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“Appearances are a glimpse of the unseen”

A shower of comets rains down on Earth while violent volcanic eruptions billow up from below. Both events may follow our planet’s passage through dark matter concentrated in the Milky Way’s plane and help to trigger extinction events.

Are we on the verge of understanding the upheavals that have shaped the earth?

Do geologists dream of a final theory? Most people would say that plate tectonics already serves as geology’s overarching idea. The discovery of plate tectonics 50 years ago was one of the great scientific achievements of the 20th century, but is the theory complete? I think not. Plate tectonics describes Earth’s present geology in terms of the geometry and interactions of its surface plates. Geologists can extrapolate plate motions both back in time and into the future, but they cannot yet derive the behavior and history of plate tectonics from first principles.

Although scientists can interpret the history through the lens of what they see today, an important question remains: Why did geologic events — such as hot-spot volcanism, the breakup of continents, fluctuations in seafloor spreading, tectonic episodes, and sea-level oscillations — occur exactly when and where they did? Are they random, or do they follow some sort of a pattern in time or space?

A complete theory of Earth should explain geologic activity in the spatial domain, as plate tectonics does quite well for the present (once you incorporate hot spots), but also in the time and frequency domains. Recent findings suggest to me that geology may be on the threshold of a new theory that seeks to explain Earth’s geologic activity in time and space in the context of its astronomical surroundings.

The solar system oscillates with respect to the midplane of the disk-shaped Milky Way Galaxy with a period of about 60 million years. The Sun’s family passes through this plane twice each period, or once every 30 million years or so. The solar system behaves like a horse on a carousel — as we go around the disk-shaped galaxy, we bob up and down through the disk, passing through its densest part roughly every 30 million years.

Surely, it is too much of a coincidence that the cycle found in mass extinctions and impact craters should turn out to be one of the fundamental periods of our galaxy. The idea seemed almost too pretty to be wrong. But people searching for cycles have been fooled before, and we still had to answer the question: How does this cycle of movement lead to periodic perturbations of the Oort Cloud comets?

The idea of a roughly 30 million-year rhythm in geologic events has a long history in the geological literature. In the early 20th century, W.A. Grabau, an expert on sedimentary strata, proposed that tectonic activity and mountain building drove periodic fluctuations in sea level with an approximately 30 million-year cycle. In the 1920s, noted British geologist Arthur Holmes, armed with a few age determinations from radioactive decay, saw a similar 30 million-year cycle in Earth’s geologic activity…

If the cycles are real, what could be driving these long-term changes in volcanism, tectonics, sea level, and climate at such regular, if widely spaced, intervals? At first, I thought that the periodic energetic impacts might somehow be affecting deep-seated geological processes. I suggested in a short note in the journal Nature that large impacts might so deeply excavate and fracture the crust — to depths in excess of 10 miles (16 km) — that the sudden release of pressure in the upper mantle would result in large-scale melting. This would lead to the production of massive flood-basalt lavas, which would cover the crater and possibly create a mantle hot spot at the site of the impact. Hot spots could lead to continental breakup, which can cause increased tectonics and changes in ocean-floor spreading rates, and in turn cause global sea levels to fluctuate. Unfortunately, no known terrestrial impact structure has a clear association with volcanism, although some volcanic outpourings on Mars seem to be located along radial and concentric fractures related to large impacts.

The potential key to resolving this geological conundrum may come from outer space. Remember that Randall and Reece suggested that Earth passes through a thin disk of dark matter concentrated along the Milky Way’s midplane every 30 million years or so. Astrophysicist Lawrence Krauss and Nobel Prize-winning physicist Frank Wilczek of Harvard University, and independently Katherine Freese, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, proposed that Earth could capture dark matter particles that would accumulate in the planet’s core. The number of dark matter particles could grow large enough so that they would undergo mutual annihilation, producing prodigious amounts of heat in Earth’s interior.

A 1998 paper in the journal Astroparticle Physics (which I am sure few geologists ever read) provided a potential missing link. Indian astrophysicists Asfar Abbas and Samar Abbas (father and son, respectively) at Utkal University also were interested in dark matter and its interactions with our planet. They calculated the amount of energy released by the annihilation of dark matter captured by Earth during its passage through a dense clump of this material. They found that mutual destruction among the particles could produce an amount of heat 500 times greater than Earth’s normal heat flow, and much greater than the estimated power required in Earth’s core to generate the planet’s magnetic field. Putting together the predicted 30 million-year periodicity in encounters with dark matter with the effects of Earth capturing this unstable matter produces a plausible hypothesis for the origin of regular pulses of geologic activity.

