Can and Can't versus Did or Didn't

kw: book reviews, nonfiction, physics, constructor theory, counterfactuals

When I saw the title of The Science of Can and Can't: A Physicist's Journey Through the Land of Counterfactuals, by Chiara Marletto, I was intrigued. I wondered whether it would be a diatribe against pseudoscience (where we most frequently encounter the word "counterfactual") or an explanation of something new. Thankfully, it is the latter.

Dr. Marletto is a disciple of Dr. David Deutsch, and together they are trying to reformulate physics. That's a tall order, but it's about time. A couple of generations have passed since the clash between the General Theory of Relativity and Quantum Theory became evident…perhaps it is better to say, the best explanations of these two theories definitely clash. It is not known whether the General Relativistic principles and Quantum principles indeed clash, or somehow mesh. If they clash, one must eventually be superseded, or both.

Studying the subject on the side I found that Dr. Deutsch presented his earliest ideas on the subject under the title Constructor Theory. I suggest reading the Wikipedia article Constructor Theory before reading the book, to get a grounding there. Then the book will be easier going. For a deeper dive, see the Constructor Theory web site.

Strangely, the words "constructor theory" do not appear in the book. Instead, the subject that previously had less emphasis has taken center stage: "Counterfactuals." I hope a better term can be found, but it may not be possible. Here is why I think so.

As an adjective, counterfactual refers to something that is not true, it is "contrary to fact." As a noun, a counterfactual is a conjecture about what might happen if something were changed, "Could a kangaroo jump if its tail were removed?" Whether the animal can still jump, you don't have a kangaroo any more, but a ruined kangaroo.

As used in the book, "counterfactual" partakes of the latter meaning, but does not extend it to "ruined" systems. Rather, a counterfactual is a statement about what is provably possible and what is provably impossible about a system, and Dr. Marletto calls it the Science of Can and Can't. Though this is never stated, it is placed in apposition to physics theory as a Science of Did and Didn't. We develop hypotheses by doing experiments and making observations about what Did happen and what Didn't happen. One or more hypotheses can be tested until we have a sufficient collection of happenings, or failures to happen, to enable us to propose a theory, or an explanation for the successes and failures of our experiments and observations. Based on the theory we can make predictions about the outcomes of experiments not yet done. Doing those experiments, assuming we have the means to do so, will either tend to confirm or refute the theory.

How does this relate to a counterfactual (or whatever it will eventually be called)? The counterfactual states what is possible or not possible for the system. It goes beyond the observations. Therefore, "counterfactual" is taken to mean, "Facts to be discovered in the future are expected to conform to this." It is a more powerful idea than it sounds at first. However, because of the on-the-street connotation of "counterfactual = false", I hope a different term can be devised. I tried to think of terms including the Latin root "potens-", for potential, because a counterfactual expresses the potential range of effect for a system, and sets its limits also. I didn't get far. Don't hold your breath; it isn't easy to find a euphonious term for this powerful concept.

This concept, that "Can and Can't" goes beyond "Did and Didn't" leads to the key focus of the book. Systems that have been considered outside the realm of "good physics", such as information theory and thermodynamics, can be analyzed using counterfactuals. The author claims that, using counterfactuals, exact statements can be propounded, while using traditional physics, the statements are approximations. Info theory and thermo and a few other systems larger than quanta are analyzed in the book, to discern the qualities that make them unique. For example, what was earlier called a Constructor is called in the book a Catalyst, generalizing the chemical term to mean any system that induces a change to another system and is either not changed or is returned to its initial condition afterward. Thus a thermodynamic engine can transform heat energy into motion but is not changed in the process; it is, in the most general terms, a catalyst for such a conversion.

The simplest system (in one view) treated is Information. A system such as a switch, or transistor, or coin (to be flipped) can carry information, and larger aggregates of such items can carry more information. Information has two counterfactual properties, Set and Copy. Turning a lamp on or off, or setting a coin to show heads or tails, is a Set operation. Information transfer refers to performing a Copy operation, so that the information is duplicated. When you see a lamp's light appear it causes a change in your brain: When the lamp was the steeple lantern and the brain was Paul Revere's, he began his ride to announce, "The British are coming!" (and if a second lamp was on it indicated a coastal invasion). The information system of the lamps was Set to send a certain signal, and the information was Copied to Paul, who further copied it by announcing it, loudly, as he rode.

Why does this have anything to do with counterfactuals? Because there is nothing in particle physics, quantum mechanics, and so forth, that delimits information. Set and Copy are characteristics of systems bigger than the particles dealt with the the Standard Model and the Modern Synthesis.

One way I began to think about "standard physics" related it to the gears on a bicycle. If you have a 3-sprocket cluster at the pedal and a 6-sprocket cluster at the wheel, you can choose among 18 gears. That's a lot more than the single-speed bicycle I used as a child, or the 3-speed bicycle I used as a teen. But it still has limitations. If you want to study bicycle locomotion, your observations will be limited to the gears available.

