The Birth of the Universe

Part Of: Demystifying Physics sequence
Content Summary: 1200 words, 12 min reading time.

Our lifespan is 80 years. Our consciousness refreshes every 300 milliseconds. Timespans beyond these, human brains are not well-equipped to conceive. Nevertheless, to learn the origin story of the universe, we must stare into the abyss of deep time.

Where do we come from?   

Poets, philosophers and theologians have explored this question for millennia, in part seeking to ascribe meaning to the cosmos. Only recently have we discovered a literal answer, which constrains and complements our narratives.

Here are the facts.

Particle Physics

The universe is built from fermions and bosons.

Fermions are the bedrock of matter, the “meat” in our particle soup. They come in two flavors: quarks and leptons. You’ve heard of antimatter, yes? This term refers to antiquarks and antileptons.

In contrast, bosons are force carriers; the “broth” of the soup. They mediate the four fundamental forces: gravity, the strong force (which holds atoms together), the weak force (radioactivity), and electromagnetism (literally everything else).

Here are the most significant species of particles:

Deep Time- Particle Physics (1)

Protons & neutrons are not elementary particles. They are coalitions! Gluons combine quarks into groups called hadrons. When hadrons contain three quarks, they are called baryons

Deep Time- Hadrons (2)

Hydrogen is one electron orbiting one proton; that is, one lepton orbiting three quarks!

The Primordial Era

13.8 billion years ago, the Big Bang happened. At that moment, a gravitational singularity (the primeval atom) exploded, and became the basis of all matter, energy, space and time.

  • What happened before the Big Bang? This question is incoherent: it reduces to “what happened before time existed”?
  • What happened after the Big Bang? To answer this, let us divide time into eight segments.

1. Planck Epoch (0 → 10-43 sec). The climate of this period of history is so intense, known laws of physics break down. We suspect that gravity merges with the other forces, but we do not yet possess a theory of quantum gravity. Only with such a Theory of Everything can we hope to better understand what caused the Big Bang.

2. Grand Unification Epoch (10-43 → 10-36 sec). Science recovers its ability to describe nature during this epoch. The Strong, Weak, and Electromagnetic Forces exist as a single entity: the electronuclear force. The universe is expanding, but it is still a small, hot ball of plasma. Physical characteristics like mass, charge, etc are completely meaningless.

3. Inflationary Epoch (10-36 → 10-32 sec). Next, the mysterious phenomenon of cosmic inflation obtained. The fabric of spacetime explodes at a rate that far, far exceeds the speed of light. The volume of the universe expands at least seventy-eight orders of magnitude (1078 times bigger).

Few people realize the implications of such an overpowered process. Have you heard the phrase observable universe? Buried within this phrase is the implication of unobservable universes. You don’t need to wander into QM interpretations to encounter Many Worlds. We already know that there are myriad universes that we can never access: inflation simply pushed them beyond any distance our radio signals could traverse.

Deep TIme- Observable Universe (1)


4. Electroweak Epoch (10-32 → 10-12 sec). At the end of this epoch, the universe has cooled enough for the Strong force to dissociate from the Electroweak force. Quarks, antiquarks, and gluons dominate the cosmos.

5. Quark Epoch (10-12 → 10-6 sec). Despite the newly independent Strong force, quarks are unable to combine. Ambient temperature is too hot, preventing nuclear fusion.

6, 7. Hadron Epoch, and Lepton Epoch (10-6 → 10 sec) . Things have finally cooled enough for quarks and antiquarks to combine! The universe fills with hadrons (e.g., protons) and anti-hadrons (e.g., anti-protons).

In this era, matter slightly outnumbered antimatter, for reasons we don’t yet understand.

Deep Time- Matter Asymmetry

Antimatter was suppressed during these epochs. At the end of the Hadron Epoch, most hadrons and anti-hadrons experience annihilation reactions. The few survivors were matter: this is baryogenesis (baryons are a species of hadron).

In the subsequent Lepton Epoch, leptons and anti-leptons (e.g., electrons and anti-electrons) also annihilate one another en masse. Antimatter was again underrepresented in the survivors: this is leptogenesis.

8. Photon Epoch (10 sec → 380,000 years). 10 seconds after the big bang, and photons dominate the universe. Protons and electrons (hadrons and leptons) exist, but are unable to come together due to high temperatures. The free electrons scatter light: photon travel is randomized by collisions with free electrons, in a process known as Compton scattering.

