Is reality really "real"?  A few thoughts on the physical and theological implications of "We're living in a simulation."
by David Brin (rough draft 11/08)

Does the emperor exist, when he dreams that he is a butterfly?  Does the butterfly dream of being an emperor? Since long before Chuang Tzu posed this ancient Chinese conundrum, some version of it has bedeviled bright youths in every generation - especially college sophomores.  It seems pretty clear now that the same specialized organs in our brains that help us make pragmatic plans and perform thought experiments (gedankenexperiments) about the near future also unleash a human imagination so eager and creative that we can -- briefly or permanently -- lose track of what is real.

For example, although it might be called a form of lying, most societies have highly valued the craft of storytelling.  In my role as a novelist, I participate this tradition in a highly-devoloped and technologized way, by stringing together lengthy chains of coded squiggles - in the Roman alphabet - that highly skilled customers (readers) later deconvolute with incredible efficiency and skill, by eye-scanning rows of black squiggles and transforming them into stirring mental images, witty conversation, rollicking action, deep pangs of empathy with imagined characters and even (possibly) an insight or two.  Motion pictures shortcut and amplify this process with a firehose stream of visual images, cues and crutches that cater to the same human genius -- a knack for picturing things, people and events that never (objectively) existed. 

Politics is another medium for the creation and dissemination of mass-roduced subjective realities, conveyed by sophisticated and expensively produced incantations.  Sure, a rational and calm mind can see qualitative and quantitative differences between parties. We observe how one side in our recent American elections promulgated their veiwpoint primarily via assertions, anecdotes and never-proved "just-so" stories, while the other side laced their emotional appeals with some statistics and metrics that correlate (somewhat) with reality. That difference was remarkable, in its own right.  Yet still, at another level, we should remain wary and cautious. Although statistics were invented in order to - at best - help us constrain our world image a bit closer to demonstrable reality, they are still a type of incantation.  At worst, as Edward Tuffte has shown, statistics can be just another way to weave convincing lies.

 If "magic" is the creation of subjective realities in the minds of other peoples, then we moderns have learned how to perform magical incantations on a vast, industrial scale.

--- What is reality?

This notions that I've presented so far are hardly unique and new.  In his Parable of the Cave, Plato spoke if our inherent dependence upon fallible and flawed human senses, as well as deeply misleading language available for description and appraisal.  He concluded that we will always be unable to know the "real" world to any degree of perfection.  In this, he seems to have agreed with many other pre-modern sages, from Jesus to Buddha, all of whom suggested that, therefore, one should give up on the mundane world and seek some kind of perfection on another plane.  Their differences over a prescribed alternative path varies. Plato offers incantations of omphaloskeptic “logic.” Jesus offers incantations of faith.  Buddha – incantations of detachment.  And so on.  But their common thread is far stronger than these differences!   To reject the gross, distatstefulness of Apparent Reality (AR) and seek to escape from it by altering the way we use our minds.

The Western Enlightenment was only in part a revolution against feudalism or oppression.  It was also a rebellion against this view of reality and its accessibility to human understanding.  In The Transparent Society, I illustrated this revolution in thinking with a little allegory -- a "conversation" between Plato and Galileo.

Plato to Galileo -- 

	“Our senses are defective, therefore we cannot discover truth through experience.  That chair, for instance.  Despite all your gritty ‘experiments’ you will never determine what it is.  Not perfectly.  
	“Empiricism is useless.  Therefore give up!  Seek the essence of truth through pure reason.”

Galileo to Plato -- 

	“You’re right.  My eyesight is poor.  My touch is flawed.  I will never know with utter perfection what this chair is.  
	“Nevertheless, I can carve away untruths and wrong theories.  I can demolish fancy ‘essences’ and epicycles, and disprove self-hypnotizing incantations.
	“With good experiments -- and the helpful criticism of my peers -- I can find out what the chair is not.”

Along with many others, Galileo made the breakthrough that liberated us.  We don’t have to be perfect, in order to keep getting better!  And that is what reductionism with a small “r” has done.  It has given us the tools to keep looking closer.  To eliminate wrong theories and force good ones to improve.  It made us very good at reciprocal criticism, allowing positive sum games like markets and democracy and science to flourish.  Further, it let us question, test and repudiate assumptions that everyone “knew” to be true – assumptions about race, class and gender roles for example., that long limited our pragmatic access to great pools of human talent.

And yes, this is related to the ancient argument over reductionism, lately remised in “Reinventing the Sacred,” by Stuart A. Kauffman, a lengthy critique of modern science and the Galilean worldview is based upon a foundation that is both simple and utterly untrue – an assumption that the Scientific Enlightenment is based upon absolute and fanatical devotion to reductionism. Alas, that is a strawman argument, since the Scientific Enlightenment is not about reductionism, per se. It is about pragmatism. Especially the pragmatic innovation of the positive-sum game.