Then, suppose you think, what kind of versatility could I have if there were many gears, thousands, perhaps? Keep thinking along those lines and you begin to wonder about a continuously variable "gear" system.

This Evans Cone Drive, patented in 1880 and used in machine shops for some decades thereafter (a few are still in use; this one is in Delaware at the Hagley Museum machine shop. I used it when I was a docent there), has a range of speeds of 16:1. The effective ratio is set by moving the leather belt right or left. This idea is behind the CVT transmissions used in Toyota Corollas, some BMW models, and a few other autos, plus many snowmobiles. This Drive has the counterintuitive quality that it yields an essentially infinite number of "gears" by doing away with the gears! Dear author, if you run across this review, and you like this example, you are free to use it.

It is early days for Constructor Theory. Drs. Deutsch and Marletto are just getting their feet wet. Perhaps a revolution in physics is on the horizon. They think so. This book might be the infant's cry of a new take on physics.

Gross alert – made you look!

kw: book reviews, nonfiction, science, discomfort

When our son was eight, he and the grandchildren of a neighbor were playing together in the back yard. I went to the other end of the yard because I saw something red and gray. I found parts of a female cardinal that a hawk had eaten. One part was a severed lower leg, including the foot. A bone and tendons were sticking out. I called the kids over. I held up the foot by the leg bone and pulled on a tendon. The claws curled. A girl said, "Cool!" I said to our son, "That's the girl for you." Years later he married a young woman who is equally unflappable.

Early last year a hawk struck again, leaving these wings of a gull, still attached to the collar bones. We never found other parts of the gull. The rest was probably carried off after the heavy wings were detached.

No matter where we live, we are going to encounter death, usually many times. We also encounter other things that might gross us out: dog poop on the front sidewalk (in some cities, it could be people poop); half a worm in an apple; a public swimming pool with a distinctly greenish tint; even a case of worms from eating sushi or sashimi at the wrong establishment.

When a dead animal is found in our yard, or dog poop on the lawn (or sidewalk), my wife insists that I clean it up. She's more squeamish than the girl next door (or our daughter-in-law). The squeamish among us might benefit from reading Gory Details: Adventures From the Dark Side of Science by Erika Engelhaupt. Then again, maybe not. Don't let me push you into feeding your nightmares! But it may be of help.

We must recognize that life is messy and frequently gross. This point is made several times in the book, which is largely expanded essays from the author's blog for National Geographic, Gory Details. We may try to insulate ourselves from nature's messiness, but even our own bodies betray us. Most of us clean up our own "bathroom leavings", although the state of many public rest rooms indicates a good many folks are lax in that regard. We do so because we have to. If we want to eat, we are certain to eliminate. The alternative is to become an emaciated, stinking corpse. Well, we're going to become a corpse someday, anyway, but why hurry the process?

Disgust is universal. Things that cause disgust are partly built-in and partly cultural. A relative who was a missionary once said, "You need to be able to eat whatever your hosts put in front of you, without hesitation. Otherwise, don't go to the mission field." Her mission field was New Guinea when it was first opened to Westerners. She ate some stuff, like live grubs rolled in hot fat and taro meal, that most of us pampered folk can hardly bear to see anyone else eat, let alone be willing to take it in hand and gulp down. Disgust warns us that something is probably unhealthy to take in. But we add taboos and restrictions for other reasons, often based on someone who got sick after eating something, but not necessarily because of eating that something.

More and better knowledge can help us overcome queasiness at eating bugs, or getting "something" on our skin, or disposing of road kill. That is a good secondary purpose of Gory Details. Its primary purpose is to demystify many things that bother us, and help us learn "what's really going on." For example, in the chapter "Sniffing Out Sickness" we find that it's a good idea to get familiar with the scents of our loved ones. A change in that scent (besides the usual changes that accompany puberty) can be an indication of a medical condition that needs to be checked. While there are trained diabetes-sniffing dogs, for example, someone's sibling or parent or child is about as good as the dog, if they'll take the time to learn to smell. Strong odors and aromas reach nearly all of us. We need practice to discern more subtle scents.

A bit of advice from "I've Got You Under My Skin": if a bug gets in your ear, get a doctor's help to remove it without killing it. A dead bug in your ear rots pretty quickly, and if it is broken open (squashed), it is likely to have internal bacteria that could cause a lot of harm.

There are also chapters on vagaries of the mind, such as the poor folks who believe ants or other insects are crawling on them or burrowing in their skin. Some do themselves a lot of damage trying to dig out "samples" to show a doctor to prove that they are infested. There are several ways our minds can play tricks on us, and we learn of doctors who have effective (if not all that rapid) treatments in "The Invisibugs". Then, why are clowns so creepy? Why does the current generation only think of evil clowns, forgetting Bozo or Ronald McDonald? The chapter "Back Off, Bozo" has a partial explanation, in the "uncanny valley" that makes us recoil from, for example, robots that are really, really close to humanoid, but aren't quite there yet. Less realistic, "cute" robots get a better reception; we don't feel like they are trying to fool us.