As the fabric of spacetime continues to expand, two other things happen:

  • Recombination: Temperatures drop to a point where electrons and protons could come together to form hydrogen atoms!
  • Rise of the Fermions: The expansion of space stretches photon wavelength, decreasing its total energy content.  Fermions, whose populations had been decimated in the destruction of antimatter (c.f. baryogenesis and leptogenesis), reclaim the title as the most energetic substance in the universe.

The eventual result was photon decoupling. Temperature finally permits light could travel freely. The universe becomes transparent.

You’ve probably heard that it takes light from the Sun eight minutes to reach Earth. If the Sun suddenly disappeared, we would only learn that fact eight minutes later. Similarly, if a star 40,000 light-years away suddenly explodes in a supernova, we must wait until 42,016 AD to learn about that. Starlight is a form of time-travel. 

What are the oldest photons we can see? How far back into our past can we peer?

Well, we can see galaxies being formed 200 million years after the Big Bang. And we can peer back farther still. We can directly see light emitted the moment the universe became transparent; this is the Cosmic Microwave Background (CMB).

Why is the CMB not smooth? The ripples are microscopic phenomena writ large: inflation exploded quantum fluctuations on a cosmic scale…

Deep Time- Cosmic Background Radiation (1)

Some of the static in TV antenna is caused by the CMB. You can literally see evidence of the Big Bang with your own eyes. 

Structure Formation

Photon decoupling has ensured that light can travel freely in a sea of hydrogen. However, there were no stars at this point: the CMB is the only light source. This is the Dark Age of the universe, a time before stars.  

Deep Time- Cosmogenesis Timeline (1)

Why is so much of space a vacuum?

In the Inflationary Epoch, inflation etched ripples into the energy distribution of the cosmos. Gravity accentuates this heterogeneity by pulling matter together. Space is mostly empty because particles like to spend time together. 

Gravity appears to operate at three different spatial frequencies.

  1. Very large clumps of hydrogen become superclusters.
  2. Within every supercluster, there are billions of smaller clumps called galaxies.
  3. Galaxies in turn comprise billions of smaller assemblies: stars and solar systems

The origin of all things is the hydrogen cloud, and gravitational attraction.  

Takeaways

  • There are two kinds of particles in the universe: fermions (“matter particles”) and bosons (“force particles”)
  • The Big Bang happened 13.8 billion years ago. The early universe was hot, and expanded quickly.
  • Three important events in occur in the first second of the universe
    • Cosmic Inflation: the fabric of the universe stretched much faster than the speed of light, creating unobservable universes.
    • Force Differentiation: the four forces (gravity, strong, weak, electromagnetic) separated from one another
    • Fermion Asymmetry: antimatter was preferentially annihilated
Deep Time- Primordial Era (4)
  • Afterwards, the universe was replete with clouds of hydrogen. Gravity pulled these together to form stars, galaxies, and superclusters.

An Introduction To Natural Selection

Part OfDemystifying Life sequence
Followup To: Population Genetics
Content Summary: 1400 words, 14 min read

How Natural Selection Works

Consider the following process:

  1. Organisms pass along traits to their offspring.
  2. Organisms vary. These random but small variations trickle through the generations.
  3. Occasionally, the offspring of some individual will vary in a way that gives them an advantage.
  4. On average, such individuals will survive and reproduce more successfully.

This is how favorable variations come to accumulate in populations.

Let’s plug in a concrete example. Consider a population of grizzly bears that has recently migrated to the Arctic.

  1. Occasionally, the offspring of some grizzly bear will have a fur color mutation that renders their fur white.
  2. This descendent will on average survive and reproduce more successfully.

Over time, we would expect increasing numbers of such bears to possess white fur.

Biological Fitness Is Height

The above process is straightforward enough, but it lacks a rigorous mathematical basis. In the 1940s, the Modern Evolutionary Synthesis enriched natural selection by connecting it to population genetics, and its metaphor of Gene-Space. Recall what we mean by such a landscape:

  • A Genotype Is A Location.
  • Organisms Are Unmoving Points
  • Birth Is Point Creation, Death Is Point Erasure
  • Genome Differences Are Distances

Onto this topography, we identified the following features:

  • A Species Is A Cluster Of Points
  • Species Are Vehicles
  • Genetic Drift is Random Travel.

