Saturday, August 22, 2015

Are We a Simulation?

Robert Kuhn host and writer of the public television program Closer to Truth has an excellent column on the theory that our universe is actually a computer simulation. He writes:
I began bemused. The notion that humanity might be living in an artificial reality — a simulated universe — seemed sophomoric, at best science fiction.

But speaking with scientists and philosophers on "Closer to Truth," I realized that the notion that everything humans see and know is a gigantic computer game of sorts, the creation of supersmart hackers existing somewhere else, is not a joke. Exploring a "whole-world simulation," I discovered, is a deep probe of reality.

Philosopher Nick Bostrom, director of the Future of Humanity Institute at Oxford University, describes a fake universe as a "richly detailed software simulation of people, including their historical predecessors, by a very technologically advanced civilization."

It's like the movie "The Matrix," Bostrom said, except that "instead of having brains in vats that are fed by sensory inputs from a simulator, the brains themselves would also be part of the simulation. It would be one big computer program simulating everything, including human brains down to neurons and synapses."

Bostrum is not saying that humanity is living in such a simulation. Rather, his "Simulation Argument" seeks to show that one of three possible scenarios must be true (assuming there are other intelligent civilizations):
  • All civilizations become extinct before becoming technologically mature;
  • All technologically mature civilizations lose interest in creating simulations;
  • Humanity is literally living in a computer simulation.
His point is that all cosmic civilizations either disappear (e.g., destroy themselves) before becoming technologically capable, or all decide not to generate whole-world simulations (e.g., decide such creations are not ethical, or get bored with them). The operative word is "all" — because if even one civilization anywhere in the cosmos could generate such simulations, then simulated worlds would multiply rapidly and almost certainly humanity would be in one.

As technology visionary Ray Kurzweil put it, "maybe our whole universe is a science experiment of some junior high school student in another universe." (Given how things are going, he jokes, she may not get a good grade.)

Kurzweil's worldview is based on the profound implications of what happens over time when computing power grows exponentially. To Kurzweil, a precise simulation is not meaningfully different from real reality. Corroborating the evidence that this universe runs on a computer, he says, is that "physical laws are sets of computational processes" and "information is constantly changing, being manipulated, running on some computational substrate." And that would mean, he concluded, "the universe is a computer." Kurzweil said he considers himself to be a "pattern of information."

"I'm a patternist," he said. "I think patterns, which means that information is the fundamental reality."
Information, of course, is the product of minds, thus, if information is the fundamental reality in our world there must be a mind that has generated it. Many people, of course, agree with this and argue that the information which comprises this world is produced by the mind of God, but scientists, at least naturalistic scientists, argue that God is a metaphysical concept which lies outside the purview of science. Instead they advert to the existence of computer hackers in other universes which is also a metaphysical posit, but since it's not God, it's okay to speculate about it.

Kuhn goes on:
Would the simulation argument relate to theism, the existence of God? Not necessarily.

Bostrum said, "the simulation hypothesis is not an alternative to theism or atheism. It could be a version of either — it's independent of whether God exists." While the simulation argument is "not an attempt to refute theism," he said, it would "imply a weaker form of a creation hypothesis," because the creator-simulators "would have some of the attributes we traditionally associate with God in the sense that they would have created our world."

They would be superintelligent, but they "wouldn't need unlimited or infinite minds." They could "intervene in the world, our experiential world, by manipulating the simulation. So they would have some of the capabilities of omnipotence in the sense that they could change anything they wanted about our world."

So even if this universe looks like it was created, neither scientists nor philosophers nor theologians could easily distinguish between the traditional creator God and hyper-advanced creator-simulators.

But that leads to the old regress game and the question of who created the (weaker) creator-simulators. At some point, the chain of causation must end — although even this, some would dispute.
In other words, the universe displays indications of having been intelligently designed rather than having been an enormously improbable accident. This poses vexing problems for naturalists who feel constrained to account for the design without invoking you-know-who. So they theorize about a multiverse of an infinite number of worlds or speculate about extra-cosmic computer programmers who've created a world that looks real but is in fact just a computer simulation.

These extraordinary hypotheses are taken seriously by some philosophers and scientists, but if someone were to suggest that maybe this universe really is the only universe, that maybe it's real and not an illusory simulation foisted on us by some pimply extra-terrestrial, and that maybe it's instead the product of a single intelligent transcendent mind, he would suffer the ridicule and scorn of those who'd sooner believe that the universe is a science project of a seventh grader in some other more technologically advanced universe. I wonder which is the more implausible hypothesis.

Kuhn points out that the simulation hypothesis has great difficulty with the phenomenon of human consciousness:
A prime assumption of all simulation theories is that consciousness — the inner sense of awareness, like the sound of Gershwin or the smell of garlic — can be simulated; in other words, that a replication of the complete physical states of the brain will yield, ipso facto, the complete mental states of the mind. (This direct correspondence usually assumes, unknowingly, the veracity of what's known in philosophy of mind as "identity theory," one among many competing theories seeking to solve the intractable "mind-body problem".) Such a brain-only mechanism to account for consciousness, required for whole-world simulations and promulgated by physicalists, is to me not obvious.
In other words, how could the sensation of seeing blue - as opposed to blue itself - be simulated? Until there is a plausible physical explanation of consciousness, which there is not at this point, it seems unlikely that conscious beings are nothing more than a simulation.

There's more of interest in this essay at the link including how physicist Paul Davies uses the simulation argument to refute the multiverse hypothesis. Kuhn closes with this:
I find five premises to the simulation argument: (i) Other intelligent civilizations exist; (ii) their technologies grow exponentially; (iii) they do not all go extinct; (iv) there is no universal ban or barrier for running simulations; and (v) consciousness can be simulated.

If these five premises are true, I agree, humanity is likely living in a simulation. The logic seems sound, which means that if you don't accept (or don't want to accept) the conclusion, then you must reject at least one of the premises. Which to reject?
Personally, I find (i) problematic, (ii) possible but questionable (it's just as likely that technological growth reaches a ceiling or collapses altogether), and (v) highly doubtful.