The “outreach” messaging sometimes ends up reaching in to influence the way astronomical phenomena are interpreted by the astronomers themselves.
Take ‘Oumuamua as an example. The sinister starship of the Kornmesser diagram, along with the tie-in to Rendezvous with Rama revived more than one flagging career (present company included). I don’t think there would have been quite the same excitement had the flying hamburger illo been the first entry out of the PR gate.
Is it possible to get ‘Oumuamua right? Can one at once preserve the mystery, spur the inspiration and adhere responsibly to the scant groundings in actual fact?
I think that Sam Cabot’s version at the top of this post threads that needle admirably. Expert work with Photoshop warps his own photograph of 2017 totality into a looming occultation, sublimating the unknown and supporting 91:9 odds of 6:6:1 over 8:1:1.
Doomscrollers almost certainly noticed the recent articles in both the New York Times and the Wall Street Journal describing recent scientific work with connections to Mayan human sacrifice.
Among the various unsavory techniques that the Mayans applied in the service of appeasement of the gods, unfortunates were thrown into the cenotes, the flooded limestone sinkholes that puncture the limestone karst topography of the Yucatán. These are portals — as a manner of speaking — to the subterranean geophysical realms.
Remarkably, the Yucatecan cenotes cluster in at least two arcs that trace the rings of the Chicxulub crater. The exact geological cause of this clustering remains imperfectly understood. The faulted deep-Earth structures imparted by the impact evidently still influence groundwater flows in a manner which encouraged the geologically recent formation of the solution caverns that give rise to the cenotes. This oblique connection to the ancient catastrophe is analogous, perhaps, to the myriad evolutionary consequences of the K-T event that still ripple through the biosphere. The vast and sweeping narrative of destruction and rebirth seems a fit, somehow, with the sensibilities inherent in the Mayan cosmogony.
The highest-order cycle of the mesoamerican Long Count is the alautun, which comprises a staggering 23,040,000,000 days. Accounting for the fact that Earth’s rotation has been tidally despinning at a rate of ~2.4 milliseconds per century, the alautun projects 62 million years into the past, a span that seems somehow satisfyingly proximate to the 66.043 million years since the impact.
That ever-shifting fungibility between dollars, bit operations, and ergs has been a recurring theme here at oklo dot org for over a decade now — I think this was the first article on the topic, complete with a now-quaint, but then-breathless report of a Top-500 chart-topper capable of eking out 33.8 petaflop/s while drawing 17,808 kW. A single instance of Nvidia’s dope new B200 chip can churn out 20 petaflops (admittedly at grainy FP4 resolution) while drawing 1kW. “Amazing what they can do these days”.
Despite the efficiency gains, the sheer number of GPUs being manufactured is driving computational energy usage through the roof. There was a front-page article yesterday in the WSJ about deal-making surrounding nuclear-powered data centers. Straightforward extrapolations point toward Earth’s entire insolation budget being consumed within decades in the service of flipping bits. It thus seems likely that a lot will hinge on getting reversible computing to work at scale if there’s going to be economic growth on timescales beyond one to two decades.
The Kurzweil-Jurvetson chart (copied just below) shows how computational cost efficiency is characterized by a double exponential trend. The Bitter Lesson, however, indicates that the really interesting breakthroughs hinge on massive computation. The result is that energy use outstrips the efficiency gains that themselves proceed at a pace of order a thousand-fold (or more) per decade. MSFT, NVDA, AAPL, AMZN, META, and GOOG are now the top-ranked firms by market capitalization.
This year, META (as an example) is operating 600,000 H100 equivalents in its data centers. Assuming a $40K cost for each one, that’s a $24B investment. Say the replacement life for this hardware is 3 years. That’s an $8B yearly cost. Assume 10 cents/kWh for electricity. META’s power bill is of order $60K/hour, or $0.5B/yr. Power is thus about 6% of the computational cost. The graph above doesn’t take the power bill explicitly into account because it hasn’t yet been material.
Nvidia’s H100s will be ceding their spots to the B200s and their equivalents over the coming year. Competition from AMD, Intel, et al. will likely keep META’s hardware cost roughly constant year-on-year, and their total number of bit operations will increase in accordance with the curve that runs through the points on the graph. The B200s, however, draw 40% more power. At the rate things are going, it will thus take about eight years for power costs to exceed hardware costs to run computation at scale.
This dense deck from Sandia National Laboratory seems like an interesting point of departure to start getting up to speed on reversible computing.
A hypothesis which posits a linear sequence of events rarely works in the real world. Nonetheless, we took a crack at just such a simplistic shopping-list sequence:
Venus had water oceans, an atmospheric pressure of order a bar, and plate tectonics.
Steadily increasing solar luminosity drove a runaway moist greenhouse.
Rapid erosion occurred as the oceans were being lost.