Some people can't tell the difference anyway. A sad condition known as prosopagnosia, or face-blindness, prevents about a percent of people from recognizing even those they know well. At the other end of the spectrum are some "super recognizers", who do well scanning security video for known "persons of interest". It made me wonder if there are also those who are exceptionally good at recognizing someone not from the face, but bodily habits such as they way they walk, or gesture and so forth. How often have you seen someone you know at a distance too great to see their face, but knew who it was anyway?

Oh, and that green swimming pool? Of course there's pee in there. A large community pool could have 20 gallons of pee by the end of a day; a back yard in-ground pool gains a gallon or two per pool party. But urban legends of a chemical that turns red or blue around you if you pee in the water just aren't so. Urea is hard to detect with chemical indicators. But the burning eyes I used to get when I was on the swim team weren't just because of the chlorine. The chlorine in the pool reacts with urea to form a more potent, eye-stinging chemical. So use swim goggles. Now you see why they want you to shower both before and after using the pool at the Y. And don't drink the water.

I hope lots of folks like this book as much as I did. And if it helps a few of us get over some of our bad feelings, even better.

Three days of Russian spidering

 kw: blogs, blogging, spider scanning

I checked in on my blog and found more than 4,000 hits in the past week, nearly all on July 28-30th. Looking at the "Audience" view I found the following:

Basically, subtract the Russian spider(s), and there were 289 "honest" hits, which is usual. It would be gratifying to have thousands of weekly views, genuine ones, but this just isn't that popular a blog.

Oh, well. Не топитесь в слезах от скуки.

Nature as healer

 kw: book reviews, nonfiction, nature, the natural world, lessons for living

The trend to divorce humanity from nature began long ago, with the Greek philosophers of the 400's BC or earlier. I remember reading that they preferred argument to experiment, sophistry to evidence, such that they could argue for hours about how many teeth a horse has, and nobody would suggest going to the nearest horse and looking in its mouth. That's probably a bit exaggerated. Curiously, the rise of experimental science (first called "natural philosophy") during the Enlightenment seems to have cemented the divorce, at least for a time.

In the recent generation or two increasing numbers of researchers and students have been willing to accept that we are part of nature. The "natural-artificial" divide is exaggerated at best, and flat wrong in most areas. It is true that human culture and technology have largely insulated us from many natural phenomena, but we see less efficacious technologies throughout the animal kingdom, in everything from bird nests to the tunnels of mice and hares, to bee hives and wasp nests, and to the tools apes and some birds use to winkle out termites and other insects to eat.

A side note: the just-delivered issue of Scientific American has, on its back page, a brief survey of the most numerous species of birds. The House Sparrow is the most numerous known wild bird, having a population estimated to be between 1 billion and 3 billion. A quick search for the numbers of mice yields an estimate of around 20 billion. There are also that many chickens and a billion swine (bonus results of the search), but those are domesticated, part of human culture; there would be far fewer of them if we weren't raising them. But this does indicate that, for our size, humans are much more numerous than we would be without our admittedly huge level of technology, even in the Third World.

It is good that at least some of us are getting more comfortable with being part of nature. The divorce from nature, almost exclusively in Western culture, has led to this quote, about the strain between proponents of the Enlightenment view and those who held back:

Those who balked at this epic drive to disenchant, who failed to champion the notion that there are eternal truths discernable, as Voltaire put it, by "anyone of good sense," were considered ignorant, underserving of respect of consideration. So should you ever wonder where hostility toward intellectuals comes from, or why educated white men have so often irritated the crap out of people from other backgrounds, the Enlightenment is a good place to start looking.

That is from page 55 of The Eight Master Lessons of Nature: What Nature Teaches Us About Living Well in the World, by Gary Ferguson. He has worked as a naturalist for the National Park Service, and writes about his experiences in this book, along with his interpretations of the lessons one can learn by spending more time in natural settings.

It is worthwhile for us to dwell on eight terms that I glean from his eight chapters:

Mystery, Connections, Diversity, Yin-Yang Balance, Zoomorphism, Efficiency, Resilience, and Memory (i.e. Mentoring)

I will dwell a moment on just three of these.

