What is fire?

No definition is perfectly concise. We associate words with images and pretend that we all agree on their meaning, but we are occasionally reminded that we don’t always agree. I remember, as a child, being surprised to hear that school buses are yellow, having been of the opinion that school buses are orange.

“Fire” is a particularly difficult word to corner. It is generally associated with the chemical process of rapid combustion, a chain reaction of oxidation reactions in a gas. This “fire” occurs in hearths, automobile engines, forests, and volcanoes.

I think we can safely agree that all such rapid oxidation events can be called “fire,” but one other phenomenon is very fire-like, though it has nothing to do with oxidation. It is the fire that we see burning on the sun. It is sometimes called stellar fire, stellar combustion, or astrophysical combustion. I’ve heard educated people say “the sun isn’t really a fire,” because they identify the word with chemical combustion, but the word is much older than combustion theory, which was first presented in 1777, a year after the American Declaration of Independence.

What is combustion? According to modern chemistry, it’s an electron transfer, but it’s called “combustion” because of its macroscopic character as an exothermic chain reaction. The word was not chosen because of any association with electron transfer, but because of its association with the phenomenon we have called fire since the Greeks called it “pyr”. The Latin root of combustion is a word that means “burning.”

What about fire leads us to call it fire? What are its characteristics—its phenomenology?

To understand the phenomenology of combustion, it helps to bear in mind that flames only occur in the presence of a gas, and that gas will not ignite without adequate heat. What is a hot gas? At the molecular level, a hot gas is just a cloud of accelerated molecules. It is the kinetic energy of free molecules colliding with each other that makes combustion possible. Molecules are broken apart in the melee, and the fragments recombine to form new molecules, often generating free electrons that will start further combustion reactions. The result of this chain reaction is a burning gas that we call “fire” and chemists call “rapid combustion.”

But how different is this chain reaction from what goes on in the sun? Sure, we know that the solar fire is driven by fusion reactions rather than molecular bonding, but that aside, we still have a chain reaction in a dense “cloud” of high energy objects breaking apart, forming new objects, and releasing light and heat. In both cases, we have a bright, circulating mass of convection, conduction, and radiation. Both phenomena are self-sustaining and self-replicating, so long as fuel is available. Given that the word “fire” predates our discovery of either molecular combustion or atomic fusion, it seems hasty to attach it to the former while keeping it at a safe distance from the latter.

Now that we can recognize the kinship of these exothermic, self-sustaining, self-replicating chain reactions as species of fire, we might consider what other processes can be recognized with similar characteristics. One obvious example occurs to me: life.

In what ways is life like a fire?

Skeptics in the Pub, Part Deux

It’s time for South Bay skeptics to gather at the pub again! Since last month’s get-together at O’Flaherty’s in San Jose went so well, we’ll be meeting there again tonight. We have fifteen freethinkers signed up to show up tonight (a veritable convention).

An Agenda

Just in case this “informal forum” doesn’t lift itself up by its own bootstraps, I’m offering up the following framework:

1. Personal Introductions

  • Personal Background (and how it inspired the skeptic in you)
  • Favorite Self-Label: skeptic? atheist? freethinker? contrarian? drunk?
  • Favorite Topics: religion, pseudoscience, alternative medicine, climate change, etc.

2. In the News

Scientology: in the FBI’s crosshairs?


Bacterial Intelligence

3. Hot Topics

Topics recently covered by noted skeptics



Climate Change


Related Links

Skeptics in the Pub

I’ve been meaning to start a local get-together for South Bay skeptics for some time now. Since nobody seems to be in a hurry to beat me to it, here goes.

Let’s start with O’Flaherty’s in San Jose, it being about as close a thing to a pub as we have in the South Bay. If the meet is successful enough to render O’Flaherty’s too cozy, we can move ourselves accordingly.

An Agenda

Just in case this “informal forum” doesn’t lift itself up by its own bootstraps, I’m offering up the following framework:

1. Personal Introductions

  • Personal Background (and how it inspired the skeptic in you)
  • Favorite Self-Label: skeptic? atheist? freethinker? contrarian? drunk?
  • Favorite Topics: religion, pseudoscience, alternative medicine, climate change, etc.