In order to understand how natural selection enriches this metaphor, we must define “advantage”. Let biological fitness refer to how how many fertile offspring an individual organism leaves behind. An elephant with eight grandchildren is more fit than her neighbor with two grandchildren.

Every organism achieves one particular level of biological fitness. Fitness denotes how well-suited an organism is to its environment. Being a measure of organism-environment harmony, we can view fitness as defined for every genotype. Since we can define some number for every point in gene-space, we have license to introduce the following identification:

  • Biological Fitness Is Height

Here is one possible fitness landscape (image credit Bjørn Østman).

Natural Selection- Fitness Landscape (1)

We can imagine millions of alien worlds, each with its own fitness landscape. What is the contours of Earth’s?

Let me gesture at three facts of our fitness landscape, to be elaborated next time:

  • The total volume of fitness is constrained by the sun. This is hinted at by the ecological notion of carrying capacity.
  • Fitness volume can be forcibly taken from one area of the landscape to another. This is the meaning of predation.
  • Since most mutations are harmless, the landscape is flat in most directions. Most non-neutral mutations are negative, but some are positive (example).

Natural Selection As Mountain Climbing

A species is a cluster of points. Biological fitness is height. What happens when a species resides on a slope?

The organisms uphill will produce comparatively more copies of themselves than those downhill. Child points that would have been evenly distributed now move preferentially uphill. Child points continue appearing more frequently uphill. This is locomotion: a slithering, amoeba-like process of genotype improvement.

NaturalSelection_Illustration

We have thus arrived at a new identification:

  • Natural Selection Is Uphill Locomotion

As you can see, natural selection explains how species gradually become better suited to their environment. It is a non-random process: genetic movement is in a single direction.

Consider: ancestral species of the camel family originated in the American Southwest millions of years ago, where they evolved a number of adaptations to wind-blown deserts and other unfavorable environments, including a  long neck and long legs. Numerous other special designs emerged in the course of time: double rows of protective eyelashes, hairy ear openings, the ability to close the nostrils, a keen sense of sight and smell, humps for storing fat, a protective coat of long and coarse hair (different from the soft undercoat known as “camel hair”), and remarkable abilities to take in water (up to 100 liters at a time) and do without it (up to 17 days).

Moles, on the other hand, evolved for burrowing in the earth in search of earthworms and other food sources inaccessible to most animals. A number of specialized adaptations evolved, but often in directions opposite to those of the camel: round bodies, short legs, a flat pointed head, broad claws on the forefeet for digging. In addition, most moles are blind and hard of hearing.

The mechanism behind these adaptations is selection, because each results in an increase in fitness, with one exception. Loss of sight and hearing in moles is not an example of natural selection, but of genetic drift: blindness wouldn’t confer any advantages underground, but arguably neither would eyesight.

Microbiologists in my audience might recognize a strong analogy with bacterial locomotion. Most bacteria have two modes of movement: directed movement (chemotaxis) when its chemical sensors detect food, and a random walk when no such signal is present. This corresponds with natural selection and genetic drift, respectively.

Consequences Of Optimization Algorithms

Computer scientists in my audience might note a strong analogy to gradient descent, a kind of algorithm. In fact, there is a precise sense in which natural selection is an optimization algorithm. In fact, computer scientists have used this insight to design powerful evolutionary algorithms that spawn not one program, but thousands of programs, rewarding those with a comparative advantage. Evolutionary algorithms have proven an extremely fertile discipline in problem spaces with high dimensionality. Consider, for example, recent advances in evolvable hardware:

As predicted, the principle of natural selection could successfully produce specialized circuits using a fraction of the resources a human would have required. And no one had the foggiest notion how it worked. Dr. Thompson peered inside his perfect offspring to gain insight into its methods, but what he found inside was baffling. The plucky chip was utilizing only thirty-seven of its one hundred logic gates, and most of them were arranged in a curious collection of feedback loops. Five individual logic cells were functionally disconnected from the rest— with no pathways that would allow them to influence the output— yet when the researcher disabled any one of them the chip lost its ability to discriminate the tones…

It seems that evolution had not merely selected the best code for the task, it had also advocated those programs which took advantage of the electromagnetic quirks of that specific microchip environment. The five separate logic cells were clearly crucial to the chip’s operation, but they were interacting with the main circuitry through some unorthodox method— most likely via the subtle magnetic fields that are created when electrons flow through circuitry, an effect known as magnetic flux. There was also evidence that the circuit was not relying solely on the transistors’ absolute ON and OFF positions like a typical chip; it was capitalizing upon analogue shades of gray along with the digital black and white.