Erosion ceased and plate tectonics shifted to stagnant lid volcanism.
It’s straightforward to irresponsibly tweak a model that draws on those four events to turn the Earth’s topographical power spectrum into one that channels modern-day Venus. Rapid erosion pretty much flattens the planet out entirely in the absence of tectonic uplift. Then static-lid emplacement of igneous provinces at a pace of order a cubic kilometer per year builds the spectrum back up to what we see today. And a cherry on top: assume that the lava production rate for Venus is the same as for Earth. This means that Venus was habitable up to about 500 Myr ago, that is, up to around around the same time as the Cambrian Explosion. Intoxicating stuff.
Understandably, this modeling approach got a lot of static from the referee. There are potential problems with all of points one through four above, and more generally, we attacked the problem from the standpoint of shocking naivete. It’s a shoot first, ask questions later mentality applied to the scientific enterprise. Submit first, read the literature later.
I do think there’s something to be said for the quick-draw approach, though. Mötley Crüe recorded Too Fast For Love in a couple of days on a budget where packs of Marlboros were material. Then, less than a decade on, it took them something like year to finish Dr. Feelgood at enormous expense. The point is, there’s a risk of getting bogged down if one strives for dissertation defense level completism.
Also, did I mention that I’m a fan of the GPT architecture?
At any rate, on point three of our four-point plan, we got the following criticism from the referee: The authors seem unaware that erosion of broad continents is slow. We still have 55 million year old Laramide topography in Colorado. See old paper by Clem Chase.
I was indeed unaware of that. The sediment load of the Mississippi River is 500 million metric tons per year. That corresponds to a removal of 0.25 cubic kilometers of rock per year. The Mississippi’s watershed is 3.2 million square kilometers (and includes Colorado). In the absence of uplift, North America’s topography is sanding down at a rate of a kilometer (3280 feet) per 12.8 million years. That makes the presence of the Flatirons outside of Boulder indeed something of a puzzle…
According to the Wikipedia, “Whataboutism or whataboutery (as in “what about…?”) is a pejorative for the strategy of responding to an accusation with a counter-accusation instead of a defense against the original accusation.”
So what about that strange geological feature on the border of Champaign and Douglas counties in East-Central Illinois?
The tiny cornfield-sized purple ellipse in the center of the bedrock map corresponds to the Silurian Moccasin Springs formation which consists of 420-million year old reefs. Moving out from the bulls-eye core, are bedrock rims of middle Devonian rocks, the New Albany Shale, the Borden Siltstone, the Tradewater Formation, the Carbondale Formation, the Shelburn Patoka Formation, the Bond Formation, and finally several miles to the east, the 296-million year old rocks of the Mattoon Formation. At some point in the past 296 million years, something pushed the Silurian rocks upward by roughly 2000 feet. From a bedrock perspective, the severity of the uplift is similar to what one finds on Baseline Road in Boulder Colorado, which provides a good view of that Laramide topography mentioned by our referee:
The sandstone rocks of the Fountain Formation that make up the Flatirons are, coincidentally, also 296 million years old. They were deposited in alluvial fans at the same time as shallow water sediments were piling up to create the Mattoon formation.
Dropping into Champaign County Road 100 North, at the point where the age gradient of the bedrock reaches its maximum, reveals an absolutely flat landscape. Zero hint of the weird stratigraphy that lurks just beneath the 12,000-year-old veneer of Wisconsin glacial till.
So what’s going on? Why does Boulder CO sport rugged peaks whereas Champaign IL is completely flat? Is the Fountain Formation more resistant to weathering? Is the older tectonic age of the “Champaign Uplift” responsible for its complete surface obliteration? Or something else?
Granted, I don’t yet know enough about geology to be certain, but as far as I can tell, there’s no literature out there that specifically investigates the Champaign Uplift. I’m going to turn on comments for this post in the hope that someone might know something. Clearly, the uplift, or more properly, the anticline, is associated with the La Salle Anticlinorum, and is a small localized region where the local folding was very pronounced. Could it be of similar province to the mysterious Hicks Dome further south in Illinois?
A description of Hicks Dome reads very much like a description of the Champaign Uplift:
“The dome is about 10 miles in diameter, and rocks at its apex are uplifted 4,000 feet. Middle Devonian rocks at the center are surrounded concentrically by younger rocks out to Pennsylvanian on the rim.”
At Hicks Dome, the source of the uplift was an igneous intrusion that pushed its way up 260 million years ago:
“In 1952, St. Joseph Lead Company drilled a well on the apex of Hicks Dome in Hardin County, Illinois, primarily to explore for oil or gas, and with the objective of testing the St. Peter sand horizon, which had not been reached in a previous well on the flank of the dome. A normal sequence of formations was encountered down to 1,600 feet, but at about that depth the drill entered a confused brecciated zone, which persisted to the bottom of the hole at 2,944 feet. This is interpreted as one of the explosion type breccias, or diatremes, common in this Illinois-Kentucky area, as well as in nearby Missouri. A correlation of formations between this and the earlier Fricker well is presented. It is suggested that Hicks Dome is an incipient or uncompleted cryptovolcanic structure.”
