The Universe of Seurat and Rovelli

I was once chastised by security guard at the Art Institute of Chicago for getting too close to A Sunday Afternoon on the Island of La Grande Jatte, the greatest work by the greatest of the pointillist painters, Georges Seurat. I remember blushing with embarrassment as other patrons flicked their attention to me to take in the barbarian careless enough to endanger one of the world’s most beautiful and important works of art.

I also felt an initial rush of outrage that anyone would think I would harm such a treasure. But then I realized that was indeed too close, that my foot was over the line of the designated safe distance to the masterpiece, that I was indeed the Philistine they took me for. But I was a curious Philistine, looking closely to tease out how he was able to pull off his technique.

Pointillism, Atomism and Digitization

The art movement known as pointillism1 is the technique of applying small strokes or dots of paint so that from a distance so they visually blend together. Largely invented by Seurat, I think the technique visually demonstrates atomism, which Rovelli associates with certain Greek philosophers but was probably first described by the Vedic sage Aruni back in the 8th century BCE. Aruni proposed the idea that there were “particles too small to be seen [that] mass together into the substances and objects of experience.” 

Seurat aesthetically anticipated not only the atomic and quantum theories but the digital age in which we find ourselves living today, an age in which so many people spend the majority of their waking hours looking at screens of pixels.2 We are entranced by pointillism all day long.

In a sense, the idea of a pixelated universe is the topic of both Seurat’s work and Rovelli’s as laid out in Reality Is Not What It Seems: The Journey to Quantum Gravity? If you read the last post (or, better yet, the book itself) you should have at least a general notion of quantum gravity.

But what prospects does the theory have? How might it be supported by scientific evidence, and where might it lead us? Let’s discuss.

Vive la Révolution

Quantum physics was a revolution in physics, but what if Rovelli is right and all of spacetime is quantum? Well, then, the revolution is just beginning. Who really knows what knowledge it could bring us? Might quantum gravity help us better understand understand how to harness gravity itself? What new technologies could be created with it? Rovelli doesn’t discuss possible applications, but I can’t think of any major physics discoveries that didn’t also bring earth-shaking new technologies.

Testing Quantum Gravity

So, how can the theory be tested? One idea is to look for evidence of a “Big Bounce” as opposed to a “Big Bang” in the origins of the universe. According to Einstein’s view of the universe, all of spacetime could be squashed ad infinitum, ultimately leading to the Big Bang. But, that’s not what quantum gravity would predict. Rovelli notes that “if we take quantum mechanics into account, the universe cannot be indefinitely squashed.” And if that’s true, then we wouldn’t get a Big Bang but, rather, a gigantic rebound that he refers to as the Big Bounce.

So, how does one test that? Well, one can look at the statistical distribution of the fluctuations of cosmic radiation. That should provide evidence of the Big Bounce. In addition, according to Rovelli, “cosmic gravitational background radiation must also exist–older than the electromagnetic one, because gravitational waves are disturbed less by matter than electromagnetic ones and were able to travel undisturbed even when the universe was too dense to let electromagnetic waves pass.”

There’s also the prediction by the quantum gravity theory that black holes are not ultimately stable because the matter inside them cannot be squeezed into a single point of infinite density. Rather, at some point, the black hole explodes (like a miniature Big Bounce). If we can locate some exploding black holes in the universe, then we have more evidence of quantum gravity.

So, basically, if we find that super dense stuff is bouncing and rebounding in the universe, the quantum gravity folks might be right. If not, well, at least we’ll have evidence the theory is wrong and we can consider the other theories that have been, and surely will be, conjured up by the endlessly creative theoretical physicists.

If the quantum gravity champions do turn out to be right, then one of the side effects will be that the infinity goes away. Or, at least, physicists are a lot less likely to get infinity as the answer when they run certain calculations based on general relativity theory. The universe itself becomes “a wide sea, but a finite one.”

Bit by Bit, Information Becomes Reality

But don’t assume that, just because the universe might be finite, it doesn’t stay weird. In fact, it may start seeming weirder than ever if humanity succeeds in merging quantum mechanics information theory not only with the theory of relativity but with information theory.

First conceived by engineer and mathematician Claude Shannon in the mid-20th century, information theory assumes that information “is the measure of the number of possible alternatives for something.”