• Diversity is not just about racial balance in schools, cities, and workplaces. It is about variety versus sameness. A litter of kittens will have one or two that are bolder, another that is more skittish or shy; some will be affectionate pets and others more aloof. The intelligence of the womb ensures that at least a few of these cats will be well adapted to a changing world. A field of wildflowers of many colors is unlikely to be wiped out entirely by some sudden event such as a new disease or a giant storm: Even though some of the species in that field may be entirely destroyed, not all. We are happiest when we have learned to relate to people of different backgrounds. It is good to be "cosmopolitan". Excessive narrowness is unpleasant. I rejoice in having, among my closets friends and associates, people from a dozen nations and a half-dozen Western "subcultures."
• Yin-Yang Balance refers to the balance of masculine and feminine qualities, as traditionally understood. The Chinese Yin-Yang diagram is shown in several ways, with the dark section sometimes ascendant, the light section sometimes ascendant (more commonly), or with the sections side by side. I chose to put them all together, with the understanding that these are "clockwise" tadpoles, and a mirror image is equally possible. The "enlightened" suppression of any roles for women "outside house and home" is thankfully ending, but we still have a ways to go. Animals and plants cannot afford to suppress anything, for reasons expressed in the chapter on Efficiency. A man with no feminine attributes is as unpleasant as a woman with no masculine attributes. We each embrace both, even though each of us will emphasize them according to our nature and learning. More exposure to nature can help us learn to achieve a more harmonious balance.
• Zoomorphism is the opposite of Anthropomorphism. For a few hundred very unenlightened years, animals were treated as automatons, having only "instincts", and any evidences of pain or emotion were denigrated as "automatic responses." If we, at least those of us with a scientific bent, truly understand what Evolution means, we realize that our feelings and emotions and reactions descended from our animal ancestors along with the size of our bodies and the strength of our muscles. As a Cheyenne elder told the author, "We're the ones who took our qualities from the animals. It's never been the other way around." (p. 127) True science embraces this.

When you get down to it, we all feel better when we spend time in a natural setting. It is a rare person indeed who, taken into a field or forest, dashes back to a cubicle as though fleeing a monster. The author describes some chemicals in the air of a forest that may explain why taking a "forest bath" makes us feel so good. Chemicals or not, getting outside, even in a manicured yard, is better than spending all one's time locked away indoors. For myself, I know I must at least take a walk frequently; daily is best. I'd rather do that outside than do "mall walking" unless it is raining (and even then, if it isn't raining too hard…).

As much as the author has worked in the natural world, some glaring ignorances appear. On p. 76 he speaks of us sharing the planet with "more than a trillion species of plants, animals, insects, and microbes." The best current estimates of the number of species, including microbes, is between 100 million and 1 billion. Perhaps he was influenced by the understanding that each of us is host to tens of trillions of bacteria, primarily in our intestines. I am also not sure why he writes of 23 "universal proteins" in all life. There are 20 amino acids, which are used to make up all the millions of proteins found in living cells. The human genome is composed of 23 chromosomes, each of which consists of around a hundred million ACGT "letters". Again, perhaps two facts got mixed-and-matched in his mind.

The writing is lyrical and enjoyable. It becomes clear that the author is still processing the death of his first wife fifteen years ago. Having had significant losses in my own life, I understand that some things you don't get over, you just learn to live with the gap. I am thankful he has married again, happily.

Opening the ocean deeps

kw: book reviews, nonfiction, submersibles, deep ocean, expeditions

Josh Young has an explanation for what drives people like Victor Vescovo to extreme exploration: as many as eleven copies of a gene that affects sensitivity to dopamine, the "feel good" neurotransmitter. Most of us get along fine with two or three copies, and we may get a thrill from the occasional bit of risk-taking (like the pursuit of a friend and myself at age 13, of trying to go from one end of a block to another through back yards and not get caught). Those with genetically enhanced dopamine metabolism need stronger stuff.

Whether that is the explanation or not, Vescovo was driven, first to build a fortune of millions in various ventures, all the while spending substantial chunks of cash to complete the Explorers' Grand Slam, defined at the EGS website thus: "The Explorers Grand Slam or Adventurers Grand Slam is an adventurer's challenge to reach the North Pole, the South Pole and all of the Seven Summits." It takes a little more digging to find that "reaching" the Poles involves skiing at least the last hundred kilometers, even if you were taken there by aircraft, and that the Seven Summits are Everest, Kilimanjaro, Denali, Aconcagua, Vinson Massif (Antarctica), Elbrus, and Kosciuszko (Australia; later replaced by an Indonesian peak, the Carstensz Pyramid).

So there you are, fifty years old, and you've just completed the Grand Slam. Now what? There's plenty of life left in those old bones! Inspired by the challenge of the deep sea, Vescovo began almost immediately to add the Five Deeps to his accomplishments. As Josh Young writes in Expedition Deep Ocean: The First Descent to the Bottom of All Five of the World's Oceans, Victor Vescovo figured he could get a deep-diving submersible built for around $10 million or so, a tenth of his net worth at the time.

The actual cost came to more than twice that. Then the sub needed a tender, a ship and crew to take it from place to place and to launch and retrieve it. The submersible, built by Triton Submarines, was named Limiting Factor (LF), and the tender, a 225-foot craft, became Pressure Drop (PD). The ship needed extensive refitting. It had been a military craft, and upgrading it to commercial standards cost millions more. A state-of-the-art sonar system, so they could verify the depths reached, cost about another million, and three "landers", robotic, autonomous submersibles, cost $300,000 each. LF and PD and the landers were named for craft in the Culture novels by Iain M. Banks, a favorite series with Vescovo. The final cost of the construction, refitting, crewing, and expeditions was about $50 million.

