This allegory serves as an ancient precursor to modern discussions about reality and perception. For a modern example, think about putting on a virtual reality headset. A high quality VR simulation can feel extremely real, tricking your brain into thinking you're somewhere else. This shows how what we perceive as reality is based on the information we receive through our senses. Philosopher Nick Bostrom has a compelling argument for why we might be living in a simulation. He suggests that if a civilization becomes advanced enough to create highly realistic simulations of reality, they would likely create many of them. Statistically, any individual is then more likely to be living in one of the many simulations, rather than the one original reality. To understand this, imagine you have a bag filled with 1,000 red balls and only one blue ball. If you randomly pick a ball, it's much more likely to be red than blue. Similarly, if there are many simulated realities but only one real reality, chances are, we're in one of the simulations. A lot of people have proposed that there's a possibility, the whole premise of matrix or anything like that is that just as we can build simple virtual realities today with simple simulated creatures living inside them. Maybe in the future with vastly more powerful computers, you could build more complex virtual realities with more complex simulated creatures inside them. Maybe these creatures could be complex enough that they would actually have brains like ours, simulated down to the level of individual neurons and synapses, such that the inhabitants of these simulations would be conscious. But what the simulation argument adds to that, is that instead of just stopping at the question of how could you ever prove with certainty that we're not in a simulation ourselves. The simulation argument tries to establish a constraint about what we can believe and it tries to show that one of three possibilities is true, although it doesn't tell us which one of them it is. Now, in a sense, this sounds more radical even perhaps than some of the multiverse theories. In another sense, it's less because it doesn't presuppose any unknown physics. So we're just assuming that it will be possible to build computers that are much more powerful in the future. So, what the simulation argument tries to show is that one of three possibilities is true. The first one is that almost all civilizations at our stage of technological development go extinct before they become technologically mature. Technologically mature meaning having developed all those technologies we can currently show are physically possible, given only uncontroversially opplainable physics. Big computers, the size of planets and stuff, we can calculate what performance they would have. We can't build them now, but So first possibility is people at our stage, they just failed to get through to that level of technological maturity. Maybe they destroy themselves on the way. Second possibility is that almost all civilizations that do reach technological maturity, lose interest in creating these kinds of ancestor simulations, as I call them. These would be detailed computer simulations of people like their historical predecessors. So they have these powerful computers, they have the ability to program them, but they have better things to do with their computers in their time. And the third possibility is that we are almost certainly living in a computer simulation. And the argument in its full version, it requires some probability theory, but the gist of it can be grasped quite simply and intuitively. So if you imagine that the the first two possibilities do not obtain, that means some non-negligible fraction of civilizations at our stage do reach technological maturity. And some non-negligible fraction of those, you know, are interested in creating these ancestor simulations. They devote some non-trivial fraction of their resources to this end. You can then show that there would be many, many more ancestor simulations than there would be original courses of history. Because if you calculate the computing power that a technologically mature civilization would have, and the computing power that would be required to simulate all human brains, it turns out that the latter quantity is a tiny, tiny fraction of the former. So, in other words, by devoting a tiny fraction of their computational resources to this end, they could create astronomical numbers. If we are in a simulation, how would we know? Critics argue that the absence of concrete verifiable evidence renders the hypothesis unfalsifiable and outside the scope of scientific inquiry. Advocates of the simulation hypothesis argue that the absence of evidence may be an inherent feature of the simulation itself, designed to maintain the illusion of a base reality. Some speculate that anomalies or inconsistencies in our universe, akin to bugs or errors in computer programs, might reveal its simulated nature. Just like bugs or errors in a video game or computer program can cause unexpected things to happen that don't fit with the normal rules, maybe we'd see similar anomalies in our simulated reality. It's happening. One example that's been proposed is the speed of light. In our universe, nothing can travel faster than light. This could be seen as a kind of speed limit that was set on the simulation, similar to how a video game might limit how fast characters can move, due to the processing power of the gaming console or computer. The immense volume of information processed by the universe every second, from the interactions of quantum particles, to the vast movements of galaxies, is profoundly vast. This remarkable observation leads to a thought provoking suggestion. Could the universe itself be akin to a grand cosmic computer simulation? Skeptics of the simulation hypothesis might argue that this immense complexity and physicality of the universe, present insurmountable challenges for any conceivable simulation, questioning whether even the most advanced civilizations could muster the computational resources to create a simulation. Yet, if we were to discover that we are indeed living in a simulation, it would fundamentally reshape our understanding of the nature of reality, consciousness, and free will. This discovery would suggest that consciousness can arise from sufficiently complex information processing, regardless of whether the substrate is biological, like our brains, or digital, like a computer simulation. I would like to introduce you to my present and the rest of the world's future. I call it stem. Some people think that some of these things are sort of science fiction. Far out there, crazy. But I like to say, okay, let's look at the modern human condition. If we think about it, we're actually recently arrived guests on this planet. Think about if the world like was created Earth was created one year ago. The human species then would be 10 minutes old. The industrial era started two seconds ago. There have only been 250,000 generations since our last common ancestor and we know that complicated mechanisms take a long time to evolve. So, a bunch of relatively minor changes take us from broken tree branches to intercontinental ballistic missiles. So this then seems pretty obvious that everything we've achieved pretty much and everything we care about depends crucially on some relatively minor changes that made the human mind. And the corollary, of course, is that any further changes that could significantly change the substrate of thinking could have potentially enormous consequences. Some of my colleagues think we are on the verge of something that could cause a profound change in that substrate and that is machine super intelligence. In this light, our pursuit of creating advanced AI and simulated worlds takes on a new significance. We are not just playing the role of creators, we may be unwittingly replicating the very process that led to our own existence. The Bostrom argument, when applied to our own technological trajectory, serves as a powerful reminder of the mind bending possibilities that lie ahead.