Excess heat from the planet’s core can raise the temperature at the base of the mantle. Such a pulse of heat might create a mantle plume, a rising column of hot mantle rock with a broad head and narrow tail. When these rising plumes penetrate Earth’s crust, they create hot spots, initiate flood-basalt eruptions, and commonly lead to continental fracturing and the beginning of a new episode of seafloor spreading. The new source of periodic heating by dark matter in our planet’s interior could lead to periodic outbreaks of mantle-plume activity and changes in convection patterns in Earth’s core and mantle, which could affect global tectonics, volcanism, geomagnetic field reversals, and climate, such as our planet has experienced in the past.

These geologic events could lead to environmental changes that might be enough to cause extinction events on their own. A correlation of some extinctions with times of massive volcanic outpourings of lava supports this view. This new hypothesis links geologic events on Earth with the structure and dynamics of the Milky Way Galaxy.

It is still too early to tell if the ingredients of this hypothesis will withstand further examination and testing. Of course, correlations among geologic events can occur even if they are not part of a periodic pattern, and long-term geological cycles may exist apart from any external cosmic connections. The virtue of the galactic explanation for terrestrial periodicity lies in its universality — because all stars in the galaxy’s disk, many of which harbor planets, undergo a similar oscillation about the galactic midplane — and in its linkage of biological and geological evolution on Earth, and perhaps in other solar systems, to the great cycles of our galaxy.

Dark matter’s shadowy effect on Earth“: Earth’s periodic passage through the galaxy’s disk could initiate a series of events that ultimately lead to geological cataclysms and mass extinctions. From Michael Rapino (@mrr1_michael)

For very different angle on the evolution of the earth, the wonderful Walter Murch: “Why Birds Can Fly Over Mount Everest.”

* Anaxagoras

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As we dig deep, we might spare a thought for Harlow Shapley; he died on this date in 1972. An astronomer known as “the Modern Copernicus,” he did important work first at the Mt. Wilson Observatory, and then as head of the Harvard College Observatory. He boldly and correctly proclaimed that the globulars outline the Galaxy, and that the Galaxy is far larger than was generally believed and centered thousands of light years away in the direction of Sagittarius: he discovered the center of our Galaxy, and our position within it.

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“Your job as a scientist is to figure out how you’re fooling yourself”*…

Larger version here

And like scientists, so all of us…

Science has shown that we tend to make all sorts of mental mistakes, called “cognitive biases”, that can affect both our thinking and actions. These biases can lead to us extrapolating information from the wrong sources, seeking to confirm existing beliefs, or failing to remember events the way they actually happened!

To be sure, this is all part of being human—but such cognitive biases can also have a profound effect on our endeavors, investments, and life in general.

Humans have a tendency to think in particular ways that can lead to systematic deviations from making rational judgments.

These tendencies usually arise from:

• Information processing shortcuts

• The limited processing ability of the brain

• Emotional and moral motivations

• Distortions in storing and retrieving memories

• Social influence

Cognitive biases have been studied for decades by academics in the fields of cognitive science, social psychology, and behavioral economics, but they are especially relevant in today’s information-packed world. They influence the way we think and act, and such irrational mental shortcuts can lead to all kinds of problems in entrepreneurship, investing, or management.

Here are five examples of how these types of biases can affect people in the business world:

1. Familiarity Bias: An investor puts her money in “what she knows”, rather than seeking the obvious benefits from portfolio diversification. Just because a certain type of industry or security is familiar doesn’t make it the logical selection.

2. Self-Attribution Bias: An entrepreneur overly attributes his company’s success to himself, rather than other factors (team, luck, industry trends). When things go bad, he blames these external factors for derailing his progress.

3. Anchoring Bias: An employee in a salary negotiation is too dependent on the first number mentioned in the negotiations, rather than rationally examining a range of options.

4. Survivorship Bias: Entrepreneurship looks easy, because there are so many successful entrepreneurs out there. However, this is a cognitive bias: the successful entrepreneurs are the ones still around, while the millions who failed went and did other things.

5. Gambler’s Fallacy: A venture capitalist sees a portfolio company rise and rise in value after its IPO, far behind what he initially thought possible. Instead of holding on to a winner and rationally evaluating the possibility that appreciation could still continue, he dumps the stock to lock in the existing gains.