It was Shannon who popularized the word “bit” to mean a unit of information. He used it in his seminal 1948 paper “A Mathematical Theory of Communication,” and he attributed the origin to a Bell Labs memo written John W. Tukey, who used bit as an acronym of “binary information digit.”

Rovelli explains, “When I know at roulette that a red number has come up rather than a black, I have one ‘bit’ of information; when I know that a red even number has won, I have two bits of information…”

I won’t belabor this because information theory gets pretty complicated and Rovelli doesn’t go too deeply into it. To get a better but non-technical understanding, I recommend reading The Information: A History, a Theory, a Flood by James Gleick. I read it several years ago and hope to give it a second read over the next several months.

Anyway, it was John Wheeler, the father of quantum gravity, who was “the first to realize that the notion of information was fundamental to the understanding of quantum reality.” He coined the phrase “from it to bit,” meaning that the universe is ultimately made up of information.

Rovelli writes:

Information…is ubiquitous throughout the universe. I believe that in order to understand reality, we have to keep in mind that reality is this network of relations, of reciprocal information, that weaves the world. We slice up the reality surrounding into “objects.” But reality is not made up of discrete objects. It is a variable flux.

Although Rovelli has one more chapter on the scientific method, I think this is the better place to wrap up a post on a blog called The Reticulum. Let’s sum up: Reality is a network of relations among bits of information in a variable flux.3

I don’t know if that’s a true description of our underlying reality. But it does feel familiar: flux and foam, bits and bytes, indeterminacy and statistical spins. Even if quantum gravity doesn’t work out as epistemology, it still captures much of the essence of our baffling, vertiginous and often wondrous modern lives.

1 The word pixel, by the way, is a portmanteau of "picture element," which is the smallest addressable and controllable element of a picture represented on a digital screen.

2 As visionary as the technique was, the term "pointillism" was actually coined by art critics in the late 1880s to ridicule Seurat and the other members of the art movement. But the artists, as they so often do vis-a-vis critics, got the last laugh. Today, the term is regarded as describing one of the great movements of neo-impressionism.

3 Which makes me think, of course, of Doc Brown's famous "flux capacitor."
Feature image: A Sunday Afternoon on the Island of La Grande Jatte by George Seurat: https://commons.wikimedia.org/wiki/File:A_Sunday_on_La_Grande_Jatte,_Georges_Seurat,_1884.jpg

Now You See Me, Now You Don’t

Out of the Frying Pan

So far, we’ve covered ancient atoms, electromagnetism and the theory of relativity. In Chapter Four of Reality Is Not What It Seems: The Journey to Quantum Gravity, we finally enter the last and strangest realm of known physics: quantum mechanics (aka, quantum physics).

In my last post, I compared trying to some to terms with the implications of Einstein’s model of reality to taking the red pill in The Matrix, leaving behind our comfortable (though false) notions of stable time and space in order to live in the bizarre, uncomfortable and yet often beautiful and exciting realm of spacetime.

Live free, Neo!

But entering the realm of quantum mechanics is something else. Just as you’re coming to terms with spacetime, you’re told that, by the way, spacetime is also a kind of matrix. An even stranger and more mysterious one. A matrix that isn’t populated by Agents trying to keep the truth from you but rather by gaggles of egghead physicists doing their damnedest to explain it to you….between their extended bouts of arcane squabbling.

Want to go back to your comfy pre-relativity matrix? Too late, Neo.

Into the Fire

So, let’s get down to explaining this new realm. Rovelli specifies that our quantum reality has three primary characteristics: granularity, relationality and indeterminism.

Hey, Why Is My Reality All Pixelated?

Let’s start with granularity. The short version is that, for the sake of convenience, a guy name Max Planck assumed that the energy comes in bite-sized (okay, smaller than that, but finite nonetheless) packets when doing his calculations.

Not long after, Einstein said something like, “Hey, you know what, Max? Energy really is made up of packets. What do you know!” (And, so, yes, the original Weird Al is one of the fathers of quantum mechanics and not just relativity).

Einstein claimed that this granularity extended to light, a form of energy. Most of the other physicists said, “No way! James Clerk Maxwell says light is a wave and waves don’t come in convenient bite-sized packets.”

To which Einstein said something like, “I guess it’s both! Beats the hell out of me how that could be true but let’s just go with it and see where it leads.”

And, wow, those breadcrumbs led to some very strange places…

Wait, They Were Just Here a Second Ago!