2. In the News

Astrology in Crisis, by Steven Novella (Jan 18)

Sign of the Times: Astrology story soars like a comet, StarTribune.com (Jan 14)

Murder, Mass Die Offs, and the Meaning of Randomness, Michael Shermer (Jan 12)

Gun violence and bird die-offs in America

Pakistan rally backs blasphemy law — Al-Jazeera (Jan 9)

Deadly warning to Pakistan liberals — Al-Jazeera (Jan 7)

3. Hot Topics

Topics recently covered by noted skeptics

TestabilitySkeptics Guide 5×5 #100 (Jan 13)

  • Falsifiability: necessary but not sufficient
  • Can it be used to make predictions?
  • Some claims are non-falsifiabile by design (e.g. the claim that the earth was created to look like it’s billions of years old)
  • “The Big Bang theory … was once considered untestable”
  • The distinction between scientific and unscientific can be fuzzy (e.g. string theory)
  • Carl Sagan’s invisible floating dragon that breathes heatless fire.
  • Untestable propositions aren’t necessarily wrong; merely outside the domain of science.

Repressed Memories: Skeptics Guide 5×5 #97 (Dec 20)

You just think we’ve never met. You’re just repressing me, that’s all.

Mystery Spots: Skeptoid #240 (Jan 11)

Patronized your local gravitational anomaly lately?

Gluten Free Diets: Skeptoid #239 (Jan 4)

Is bread making you sick?

Related Links

The Fool and the Prince

Once upon a time, in a land not so far away, there lived a fisherman’s son. He was not favored by the girls of the village, for he was neither smart nor good looking. He was such a fool; in fact, that the village folk got much pleasure at his expense, for he in his foolishness had given them many a humorous anecdote. Many of them would reflect that the boy had once, not very long ago, caused a great uproar of laughter when a royal procession had passed through the village. The boy had invited the crown princess to take lunch with him! Not only had the village folk broken out in laughter (many of them injuring themselves by laughing too hard), but the boy had been compelled to flee for his life when two of the royal guards tried to arrest him for his impertinent mouth. Lucky for the foolish boy, he leaped into the harbor before the guards could grab him, and he hid beneath the dock until the guards were ordered to proceed.

It happened one day that when the boy was out fishing on the sea, pulling in his nets, he found a large fish snagged among the few fish that he’d caught. The boy congratulated himself on pulling in such a large catch. There would be plenty of meat for his family, and they’d make a dime or two from selling what they couldn’t eat themselves. “Father will be so proud of me!” he exulted, and the creature spoke. “Please, fair fisherman, show mercy on me and return me to the sea, and I will surely make it worth your while!” The boy laughed “ha! Ha! What do you have that I could use beside your meat and bones?” The creature answered, “Surely you see that I am a magical creature. Has it not occurred to you that I might grant you your dearest wish? Have you not heard of such things?”

“Heard? Heard, yes!” laughed the young fisherman. “I’ve heard it in fairy tales. Surely you have too!”

“Ah but this is no child’s tale,” argued the creature. “I am quite heavy, no? Have you ever known a fairy tale so heavy?”

“Yes, you are quite heavy, and you talk,” but the same is true for my aunt Mathilda. She is even heavier than you, and she chatters on just as you do, but she grants no wishes.”

“That is fair,” conceded the creature, “so I shall have to prove myself.”

“Yes, you shall,” the boy nodded and paused for a moment, the he said “go, you’re such a talker. You tell me my wish!”

“Oh ha-ha!” the creature laughed. “That’s easy! What magical fish in all the sea doesn’t know that your wish is to sit at lunch with the crown princess! But lo, no magical creature could ever grant such an absurd wish. One such as you could never sit at the table of a princess! You are so foul to look upon, and even more foul to smell! The poor princess would not be able to eat. It would be like having a pile of dead fish at the table!”

“’Tis true. ‘Tis true” conceded the fisherman. “There is no hope of it. I shall not be able to spare you.” And the fisherman turned to take up his oars and row back home.

“Wait. Wait!” cried the creature. “There must be a way.” It paused, and then cried out, “yes! I know.”

Just then, a strange feeling came over the boy from his head to his toes, and creature said, “There! Now look overboard into the water, and tell me what you see.”

The boy hesitated, but then he noticed that the soiled and bloodied rags that he’d been wearing had been replaced by clean, embroidered sleeves, and his hands had changed: they were clean and soft. “Look!” the creature cried out, and the boy hesitated no more. He looked overboard into the water to see his reflection, but he did not see himself. He saw a prince! And it was not just any prince that he saw; he saw the prince who had come courting the princess from the land over the sea. The young fisherman was thrilled.