In gradient descent, there is a distinction between global optima and local optima. Despite the existence of an objectively superior solution, the algorithm cannot get there due to its fixation with local ascent.

Natural Selection- Local vs. Global Optima

This distinction also features strongly in nature. Consider again our example of camels and moles:

Given such a stunning variety of specialized differences between the camel and the mole, it is curious that the structure of their necks remains basically the same. Surely the camel could do with more vertebrae and flex in foraging through the coarse and thorny plants that compose its standard fare, whereas moles could just as surely do with fewer vertebrae and less flex. What is almost as sure, however, is that there is substantial cost in restructuring the neck’s nerve network to conform to a greater or fewer number of vertebrae, particularly in rerouting spinal nerves which innervate different aspects of the body.

Here we see natural selection as a “tinkerer”; unable to completely throw away old solutions, but instead perpetually laboring to improve its current designs.

Takeaways

  • In the landscape of all possible genomes, we can encode comparative advantages as differences in height.
  • Well-adapted organisms are better at replicating their genes (in other words, none of your ancestors were childless).
  • Viewed in the lens of population genetics, natural selection becomes a kind of uphill locomotion.
  • When view computationally, natural selection reveals itself to be an optimization algorithm.
  • Natural solution can outmatch human intelligence, but it is also a “tinkerer”; unable to start from scratch.

An Introduction To Population Genetics

Part Of: Demystifying Life sequence
Content Summary: 1200 words, 12 min read

Central Thesis Of Molecular Biology

In every cell of your body, there exist molecules called deoxyribonucleic acid. Such cells come in four flavors and (due to their atomic shape) tend to pair up and create long strings. These strings become very long, over two inches when held end-to-end (but of course, they fold up dramatically so each can comfortably inhabit a single cell). Since your cells have about 46 inches worth (six billion molecules), each cell contains twenty-three unique strings. They look like this:

Natural Selection- Chromosomes

Let us refer to these strings as chromosomes, and to all of them collectively as the human genome. Finally, since typing “deoxyribonucleic acid” is fairly onerous, we will use the acronym DNA.

In 1956, Francis Crick presented his Central Thesis Of Molecular Biology, which describes how the causal chain DNA → RNA → amino acids → protein ultimately motivates every trait of every living organism.  A gene is a sequence of DNA that encodes a protein. A genotype (some animal’s unique DNA) explains phenotype (that animal’s unique traits).  Genotype-phenotype maps (GP-maps) turn out to be very important in what follows.

Duplication vs. Mutation

Every time a cell duplicates itself (mitosis), its DNA is copied into the new cell. If every cell contains exactly the same code, how can they be different? The basic explanation of cellular differentiation involves feedback loops in the genetic causal chain (collectively named the Gene Regulatory Network). When a lung cell is duplicated, for example, it inherits not just the entire genome, but also proteins for activating lung genes and deactivating other code.

Germ cells are created by a different process entirely. Instead of genome duplication (mitosis), germ cells inherit what is essentially half a genome, in a process known as meiosis. Here’s how these two processes work:

Natural Selection- Mitosis vs. Meiosis

Recall that deoxyribonucleic acid is a collection of atoms. Replicating such a fragile object is imperfect. There are many kinds of ways the process can go wrong; for example:

  1. Replacement Mutation (e.g., AGTC → AATC)
  2. Duplication Mutation (e.g., AGTC → AGGTC)
  3. Insertion Mutation (e.g., AGTC → AGATC)

How many mutations do you have? While you can always get your DNA sequenced to find out, the answer for most people is about sixty.

The Landscape Of Gene-Space

Consider all animals whose genome is three molecules long. How many genetically unique kinds of these animals are there?  Recall there are four kinds of DNA: cytosine (C), guanine (G), adenine (A), or thymine (T). We can use the following formula:

|Permutations| = |Possibilities|^{|Slots|}

Here we have 3^4 = 81 possible genotypes in this particular gene-space. To visualize this, imagine a 4-sided Rubik’s Cube: each dimension is a slot, each cube a particular genotype in the space.