An aid to thinking about thinking: “Every Single Cognitive Bias in One Infographic.” From DesignHacks.co via Visual Capitalist.

And for a fascinating look of cognitive bias’ equally dangerous cousin, innumeracy, see here.

* Saul Perlmutter, astrophysicist, Nobel laureate

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As we cogitate, we might recall that it was on this date in 1859 that “The Carrington Event” began. Lasting two days, it was the largest solar storm on record: a large solar flare (a coronal mass ejection, or CME) that affected many of the (relatively few) electronics and telegraph lines on Earth.

A solar storm of this magnitude occurring today would cause widespread electrical disruptions, blackouts, and damage due to extended outages of the electrical grid. The solar storm of 2012 was of similar magnitude, but it passed Earth’s orbit without striking the planet, missing by nine days. See here for more detail on what such a storm might entail.

Sunspots of 1 September 1859, as sketched by R.C. Carrington. A and B mark the initial positions of an intensely bright event, which moved over the course of five minutes to C and D before disappearing.

“In the long run, we are all dead”*…

I’ve spent several decades thinking (and helping others think) abut the future: e.g., doing scenario planning via GBN and Heminge & Condell, working with The Institute for the Future, thinking with the folks at the Long Now Foundation; I deeply believe in the importance of long-term thinking. It’s a critical orientation– both a perspective and a set of tools/techniques– that can help us off-set our natural tendency to act in and for the short-run and help us be better, more responsible ancestors.

But two recent articles warn that “the long term” can be turned into a justification for all sorts of grief. The first, from Phil Torres (@xriskology), argues that “so-called rationalists” have created a disturbing secular religion– longtermism– that looks like it addresses humanity’s deepest problems, but actually justifies pursuing the social preferences of elites…

Longtermism should not be confused with “long-term thinking.” It goes way beyond the observation that our society is dangerously myopic, and that we should care about future generations no less than present ones. At the heart of this worldview, as delineated by [Oxford philosopher Nick] Bostrom, is the idea that what matters most is for “Earth-originating intelligent life” to fulfill its potential in the cosmos. What exactly is “our potential”? As I have noted elsewhere, it involves subjugating nature, maximizing economic productivity, replacing humanity with a superior “posthuman” species, colonizing the universe, and ultimately creating an unfathomably huge population of conscious beings living what Bostrom describes as “rich and happy lives” inside high-resolution computer simulations.

This is what “our potential” consists of, and it constitutes the ultimate aim toward which humanity as a whole, and each of us as individuals, are morally obligated to strive. An existential risk, then, is any event that would destroy this “vast and glorious” potential, as Toby Ord, a philosopher at the Future of Humanity Institute, writes in his 2020 book The Precipice, which draws heavily from earlier work in outlining the longtermist paradigm. (Note that Noam Chomsky just published a book also titled The Precipice.)

The point is that when one takes the cosmic view, it becomes clear that our civilization could persist for an incredibly long time and there could come to be an unfathomably large number of people in the future. Longtermists thus reason that the far future could contain way more value than exists today, or has existed so far in human history, which stretches back some 300,000 years. So, imagine a situation in which you could either lift 1 billion present people out of extreme poverty or benefit 0.00000000001 percent of the 1023 biological humans who Bostrom calculates could exist if we were to colonize our cosmic neighborhood, the Virgo Supercluster. Which option should you pick? For longtermists, the answer is obvious: you should pick the latter. Why? Well, just crunch the numbers: 0.00000000001 percent of 1023 people is 10 billion people, which is ten times greater than 1 billion people. This means that if you want to do the most good, you should focus on these far-future people rather than on helping those in extreme poverty today.

[For more on posthumanism, see here and here]

The Dangerous Ideas of ‘Longtermism’ and ‘Existential Risk’

The second, from Paul Graham Raven (@PaulGrahamRaven) builds on Torres’ case…

Phil Torres… does a pretty good job of setting out the issues with what might be the ultimate in moral philosophies, namely a moral philosophy whose adherents have convinced themselves that it is not at all a moral philosophy, but rather the end-game of the enlightenment-modernist quest for a fully rational and quantifiable way of legitimating the actions that you and your incredibly wealthy donors were already doing, and would like to continue doing indefinitely, regardless of the consequences to other lesser persons in the present and immediate future, thankyouverymuch.