Yes, those who see a need for something sweeping and all-encompassing are often put off by the relentless way that science accumulates mountains of minutiae and details, in a ponderous and seemingly endless effort to parse ever-smaller divisions of reality, like Achilles chasing the hare in ever-diminidhing intervals that seem doomed never to actually reach the goal. The fact that this has resulted not only in vast numbers of pragmatic solutions to real world problems can be waved-away by such purists as irrelevant to the bigger picture.  Nor do most of them credit the theological implications (discussed in detail elsewhere) of a humanity that is picking up - like bright apprentice creators - the very tools and skills by which God must have made the world.

(The Bible itself seems to support this view, since the only brief passage shedding light upon what our "purpose" might have been, in the complete absence of sin, appears to point to co-creation and - implicitly - science.)

But I am not here to discuss that aspect of things.  Here, the core topic is the possibility that the Apparent Reality we see around us may be artificial, in some way.  And, strangely, that notion seems to bring us, at last, full circle.  For it was only the pell mell tumult of progress spawned by a Galilean Enlightenment that enabled us to create new simulation media -- from the mass education that enables a novelist to spread industrial-grade suspension-of-disbelief incantations, all the way to computerized simulated worlds that grow more subtle every year.  And that same scientific and technological revolution empowered human beings to push back the edges of science so hard that we can start to envision models of... well... how we might even model ourselves. Or even create "caves" within which simulated entities would imagine themselves to "actually" exist.

In other words, the pragmatists have brought us to a point where we must contemplate the riddles of Plato, Jesus and Buddha, from a completely fresh angle.

--- Can "reality" be simulated?

And now comes an era when we live immersed in computer-generated "virtualities", rendered through lavish games where ersatz selves get to do countless things that our mundane, fleshy selves cannot.  Is it any wonder that some people have been talking about a near future when this process may reach its ultimate conclusion?  When the denizens of Reality will not be able to verify, by any clearcut means, that they aren living in  a "real world"?  Or possible only even existing in a simulation?

Picture some future time when thinking beings may occupy simulated software realms within some vast cybernetic space -- either in "holodeck" style physical manifestations or in purely cybernetic downloads.  Realms that emulate the palpable "pinch-me test" of reality, with fine attention to every detail.  We don’t yet know how far simulation can be extended, or whether there are inherent limits.  Some very smart people believe there aren’t any, in which case there’s no guarantee that you, reading this paragraph right now, aren’t already living in such a simulation.  

In such a software-emulated world, Descartes's brain-body dualism might easily be true! And if it ain’t true now, it could plausibly become true, tomorrow.  And if it could come true tomorrow (getting recursive again), how do you know that you aren't right now living as a character of a simulation of the early Twenty-First Century, that is being implemented in some machine or demigod imagination, hudreds or thousands of years farther ahead, along the river of time?  In much the same way that you might implement a version of Captain Ahab, just by thinking for a little while about Moby Dick?

To illustrate, let me offer a scene from one of my own short stories, set in a future far in advance of ours.  (One of those rare and difficult beasts - a tale that takes place in post-singularity future: http://www.davidbrin.com/stonesofsignificance1.htm)  A tomorrow wherein the main character - a designer of simulated worlds - has has been asked about his relationship with the artificial beings that live in them:

	In every grand simulation there is a gradient of detail.  Despite having access to vast computing power, it is mathematically impossible to re-create the entire world, in all its texture, within the confines of any calculating engine.  That will not happen until we all reach the Omega Point.
	Fortunately, there are shortcuts. Even today, most true humans go through life as if they were background characters in some film, with predictable ambitions and reaction sets. The vast majority of my characters can therefore be simplified, while a few are modelled in great detail. 
	Most complex of all is the point-of-view character -- or “pov” -- the individual simulacrum through whose eyes and thoughts the feigned world will be subjectively observed. This persona must be rich in fine-grained memory and high fidelity sensation.  It must perceive and feel itself to be a real player in the labyrinthine tides of causality, as if part of a very real world.  Even as simple an act as reading or writing a sentence must be surrounded by perceptory nap and weave... an itch, a stray memory from childhood, the distant sound of a barking dog, or something leftover from lunch that is found caught between the teeth.  One must include all the little things, even a touch of normal human paranoia -- such as the feeling we all sometimes get (even in this post-singularity age) that “someone is watching.”
	I’m proud of my povs, especially the historical recreations that have proved so popular -- Joan on her pyre, Akiba in his last torment, Galileo contemplating the pendulum.  I won awards for Ghenghiz and Napoleon, leading armies, and for Haldeman savagely indicting the habit of war. Millions in Heaven have paid well to lurk as silent observers, experiencing the passion of little Ananda Gupta as she crawled, half-blind and with agonized lungs, out of the maelstrom of poisoned Bhopal.
	Is it any wonder why I oppose reification? Their very richness makes my povs prime candidates for “liberation.” 
	Once they are free, what could I possibly say to them?