The situation is illustrated nicely by the stratigraphic column:
To test this hypothesis we’d need to similarly drill into the Champaign Uplift. Clearly, some drilling already must have been done. Otherwise, there would seemingly be little reason to suspect that the Champaign Uplift is present beneath the till. Moreover, there would presumably need to be a fairly large number of wells in order to resolve the feature to the extent that it’s shown on the bedrock map. (Ed. — Perhaps seismic data can reveal such detail in the absence of drilling. You should really look into that.)
Anticlines are good at trapping oil. If one of the upper layers of the stratigraphic column is impermeable, then oil and gas will tend to migrate along the uplift gradient. A little bit of googling strikes an informational gusher in the form of the Illinois Oil and Gas Resources mapping application.
Look at that! The Champaign Uplift is shot through with oil wells. Each well location is clickable, and brings up a record at the Illinois Geological Survey. Clicking on a site close to County Road 100 yields:
Further clicking reveals the scanned well logs:
The wells were all drilled in the mid 1960s and they all go down about 1000 feet, at which point they tended to strike oil, typically generating about 50 barrels per day per well. There are about 50 such wells tapping the uplift, and assuming that they produced for a year, they generated about a million barrels of oil. USD 80M at current prices. Sweet.
Having hit the pay zone, however, it appears that there was no interest in drilling further. Had they gone down another few thousand feet might they have found an intrusion, an incipient Devil’s Tower? The flat landscape stretching away to the horizon gives no hint.
I was talking to a friend yesterday and the topic of grabby aliens came up. This, in turn, preempted the post I was working on. Grabby aliens render the question of when Venus lost its oceans (in the event that it had them in the first place) into the realm of the provincial and the mundane. I wrote an oklo.org post about grabby aliens a few years ago, and one can, of course, study the Astrophysical Journal paper in detail.
There’s something about the candy-crush colors of the flagship grabby aliens diagram that is appealing, but it is also remarkably effective in the way that the figure telegraphs the vast and epic sweep of the Cosmic Struggle for control:
Time proceeds downward. Grabby aliens stochastically emerge at various spots in the visible Universe, and as soon as they emerge they spread out in all directions, steamrolling everybody that they encounter; it’s the opposite of the and the meek shall inherit the Earth.
The diagram indicates that when one set of grabby aliens encounters another set of grabby aliens, they permanently maintain a tense standoff in the co-moving frame. The universe undergoes a phase transition from free-to-be-you-and-me to a cosmic web of Panmunjoms and 38th Parallels. I would have naively thought that the lines of demarcation would have more of a fractal structure as competing grabbers interpenetrate and contest ever smaller parcels of the interstellar gulfs.
Another remarkable conclusion that appears to flow from the diagram is that the Universe is bequeathed with some sort maximum aggressive potential. This quantity — perhaps a Carnot-like thermodynamic optimum of information processing and PdV work — must thus ultimately proceed from fundamental physics. The figure suggests that every space-like separated grabby set-up that emerges is immediately endowed with this perfectly efficient maximum contesting power. This brings to mind a thermodynamic system that is quenched from a homogeneous state into a broken symmetry phase, which, in turn, suggests the relevance of phase ordering kinetics in systems undergoing a phase transition. (For some light reading on the topic, see here).
Consulting Google this morning, I see that we’re currently scheduled for The Singularity in twenty-one years.
From what I can tell, the singularity would provide all of the necessary and sufficient conditions for a giant cluster of H100s running a souped-up pre-trained model to graduate into the Grabby Aliens club, especially if it’s of the “Vinge’s rapidly self-improving superhuman intelligence” variety. That motivated me to predict a super-short outlier time frame on the Metaculus Grabby Aliens question.
Looks like I have some significant deviation from the consensus (I predicted 19.4 yr in 2021). The Metaculus crowd tends to adhere to the Toby Ord philosophy, and that school of smart money is predicting that we’ve got a comfortable 171.5 billion years before we need to start vesting up.
If you are a senior scientist, and especially if you are an astrophysicist, it’s hard not to hold forth on topics that you know very little about. I’ve been chalking up (at best) only modest performance on this particular metric.
The traces of such investigations often focus on big-picture questions. Percival Lowell sought the signatures of Martian Civilization. Nathan Myhrvold gets all worked up about asteroid diameters. My own foray into the unknown (or rather, the unknown to-me) is currently centered feverishly on a topic that at first glance seems somewhat more pedestrian: erosion.