In the picture above a portion of the pressure sphere and its portholes can be seen. The sphere is titanium, 59" in diameter (because of some international regulation), and weighs 8,000 lbs. From the size and weight I calculated that the wall thickness is 5.5". The sphere was certified in a testing chamber in Russia, the only one in the world that could test it to a pressure of 20,000 psi; the pressure at the Challenger Deep (Marianas Trench) is about 16,000 psi.

Much of the book relates the sturm und drang of getting the sub built and the tender refitted, plus the regulations and red tape Vescovo's team had to contend with, plus the friction that always develops when you have at least a dozen alpha males striving to work together. Much of the second half relates the year-long expedition to visit the Five Deeps (see more here). These, with their verified depths, are:

• Puerto Rico Trench, Atlantic Ocean, 8,376 m, 24,390 ft.
• South Sandwich Trench, Southern Ocean, 7,434 m, 24,390 ft.
• Java Trench, Indian Ocean, 7,192 m, 23,596 ft.
• Challenger Deep in Marianas Trench, Pacific Ocean, 10,925 m, 35,843 ft.
• Molloy Deep, Arctic Ocean, 5,551 m, 18,212 ft.

Of these, the Molloy Deep is the only one that is "shallower" than 6,000 m, the defined boundary of the Hadal Zone. Along the way, a few other deeps were plumbed, including the Sirena Deep, also in the Marianas Trench, at 10,714 m or 35,151 ft, which makes it the second-deepest Deep. Vescovo made at least one solo dive at each of the Five Deeps plus Sirena. He also made a solo dive to the wreck of the Titanic, and others made multiple dives at all locations.

A secondary function of the expedition was scientific, and a number of scientists were involved. So also were a couple of "tourists", including astronaut and game developer Richard Garriott, seen here with Vescovo inside LF. Garriott flew with ISS at his own expense ($30 million); I don't know if he self-funded his dive to the Challenger Deep, piloted by Vescovo.

Vescovo was one of a few pilots of LF, but when there was a celebrity to "take deep", such as Kathy Sullivan, the first woman to conduct a spacewalk and the now first woman to descend to the Challenger Deep, Vescovo piloted.

Triton and Vescovo were hoping the Triton Hadal Exploration System (LF plus PD) could be sold to a country, company, or consortium, but that has not yet occurred. Vescovo and his company Caladan Oceanic have conducted further explorations, typically with a more intense scientific component.

Although eating within LF is mentioned a few times, there is nothing about how toileting is handled in a sphere with an inside diameter of about four feet, further encumbered by oxygen tanks and other equipment, particularly with two occupants. If it were me (in my younger days, before my colon was shortened), a day or two of fasting, and abstaining from water for several hours before a twelve hour dive, would be needed. But I care for my creature comforts too much!

That's enough from me. It's a thrilling book, a great story well told.

A book for inquisitive children

 kw: book reviews, nonfiction, science, questions answered, compendia

We all know a youngster who asks "Why?" about almost everything. Sometimes they're just challenging a parent's decision, but other times the question is, "Why is the sky blue?", or, "Why do knuckles crack?"

Jay Ingram likes to answer questions…in detail. In Why Do Onions Make Me Cry: Answers to Everyday Science Questions You've Always Wanted to Ask (a follow-on to The Book of Why), he tackles 51 such questions, with answers ranging from two to five pages, plus each of the five sections of the book has a "History Mystery" such as "Did Newton really get hit on the head by an apple, inspiring his thoughts on gravity?" The length of the answers and their comprehensiveness indicate that Mr. Ingram knows you'll get follow-on Why's.

Some questions lead to others, sometime in interesting directions. In his answer to "Why is the sky blue?", he also digs into how the words for colors seem to have developed over time. "Blue" wasn't much of a concept long ago, possibly because other than the sky, not much is blue (flax flowers and certain butterflies, and that's about it), while purple was well known because purple dye is made from chemicals obtained from certain sea snails. Thus, blue things were called "purple" until truly blue dyes, such as woad, became economical to produce, while words for red, yellow and green arose very early. Color perception probably didn't change, but people's ideas about colors changed.

While we're in the blue sky area, look closely at this satellite photo. The bluish tint in the upper right area is from looking through the blue sky from above! The higher mountains don't have nearly so much air above them, and the color doesn't show.

This leads me to a question about blue skies that this book doesn't answer, and I'll dig into it as a bonus: 

Does every planet with an atmosphere have a blue sky?

The easy answer is No, because we have all seen recent pictures from Mars and the sky is pinkish. But there is an underlying complication. Mars has such a thin atmosphere that Rayleigh scattering, which makes the sky so blue on Earth, is a very, very small effect. The pinkish dust that is nearly always present in the air on Mars overwhelms the scattered blue light. On rare occasions, the wind on Mars calms enough for dust to settle, and the sky gets almost black, with just a bit of very deep blue. So let's refine the question: Does every planet have a blue sky when the air is very clear?

