by Lee Billings
Writing in the journal Science in 1960, the physicist Freeman Dyson carried humanity’s recent, relentless energy consumption to its logical extreme, postulating that someday if we mastered living and working in space we could harness essentially all of the Sun’s light by constructing a cloud of solar collectors around our central star. Dyson didn’t sweat what he saw as relatively minor technical details, such as how we would acquire the vast amounts of necessary raw materials—he proposed that by the time we needed all the Sun’s energy, we would be more than capable of simply dismantling a planet or two. Viewed from light-years away, the Sun’s optical emission would fade and be replaced by the infrared glow of waste heat emanating from its enclosing shell. If astronomers ever saw a distant star characteristically dim and shift entirely to infrared emissions, Dyson wrote, they would most likely be glimpsing evidence of another energy-hungry galactic civilization. Operating with perfect efficiency, such a “Dyson sphere” would capture some 400 billion petawatts of power—the total radiant output of the Sun. And yet, based on an ongoing 2.3 percent annual growth in energy usage, Murphy calculated it would cease to meet our expanding energy needs in just less than a millennium. There are, of course, a few hundred billion stars in the Milky Way. Assuming humanity somehow managed to instantaneously encase each and every Sun-like star in the Milky Way within perfectly efficient Dyson spheres, the inexorable 2.3 percent increase in energy used per year would still bring us to the limits of our galactic capacity within another millennium.
“Thus in about 2,500 years from now, we would be using a large galaxy’s worth of energy,” Murphy has written. “We know in some detail what humans were doing 2,500 years ago. I think I can safely say that I know what we won’t be doing 2,500 years hence.” If technological civilizations like ours are common in the universe, the fact that we have yet to see stars or entire galaxies dimming before our eyes beneath starlight-absorbing veneers of Dyson spheres suggests that our own present era of exponential growth may be anomalous in comparison not only to our past, but also to our future.
• • •
Long before the General Dynamics capsule was entombed—at the onset of the Jurassic Period, to be precise—San Diego was ordinary marine limestone on the bottom of a seabed, much like the rest of what would eventually become present-day California. Sometime less than 200 million years ago, colliding tectonic plates caused vast batholithic plutons of magma—viscous city-size bubbles of molten granite—to surge up from the mantle into the crust beneath that ancient coastal ocean. The plutons were variously enriched with copper, lead, silver, gold, and other metals. They heated the waterlogged rocks from below, cooking limestone into marble. When magma mixed with water seeping down from above, some of the metals precipitated out to form veins of ore in overlying fissures. Over millions of years, the ongoing tectonic collision gradually thrust and uplifted the former seabed to become dry land. Great blocks of the crust were overturned, to lie across and bulldoze through the countryside in reverse stratigraphic order. A California mountain’s summit might be made of granite from the subterranean depths, with sides formed from intermediate regions of ore-veined marble and limestone. Strewn along its base would be a jumbled melange of younger surface rock mixed with unconsolidated mudstone from the toppled ancient seafloor. Rain falling on the mountains eroded the sides, exposed the ore veins, and flushed flakes and fragments of precious metals into rivers.
On January 24, 1848, while building a sawmill along the American River to float logs to the small coastal settlement of San Francisco, a carpenter named James Marshall found a few pieces of that washed-down gold, sparking the great California Gold Rush. Soon, some 300,000 people from around the world had swarmed the region to seek their fortunes, exponentially increasing its population and propelling the unorganized territory into official U.S. statehood. Boomtowns bubbled and burst throughout northern California. San Francisco became a bustling city. The redwood forests fell to feed furnaces that reduced quarry-hewn limestone into lime, which went into the cement for marble-faced buildings. By 1863, a transcontinental railroad was under construction, and the great opening of the American West had properly begun. All because of gold, by chance delivered in a Jurassic upwelling of magma beneath the sea.