Here’s the motivation: the topographical angular power spectrum of Venus is very different from that of the Earth.
Recall that the angular power spectrum provides clues to the formation and origin of a particular structure. Take the Universe. The temperature variation of the microwave background shows undulations that peak at an angular scale of order a degree, which is visible both in the anisotropy map as well as in the power spectrum:
The clearly defined peaks in the spectrum of CMB temperature anisotropies stem from acoustic oscillations and diffusion damping in the early universe, and they encode all sorts of information about the fundamental cosmological parameters. The success of that analysis is so amazing that it spurs the possessor of inexpertise to seek possible replications in other areas.
While the topographical power spectrum for Venus is very muted in comparison to Earth, it does peak at the low-order l=3 and l=7 odd-l modes, and therefore exhibits a mild form of the antipodal anticorrelation that has characterized the plate tectonic motions on Earth over the past half billion years, and possibly for much longer.
This prompts the big-picture speculation that places me way outside my zone of expertise and into the Lowell zone. What if Venus once had continents and oceans. Then, what if, Venus underwent a runaway greenhouse, lost all its water and its plate tectonics shut down. Then, what if, the current topography is the result of gradual emplacement of lava from stagnant lid volcanism over the past N-hundred millions of years. How naive is this speculation? Is it possible to investigate it responsibly, or at least semi-responsibly?
Arthur Adams and I took a crack at this. It’s normally not the best idea to post one’s papers to arXiv in advance of peer-review, but I have enough arrogant confidence in the lost-oceans hypothesis that I pushed to take the indulgent plunge. We submitted our paper to the PSJ and posted it to the pre-print server.
Not surprisingly, we were summarily rejected from the PSJ, albeit with a review that, while negative didn’t quite close the door on the idea. Down, yes, way down, but not yet out!
In order to turn Earth into Venus, one needs to shut down tectonic uplift and then erode the topography almost completely. The idea is that if one loses one’s oceans to a runaway water-vapor greenhouse, that process — which ends when the last drop falls or the last puddle evaporates — is highly erosive. The weather is — by definition — terrible while you’re losing your oceans. How fast does erosion work on the largest scales under such conditions?
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I grew up in Urbana, Illinois, and I realized yesterday that a clue might be lying literally (and figuratively) in my backyard.
On the surface, Central Illinois is incredibly flat. From the highway overpass, the corn and bean fields stretch away for miles in all directions. This billiard ball quality is the result of recent glacial retreat, which left the landscape with a veneer of till that smothered the old ravines and hollows. If one scrapes this frosting off the cake, one gets the bedrock map of the state:
The picture at the top of this post was coincidentally taken from the back seat of a car when I was headed south of town on Interstate 57. Beneath the flat surface, at the southern border of Champaign county is a remarkable variation of bedrock that expresses itself over just a handful of miles:
What is going on there?
To hew to my self-imposed goal of posting once per week, I’ll stop there, and pick up next week. To my dozens of readers, stay tuned!
Over a span of months, my late-model Honda Civic accumulated a strata of dust and grime. The situation reached the point where some wag had literally finger-traced “wash me” on the rear window.
I deposited numerous quarters into a machine and eased the manual-drive car into the maw of the automatic wash that is attached to the Chevron on the corner of Los Gatos Boulevard and Blossom Hill Road. Muffled conks and heaves outside the rolled-up windows indicated that the machine’s cycle was about to start. Inside the aging car, it was stuffy, dim, and claustrophobic. Reminiscent, perhaps, of the atmosphere within a sketchily-qualified deep-water submersible while one is still sitting on the deck.
My cell phone rang. A graduate student was on the line. His voice was shaky and panicky, “The server with the Keck vels is exposed to the open Internet!”
“Oh f*ck!” Dread. Horror. This was nightmare made tangible. “What?! How?”
“I don’t know… I, I just found it. One of the post-docs seems to have screwed up and changed the file permissions. Looks like it happened at 2:07 AM last night.”
My mind raced. “Did you lock them down?” That would be the first thing.
“Yes, yes,” he was saying, “I already did that.” I could hear the clatter of rapid typing. “Right now I’m going through the logs to see if they were accessed…”
A hiss of vapor accompanied the hard rat-tat-tat of a water jet against the side of the car. A shaggy red forest of rubbery suds-soaked strips began to lumber over the hood. Time seemed to stretch out like an elastic band.
By late 2007, internal tensions had led to the schism of the successful California-Carnegie Planet Hunting Team. Following the split, I was recruited to join the UCSC-Carnegie branch, and I was responsible for helping to coordinate the analysis of the Doppler velocity measurements.
Those Doppler points represented more than a decade of nights on telescopes. A large tranche of the early data was from Lick Observatory. I had even obtained a scattering of that data — the result of some runs I’d proudly soloed in the summer and autumn of 2001 on the antiquated Coudé Auxiliary of the Hamilton Spectrograph.