This gets into the colors of stars! We call the Sun a yellow star because we see it through our atmosphere, and 1/3 of its light is scattered by the air to make all that blueness. The light that gets straight to us is thus a pale yellow. From the International Space Station or any other orbiting craft, the Sun appears utterly white. This makes sense. Our eyes evolved to see "average daylight" as "white", and the color of the light that reaches a colorless object on Earth is direct sunlight plus blue light from the rest of the sky, and that adds back to the pale yellow to be white.

You might have heard or read about bluish and reddish stars. Most of the stars we see at night are a bit bluish compared to the Sun. The visible ones are bright, hot stars, and stars hotter than the Sun are bluer. A few stars, such as Betelgeuse in Orion and Antares in Scorpio, look reddish if you look carefully. Looking at one of these stars with slightly out-of-focus binoculars lets you see the rather orange color more clearly. They are redder than the Sun because they aren't as hot. However, they are still hotter than the filament in an incandescent light bulb, which actually emits a rather orange-colored light. Our color vision adapts to this and it looks "white enough" to us, unless we look at a lamp next to a well-lit window.

Suppose there is a planet orbiting one of those orange-colored stars. Would it have a blue sky? There are two answers to this. Firstly, to us, the star would look slightly more orange than the Sun does, and the sky, if very clear, would be "less orange", and probably would look pale blue. But Secondly, if there are creatures on that planet which evolved there, they to them their star looks white, and the sky would look blue! On a hotter star such as Sirius, which is already bluish, the sky above any planet would be a more intense blue than our sky, barring pink dust, of course.

Enjoy this book, and if you have kids that are full of questions, keep a copy on hand, so you'll have at least 50 questions that you can actually answer.

Before and after the Lensmen

 kw: book reviews, science fiction, space opera, story reviews

In my late teens and early twenties I read science fiction obsessively. So much so, the local library began buying more to meet the demand, though it was a "demand of one." Very early I read the Lensman novels by E.E. "Doc" Smith. The themes I remember are the Lens as an unforgeable authentication device; mental telepathy and other mental powers, first in the Arisians and later in the Lensmen; and the inertialess drive, which enabled space travel across the galaxy with the ease of crossing a county or state by automobile. The seven Lensman novels were published between 1948 and 1954.

I recently obtained the eBook The Space Opera Megapack, which contains two of Doc Smith's books in the form first published as serials. One is his first published novel, The Skylark of Space, published serially in Amazing Stories in 1928, where it got the cover illustration and his name highlighted (spelled out!), but his co-author Lee Hawkins Garby (who wrote the "love interest" parts) was not mentioned.

Skylark was published in 1946 as a hardcover, greatly edited, after other novels in the series had become popular; the Megapack version is the 1928 text.

It's funny. I've known about Skylark and its siblings for decades, but I don't remember reading any of them. I remember only the Lensman books. The space drive in Skylark, set in a thoroughly Newtonian universe, involves "release of binding energy" of the copper atom, facilitated by a newly-discovered element called "Metal X". Doc Smith had a dark view of human progress. The Military-Industrial Complex that President D.D. Eisenhower warned us about in the 1950's was already well advanced, and Smith expected it to worsen (Even he would be shocked at how bad is has become!). In the novel industrialists run things (as venally as possible), and the chemist-protagonist Dick Seaton has to covertly develop a spacecraft with the (expensive!) help of an honest industrialist, Martin Crane. It proves a success.

It's an engaging tale, though the social and romantic aspects are too saccharine for my taste. The riders of the Skylark find humans and near-humans on other planets they visit. Doc Smith thought of the Skylark books as "semi-science fiction". Indeed, if there were no relativity, no "speed of light limit", the energy needed to accelerate a huge spaceship to speeds many times that of light would require total annihilation of a mass greater than that of the spacecraft. A few hundred pounds of copper would hardly suffice.

The story suited the times. It is credited with setting off the entire genre of Space Opera, so its inclusion in the Space Opera compendium is entirely fitting.

The same volume includes Galaxy Primes, serialized in 1959 in Amazing, a very different story. Doc Smith wrote it with no co-author. The protagonists are "psionic Primes", with the highest order of mental abilities known on Earth (or Tellus, Smith's designation in most of his books). Two male Primes and two female Primes are put aboard a spacecraft with an experimental interstellar drive that is engaged by pushing a button. They push the button and find themselves so far from Tellus that no constellations can be recognized. There is a shorter-range drive, of an unknown type, for zooming around among planets in stellar systems. They eventually find out they are in a different galaxy!

The Primes find human life everywhere, plus Guardians who are semi-humanoid (4 arms and hatchet-shaped head), that oversee the human planets, to ends not discussed and thus secondary to the plot. Tellus has no Guardians (yet). The powers of the Primes using "Gunther" techniques, are godlike. There are lower-level psionic persons on most planets, and a few Primes scattered here and there.

The first part mainly involves the four Primes learning to get along and how they discover the way to control their interstellar drive. Once that is accomplished, they gather Primes from many other systems to form a pan-galactic organization, with ties to other galaxies. The distance the ship can jump depends on the power of the Prime who directs it, and only the leading Tellus Prime, Clee, and a few others, can jump galaxies.