After the gold rush, the transcontinental railroad ensured that the surge of new settlers never truly abated. They rolled across the land in waves, chasing boom after boom, and at the end of each day, as the Sun fell into the Pacific, it set upon what appeared to be the truest expression of the American Dream. Almost everyone, it seemed, could make a fortune in the wide-open spaces of California. Farmers flocked to the Central Valley’s mild climate and fertile soil. Oilmen found light, sweet crude locked away in the state’s southern strata. Filmmakers found refuge in Hollywood from Thomas Edison’s packs of patent lawyers back east. The U.S. military built bases, airfields, and shipyards along the Pacific frontier. Technologists gave birth to new high-tech industries in Silicon Valley. Throughout it all, real-estate speculators bought up parcels of land, subdivided and sold them, and became rich. Housing prices and infrastructural necessities rose as capital continued pouring in, and property taxes rose with them, until in the 1970s wealthy, established Californians rebelled. They voted to keep property taxes artificially low, and shifted the state toward a dysfunctional political culture where time and time again voter-led “ballot initiatives” earmarked spending while also eliminating sources of revenue. Since the turn of the millennium, the state had been in near-constant budgetary crisis. When the real-estate bubble burst in 2007, it helped kick off the Great Recession of 2008, which reduced California’s coffers to catastrophic lows. Funding was slashed for public assistance to the poor and disabled, for state colleges and courts, for municipal emergency services, and more. For a time in 2009, the state government of California could only pay its debts with official, printed IOUs.
California’s scars, old and new, were on display when I visited Laughlin at UC Santa Cruz. The campus is built over and around abandoned nineteenth-century limestone quarries and cattle pastures, surrounded by sparse redwood shadows of a great former forest. In a long sunlit hallway of the Interdisciplinary Sciences Building, which houses Laughlin’s office, I came across a bulletin board filled with student notices protesting the school’s budget cuts, flanked by two massive empty dewars meant to store liquid helium.
Laughlin no longer had the option of simply protesting the University of California’s systematic belt-tightening. He was a tenured professor, and had just been appointed chair of the astronomy department. His office was small and sparsely decorated. A whiteboard, filled with knots of equations and hand-drawn graphs, took up much of one wall. A topographic globe of Mars rested on a file cabinet, surrounded by sparkling pieces of pyrite-laced granite Laughlin had fished from a nearby stream. In contrast to the globe’s crimson-colored highlands and mountains, its basins and lowlands were tinted blue, like the seas they probably held billions of years ago. “No two days are the same; every day is exactly the same,” Laughlin said as he showed me the office. “There’s very little variation—I come in, I sit at my desk, and I work. But each day is a unique, mad scramble from one emergency to another to keep the research enterprise going. I’m trying to secure more funding for the department. I’ve got four grad students that all have to get funded. I’m making sure my own work is funded. Right now funding is like the old Martian seas—drying up at the margins.”
Some of the younger members of his department, Laughlin thought, might soon leave the field, offering their analytic, numerical skills to more lucrative patrons in Silicon Valley or on Wall Street. In the meantime, some of his students and colleagues, hard-pressed for costly telescope time, simply made do with using cheap desktop computers to analyze free batches of public Kepler data, looking for valuable discoveries the Kepler team’s initial analyses might have missed.
Laughlin himself was grappling with a mystery that American and Swiss RV surveys had glimpsed, and that
Kepler had fully revealed: a wealth of Neptune-mass planets in hot, flat, circular, sub-100-day orbits, the apparent default architecture of inner planetary systems. Conventional theory holds that, since planets form from flat, circular, swirling disks of material around young stars, nearly all planets should reside in flat, circular orbits aligned to a star’s equator, its ecliptic plane. Small, rocky planets would form close to a star, where it is hot and most gas evaporates away. Large, gassy planets would form farther away, past the “snow line,” where gas and ice linger in the cold. Ever since their discovery in 1995, hot Jupiters had forced new theories. They were found in wildly elongated orbits, eccentric orbits that took them swooping far out of the ecliptic at one end, then plunging to graze their stars on the other. Theorists could only explain such worlds as products of planetary migration, a collection of theoretical mechanisms by which far-out giant planets could interact with their formative disks to bleed off momentum and fall closer to their star. The trouble was, when a massive planet began migrating mid-formation, it would tend to accumulate lots of material as it moved through the disk, growing to be about the size of Jupiter, not a relative runt like Neptune. Further, a migrating giant’s gravitational influence would tend to shake up the rest of the system, scattering other planets from flat, circular orbits into elongated, eccentric paths tilted out of the ecliptic plane. According to most new theories, intermediate Neptune-mass planets simply should not exist close to their stars, and certainly not in flat, pristine orbits. Consensus held they could only form farther out, and that, migrating in, they would have grown larger while also disrupting the delicate coplanarity and circularity left over from the primordial process of planet formation.