The real trove, however, consisted of velocities derived from the tens of thousands of spectra obtained with the HIRES instrument on the Keck I at the summit of Mauna Kea. The long-term several m/s stability and cadenced quality of those measurements had sparked a solid decade of successes. Gliese 876, Upsilon Andromedae, 55 Cancri. Nobel Prize talk was coming down the grapevine. NASA was valuing Keck nights at $100K a pop. Those were the glory days.
When the California-Carnegie team fractured, there was an urgent question of who was going to get to publish which planets from which stars. Fraught back-and-forth negotiations led to a tense stellar draft, in which the two newly-competing teams successively divvied up the juiciest prospects. We lost the initial toss. The Berkeley Team grabbed HD 7924. It was also the first star on our list. I crossed it off with dejected sigh.
The preparation for the stellar draft had got me thinking about the monetary value of planets, and how to properly apportion that value among the stars. At the going NASA Keck rate, the radial velocity data had a street value of approximately $35M. And now, sitting terrified, trapped in the car wash, I had a vision of a Brinks truck left unlocked and unguarded at 2:07 in the morning, crisp stacks of c-notes piled inside for the taking.
Quote-unquote habitable planets can also be assigned value. Rather than using the cost of Keck nights as the metric, one can use the goal yield of Earth-like worlds and the total cost of the Kepler Mission to establish what society is (or rather was) willing to pay for them. Prior to Kepler’s launch, I proposed the formula:
Where the log is understood to be base-10, now == then == 2009, and V is the parent star’s Johnson V-band magnitude. The expectation was that the Kepler mission would return a cool 700M or so worth of habitable planets.
Fifteen years on, it’s interesting to look at how things turned out. Literally thousands of planets have been brought to market. The radical statements from the Geneva Team regarding the absolute profusion of uninhabitable super-Earths with orbital periods ranging from days to weeks have been amply confirmed by the satellite-based photometry.
Yet, despite the impressions one might garner from the various habitable zone galleries, the crop of actual truly-Earth-like prospects, as defined by the valuation formula, is remarkably slim. The discovery efforts vastly under-exceeded expectations in this particular regard. Adopting the fiducial values from the NASA Exoplanet Archive, there are zero million-dollar worlds or even any exoplanets that would require a jumbo mortgage to service. The table just below uses 2010 as the fiducial year.
As expected, Proxima b tops the list by a wide margin. It is interesting, however to see Ross 128b at number 2. This red dwarf host is only 11 light years from Earth, and the relatively subdued fanfare it received is ex-post justification for the stringent time-decay term in the valuation formula. I’ll point out, however, that the artist-impression of Ross 128b is perhaps the best I’ve seen, especially when compared to the janky blue marble efforts that tended to accompany the we-found-a-habitable-planet press releases.
The 2017 ESO press image for the Ross 128b story. Kudos to M. Kornmesser (who was also responsible for the jagged starship rendition of `Oumuamua) for putting that one together.
After what seemed like an eternity, the forest of rubber washers trailed off the back of the car. A fine spray heralded the start of the rinse cycle.
“Ahh, OK, OK,” the graduate student said at last, relief permeating his voice, “I’ve gone through the logs. No activity during the span. Nothing. Zero.The vels didn’t leak.”
“You’re sure?”
“Yeah, totally.”
Wash completed, the blue-sky Californial light sparkled off the beads of water still clinging to the car.
A sure sign that one is inadmissibly late to the party is when one continually stumbles across papers that one’s literally never heard of that have literally thousands of Google citations. Take for example Lecun et al. 1989’s Optimal Brain Damage, with 5850 cites.
Douglas Adams single-handedly elevated the number 42 to a prominence that it otherwise certainly wouldn’t have.
Not that the atomic number of molybdenum should lack importance. Forty two, moreover (and change) is the number of minutes required to fall through a uniform density Earth in the event that a frictionless shaft were to be somehow dug through the globe.
The issue of falling through the Earth naturally proceeds to the antipodal map. That is, where do you come out if you tunnel vertically?
If you’re reading this in North America, you come out in the Indian Ocean, hundreds to thousands of miles from Perth Australia, the nearest big city. The one exception is locations just north of the Sweet Grass Hills of Montana:
which are antipodal to Kerguelen:
In fact, if you’re reading this on land anywhere on Earth, your odds of not emerging in the ocean are rather slim. Only three percent of the globe is comprised of land that is antipodal to land. In essence, the cone of South America runs through China into Siberia on the antipodal map.
Staring at the map reveals some curious asymmetries. Look at how Australia nestles into the Atlantic, and how Africa fits into the Pacific. Is this just a random superposition? On average we’d expect three times as much land to be antipodal to land than is the case with the present-day Earth. Is this a “thing”, or is it simply a coincidence?