I have one bone of contention, though the fault is not that of Torres but rather the Longtermists themselves: the labelling of their teleology as “posthuman”. This is exactly wrong, as their position is in fact the absolute core of transhumanism; my guess would be that the successful toxification of that latter term (within academia, as well as without) has led them to instead identify with the somewhat more accepted and established label of posthumanism, so as to avoid critique and/or use a totally different epistemology as a way of drawing fire…

[For more on transhumanism, see here and here]

Longtermism is merely a more acceptable mask for transhumanism

Both pieces are worth reading in full…

And for more on a posthuman (if not in every case posthumanist) future: “The best books about the post-human Earth.”

* John Maynard Keynes

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As we take the long view, we might send far-sighted birthday greetings to John Flamsteed; he was born on this date in 1646. An astronomer, he compiled a 3,000-star catalogue, Catalogus Britannicus, and a star atlas called Atlas Coelestis, and made the first recorded observations of Uranus (though he mistakenly catalogued it as a star). Flamsteed led the group of scientists who convinced King Charles II to build the Greenwich Observatory, and personally laid its foundation stone. And he served as the first Astronomer Royal.

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“I’m sure the universe is full of intelligent life. It’s just been too intelligent to come here.”*…

Email migration should now be complete; email subscribers should now be getting (Roughly) Daily via Mailchimp, and should not be getting a duplicate from Feedburner. If you are getting a dupe, please let me know (roughlydaily@gmail.com). Note that this new service may be landing in your Gmail “Promotions” folder; you can move it to your main folder. With apologies for the turbulence over the last few days, and thanks for your continued reading, on to today’s post…

A new computer simulation shows that a technologically advanced civilization, even when using slow ships, can still colonize an entire galaxy in a modest amount of time. The finding presents a possible model for interstellar migration and a sharpened sense of where we might find alien intelligence.

Space, we are told time and time again, is huge, and that’s why we have yet to see signs of extraterrestrial intelligence. For sure, the distances between stars are vast, but it’s important to remember that the universe is also very, very old. In fact, I’d go so far as to say that, in terms of extremes, the Milky Way galaxy is more ancient than it is huge, if that makes sense. It’s for this reason that I tend to dismiss distances as a significant variable when discussing the Fermi Paradox—the observation that we have yet to see any evidence for the existence of alien intelligence, even though we probably should have.

New research published in The American Astronomical Society is bolstering my conviction. The new paper, co-authored by Jason Wright, an astronomer and astrophysicist at Penn State, and Caleb Scharf, an astrobiologist at Columbia University, shows that even the most conservative estimates of civilizational expansion can still result in a galactic empire.

A simulation produced by the team shows the process at work, as a lone technological civilization, living in a hypothetical Milky Way-like galaxy, begins the process of galactic expansion… Things start off slow in the simulation, but the civilization’s rate of spread really picks up once the power of exponential growth kicks in. But that’s only part of the story; the expansion rate is heavily influenced by the increased density of stars near the galactic center and a patient policy, in which the settlers wait for the stars to come to them, a result of the galaxy spinning on its axis.

The whole process, in which the entire inner galaxy is settled, takes one billion years. That sounds like a long time, but it’s only somewhere between 7% and 9% the total age of the Milky Way galaxy.

As noted, the new model is constrained by some very conservative rules. Migration ships are launched once every 10,000 years, and no civilization can last longer than 100 million years. Ships can travel no farther than 10 light-years and at speeds no faster than 6.2 miles per second (10 kilometers per second), which is comparable to human probes like the Voyager and New Horizons spacecraft. 

“This means we’re not talking about a rapidly or aggressively expanding species, and there’s no warp drive or anything,” said Wright. “There’s just ships that do things we could actually manage to do with something like technology we can design today… Even under these conditions, the entire inner part of the simulated galaxy became settled in a billion years. But as Wright reminded me, our “galaxy is over 10 billion years old, so it could have happened many times over, even with those parameters.”…

A new simulation published by the American Astronomical Society suggests that aliens wouldn’t need warp drives to take over an entire galaxy in (relatively) short order, as George Dvorsky (@dvorsky) explains.

[Image above: Andromeda Galaxy, source]

* Arthur C. Clarke

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As we spread out, we might spare a thought for Jacobus Cornelius Kapteyn; he died on this date in 1922. An astronomer, he used photography and statistical methods to determine the motions and spatial distribution of stars (especially with the Milky Way), the first major step after the works of William and John Herschel. He introduced absolute magnitude and color indexing as standard concepts in cataloguing stars.

