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Fundamental Limits to Virtual Reality, Part 1

Monday, March 3rd, 2008

I’m in Pinedale, Wyoming, visiting my daughter Isabel and doing some cross-country skiing among the aspen trees. They have great patterns like eyes on them. Today’s pictures are all from Pinedale, which is a nice example of an RR “real reality” far richer than any VR “virtual reality” we’re ever going to see.

In the last couple of weeks I twice noticed people online questioning my scientific accuracy when I claim in Postsingular that it’s bogus to talk about porting humanity into a complete virtual model of Earth. So today I want to explain some of the reasoning behind my claim.

Arguments for Vearth are sometimes start by talking about an imaginary substance wittily dubbed “computronium” by one of my favorite writers, Charles Stross. In Accelerando, he says computronium is “matter optimized at the atomic level to support computing.”

Although it’s a cute idea, I think computronium is a fundamentally spurious concept, an unnecessary detour. Matter, just as it is, carries out outlandishly complex chaotic quantum computations just by sitting around. Matter isn’t dumb. Every particle everywhere everywhen is computing at the maximum possible rate. I think we tend to very seriously undervalue quotidian reality.


[The ice fishing derby on Lake Fremont in Pinedale]

In an extreme vision—which is the one I disparage in my novel Postsingular—Earth is turned into a cloud of computronium which is supposedly going to compute a virtual Earth—a “Vearth”—even better than the one we started with.

This would be like filling in wetlands to make a multiplex theater showing nature movies, clear-cutting a rainforest to make a destination eco-resort, or killing an elephant to whittle its teeth into religious icons of an elephant god.


[Alley near the Teton Court Motel]

Ultrageek advocates of the Vearth scenario like to claim that nothing need be lost when Earth is pulped into computer chips. Supposedly the resulting computronium can run a VR (virtual reality) simulation that’s a perfect match for the old Earth.

As I’ll explain below, this is factually incorrect. Before getting into that, I might also ask why someone would passionately want to believe that we can be translated from flesh into bits? There’s something ascetic and life-hating about the notion. It’s a bit like a religious belief; one thinks of the old “work now, get rewarded in heaven” routine.


[Game heads on display in Ridley’s Grocery (formerly Faler’s)]

Anyway, let’s get back to my main point, which is that VR isn’t ever going to replace RR (real reality). We know that our present-day videogames and digital movies don’t fully match the richness of the real world. What’s not so well known is that computer science provides strong evicence that no feasible VR can ever match nature.


[Girl holding a fish as if it were a stuffed animal]

This is because there are no shortcuts for nature’s computations. Due to a property of the natural world that I call the “principle of natural unpredictability,” fully simulating a bunch of particles for a certain period of time requires a system using about the same number of particles for about the same length of time. Naturally occurring systems don’t allow for drastic shortcuts.

For details see The Lifebox, the Seashell and the Soul, or Stephen Wolfram’s revolutionary tome, A New Kind of Science—note that Wolfram prefers to use the phrase “computational irreducibility” instead of “natural unpredictability”.


[On a ridge above Fremont Lake on a climb led by Sherpa Iz-teng]

Natural unpredictability means that if you build a computer sim world that’s smaller than the physical world, the sim cuts corners and makes compromises, such as using bitmapped wood-grain and cartoon-style repeating backgrounds. Smallish sim worlds are doomed to be dippy Las Vegas/Disneyland/Second Life environments.


[A lo-resolution lodging near Pinedale]

But wait, answer the true-believer ultrageeks, if you do smash the whole planet into computronium, you have potentially as much memory and processing power as the intact planet possessed. It’s the same amount of mass, after all. So then we could make a fully realistic world-simulating Vearth with no compromises, right?

Wrong. Perhaps you can get the hardware in place, but there’s the vexing issue of software. Something important goes missing when you smash Earth into dust: you lose the information and the embodied software that was embedded in the world’s behaviors. An Earth-amount of matter with no high-level programs running on it is like a powerful new computer with no programs on the hard drive.


[Non-bit-mapped wood grain]

Ah, says the VR true believer, what if the nanomachines first copy all the patterns and behaviors embedded in Earth’s biosphere and geology? What if they copy the forms and processes in every blade of grass, in every bacterium, in every pebble, and so on?

But, come on, if you want to smoothly transform a blade of grass into some nanomachines simulating a blade of grass, then why bother pulverizing the blade of grass at all? After all, any object at all can be viewed as a quantum computation! The blade of grass already is an assemblage of nanomachines emulating a blade of grass. To the extent that you can realize an accurate VR world, the exercise becomes pointless.

Just as she is, Nature embodies superhuman intelligence. She’s not some piece of crap to tear apart and use up.

***

By the way, I have written a full-length essay expanding on some of these topics; it’s called “The Great Awakening,” and you can read it free online. It appeared in Asimov’s SF magazine in August, 2008, and in the anthology Year Million, edited by Damien Broderick, from Atlas Books in August, 2008.

For my answers to the many comments on this post, see my next blog post.