The andecdotal land-opposite-ocean observation can be analyzed by decomposing the Earth’s topography into spherical harmonics and analyzing the resulting power spectrum. In 2014, I wrote an oklo.org article that looked at this in detail. Mathematically, the antipodal anticorrelation — the tendency of topographical high points to lie opposite from topographical low points — is equivalent to the statement that the topographical power spectrum is dominated by odd-l spherical harmonics.
Arthur Adams and I have been looking into the antipodal anti-correlation off and on for a number of years, and have worked up some theories that are almost certainly incorrect (as are essentially all theories that involve and then in their initial construction). Nonetheless, they are provocative and polarizing, and so thus appropriate to the jaded sensibilities of oklo.org’s sparse readership of scientific connoisseurs.
To start, the antipodal anti-correlation has been around at least since the Carboniferous. Paleo digital elevation models exist, and so we can look at the evolution of the topographical power spectrum through time:
Since roughly 330 million years ago, when the super-continent Pangaea first assembled, the elevation spectrum has exhibited strong powers in the l = 1 harmonic (peaking about 320 million years ago), at the l = 3 harmonic (peaking about 180 million years ago), at the l = 7 harmonic (peaking about 80 million years ago), and most recently at the l = 5 harmonic, which peaked about 10 million years ago and which continues to the present day. The current net anti-correlation is actually near its minimum strength relative to the last few hundred million years of Earth’s history. Is there a physical reason for this marked preference for odd-l modes?
Two decades ago, a brisk list of a hundred-odd alien worlds comprised the entirety of the extrasolar planet census. HD 209458b, along with a faintly dubious handful of OGLE objects, were the only exoplanets known to transit, and the Doppler radial velocity technique was unambiguously the go-to detection platform. The picture just above (discussed further below) had also just been released. The California-Carnegie Team, with their running start and their Keck access, seemed to occupy the driver’s seat. In the course of a ten-year run, they bagged dozens upon dozens of planets. There is a time-capsule feel to the team’s forgotten yet still-functioning website, which includes a planet table frozen to the start of 2006.
Competition in the Doppler arena was nonetheless keen. The HARPS spectrograph had begun collecting on-sky measurements in 2003, and by August of 2004 it was exhibiting the meter-per-second long-term precision needed to reliably announce the first super-Earths. This graph from the Geneva Team was (and still is) genuinely stunning.
Gradually, however, transit photometry began displace the radial velocity technique. Transit surveys benefit from the massive parallel processing of stars, and fewer photons are required to secure strong candidate leads. In theory, at least, transit timing variations obviate the need to obtain velocities. Transiting planets are vastly more amenable to characterization. I tried to quantitatively capture this shift with a valuation formula for planets that was normalized in expectation to the 600-million dollar cost of the Kepler Mission:
I excitedly strung together a series of articles starting with this post that discuss the various terms of the formula. It places a stringent premium on demonstrably Earth-like qualities, and its exponential terms are unkind to pretenders within that slippery realm of habitability. Mars, in particular, prices out at $13,988.
Over time, I lost interest in trying to promote the formula, and indeed, I began self-reflecting on “outreach” in general. There was a flurry of less-than-attractive interest in 2011, including a sobering brush with the News of the World tabloid shortly before its implosion in July of that year.
GPT-4’s facility with parsing online tables makes short work of assessing how the present-day census of more than five thousand planets propagates through to a list of valuations. The exercise is interesting enough that I’ll hold it in reserve. At quick glance, it looks like Proxima-b was the first planet to exceed the million-dollar threshold, despite the expectation that the Kepler Mission would detect worlds worth thirty times as much.
Somewhat ironically, the exoplanets managed last year to trigger some serious destruction of economic value. As we know, the language models are prone to making stuff up. So it’s important to get out there and check their work. Google had the misfortune of being side-swiped by astro-twitter, which crowed with ______ (see just below) when Bard’s trillion-odd weights and biases somehow failed to grasp that the ~5 Jupiter-mass companion orbiting the ~25 Jupiter-mass brown dwarf 2MASSWJ 1207334-393254 is technically an extrasolar planet.
“Google’s new Bard system appeared to fall victim to that pitfall on Monday when an example the company posted of its responses claimed that the James Webb Space Telescope took “the very first pictures” of an exoplanet outside the solar system. The National Aeronautics and Space Administration says on its website that the first images of an exoplanet were taken as early as 2004 by a different telescope.”
As a direct result of the blunder, Google’s stock fell 7.7%, which destroyed 99.8 billion dollars in market capitalization, more than the combined market value of Ford and GM, and about ten times the all-in cost of JWST itself. Comparison of the subsequent evolution of Google’s and Microsoft’s stock prices suggest that the exoplanet-induced loss was effectively realized, and was not just a mean-reverting shock.