Next up is relationality, which is a boring name for something utterly bizarre. Rovelli sums it up in just three short sentences: “Electrons don’t always exist. They exist when they interact. They materialize in place when they collide with something else.”

So, you’re asking, how can that possibly be? Aren’t electrons just a part of an atom, like your arms and legs, nose and mouth are part of you? It’s like saying a person’s left arm doesn’t exist unless they happen to bump into somebody else. How does that work? you ask. I haven’t a clue, but electrons are apparently just ghosts that appear during interactions with one another.

Even though it was his personal bread crumb trail, Albert Einstein thought this was all too strange to be true. But there’s this other physicist, Paul Dirac, who didn’t seem to have problems with it. Rovelli writes, “For him the world is not made of things; it’s constituted of an abstract mathematical structure that shows us how things appear, and they how behave when manifesting themselves.”

Speaking of the problems posed by Dirac, Einstein groused, “To maintain an equilibrium along this vertiginous course, between genius and madness, is a daunting enterprise.”

Rovelli indicates that objects (though what really constitutes an object?) can still have characteristics such as mass while they are not interacting with one another, but the object’s “position and velocity, its angular momentum and its electrical potential only acquire reality when it collides–interacts–with another object.”

Okay, can it get any weirder? Glad you asked!

I’ve Determined that I Can’t Determine

Last up is indeterminacy. Einstein hated this part. He famously said, “God does not play dice with the universe.”

What he objected to was the fundamental quantum physics idea that one cannot predict what any given particle is going to do. Rovelli wraps it up like this: “While Newton’s physics allows for the prediction of the future with exactitude, if we have sufficient information about the initial data and if we can make the calculations, quantum mechanics allows us to calculate only the probability of an event. This absence of determinism at a small scale is intrinsic to nature.”

“Intrinsic to nature” — let that one sink in. All you can do is give and get probabilities. It’s all a big dice game, as far anyone can tell.

Or maybe it’s a baseball pitcher with lousy ball control. For some reason, I think of the movie Bull Durham in which the rookie pitcher Nuke can throw hard but doesn’t know where any given pitch is going to go. “Hell if I know where the damn thing’s going…” Nuke’s catcher, Crash, tells a nervous batter. (And, yes, Bull Durham fans, I know it’s a ploy on Crash’s part but, hey, it’s just a metaphor).

Anyway, what Dirac’s equations can do is give you a range of the possibilities and then a calculation of the probabilities within that range (At least, I think that’s right, based on what I can determine. Get it? Determine. Indeterminacy? Ok, never mind).

We Cobbled Her Together But She Sure Does Run Good

Over the years, physicists “cobbled together” (Rovelli’s phrase) what we now call the Standard Model (physicists are crap at naming and marketing, it appears). He sums up:

The Standard Model is completed by the 1970s. There are approximately fifteen fields, whose quanta are the elementary particles (electrons, quarks, muons, neutrinos, Higgs, and little else), plus a few fields similar to the electromagnetic one, which describe electronmagnetic forces and the other forces operating at a nuclear scale, whose quanta are similar to the photons.

The thing is, this junky heap of particles, fields, equations and whatnot turn out to be extremely robust and fast around the corners. Experiments keep confirming it and engineers depend on it to build all our fancy electronic gadgets. In the end, it’s the model that everybody buys.

Now Comes the Hard Part

So, quantum mechanics works like a charm. But so does Einstein’s theory of relativity. The problem is that the two explanations don’t work well together. One works super well in the macro world and one works super well in the micro world, but nobody knows how to marry the two.

So, that’s where Rovelli and others come in. They want to settle these irreconcilable differences by building a house that both theories can comfortably fit in. Heck, they want more than that. They want our two theories spooning each other, finishing one another sentences, lovingly telling us stories of how their many zany antics and impassioned conflicts finally ended in a Harry-and-Sally-type romance that we can all laugh about now.

So, will they or won’t they? Stay tuned. Next week: Falling For Loop Quantum Gravity

Feature image: Clara Ewald's portrait of Paul Dirac: From https://commons.wikimedia.org/wiki/File:Clara_Ewald_-_Paul_Dirac.jpg

Einstein and the Big Squid

Taking the Red Pill of Relativity

Now things get weird. In the first post about Rovelli’s Reality Is Not What It Seems, we focused on atoms. Despite the strange fact that medieval Christians tried to censor the concept of atoms, they do not score very high on my weird-shit-o-meter. I was brought up with them, so they seem as friendly as eating potato chips on a comfortable couch.