Kapteyn was also among the first to suggest the existence of dark matter (which he deduced from examining stellar velocities).

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“Happy accidents are real gifts”*…

Fresco by Bertini, “Galileo and the Doge of Venice”

On the morning of July 25, 1610, Galileo pointed his telescope at Saturn and was surprised to find that it appeared to be flanked by two round blobs or bumps, one on either side. Unfortunately, Galileo’s telescope wasn’t quite advanced enough to pick out precisely what he had seen (his observations are now credited with being the earliest description of Saturn’s rings in astronomical history), but he nevertheless presumed that whatever he had seen was something special. And he wanted people to know about it.

Keen to announce his news and thereby secure credit for whatever it was he had discovered, Galileo sent letters to his friends and fellow astronomers. This being Galileo, the announcement was far from straightforward:

SMAISMRMILMEPOETALEUMIBUNENUGTTAUIRAS

Each message that Galileo sent out contained little more than that jumbled string of letters, which when rearranged correctly spelled out the Latin sentence, “altissimum planetam tergeminum observavi”—or “I have observed that the highest planet is threefold.”

As the outermost planet known to science at the time, Saturn was the “highest planet” in question. And unaware that he had discovered its rings, Galileo was merely suggesting to his contemporaries that he had found that the planet was somehow divided into three parts. Announcing such a discovery in the form of an anagram might have bought Galileo some time to continue his observations, however, but there was a problem: Anagrams can easily be misinterpreted.

One of those to whom Galileo sent a letter was the German scientist Johannes Kepler. A keen astronomer himself, Kepler had followed and supported Galileo’s work for several years, so when the coded letter arrived at his home in Prague he quickly set to work solving it. Unfortunately for him, he got it completely wrong.

Kepler rearranged Galileo’s word jumble as “salve, umbistineum geminatum Martia proles,” which he interpreted as “be greeted, double-knob, children of Mars.” His solution was far from perfect (umbistineum isn’t really a grammatical Latin word, for one thing), but Kepler was nevertheless convinced that, not only had he correctly solved the riddle, but Galileo’s apparent discovery proved a theory he had been contemplating for several months.

Earlier in 1610, Galileo had discovered the four so-called “Galilean moons” of Jupiter: Io, Europa, Ganymede and Callisto. Although we now know that Jupiter has several dozen moons of varying shapes, sizes, and orbits, at the time the announcement of just four natural satellites had led Kepler to presume that there must be a natural progression in the heavens: the Earth has one moon; Jupiter, two places further out from the Earth, has four; and sat between the two is Mars, which Kepler theorized must surely have two moons, to maintain the balanced celestial sequence 1, 2, 4 and so on (his only question was whether Saturn had six or eight).

Kepler got the anagram wrong, and the presumption that Jupiter only had four moons had been wrong. Yet as misguided as both these facts were, the assumption that Kepler made based on both of them—namely, that Mars had two moons—was entirely correct. Unfortunately for Kepler, his theory would not be proved until long after his death, as the two Martian moons Phobos and Deimos (named after Ares’s sons in Greek Mythology) were not discovered until 1877, by the American astronomer Asaph Hall.

Nevertheless, a misinterpretation of the anagram had accidentally predicted a major astronomical discovery of the 19th century, nearly 300 years before it occurred…

Serendipity in science: “How A Misinterpreted Anagram Predicted The Moons of Mars.”

(For an account of Isaac Newton’s use of anagrams in his scientific communications, see here.)

* David Lynch

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As we code and decode, we might recall that it was on this date in 1781 that English astronomer William Herschel detected every schoolboy’s favorite planet, Uranus, in the night sky (though he initially thought it was a comet); it was the first planet to be classified as such with the aid of a telescope.  In fact, Uranus had been detected much earlier– but mistaken for a star: the earliest likely observation was by Hipparchos, who (in 128 BC) seems to have recorded the planet as a star for his star catalogue, later incorporated into Ptolemy’s Almagest.  The earliest definite sighting was in 1690 when John Flamsteed observed it at least six times, cataloguing it as the star 34 Tauri.

Herschel named the planet in honor of his King: Georgium Sidus (George’s Star), an unpopular choice, especially outside England; argument over alternatives ensued.  Berlin astronomer Johann Elert Bode came up with the moniker “Uranus,” which was adopted throughout the world’s astronomical community by 1850.

 Uranus, photographed by Voyager 2 in 1986.

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Written by (Roughly) Daily

March 13, 2021 at 1:01 am

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