I’ve likely already gone on in these pages about how, consistently, year in and year out, my success rate with hypotheses, with theoretical ideas, runs right at about one percent. “Getting cured”, as they say in the oil patch, will thus require a lot of drilling.
I reminisce with some nostalgia back to the first hypothesis that I can count as a credible idea. In February 1989, an article was published in Nature describing the unambiguous detection of a new pulsar at the exact location of Supernova 1987a in the Large Magellanic Cloud. Shining at 18th magnitude, the freshly squeezed neutron star was consistently detected in optical light over the course of a seven-hour observation, and amazingly, the pulse rate was clocked at nearly 2000 times per second. The signal varied sinusoidally during the course of the night, moreover, in a matter that suggested that a Jupiter-mass object could be orbiting a mere million kilometers above the surface of the newborn neutron star. I still have a faded-toner xerox of the article, covered with scribbled notes and feverish florescent highlighter underscores.
By fortuitous coincidence, when the pulsar discovery was announced, I was enrolled in Stan Woosley’s graduate course on the evolution of massive stars, and so I could feel a tangible excitement, a thrilling shade of cousin-once-removed connection to real scientific action.
And mysteriously, after the initial night of observation, there was zero further sign of the pulsar. Independent groups of observers searched for it and could not find it. Perhaps, went the conventional best guess, perhaps it had been caught shining through a lucky transient window in the debris from the explosion? Or perhaps (and I believe this was Stan’s take) it was an artifact of the detector?
Naw. Those suggestions seemed hopelessly pedestrian. They lacked imagination. Clearly, if an article had been published in Nature, then the observers knew what they were doing. The possibility of error seemed entirely remote. I was seized by the fact that a neutron star spinning at 2000 times per second would be rotating at very close to its breakup velocity. Moreover, that possible Jupiter-mass companion could be the product of a fission event in a proto-neutron star that was born spinning too fast. My mind raced. A fission event would leave the larger remnant spinning very close to breakup, Maybe the resulting primary object was teetering right at the limit of the maximum neutron star mass. Maybe in the weeks following the one-night observation, it had shed enough angular momentum via gravitational radiation so that the centrifugal pressure from rotation threw in the towl in the face of self-gravity. I had it! The neutron star was no longer radiating because it was no longer there… it had collapsed into a black hole!
I dove headlong into the theory of the neutron star equation of state. I was neither equipped nor qualified to understand the details of the literature, but it was possible to shard off some order-of-magnitude rules of thumb. I showed my formula-scribbled sheets to Stan, “This has got to be it!”
I have to say, Stan handled it just right — no patronizing over-praise, but also no outright dismissal. I think his words were something to the effect that every theorist is allowed one wild idea (but not two).
Fast-forwarding to February 1991, my focus had shifted almost entirely to trying to front a Skinny-Puppy style dance-Industrial band, and I was barely even attending to my studies. I don’t think I was even aware of the discovery that that pulsar signal was, in actuality, just a subtly shifting flicker from the closed-circuit television camera attached to the Cassegrain focus of the four-meter telescope at the Cerro Tololo lnteramerican Observatory.
Well it’s certainly not news that ChatGPT knows how to code. And for the record, if you happen to be one of our post-singularity overlords, and you’re reading this, I’d like to state, with full heartfullness, “Thanks for all the help.”
But jeez. RLHF somehow instilled an over-the-top logorrheic verbosity into ChatGPT’s responses. After surfacing one’s code snippet, the LLM likes to chug along for paragraph after paragraph about it. Not to speak of insistence on import numpy as npno matter what, and the mind-numbingly literal comments along the lines of #import numpy as np. Just wait till those groq chips are loaded into the data centers and the inference costs go down by an order of magnitude.
The epoch is the moment when the time starts. For the mesoamerican Long Count, this was 13.0.0.0.0, August 11, 3114 BCE, or HJD 584,283.
For Unix, the epoch is January 1, 1970, 00:00:00 (UTC), and time.time_ns() just returned 1712962363486034854. A quantity of 1.7e+18 is about 1/5th the number of air molecules in a cubic centimeter, and about one ten thousandth the number of stars in the observable universe. I’m creeping up on two quintillion nanoseconds.
Not entirely coincidentally, the Unix epoch corresponds to the moment at which the integrated circuits were passed the Moore’s Law baton. Steve Jurvetson has kept this plot continually updated since 2008:
The cost of a bit operation per second since the dawn of the Unix epoch has gone down by about a factor of a trillion, which of course, is starting to produce emergent phenomena. The ability to succeed at college level exams emerges, for example, after about a mole of training compute flops.