“Now you must cast us all overboard now, or our smell will betray you!”

“Yes,” the boy agreed, and he unloaded the net into the sea. A moment later, the creature arose from the water just enough to speak, and it said, “Ye must act today! The spell wears off at sunset!”

So the boy returned to the land with haste, and upon finding one of the royal guard at the market, he commandeered the guard’s steed and rode, not very gracefully, to the castle, where he was invited in straightaway. “I have come to beg the company of the princess at the noon hour,” he spoke with authority to the captain of the guard. And so it was granted.

The princess gladly admitted the prince to her table at the noon hour, thinking him to be her beloved. When he took his seat she sniffed the air, frowned, and observed, “fair prince, you have been at sea.” Then she remembered to smile.

“Indeed I have, fair princess” he replied. “I must cross that foul pond to gain your sweet presence.”

The prince glanced left and right, as if wondering who it was that had said such noble words. Then he realized that the spell must have affected his mouth with the rest of his face.

And so they dined together that day, and after lunch they went riding across the royal hunting grounds. When the prince noticed that the sun was sinking near the horizon, he begged her leave, rode away, and returned the guard’s steed.

And so it was that the fisherman’s son got his wish, and he was not too wise to brag when the townsfolk would mock, “been to lunch with princess lately, have ye?”

“Indeed, you have heard!” he would reply.

And so this fool happily carried on. He never married, for no village girl would have him, but he could be found out at sea early every morning, casting his nets with noble anticipation.

Cannibal Planet

It sometimes seems to me that eating fellow vertebrates is a degree of cannibalism, for we do share very much with our fellow vertebrates in the way of anatomy and natural intelligence, and when it comes to dining on fellow mammals—all the more.

Cannibals? who is not a cannibal? I tell you it will be more tolerable for the Fejee that salted down a lean missionary in his cellar against a coming famine; it will be more tolerable for that provident Fejee, I say, in the day of judgment, than for thee, civilized and enlightened gourmand, who nailest geese to the ground and feastest on their bloated livers in thy paté-de-foie-gras.

Ishmael, Moby Dick

The consumption of alien beings such as octopi also seems a degree of cannibalism since they too share a degree of intelligence with us, though their intelligence is quite alien to ours.

California v. II

… continued


About thirty million years ago, the trailing edge of the Farallon Plate began to disappear under North America in the shape of an inverted 90° wedge, beginning at the location of present-day Los Angeles, and proceeding northeast under the continent, leaving nothing but hot mantle where before was the cold, subducting oceanic plate.

Burial of the Farallon Plate

Burial of the Farallon Plate

Over the past twenty million years, that trailing edge has been crossing the Sierra Nevada region, and it’s traveled nearly as far north as Mount Lassen thus far, creating a great triangle between the trailing wings of the subducted Farallon Plate and the Pacific Plate.

With no more subduction to trigger the kind of volcanic activity characteristic of Mount Lassen and the Cascade Range to the north, the Sierra Nevada has transitioned into a new phase of plutonic activity. The hot, underlying mantle has pressed up through the great triangle, causing uplift and, as the uplifted dome has increased the surface area above, spreading. The spreading, in turn, has created grabens such as Owens Valley.

Though the stone that makes the Sierra Nevada was formed long before this uplift and spreading, it was this event, beginning about thirty million years ago, that actually gave rise to the Sierra Nevada that we know today. Still, there have been much more recent events that have contributed greatly to the general, large-scale structure of the range.

A New Age of Volcanism

This new incarnation of California lacks the Cascadian volcanism of its past, yet the existence of the eruption of the Long Valley supervolcano 760,000 years ago attests to the volatility of the present-day Sierra Nevada. It was an eruption 500 times the size of the 1980 Mt. St. Helens eruption and 30 times the size of the 1883 Krakatoa eruption, surpassed by only four eruptions over the last million years:

  1. Lake Toba, Sumatra, Indonesia
  2. Whakamaru, North Island, New Zealand
  3. Lake Taupo, North Island, New Zealand
  4. Yellowstone Caldera, Wyoming, USA

There are no stratovolcanoes along the spine of the Sierra Nevada, but there is evidence of something more terrible.

Localized Foundering of the Farallon Plate

As the trailing edge of the cold, dense Farallon Plate was detached from the supporting mass of any trailing oceanic plate, that trailing edge must have begun to sink — not merely as a caboose follows a train downhill, but rather more directly down, as it was no longer supported on its western boundary.