In the second post, we got into electromagnetism. But, considering that most of us live enmeshed in cocoons of wire and wifi, it’s hard to see that topic as outlandish, however much our forebears would have been astonished.

But in Rovelli’s third chapter, the topic of this post, we’re forced to choke down a red pill if we want to enter the spacetime reality of Albert Einstein’s mind, thereby exiting The Matrix of our comfortable everyday reality where time and velocity seem as easy to grasp as a digital readout.

You’d think that by now we’d be accustomed to the original Weird Al’s big brain. I mean, we’ve had a century or so to get acclimated to this stuff. But, speaking for myself, I’m still struggling to cope with the idea that the world is not what it seems.

Present But Not Accounted For

Rovelli tries. But, despite the cartoons, his section on the “extended present” is hard to swallow. How and why has the present moment been extended by the Special Theory of Relativity?

I assume it has to do with the speed of light and relative time, but you’ll need to take it on faith within the context of this chapter. Here’s an example:

[O]n the moon, the duration of the extended present is a few seconds, and on Mars a quarter of an hour. This means we can say that on Mars there are events that are yet to happen, but also a quarter-of-an-hour of events during which things occur that are neither in our past nor in our future.

I find this hard to wrap my brain around and wish Rovelli had gone to greater lengths of explain the details. I remember getting a deeper glimpse of time relativity when pondering the ideas in the book Why Does E=mc2 (And Why Should We Care?), but I’ve since lost it (the glimpse, not the book). And now I’m wondering if I’ll need to bear down on that text again in order to grasp Rovelli’s arguments. We’ll see.

Space Is a Monster Mollusk

Okay, let’s put the “extended present” into a box (perhaps along with Schrodinger’s cat) and come back later to see what happened. For now, I want to focus on another statement in Chapter Three:

What if Newton’s space was nothing more than the gravitational field? This extremely simple, beautiful, brilliant idea is the theory of general relativity…. Newton’s space is the gravitational field. Or vice versa, which amounts to saying the same thing: the gravitational field is space….We are not contained within an invisible, rigid scaffolding: we are immersed in a gigantic, flexible mollusk (the metaphor is Einstein’s).

Okay, despite the Cthulhu vibe, I understand this better than the concept of extended present. I get the whole spacetime-curved-by-big-hunks-of-matter idea. I get that everything’s moving and has speeds only relative to everything else and everything is in constant flux. I even kind of (though not really) get the idea that time flows faster at the top of a mountain rather than in a valley.

But spacetime is the same thing as the gravitational field? Was that originally part of the Theory of Relativity? Apparently I’m not the only one confused. I wonder if that’s part of scientific history or just a tenet of the quantum gravity hypothesis, which is the ultimate subject of the book.

A Universe Designed by Escher

The latter sections of Chapter Three are mostly focused on how the universe may be a humongous globe with an extra dimension stuck in there. Einstein conceived a way in which the universe might be finite while still having no discernable boundary. Rovelli uses the metaphor of a globe:

On the surface of the Earth, if I were to keep walking in a straight line, I would not advance ad infinitum: I would eventually get back to the point from which I started. Our universe could be made in the same way. I fly around the universe and eventually end up back on Earth. A three-dimensional space of this kind, finite but without boundary, is called a “3-sphere.”

Although he goes on for another 12 pages or so, for me the above is the essence of the discussion. And, I kind of get it, or at least think I do, because we all understand the metaphor of the globe. Whether I can can truly conceive the shape of the universe like this, however, is another matter. It’s something to work on.

It’s Networks All the Way Down

Boiling it all down, I take away two main insights from this chapter. First is the idea that space as we (or at least I) sometimes think of it doesn’t exist. There are no vast empty spaces in space. It is jam-packed with gravitational and electromagnetic fields light waves, radio waves, gamma rays, microwaves, etc. In fact, maybe space is nothing more nor less than an unthinkably immense gravitational field.

Whatever space is, however, it’s certainly not mostly empty. It is a packed and fluctuating landscape in its own right. Jupiter is a not a planet but a mountain, one that we can climb and look down at the curved and rippling real estate of our solar system, if we’re willing to see beyond the merely visible.

