Is our world a simulation? Why some scientists say it’s more likely than not

October 18, 2017

When Elon Musk isn’t outlining plans to use his massive rocket to leave a decaying Planet Earth and colonize Mars, he sometimes talks about his belief that Earth isn’t even real and we probably live in a computer simulation.

“There’s a billion to one chance we’re living in base reality,” he said at a conference in June.

Musk is just one of the people in Silicon Valley to take a keen interest in the “simulation hypothesis”, which argues that what we experience as reality is actually a giant computer simulation created by a more sophisticated intelligence. If it sounds a lot like The Matrix, that’s because it is.

According to this week’s New Yorker profile of Y Combinator venture capitalist Sam Altman, there are two tech billionaires secretly engaging scientists to work on breaking us out of the simulation. But what does this mean? And what evidence is there that we are, in fact, living in The Matrix?

One popular argument for the simulation hypothesis, outside of acid trips, came from Oxford University’s Nick Bostrom in 2003 (although the idea dates back as far as the 17th-century philosopher René Descartes). In a paper titled “Are You Living In a Simulation?”, Bostrom suggested that members of an advanced “posthuman” civilization with vast computing power might choose to run simulations of their ancestors in the universe.

This argument is extrapolated from observing current trends in technology, including the rise of virtual reality and efforts to map the human brain.

If we believe that there is nothing supernatural about what causes consciousness and it’s merely the product of a very complex architecture in the human brain, we’ll be able to reproduce it. “Soon there will be nothing technical standing in the way to making machines that have their own consciousness,” said Rich Terrile, a scientist at Nasa’s Jet Propulsion Laboratory.

At the same time, videogames are becoming more and more sophisticated and in the future we’ll be able to have simulations of conscious entities inside them.

Elon Musk on simulation: ‘The odds we’re in base reality is one in billions’

“Forty years ago we had Pong – two rectangles and a dot. That’s where we were. Now 40 years later, we have photorealistic, 3D simulations with millions of people playing simultaneously and it’s getting better every year. And soon we’ll have virtual reality, we’ll have augmented reality,” said Musk. “If you assume any rate of improvement at all, then the games will become indistinguishable from reality.”

It’s a view shared by Terrile. “If one progresses at the current rate of technology a few decades into the future, very quickly we will be a society where there are artificial entities living in simulations that are much more abundant than human beings.”

If there are many more simulated minds than organic ones, then the chances of us being among the real minds starts to look more and more unlikely. As Terrile puts it: “If in the future there are more digital people living in simulated environments than there are today, then what is to say we are not part of that already?”

Reasons to believe that the universe is a simulation include the fact that it behaves mathematically and is broken up into pieces (subatomic particles) like a pixelated video game. “Even things that we think of as continuous – time, energy, space, volume – all have a finite limit to their size. If that’s the case, then our universe is both computable and finite. Those properties allow the universe to be simulated,” Terrile said.

“Quite frankly, if we are not living in a simulation, it is an extraordinarily unlikely circumstance,” he added.

So who has created this simulation? “Our future selves,” said Terrile.

Not everyone is so convinced by the hypothesis. “Is it logically possible that we are in a simulation? Yes. Are we probably in a simulation? I would say no,” said Max Tegmark, a professor of physics at MIT.

“In order to make the argument in the first place, we need to know what the fundamental laws of physics are where the simulations are being made. And if we are in a simulation then we have no clue what the laws of physics are. What I teach at MIT would be the simulated laws of physics,” he said.

Harvard theoretical physicist Lisa Randall is even more skeptical. “I don’t see that there’s really an argument for it,” she said. “There’s no real evidence.”

“It’s also a lot of hubris to think we would be what ended up being simulated.”

Terrile believes that recognizing that we are probably living in a simulation is as game-changing as Copernicus realizing that the Earth was not the center of the universe. “It was such a profound idea that it wasn’t even thought of as an assumption,” he said.

Before Copernicus, scientists had tried to explain the peculiar behaviour of the planets’ motion with complex mathematical models. “When they dropped the assumption, everything else became much simpler to understand.”

That we might be in a simulation is, Terrile argues, a simpler explanation for our existence than the idea that we are the first generation to rise up from primordial ooze and evolve into molecules, biology and eventually intelligence and self-awareness. The simulation hypothesis also accounts for peculiarities in quantum mechanics, particularly the measurement problem, whereby things only become defined when they are observed.

“For decades it’s been a problem. Scientists have bent over backwards to eliminate the idea that we need a conscious observer. Maybe the real solution is you do need a conscious entity like a conscious player of a video game,” he said.

For Tegmark, this doesn’t make sense. “We have a lot of problems in physics and we can’t blame our failure to solve them on simulation.”