Dead Pigs on YouTube

Thursday, February 28th, 2008

I’ve blogged about the Dead Pigs before, and our epochal performance at the faculty show of Randolph-Macon Woman’s College, where I taught math from 1980 to 1982..

And now Andy Warren has put two Dead Pigs clips on YouTube, the opener and the encore In the encore clip above—thich I think is the better of the two—we’re doing a version of “Duke of Earl,” perhaps better called “Duke of Pigs.”

Daddy sent me to Randy-Mac.
He bought me a horse and a Cadillac.
I sold the car and bought me a brain.
Now I’m half grown up and I’m goin’ insane.
Duke duke duke, Duke of Earl
duke duke, Duke of Earl,
duke duke, Duke of Earl.

I was still a mathematics professor there at that time (although I knew I wouldn’t be back the next fall) and I went to meet my Calculus section the next morning. I’ve never had so attentive a class! But then I started talking about Calculus, as usual, and the glamor wore off.

In the opener clip shown above, we’re first doing an (improvised) warm-up called “Dead Pigs” — and I kept trying to get the band to start in on the second song, which is something like “Louie Louie.”

Apparently a guy who was interviewing to replace me as math professor was in the audience with the math department chairman at the show. I remember laughing about this with Mike Gambone, our saxaphonist and my best freind at RMWC. He was imagining the chair saying, like, “And, um, here’s Dr. Rucker, whom you’ll be stepping in for…”

We had a few other songs, that we played in rehearsals and in our one other live show—such as the original “Year after Year,“—but I don’t think we ever thought to record those. I still can hear them, though…

On another front, Charlie Jane Anders put a nice write-up about my novel Postsingular on io9, the vibby new SF blog.

Tesseract Outtake

Tuesday, February 26th, 2008

I’m still working on the second draft of Hylozoic, without much time to think or write anything fresh for the blog. I do have a few new pictures, so to have something to weave among them, here’s an unused bit I cut from Hylozoic for being too arcane.

Chu felt confident. His dreams had unearthed a powerful quantum-mechanical metashape, a hyperdimensional operator resembling a tesseract pattern with a tiny cube set into the center of a large cube, and slanting lines connecting the two cubes’ corners. The lines sketched out six skewed cube-like shapes connecting the inner and outer cubes.

The little cube was the size of an atom, and the big cube was ten centimeters on an edge, the size of a large man’s fist. The vibby thing was that the pattern was undergoing a four-dimensional rotation that continually had the center cube sliding over to become one of the skewed in-between cubes and then somehow jiggling out to be the outer cube, then skewing in from the opposite side and eventually ending up in the center again.

In a painfully strong flash of inspiration amid the lucid dreams, Chu had deduced that his tesseract-shaped operator could transform an atomic-level rune into a rune to be cast onto a quantum-computation to be carried out by a fist-sized region of space. Instead of having to program ten tridecillion atoms with the original rune, it would be enough to program a quintillion cubic decimeters—in exponential notation, 10^18 cubic decimeter chunks instead of 10^43 atoms. A quintillion was just on the border of the current abilities of a kiqqie human who didn’t happen to be a zenohead.

“Tesseract?” said Kakar, shadowing the motions of his mind.

“Gaia dug up the name,” said Chu. “But I thought of the math.”

Feeling a little shaky with excitement, he squeezed the conch-like rune into the tiny central cube of his tesseract, and watched as the shape spun around, producing an warped, inside-out seashell with most of the extra spikiness smoothed away.

“Wait, wait,” clucked Kakar. “I don’t get it. Show me again how you did that.”

“You put the atomic rune into the middle of the tesseract and it turns into a puffed rune that you map onto fist-sized chunks of space,” said Chu.

“Oh,” said Kakar, trying to keep his cool. “I see. It’s simple.”

Now it is. And we’re going to name the trick after me. Chu’s Kludge.”

“Kludge…” said Kakar, searching Gaia’s database. “Ah. A clumsy and inelegant workaround.”

“I’m brilliant but humble,” said Chu.

Rudy on the Radio. (Fixed Broken Permalinks).

Saturday, February 23rd, 2008

Sunday (tomorrow) you can hear me on the radio live in the Bay Area. I’ll be on the Stanford sponsored Philosophy Talk show, talking about my books Infinity and the Mind and White Light. The show airs on KALW, FM 91.7, San Francisco, CA, Sunday, 10am PT, Feb 24, 2008, and at other times nationally. In a week or two a podcast version will be online.

Yesterday the so-called permalinks (sometimes a sad misnomer) on my blog were temporarily broken as we upgraded to the latest version of the WordPress ware that runs the blog, and we needed to do some Apache type deep Weenix alteration as well. Yesterday, all you could see was this top page of the blog, and all links to past entries or dates were temporarily broken. But now, thanks to the genial tech support at our host Monkeybrains, it works again. Nothing like doing live brain surgery on your lifebox in public.

The built-in Search box is currently broken, but I’ve added a “Google Search Blog” box that uses the Google engine. In some ways this is nice, but the link info is a bit confusing as it lumps in stuff from the page titles.


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