But humans have approximately three billion base pairs; the size of a realistic gene-space is almost incomprehensibly large (4^3,000,000,000), far exceeding the number of atoms in the universe. Reasoning about 3D cubes is easy, reasoning about 3,000,000,000-D hypercubes is a bit harder. So we employ dimension reduction to aid comprehension. If you laid all 4^3,000,000,000 numbers out on a two dimensional matrix, each cell would be so tiny that the surface would appear continuous. We have arrived at our first metaphor identification:

  • A Genotype Is A Location

We can summarize our discussion of mitosis, meiosis, and mutation as follows:

  • An Organism Is A Stationary Point
  • Birth Is Point Creation, Death Is Point Erasure.

Finally, let us explore the concept of genetic distance. From our toy gene-space, let me take seven nodes and draw lines indicating valid replacement mutations between them.

Population Genetics- Visualizing Genetic Distance

The key observation is that distances vary. Many nodes are connected via one mutation, but the minimum distance from top (ATG) to bottom (CCC) is three mutations. In other words:

  • Varying Genome Differences Are Varying Distances

Our gene-space landscape, then, looks something like this:

Population Genetics- Gene Landscape (1)

Species Are Clusters

What is a species? After all, there is no encoding of the word “jaguar” in the jaguar genome. Rather, members of a species share more genetic similarities to one another than other organisms. In terms of our metaphor:

  • A Species Is A Cluster Of Points

In the above landscape, we might have two species. But there are many ways to cluster data. Consider these competing definitions:

Population Genetics- Species Granularity (1)

Which clustering approach is correct? It depends on the scale of our axes:

  • If we chose Granular but are too “zoomed in”, we have accidentally defined four new species of Shih Tzu.
  • If we chose Course but are too “zoomed out”, we have accidentally defined Mammal as its own species.

The point is that scale matters, and we should define species on a scale that makes good biological sense. The most popular scale is that defined by successful interbreeding (i.e., produce fertile offspring). For greater distances (large genetic dissimilarity), such interbreeding is impossible. We therefore constrain the size of our specie clusters by maximum interbreeding distance.

The approach just outlined is the one in use today. However, any man-made criteria for categorizing reality has its stretch points. For example, consider ring species.

Population Genetics- Ring Species (2)

Consider the Larus gulls’ populations in the above image. These gulls habitats form a ring around the North Pole, not normally crossed by individual gulls. The European herring gull {6} can hybridize with the American herring gull {5}, which can hybridize with the East Siberian herring gull {4} which can hybridize with Heuglin’s gull {3}, which can hybridize with the Siberian lesser black-backed gull {2}, which can hybridize with the lesser black-backed gulls {1}. However, the lesser black-backed gulls {1} and herring gulls {6} are sufficiently different that they do not normally hybridize.

Genetic Drift Is Random Travel

Landscapes without movement aren’t very interesting. With our brand-new concept as Species As Clusters, let’s see if we can make sense of travel.

Consider the phenomenon of population bottleneck. Many factors may contribute to population reduction (e.g., novel predators). Often, the survivors are just lucky. Descendants of the survivors tend to be more similar to them than the average genome of the original species. By this process, bottlenecks induces change in the species as a whole:
Population Genetics- Genetic Drift (1)

Why wouldn’t such movement cancel itself out in the long run? The reason why resides in the size of gene-space. For our genome is length two, mutations cancelling each other out would be a fairly common occurence. Would cancelling out increase or decrease on a genome of length 1,000? Surely less. How much less (a forteriori!)  the case for genomes with three billion molecules. By the extreme dimensionality of gene-space, then, we are witness to non-cancellative genetic movement!

  • Genetic Drift Is (Random) Travel.

Importantly, it is not the individuals that travel (modify their genomes), but the species as a whole.

  • Species Are Vehicles.

Viewing the species itself as actor, rather than the individual, is an important paradigm shift of population genetics.

Takeaways

In this post, I introduced the following metaphor:

  • A Genotype Is A Location.
  • Organisms Are Unmoving Points
  • Birth Is Point Creation, Death Is Point Erasure
  • Genome Differences Are Distances

We then strengthened our metaphor with the following considerations:

  • A Species Is A Cluster Of Points
  • Species Are Vehicles
  • Genetic Drift is (Random) Travel.

We are left with the image of specie vehicles clumsily moving around gene-space. But genetic drift is not the only mechanism by which species navigate gene-space. In our next post, we explore a more sophisticated property of living things.