My second insight is that network describes the scene even better than landscape. In my mind’s eye, I see block-and-tackle pulleys everywhere, connecting everything in our solar system (and the greater universe, of course) in a constantly shifting network.

Some mythologies have it that the Earth is supported on the back of a giant World Turtle. But what does the turtle stand on? There’s the old joke that, well, it’s “turtles all the way down” in a kind of infinite regress.

Perhaps it’s less of a joke to say that the universe is a network of networks. What do the networks attach to? Well, other networks via gravitational forces. I guess we could say it’s networks all the way down.

Featured image: Artist's concept of the Interplanetary Transport Network. The green ribbon represents one possible path from among the infinite number possible within the larger bounding tube. Constricted areas represent locations of Lagrange points. Wikimedia Commons 

Minding the Universe

I read an article about how a study finds similarities between the human brain and networks of galaxies in the universe.

Camerae Ready

Surprising? I don’t know. It seems as if the universe uses a lot of its same basic structures over and over at different scales, and these structures often have mathematical counterparts. One of the more famous examples is the Fibonacci sequence, in which each number is the sum of the two preceding ones, starting from 0 and 1. That is, 0 + 1 = 1, 1 + 2 = 3, 2 + 3 = 5, 3 + 5 = 8, 5 + 8 = 13, 8 + 13 = 21, etc. So, the actual sequence looks like 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, and on and on.

What’s interesting is that this pattern shows up with some frequency in nature. Perhaps the most robust and convincing example is the spiraling nautilus shell, which is composed of chambered sections called camerae. Each chamber is equal to the size of the two camerae before it, creating a logarithmic spiral.

But there are there other examples as well: tree branches, flower petals, the seeds in sunflowers. It may extend to much larger phenomena as well, such as hurricanes and spiral galaxies.

So, perhaps it should not be surprising to find that brains and the universe are largely defined by their networks (that is neurons and galaxies) made up of nodes connected by filaments. In short, both are kinds of reticula. To read the actual report, go here.

Assuming the authors have a legitimate point, what do we make of the similarities between the universe and the human brain? Are we supposed to consider the idea that the universe is itself a thinking organism of some sort, that we exist in the mind of God?

Panpsychism

That’s too great a logical leap for me to make, but maybe it does lend support to the pseudo-scientific notion that the universe is conscious. In his book Galileo’s Error: Foundations for a New Science of Consciousness, philosopher Philip Goff considers the idea that consciousness is not something special that the brain does but is instead a quality inherent to all matter, a theory known “panpsychism.” To read an interview in which he discusses the notion, go here:

 Goff isn’t alone in wondering about the consciousness of the universe. Astrophysicist Ethan Siegel has discussed it in Forbes, and NBCNews highlights other thinkers in its article “Is the Universe Conscious?”

I don’t know what to think about all this. It feels a bit like the Gaia hypothesis (which is the idea that the interconnected biological systems of the Earth act as one, enormous organism), except extended to “infinity and beyond” (in the immortal words of Buzz Lightyear).

Our Town

Back in my college days, I was in a staging of the play Our Town, in which I played the character George. I don’t remember many of George’s lines but I do remember a scene in he was speaking with his sister Rebecca at the end of Act One:

REBECCA: I never told you about that letter Jane Crofut got from her minister when she was sick. He wrote Jane a letter and on the envelope the address was like this: It said: Jane Crofut; The Crofut Farm; Grover’s Corners; Sutton County; New Hampshire; United States of America.

GEORGE: What’s funny about that?

REBECCA: But listen, it’s not finished: the United States of America; Continent of North America; Western Hemisphere; the Earth; the Solar System; the Universe; the Mind of God–that’s what it said on the envelope.

GEORGE: What do you know!

REBECCA: And the postman brought it just the same.

GEORGE: What do you know!

I doubt Thornton Wilder was the first writer or mystic to envision the universe as the mind of God. But I do wonder what he’d think about the fact that here in the third decade of the 21st century, it has become an idea taken seriously by the likes of philosophers, physicists, and science journalists. What do you know!

Featured image from https://en.wikipedia.org/wiki/File:NautilusCutawayLogarithmicSpiral.jpg. Nautilus shell cut in half. Photo taken by Chris 73 | Talk 12:40, 5 May 2004 (UTC)