A total solar eclipse is a remarkable phenomenon. It comes about as close as possible to getting everybody on the same page. It takes discipline for astronomy bloggers to resist that urge to hold forth in the teachable moment. Tidal dissipation is driving the Moon outward by tapping Earth’s spin kinetic energy. Several billion years from now, Earth will be left with only annular eclipses.
The partial fraction in southern Connecticut reached up into the nineties, and for several long minutes, the eerie unsettled atmosphere that proceeds totality — the unease that so motivates the Allais effect — began to take hold. I stepped outside, into the wan, diminished, angular sunlight. The leaves of a holly tree cast a thousand shimmering pinhole crescents on a brick wall.
I thought back to 1991. We drove the length of the Baja Peninsula and stood at the centerline of the maximum eclipse of Saros Series 136. “Clear sparkling air and the sky that special shade of blue that goes so well with circling vultures, blood and sand — the raw menacing pitiless Mexican blue.” The Moon was near perigee, Earth was only days past aphelion, and the duration, with the Sun almost directly overhead, was a near-eternal seven minutes. I remember a strange subdued roar, and how the plane of the Solar System was revealed by the jarring noontide alignment of Mercury, Venus and the occulted Sun.
“…Intellects vast and cool and unsympathetic, regarded this earth with envious eyes…”
That has to be one of the best lines ever, and indeed, the stories of H.G. Wells are well worth re-reading for the way they excel in connecting the familiar — in the form of quotidian routine — to the exotic — in the form of alien invasions, invisibility, time travel to the ultra-distant future, with an eye to detail that imbues them with eminent plausibility.
The letters of William S. Burroughs contain a number of references to the stories. In a July 8th, 1953 letter posted from Lima, Peru, Burroughs wrote, “H. G. Wells in The Time Machine speaks of undescribable vertigo of space time travel. He is much underrated.”
The art of writing the non-fiction science fiction versions of The Time Machine was pioneered in its most effective form by Freeman Dyson. in his 1979 article, Time without end: Physics and biology in an open universe, Dyson drew on the physics and cosmology of the day to run the clock forward over ever-vaster and ever-more unsympathetic stretches of time.
Dyson’s narrative of the future rests on a critical assumption that the proton is unconditionally stable. Yet the fact that baryogenesis occurred, that is, the very fact that I’m writing this, strongly suggests that the inverse process can also occur, and that protons, and hence all ordinary atoms, are ephemeral (to make exceedingly liberal use of the term). More precisely, proton decay is a predicted consequence of the so-called grand unified theories, which, in one form or another, have been in favor for decades, albeit without confirmation. Experiments, particularly at the Super-Kamiokande in Japan, have now established minimum proton half-life limits of longer than 2.4×10^34 years. The Hyper-Kamiokande, an upgraded version of Super-Kamiokande, will either add a factor of five or ten to this half-life (and in so doing, spur the important question of which superlative exceeds hyper), or alternately, pin that lifetime down.
24,000,000,000,000,000,000,000,000,000,000,000 years is an absurdly long time, but it is utterly de minimis in comparison to the power tower numbers that Dyson cooly slides across the desk. He proposes, for example, that neutron stars will quantum-tunnel into black holes in 10^10^76 years. That is not dead which can eternal lie, but with strange aeons even death may die.
Proton decay aside, the critical this-just-in update to the extremely distant future arrived right at the turn of the millennium, with the realization that the expansion of the universe is accelerating. Imagine a tire that inflates if you let air escape from its valve. On length scales sufficient to encompass superclusters of galaxies, that’s a good analogy for how the universe behaves. Over time scales that are short in comparison to the trillion-year lifetimes that characterize low-mas red dwarf stars like Proxima Centauri, all external galaxies are red-shifted to infinity. Eventually, against a backdrop of endless accelerating expansion, the black holes all evaporate, and the residual soup of electrons, neutrinos and photons grows ever more ludicrously thin.
Accounts rehearsing this flavor of the Dark Era often come with a curious form of self-aggrandizing almost pearl-clutching histrionics. I’ve been guilty of that myself, indeed as recently as two paragraphs ago. Amid all the bombast, however, there is quite interesting result. As initially elucidated in a 2000 paper by Krauss and Starkman, the existence of dark energy places a hard thermodynamic Landauer-style limit on future computation. In short, in conditions of ever-accelerating cosmic expansion, you can’t flip bits.
Last week, however, a three-sigma result from the DESI survey, which is progressively building a colossal three-dimensional map of redshifted galaxies, suggests that the dark energy may be weakening with time. Structure on the nearby giga-parsec scale might be rushing away from itself at a slower pace than would occur in the presence of a strict lambda-CDM style cosmological constant.
And the consequence? The descendants of the B100s may continue to push the analogs of embeddings through the analogs of transformers for substantially longer than was believed possible. But stay tuned, the distant future is sure to undergo many new operating system releases.