--- The Prime Theological Question

This notion of simulated realities is getting a lot of attention lately, both in philosophical scientific literature and in serious science fiction.  There are endless ramifications, more than we could go into here.  But to me, one implied conundrum stands head and shoulders above the rest.

Here is the prime theological question. The one whose answer affects all others.  And yet, one that is almost never asked.

Is there moral or logical justification for a creator to wield capricious power of life and death over his creations... and is there any fundamental moral reason why those creations should have to obey?  

Humanity long ago replied with a resounding “no!”... at least when talking about parents and their offspring.  (There have been a few exceptions, e.g. the principle of pater familias in Roman law, that permitted a father to kill even adult offspring, if they offended him.) In most cultures, the created - our kids - eventually get full authority and a right to make their own way.  In some societies, they are even welcome to argue with their creators, along the way.

 And yet, without noticing any irony, we have implicitly answered the same question “yes” when it came to God!  The Creator, it seemed, was owed unquestioning servitude, just because He made us.

 It is the ghost at the banquet, the underlying assumption of all religions, taken for granted for far too long. Is it puzzling that - after more than four millennia of theological wrangling, and the investment of millions of hours of thought to religious matters - this question only comes up now?  Now that we are picking up creation's tools, like bright apprentices?  Tools of physics and biology, and also tools that let us simulate the creation of whole worlds?

It provokes some odd thoughts.  For example, Heaven and Hell may not be such bizarre notions, after all!  Consider our demigodlike descendants, with power at their fingertips to compute and emulate any reality.  They will be able to “call up“ simulated versions of people from times past, especially 20th century folk, what with all the data available about us, including skin cells in all our old letters and scrap books, etc.  What will they do with that power?  Perhaps, those who helped build the utopia of tomorrow will be remembered, immortalized, in software simulations by our descendants.  Those who hindered progress, who obstructed or simply did nothing, will at best not be invited back.  At worst, they might be assigned unpleasant roles in software scenarios.  Might the old notion of Purgatory have some resurrected relevance, after all?  I leave possible extrapolations of this idea to the reader.

---  The New Theologians

Let us put aside the latest trend, the so-called "new atheists" like Daniel Dennett, who have lately been  raging at religion, calling it a perfidious and malignant vice... in self-righteous and judgmental tones that suggest frenetic addiction to the very same brain chemicals that are released in the brains of indignant dogma-thumpers! (See: http://www.davidbrin.com/addiction.html)   Far more interesting (to me) is where scientists continue Galileo's quest, to push at the definitions and assumptions of sloppy theology and keep trying to corner God, whether or not He actually exists!

For example in his book The Physics of Immortality,  Tulane University Frank Tipler attempted to take our present topic - the notion of reality-as-simulation - to its most extravagant extreme, by positing a distant future time when the entire cosmos might be on the inward-falling phase of an endless cycle, when all of the matter and energy in the universe might come crashing together in an anti-BigBang.  When - briefly in objective terms - the super beings of that far future era would have virtually instant cross-universe communications and virtually infinite (and exponentiating) mass-energy to devote to computation.  Within the few final objective years of the universe, an effectively infinite number of subjective world years could take place, for any beings that chose to take advantage of simulated realities. 

 Those future, godlike beings living at Tipler's "omega point" would also have access to nearly all of the photons that once were emitted as infrared body heat by any past living being who ever stood outside, under the stars.  Thus, if they cared to make the effort, they might collect stunning levels of information about their ancestors and nearly all past times. 

Under such circumstances, Tipler calculated, (yes, using physics!) that such beings would have sufficient information and resources to plausibly "resurrect" those ancestors into virtual realities of limitless texture and believability. When asked why such entities would bother to do so, Tipler replied "why not?"  Indeed, he considered it to be highly likely that we now exist within one (or more) of those end-of-days simulations.

Alas for this marvelous vision, astronomy has recently shown that our Big Bang Cosmos appears not to be headed for a final, cycle-ending infall, but rather, toward limitless expansion and eventual "heat death" as all mass and energy get smeared into a flat, entropic void -- the far future alternative discussed by Freeman Dyson, who was Tipler's rival for Top Scientific Theologian of the Twentieth Century.  (Congratulations Freeman.  At least, so far.)

Only, Tipler could respond quite simply. "Isn't that exactly what the owners of the simulation would want us to think?" 