Evans-Pritchard: Witchcraft, Oracles & Magic Among The Azande Summary

Part Of: Witchcraft, Oracles & Magic Among The Azande sequence
Content Summary: 1600 words, 16 min read

Chapter 1: Witchcraft is an organic and hereditary phenomenon

Witchcraft is discovered by means of oracles.  Both oracles and stories of witches obey certain hierarchical expectations.  Witchcraft is not strange, but an expected part of everyday life.  Azande believe it to physically manifest through the the small intestine.  In accord with their sexual beliefs, being-a-witch promulgates along relatives of the same sex.  Witchcraft powers grow with the small intestine, and so children are generally considered harmless.  As a strategy, accusing social superiors of witchcraft often backfires. Distance is seen as proportional to susceptibility to witchcraft. By these mechanisms, witchcraft accusations are local affairs that do not often cross social boundaries of class, sex, and age.

Chapter 2: The notion of witchcraft explains unfortunate events

Witchcraft is primarily invoked for social phenomena that are deemed significant and/or slow-moving.  Witchcraft complements, rather than dominates, the causal beliefs of the Azande.  If a man is killed by spear throw in battle, the explanatory criteria (social, involves death) point towards witchcraft.  But the Azande do not deny that the spear killed the man; rather, they say that the witchcraft and the spear in tandem caused the tragedy.  They draw parallels to their hunting experience where a man first spears an animal, and his compatriot delivers the fatal second blow – witchcraft is often denoted as “the second spear”.  In this way, the Azande infuse a narrative into socially significant events.

Chapter 3: Sufferers from misfortune seek for witches among their enemies

Witchcraft is most often invoked for slow-developing illness.   The victim’s kinsmen will appeal to an oracle, bringing forward names of social equals typically suspected of the jealousy motive. If the oracle indicates the witchcraft-inspired responsibility of one or more of these, a messenger will be sent to politely request cessation of psychic violence.  The accused will deny the charges while maintaining goodwill towards the victim.  Should the victim recover, life proceeds; else the cycle continues.  If the victim should die, the kinsmen can resort to compensation demands or vengeance magic.  Since this process is considered private, little is known about individual cases other than by the kinsmen, oracle, and political authorities.  Witchcraft, not theism, is the fuel of Azande morality: witches are generally accused as a function of their adherence to social norms.

Chapter 4: Are witches conscious agents?

Azande asserts intentionality and scheming to participants of witchcraft.  However, for Europeans, witchcraft was an omnipresent, metaphysical reality; for the Azande, witchcraft only manifested for personal misfortunes.  As such, accused Azande could not deny the oracle’s decision, but typically denied intentionality of their purported actions.  Contrary to many accused European witches, Azande were willing to live with this inconsistency, modelling themselves as exceptional cases.

Chapter 5: Witch-doctors

Witch-doctors practice magic to provide leechcraft, revelatory information, and witchcraft protection.  Their modus operandi is the seance, which serves as a rare opportunity for the community to participate in an extra-familial social situation.  Seances are typically hosted by someone affected by misfortune desiring the services of the witch-doctor.  At least one practitioner performs for the commoners in attendance; to drums and song he wildly dances, so as to acquire answers to questions.

Chapter 6: Training of a novice in the art of a witch-doctor

Trade information obtained through sole informant, although it is typically well-protected.  Witch-doctors generally charge prospective students fees for ritual participation and medicinal information.  Trade knowledge of medicines and their correlated plants are shared by journeys into nature.

Chapter 7: The place of witch-doctors in Zande society

This particular profession is not considered politically important; only commoners adopt its methods.  The associated magic and revealed wisdom are not held to be as important as the poison oracle, or even the termite oracle; rather, it is held roughly as authoritative as the lowest of the oracles: the rubbing-board oracle.  Witch-doctors apart from the seance are treated as any other commoner.  Intelligent commoners may pursue the craft in order to explore more diverse social roles.  Skepticism on the efficacy of witch-doctors is prevalent, and possibly increasing on account of contemporaneous developments (influx of more practitioners more readily revealing a greed-motive).  However, observer suspicions of trickery are couched in context of the Azande metaphysic: witch-doctor spells do not work but they secretly coordinate efforts with witches.  Even witch-doctors themselves may believe in the authenticity of their colleagues; and their secret understanding of the efficacy of their medicines does not conflict with their beliefs.  Azande cannot readily explore pure skepticism as they know no other explanatory worldview than the witch-oracle-magic paradigm.