Apparently Doc Smith wanted an Earth-grown version of the Arisians, and the novel investigates the implications of almost godlike humans. It's a fun read, though I don't imagine such powers being properly used by anyone until a few tens of thousands of years of moral development have occurred. We consistently misuse the feeble power we have…

Some of the other stories in the Megapack are quite good, but I found many others to be "barrel scrapings." Whatever it took to fill an eBook of 1,400 pages, of which I read about 3/4.

Will any lock ever be good enough?

kw: book reviews, nonfiction, cyberwar, computer hacking

A wag once said, "If we built houses the way we build software, the first woodpecker to come along could destroy civilization." I wrote software for forty years, and I must say, with some chagrin, that I agree.

Sandworm: A New Era of Cyberwar and the Hunt for the Kremlin's Most Dangerous Hackers, by Andy Greenberg makes it clear that the woodpeckers are winning. (To see a fictional forecast of a war with China that includes cyberwar, see the recent book 2034: A Novel of the Next World War, which I reviewed this past May.)

American security analysts use "Sandworm" to refer to the penchant the Russian hacking team initially had for Frank Herbert's Dune novels, as seen in names and comments in their code. Other security groups around the world have different monikers.

The book Sandworm is primarily a history of the damaging cyberwar carried out by this group, and apparently a few other allied groups, plus forays into cyberwar by others, including the US/Israeli team that launched Stuxnet to disable Iran's equipment for preparing bomb-grade uranium. By far the most beleaguered victim of the Sandworm hackers has been the Ukraine. Their computer-connected infrastructure, from electric utilities to the post office, has been attacked repeatedly, leading to blackouts and other disruptions. The author considers Ukraine the test bed for the Russian hackers.

One would think that the nations, or at least the NATO allies, would get together to create and invoke Geneva-Convention-styled measures to "outlaw" cyberwar carried out against civilian populations. When the author questioned a number of security leaders about this, however, the cynical response was that "we" don't want to hobble ourselves from using such measures.

I noticed that it was an American, Mike Assante, who first demonstrated, to Pentagon leaders and others, the capability to destroy a running powerhouse generator using software commands. It was also American (plus Israeli) software that was first used to destroy physical equipment, with the Stuxnet attack. I couldn't avoid the analogy with the first use of nuclear weapons, again by America. I don't like where this is going.

I am puzzled that, in the face of what is known about Russian cyberwar—going on right now—, and Western cyberwar capabilities, the American military seems hell bent on making all our weapons systems Internet-dependent and GPS-dependent. It's like giving a key to your house to "the mob."

About the time I was born the term "fail safe" appeared, and it enjoyed a few decades of popularity. Somehow, it was not much applied to software. Over time, it was changed to "failsafe", and the term is becoming current again, but it did not appear in Sandworm. I don't know how "popular" it is in the Pentagon. One would think that system robustness would be a top priority, particularly for the American military with billions at their disposal. Utilities and others need failsafe systems also, even though their budgets are tiny by comparison.

Bottom Line: All the test cases have been tested, by the Sandworm folks and others. Every red line has been crossed. Software bombs have already been emplaced, almost anywhere a security analyst cares to look. When will the triggers be pulled? It apparently isn't up to us. Fat, Dumb & Happy, that's what we are, with a target front and center on our T-shirts. Not a good feeling.

History hidden in chair seats

kw: historical investigations, upholstery, side chairs, photo essays

When my wife and I were married we bought a set of four side chairs and a small dining table at a thrift store. After we bought a house we bought another set of five chairs, four side chairs and one with arms, and a better table (still at a thrift store); we gave the old table away. Soon after that a relative sent us an antique table with its own set of five matching lyreback chairs, one of them having arms. We gave away the thrift store table, and now we could have big dinners!

The original four chairs had some kind of whitish plastic on the seats, and both sets of the others had patterned fabric seats. All were looking quite worn. We bought several yards of a darkish teal-colored upholstery fabric and I reupholstered all of them. I left the plastic on the original set—I just covered it—but I stripped and replaced the fabrics from the other ten chairs. For those ten I also added a half inch more padding of "fiberfill" to match the thicker padding on the first four.

About thirty years later the teal fabric had done its duty and it was getting tattered, so we bought a patterned blue-and-tan fabric, getting enough so I could center the pattern on each seat, as this photo shows. However, this is a less durable fabric, and fifteen years of use left the chairs in the condition shown here.

We decided to reupholster them again, a third time. We had long since moved all the lyreback chairs to bedrooms where they'd get less use because the backs are fragile, so their seats are in good condition. We decided to redo only eight of the nine original chairs, leaving the chair with arms alone. The new fabric will be seen later on. We also decided to add a couple of inches of foam. As we've aged, the chairs have begun feeling a little too stiff for us.

You can see above that one set of chairs—the first set we bought—is oak with a walnut stain, and the other is of a lighter-colored wood, probably maple. The lyreback chairs are cherry with a walnut stain.