How can the hypothesis be put to the test? On one hand, neuroscientists and artificial intelligence researchers can check whether it’s possible to simulate the human mind. So far, machines have proven to be good at playing chess and Go and putting captions on images. But can a machine achieve consciousness? We don’t know.

On the other hand, scientists can look for hallmarks of simulation. “Suppose someone is simulating our universe – it would be very tempting to cut corners in ways that makes the simulation cheaper to run. You could look for evidence of that in an experiment,” said Tegmark.

For Terrile, the simulation hypothesis has “beautiful and profound” implications.

First, it provides a scientific basis for some kind of afterlife or larger domain of reality above our world. “You don’t need a miracle, faith or anything special to believe it. It comes naturally out of the laws of physics,” he said.

Second, it means we will soon have the same ability to create our own simulations.

“We will have the power of mind and matter to be able to create whatever we want and occupy those worlds.”

Original source:


Why the “You” in an Afterlife Wouldn’t Really Be You

July 23, 2017

The Discovery is a 2017 Netflix film in which Robert Redford plays a scientist who proves that the afterlife is real. “Once the body dies, some part of our consciousness leaves us and travels to a new plane,” the scientist explains, evidenced by his machine that measures, as another character puts it, “brain wavelengths on a subatomic level leaving the body after death.”

This idea is not too far afield from a real theory called quantum consciousness, proffered by a wide range of people, from physicist Roger Penrose to physician Deepak Chopra. Some versions hold that our mind is not strictly the product of our brain and that consciousness exists separately from material substance, so the death of your physical body is not the end of your conscious existence. Because this is the topic of my next book, Heavens on Earth: The Scientific Search for the Afterlife, Immortality, and Utopia (Henry Holt, 2018), the film triggered a number of problems I have identified with all such concepts, both scientific and religious.

First, there is the assumption that our identity is located in our memories, which are presumed to be permanently recorded in the brain: if they could be copied and pasted into a computer or duplicated and implanted into a resurrected body or soul, we would be restored. But that is not how memory works. Memory is not like a DVR that can play back the past on a screen in your mind. Memory is a continually edited and fluid process that utterly depends on the neurons in your brain being functional. It is true that when you go to sleep and wake up the next morning or go under anesthesia for surgery and come back hours later, your memories return, as they do even after so-called profound hypothermia and circulatory arrest. Under this procedure, a patient’s brain is cooled to as low as 50 degrees Fahrenheit, which causes electrical activity in neurons to stop—suggesting that long-term memories are stored statically. But that cannot happen if your brain dies. That is why CPR has to be done so soon after a heart attack or drowning—because if the brain is starved of oxygen-rich blood, the neurons die, along with the memories stored therein.

Second, there is the supposition that copying your brain’s connectome—the diagram of its neural connections—uploading it into a computer (as some scientists suggest) or resurrecting your physical self in an afterlife (as many religions envision) will result in you waking up as if from a long sleep either in a lab or in heaven. But a copy of your memories, your mind or even your soul is not you. It is a copy of you, no different than a twin, and no twin looks at his or her sibling and thinks, “There I am.” Neither duplication nor resurrection can instantiate you in another plane of existence.

Third, your unique identity is more than just your intact memories; it is also your personal point of view. Neuroscientist Kenneth Hayworth, a senior scientist at the Howard Hughes Medical Institute and president of the Brain Preservation Foundation, divided this entity into the MEMself and the POVself. He believes that if a complete MEMself is transferred into a computer (or, presumably, resurrected in heaven), the POVself will awaken. I disagree. If this were done without the death of the person, there would be two memory selves, each with its own POVself looking out at the world through its unique eyes. At that moment, each would take a different path in life, thereby recording different memories based on different experiences. “You” would not suddenly have two POVs. If you died, there is no known mechanism by which your POVself would be transported from your brain into a computer (or a resurrected body). A POV depends entirely on the continuity of self from one moment to the next, even if that continuity is broken by sleep or anesthesia. Death is a permanent break in continuity, and your personal POV cannot be moved from your brain into some other medium, here or in the hereafter.

If this sounds dispiriting, it is just the opposite. Awareness of our mortality is uplifting because it means that every moment, every day and every relationship matters. Engaging deeply with the world and with other sentient beings brings meaning and purpose. We are each of us unique in the world and in history, geographically and chronologically. Our genomes and connectomes cannot be duplicated, so we are individuals vouchsafed with awareness of our mortality and self-awareness of what that means. What does it mean? Life is not some temporary staging before the big show hereafter—it is our personal proscenium in the drama of the cosmos here and now.”

This article was originally published with the title “Who Are You?”


Michael Shermer is publisher of Skeptic magazine ( and a Presidential Fellow at Chapman University. His next book is Heavens on Earth. Follow him on Twitter @michaelshermer

What It Will Take for Computers to Be Conscious

November 9, 2014