Chapter 8: The Poison Oracle in daily life

Oracle poison is socially valuable, and its potency must be preserved.  Poison is protected via observance of taboos, hiding it from malevolent witches and women, and from the sun.  Use of the poison oracle represents a function of social control: women are formally prohibited from its use, or even knowing its relevance, and the poor cannot often afford to spare fowls during the ceremony.  The seance is performed away from the village, and the constituents are the operator, the questioner, the witnesses, the poison, and the fowls.  First, the operator administers the poison to the fowl (proportionate to its size).  Then, the questioner formally addresses the poison inside the fowl, its lethality is thus hinged on the answer to a certain pressing question.  No mechanism of the operator to manipulate the resultant verdict is known.  Verdicts are not considered binding until their opposite verdict is confirmed (oracle must kill for confirmation of the affirmative, and then spare for dis-confirmation of the negative); however, questioners are known to delay secondary verdicts according to their interests.

Chapter 9: Problems arising from consultation of the poison oracle

All Azande oracles are addressed as people, even though they are not personified.  Rather, their efficacy is attributed to their spiritual dynamism, or soul.  Further, Azande exhibit contradictory behavior and beliefs when it comes to benge poison.  Azande are careful not to eat fowls killed through the poison-test of the seance.  However, no one can express the reasons behind this behavior – for an Azande, benge only functions as poison when in a magical context.  Further, given that the poison acts randomly, often the confirmatory answer will contradict the initial answer.  However, the Azande utilize no less than eight explanatory vehicles to justify these contradictions, the result of which paradoxically results in a stronger affirmation of poison oracle efficacy.  Contradictions are further dismissed via a combination of language barriers, disinterest, and the promotion of ambiguous expectations.  Doubt is not repressed but is always couched in the context of the mystical paradigm.

Chapter 10: Other Zande oracles

Azande use other, less expensive and reliable, oracles for preliminary or less significant matters.  The termites oracle is operated by sticking two different sticks into a termite mound and assigning different answers to the consumption of either stick.  The rubbing-board oracle is imbued with medicine and had the detachable rim circumvents the table, with smooth motions and getting stuck being associated with different outcomes.  The three sticks oracle is arranged as a tent on the hut floor, and its status overnight (collapsed or not) is indicative of its message.  Finally, dreams are sometimes imbued with oracle-like significance.

Chapter 11: Magic and medicines

Magic is the third component of the Azande belief-triangle.  Its use through various medicines can either be socially accepted (positive magic) or condemned (sorcery).  Use of magic is used towards a large set of social goals, through a diversity of plants.  Magic is generally private and rarely practiced.  Magic is moral.  Good magic is impersonal: it will affect unknown individuals whose guilt is assured.  Bad magic is personal: it is used against a particular person in malice.  Sorcery in its full sense probably is not practiced, and only exists in rumors.  Light afflictions are treated empirically, only significant ailments are cause for magical remedies.  Magic is not thought to positively affect everyday life, but only to ward off negative mystical effects.

Chapter 12: An association for the practice of magic

New communal, illegal magic gatherings have become eminent due to current (circa 1920s) political events.  They represent wide and deep social change.  These Mani exhibit crude evidences of associative groups: organization, leadership, grades, feeds, initiation rites, and esoteric vocabulary.  Water immersion contributes to initiation rites, as does other behavior reminiscent of freshman hazing.  Four officials lead the group: the leader, cook, stirrer, and sentry.  None have much authority.  Meetings are highly emotional, in stark contrast with more public ceremonies.  Mani allow for female members, youth, poor (fees are minimal), and royalty (although, significantly, their authority is moot).  Nobility dislikes these groups on grounds of sorcery suspicion, marital jealousy, and general conservatism.  The organizations are grassroots, and lack inter-group cohesion.

Chapter 13: Witchcraft, oracles, and magic, in the situation of death

Azande belief structures are ill-defined and are only partially expressed in any given situation.  Their beliefs reach an cohesion and the height of synthesis in situations of death.  During later stages of illness, witchcraft is identified and addressed and both magic and leechcraft are invoked.  Should these efforts be unsuccessful, vengeance magic is prepared.  Vengeance practitioners are generally young men who will not suffer sex and food taboos as forcefully as others, although all kinsmen are affected.  Vengeance magic requires significant patience, and after enough time has past, kinsmen will oracle-inquire whether a socially-relevant death is the result of their magic.  Reactionary outburst are thus channeled through magical recourse, and are thereby tempered through uncomfortable, extended taboo-observances and wait-times that scale to years.

See Also: Quotes from The Azande Book