Delamination and Mantle Drip

Such a sinking mass must have pulled on the lithosphere above it, and possibly pulled the dense root of the Sierra Nevada downward and away from the mountain range. Once the trailing edge of the subducted plate passed, the detached root of the Sierra — being relatively dense — may have begun to sink more directly into the depths of the mantle, causing local downwelling.

Subsidence east of Fresno

Sinking mountains east of Fresno

Asthenospheric mantle flowed in to fill the gap where the Sierra’s root had been — probably liquefying under reduced pressure, and the Sierra, without the ballast of its dense root, became more buoyant, and began to rise, pulling even more asthenospheric mantle up with it, some of which would have liquefied. As magma, it would have injected itself into cracks in and around the thin Sierra block, ushering in the current phase of Sierra volcanism.

As the delaminated Sierra root descends into Earth’s mantle, it has created a local convection cell. The sinking root is causing downwelling in its wake, and pushing mantle rock downward and outward ahead of it. This downdraft appears to be causing subsidence in the Tulare Basin and the western Sierra adjacent to the basin.

As the displaced mantle rock is pushed aside, it then begins to rise, creating upward pressure at its edges — probably more along one edge, due to asymmetry. The upward pressure creates a local updraft, which may be adding to the uplift of the Sierra.

Further Reading:

Active foundering of a continental arc root beneath the southern Sierra Nevada in California

Watching Whales in the Sink

California v. I

It’s common knowledge that water is the bane of fire, but the Earth tells us a different tale.

The continents of Pangaea

The continents of Pangaea

Up to about 200 million years ago, at the dawn of the Jurassic Period, there was no California. It might be said that even North America didn’t exist. North America had then part of the supercontinent of Pangaea, which was about to break apart.

As ancient peoples once imagined their world an island in a great sea, so Pangaea was an island in a great sea. For eons, the rivers of Pangaea carried sediments to that sea, loading down the dense, cool crust beneath the waters. That crust, it turn, was floating upon an ocean of lithospheric mantle, but the crust was getting heavier and losing its buoyancy, until finally it gave way, and began to list like a ship giving in to the sea.

Around Pangaea, ocean floors began to dive beneath it for the same reason, leading to what we know today as the Pacific Ring of Fire, and the Triassic supercontinent began to fracture under the strain of the spreading triggered by the suction of ocean floor subducting into its perimeter.

Here on the eastern shore of the great ocean, the Farallon Plate was born out of the disintegration of Pangaea. As this young oceanic plate dove under Pangaea (and later Laurasia), the uppermost layer of the plate was scraped off and piled against the edge of the continent, and so Cascadia was born. Cascadia is that land commonly known today as the Pacific Northwest. When California was young, it was part of Cascadia.

The continent was pulled westward and stretched along its margin, giving rise to the forearc basins known today as the Puget Sound, the Willamette Valley of Oregon, and California’s Central Valley.

The water-loaded serpentine hydrated the rock beneath the continent, liquefying the rock and causing streams of melt to form. This led to the formation of a volcanic arc along the Pacific Coast, and deep below, the plutons that would eventually uplift to become the Sierra Nevada and Klamath Mountains of the present.

The hydrated magma streams that feed the volcanoes of Cascadia are not pacified by their water continent, but contrarily, rendered all the more volatile by the resulting steam, making for explosive releases of subterranean fire, not unlike the sudden expansion of a grease fire when fed with water.

Down in Cascadian California, there was no San Andreas Fault, nor any great granitic Sierra Nevada. These and other characteristic features of present-day California would arise as the trailing edge of the Farallon Plate began to disappear under North America.

To be continued …

Beware Anonymous Cheques!

… and keep your credit cards close to your vest!

… and Burn in Hell, Budget!

Keep your credit cards close to your vest!

Keep your credit cards close to your vest!

I just got a cheque in the mail for $9.95 to be paid to me. It’s a very official, professional-looking cheque, addressed to “California Resident”, and issued from “California Processing Center”. I was set to cash the damned thing, when my wife Carolyn — bless her observant soul — pointed out to me that I was being scammed. She showed me the small print on the back of the cheque:

By cashing this check I agree to a thirty-day trial offer in Just for Me. I understand that the $13.99 monthly fee will be automatically billed to the card I have on file at Budget unless I cancel my membership by calling 1-877-658-9097 before the end of the trial period …

From another blogger who nearly got suckered by the same scam: Beware: Budget Car Rental Autovantage $10 Check Scam