Some theorists had been so confident that they predicted Kepler would find a “planetary desert” bereft of close-in Neptune-size planets. And yet when Kepler’s data began streaming in, it was filled with hundreds of transiting multiplanet systems—systems of hot Neptunes, some with orbits proportionally flatter and more circular than an LP or a compact disc. The predicted planetary desert proved to be a rainforest of inexplicable worlds. Theorists knew no migratory mechanism that could have transported the planets to their present positions with such quiescence. Yet there they were, like angry bulls pawing the dust amid floor-to-ceiling stacks of untouched, unbroken china. Finding one would have been a fluke; finding hundreds meant something fundamental was missing from the accepted theories of how planetary systems form and evolve.
Kepler’s revelation had left Laughlin flabbergasted, like most every other player in the exoplanet game. He said as much as we left his office to walk among the redwood stands and old limestone quarries that laced the campus. The complete Kepler data, he believed, would keep theorists busy for the next twenty years.
“I just don’t know yet how those planets formed,” he said as we mucked along through a damp creek bed. “No one does. Something is wrong. Our paradigm of planet formation was built to weave two distinct things into a coherent picture: our own solar system, and the very easily studied hot Jupiters. We now know that hot Jupiters are only around maybe one percent of stars. Architectures like our own solar system seem to show up around more like ten percent or less of stars. So it looks like we’ve been trying to build a unified theory out of these two disconnected, fringe outcomes of planet formation. You don’t need to be a scientist to see that’s probably not the right way to go about it.”
We climbed from the creek bed and began moving up a gentle redwood-covered grade. Laughlin likened the new planetary confusion to Bode’s law, an idea named for and popularized by the German astronomer Johann Bode in 1772. Bode’s law postulated that the spacing of planetary orbits followed a specific, harmonic pattern, one that neatly accounted for the observed orbits of Mercury, Venus, Earth, Mars, Jupiter, and Saturn. When Uranus was discovered in 1781, it fit the pattern too. But over the years, Bode’s law fell into pseudoscientific disrepute as new discoveries such as Neptune, Pluto, and the asteroid belt failed to fit its harmony. Its early success had just been a coincidence, born of the fact that planetary orbits do indeed follow a much more general hierarchical spacing.
“The idea of a ‘snow line,’ with gassy planets only forming far from stars—that came about because it’s what we see in our own solar system,” Laughlin went on. “Now that we’re seeing the reverse so often around other stars, I’m not sure anymore that the snow line is a relevant concept. It might be a modern example of Bode’s law, but I don’t think you’re going to see people just stop talking about it. . . . You look at these new multiplanet systems, and in their orbital spacing and their masses in proportion to their host bodies, they follow the exact same patterns as the Jovian satellite system, Jupiter’s big moons. And those moons probably formed right where they are now. I wouldn’t be surprised if it turns out these worlds formed right where they are now, too. The process simply hasn’t been studied very well because of the focus on our own solar system.”
The redwoods thinned as we continued up the slope. Larger patches of midday sunlight blazed down through a canopy of ponderosa pines made sickly and sparse by bark-beetle infestation. We began to sweat. The earth’s color had gradually shifted from grayish-brown at the creek bed to reddish-orange beneath the pines. A glitter in the soil caught Laughlin’s eye, and he bent over to pick up a crumbly rust-colored rock. He apologized for his “grasshopper-level attention span,” and pivoted to talking geology.