 In light of how strangely nonsensical all the recent talk of "dark energy" seems -- and the bizarre way that cosmologists have blithely reversed their former Standard Dogma: that the Big Bang was not an explosion into a pre-existing spatial context (they now seem quite happy to posit that it was, without even owning up to the fact that this is the biggest theory-reversal of modern times!) -- one can be forgiven for giving Freeman Dyson the encomium only tentatively.  There's more to come.

---  Does this have anything to do with the Singularity?

As I said, this topic has a million permutations. For example, how does it tie into the growing notion of a looming "technological singularity?"  (The notion that a super-acceleration of human progress may occur in the very near future, in which either runaway Artificial intelligence or human augmentation - or some combination - could confer "godlike" capabilities upon us, or our replacements, for well or ill.) Might all the fantastic creative and/or redemptive powers that Frank Tipler foresaw happening at the end of time be (at least somewhat) accessible much sooner? 

And while some speak hyperbolically about this near-future prospect, there appear to be a myriad potential up and down side  possibilities, some of them deeply worrisome.  I discuss a wide range of possible singularities -- and the renunciation movement that seeks to reject them -- at: http://lifeboat.com/ex/singularities.and.nightmares.    

 In contrast, Frank Tipler's far-future redeemers, after all, would seem dispassionately less likely to capriciously turn the simulation off! Especially if one of the simulated entities just happens to say or write the wrong thi...)

--- Can we settle this experimentally?

Can we see any evidence that we live in a simulation already?  A few potential clues have been brought up, from time to time.

For example, there is quantum mechanics. Specifically, the division of reality into sub-atomic "quanta" that are fundamentally indivisible, like the submicroscopic Planck Length, smaller than which which no questions may be asked.  But isn't that exactly the sort of truncation effect that a computer model would use, in order to prevent being taxed with infinite demands on processing power?  Imagine what would happen if the universe-emulation model had to look into ever-smaller domains, ad-infinitum, like the fractal Mandelbrot set... and do it for every speck, however small, everywhere in the cosmos?  

Likewise, at the high end, both the speed-of-light limit on how far we can observe and the intrinsically-contained dimensions of a Big Bang universe may be artificially imposed boundary conditions. introduced in order for the simulation's hardware and software not to have to deal with the computational loads of modeling a cosmos that is infinitely observable.

Moreover, take the failure to discover extraterrestrial advanced civilizations -- called The Great Silence or the Fermi Paradox -- despite the appearance of a galaxy that should generate a fecundity of life forms.  This would appear to conveniently limit the human experience to manageable levels, without having to deal with the exponentiating effects that might result from interstellar cultures exchanging notes. (See: http://www.davidbrin.com/science.htm and/or http://www.brin-l.com/brin/silence.html)  Moreover, that could even be the topic or goal of the present simulation.  To discover what interesting and unique cultural innovations human beings might come up with, if left entirely to their own devices, without influence by an overwhelming galactic civilization.

Indeed, we might see added clues in ourselves! Any characteristic of human nature that limits our ability to push at the amorphous boundaries of our cage might likewise be damping mechanisms -- including our propensity to get distracted by incantations and hifalutin, arm-waving thought experiments! (Like this one.)

Oh, but any decent simulation should be designed such that all of these hints and glimmers never become anything more than hints and glimmers.  Clues perhaps, but never proof.

--- The evidence of an immature author...

On the other hand, some of the "clues" are far more visceral and impulsive than others, leaving us with that frisson or chill up the spine, and a temptation to step outside, under the starry sky, look upward and shout "I'm on to you!"

Take the coincidence of names that keeps cropping up, almost as if the "author" of our cosmic simulation were having a little joke on us, now and then. 

 The most recent example that I see is the almost unlimited amount of fun you can have with Barack Obama's name. (Are we to be an "Obama-nation"?)  I don't hold this against Obama, mind you!  Indeed, he jokes about it, and one measure of our growing maturity may be how little any of that puerile stuff mattered to most of the electorate. 

Still, is he the guy dropping quarters into this holodeck, in the year 2050?  If so, it is a relief, after we endured existing as characters in the simulation which the 90-year old George W. Bush demanded from the simulator, allowing him to experience prodigiously statistics-violating luck and to live through a series of implausible fantasy jobs.

Oh, the list could go on and on. Take the fact that World War Two featured a battle in which Adolf the Wolf attacked the Church on the Hill, who begged help from the Field of Roses, who thereupon asked its Marshall to send an Iron-hewer to fight in the Old World and a Son of Arthur to fight across the greatest lake (the Pacific)... 

I mean, does the Designer really think we don't notice stuff like this?  

Or maybe He just assumes that we ca't do anything about it.

David Brin

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Note:  This is a draft in progress.  Please do not circulate except in an extremely limited way, Feedback and suggestions are welcome vis http://www.davidbrin.com
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