“This area, this rock right here, is transitional. It’s the kind of rock you’d prospect for gold. It sparkles from the pyrite crystals. We’ve got limestone downslope that’s been heavily cooked and altered with magmatic fluids. Upslope we’ve got the granite that did the cooking. The forest changes here, I think, because the redwoods like the limestone soil better. It’s weird. The naive observation is that the granite formed where it lies and is somehow younger. You’d think as you go upslope you’re reaching younger layers. That’s what geologists thought for a long time. In reality, it’s just the opposite. The theory of plate tectonics was a big leap that made more of the puzzle pieces fit together. We’re going up in terms of topography but we’re going down in stratigraphic layers because of how this entire block of crust has been tilted and eroded. The older rock is on top of the younger rock here. We could walk this long, slow grade for another fifteen kilometers, and the whole way up it’s granitic plutonic rock from deeper and deeper down.”
I asked him how he knew all this. He said, “My sense is, if you really want to understand Earth-like planets, you have to become an expert on the Earth.”
Back in his office, Laughlin elaborated that a good bit of his knowledge of Santa Cruz’s geology actually came from a lingering fascination with financial markets. He gestured to his office’s equation-filled whiteboard. That particular day, the differential equations didn’t directly concern astronomy at all, he confessed, but rather the fluctuating commodity prices of precious metals, which he wished to predict on timescales of months and years. To do that, he had needed to understand supply and demand—the cost of building new mines, the manner in which metals were extracted and used—so he had educated himself in the geology of ore-forming bodies, the same geology that so long ago put gold in California’s hills.
Laughlin had reveled in using his skills in a technical field with direct commercial applications. Astronomy was a technical field, he acknowledged, but for as long as humans remained a single-planet, single-star species, it would be disconnected from the profits associated with semiconductor physics, petroleum prospecting, or quantitative finance. His new investigations had borne strange fruit: he had become preoccupied with what certain obscure market trends revealed about the nature of prediction and the formation of monetary value, and had begun to closely scrutinize various trades as they propagated through the global financial system. Viewing the scintillating patterns of trades, his “bird’s-eye view” on what would otherwise be “a mostly hidden world,” Laughlin had begun feeling the familiar effervescence
once again. He saw battle lines being drawn in virtual space, occasionally spilling out into the real through volatile bubbles of liquidity, low-latency arms races, and high-frequency information warfare. The vista newly unveiled before his eyes was of a planet on the brink of some profound transformation, one driven as much by high-speed telecommunications and computing as by biology and geology.
In its reliance on the high technologies of ultrafast mainframes, undersea fiber-optic cables, microwave relay networks, and communications satellites, the frontier of modern finance almost seemed to constitute a new Space Age, though one that would be unrecognizable to the astronauts and rocketeers of half a century before. The planet’s brightest scientific minds no longer leveraged the most powerful technologies to grow and expand human influence far out beyond Earth, but to sublime and compress our small, isolated world into an even more infinitesimal, less substantial state. As he described to me the dark arts of reaping billion-dollar profits from sub-cent-scale price changes rippling at near light-speed around the globe, Laughlin shook his head in quiet awe. Such feats, he said, were “much more difficult than finding an Earth-like exoplanet.”
• • •
In early January of 1848, a fifty-two-year-old master carpenter named James Lick arrived in the small village of San Francisco. He had been born in Pennsylvania but had made his fortune building and selling fine pianos in South America. He hoped to expand that fortune through purchasing cheap land in the new California territories, which he thought would soon be annexed by the United States. Along with his tools and workbench, Lick had brought along an ironclad chest filled with $30,000 in gold. He immediately began buying up vacant lots around town. Seventeen days after Lick’s arrival, James Marshall discovered gold at Sutter’s Mill, the California Gold Rush was set in motion, and Lick found himself the biggest player in a buyer’s market for San Francisco’s abundant real estate. Soon he was swamped with sales offers, as residents abandoned their coastal harbor homes in droves to seek gold in the inland hills. He bought up all the land he could at cut-rate prices, then netted huge profits as San Francisco’s population exponentially boomed from wave after wave of arriving prospectors. Within a decade he had become one of the new state’s most successful land barons, with vast holdings in San Francisco, Santa Clara, and San Jose.