Turning the chairs over we can see the makers' marks. The oak chairs were made by Richardson, but which of the many companies by that name, I don't know. At least three companies by that name, in different states, use an "R" logo similar to the capital "R" in this mark. One of the companies, in Arizona, was founded in 1972, while these chairs were decades old when I bought them in 1976, so we can rule that company out.

Morris Furniture Manufacturing Co. of Los Angeles is less of a mystery. This is not the Phyllis Morris company, which seems to have specialized in fancy, ornate beds for celebrities, founded in 1952, but a different company that was founded in 1936, so there is plenty of room for the maple chairs to be from the 1960's or earlier, perhaps much earlier.

As I mentioned, the oak chairs still had the plastic covers under the upholstery I'd used before. This time I decided to remove it to see what was underneath. It was this action that triggered the historical adventure.

When I removed the plastic and cleaned it, I found it is Naugahyde, and that it was not the original seat cover. It was held on with tiny tacks, ¼" long (7mm). Underneath I found staples from an earlier event, apparently the original cover attachment, which had bits of greenish, patterned plastic remaining as though whoever put on the Naugahyde just ripped the plastic off and nailed over it.

This is the collection of little tacks I removed from the four oak chairs. There is one larger tack, that had apparently been used to hold a corner where several layers needed to be held. I found only the one.

The picture below shows what I found under the Naugahyde.

The staples left behind frequently held a small bit of greenish-gray plastic. Two of the chairs also had the torn edge of the label; you know, the one that says, "Not to be removed under penalty of law." The bits of remaining text indicate that the chairs were made after 1929, but not how much later. They are probably from the 1940's or even a little later.

After I took the Naugahyde from the first chair, my wife and I discussed what to do. We decided to replace the Naugahyde as a foundation for the added padding.

Before going on I'll show what the older staples looked like, compared to the ones I used for this work.

The old staples are quite robust. You can see from the dents in the wood nearby that they were inserted with a lot of force, so I infer that a powered staple gun was used. Such tools were invented in the early 1950's, so that puts an age limit on the oak chairs.

The scattering of holes along the edge were made by the little tacks, which were clearly put in by hand. Someone with good aim can use a magnetized tack hammer to hold the tack and drive it in, right next to the thumb holding the fabric! Missing is even more painful than simply hitting the thumb with a hammer.

The way the Naugahyde was cut in an in-and-out way near the tacks indicates that it was first pulled taut, then the tacks were put in, after which it was cut closer to the tacks. That reduced the need for such excellent aim.

Once we decided to keep the Naugahyde in place, I put it back on the first chair with staples.

My initial process for the oak chairs was this: 

1. Remove the blue-and-tan fabric.
2. Remove the tacks holding the Naugahyde, along one edge.
3. Staple that edge back into place.
4. Continue with all edges. These chairs have a curved back to the seat, so they had to be attached a little at a time along the curve.
5. Use a felt tip marker to indicate where the screws go (illustration later).

To get the maple chairs to this point, I just had to remove the blue-and-tan fabric. To explain what I had to do to measure the new fabric, I need this picture:

The padding we used was cut from a Queen size mattress topper. Each chair was to be padded with two thicknesses. To partially compress it while attaching the fabric, I gathered weights from our various workout spaces to total 40 lbs (18 kg).

At the bottom we see the wrong side of the new fabric, the two thicknesses of "eggcrate" foam, back to back (I used the chair bottom as a template), then the chair bottom, and the weights on top.

To get the fabric the right size I laid out a large piece of newsprint in place of the fabric shown here, drew it up to about two inches inside the edge of the chair bottom, and marked it. I made separate templates, because the two kinds of chair have quite different seat sizes and shapes. The templates were used to cut the fabric, laid out in our spare bedroom, using a drywall square under the cut line to keep the scissors from harming the carpet.

At the point in the process shown above, I cut the curve by eye. I also removed a square of fabric from each corner (two per chair for the oak chairs, and four per chair for the maple chairs later), to reduce bulk in the overlap areas.

Right after I made the photo above, I cut the curve from the lower part of the fabric, and stapled it into place.

Once that was done I measured the hole-to-hole spacing in the chair support, to refine the felt tip marker lines, such as those seen here. In this corner, and in about half the others, repeated removal-and-replacement had resulted in a real mess. I cleaned out the holes. Then I carved bits of wood and glued them in, and used a rotary tool with a sanding wheel to flatten them after the glue dried. I used Elmer's Wood Glue. When each repaired screw location was ready, I marked the location and drilled a 1/8 inch pilot hole.

I should mention a detail about stapling the fabric to the plywood. I had cut enough extra so I could fold about an inch under; thus there is not a cut edge showing. I used 5/16 inch staples rather than 1/4 inch so the extra thickness would not be a liability.

Here is the first of the oak chairs to be reupholstered next to one that is ready to be done.

We like the darker fabric color and denser pattern. It won't show spills nearly as badly as our prior fabrics.

This chair design is also quite a bit more robust than that of the maple chairs. I have not had to knock any of these apart and re-glue the joints, while all of the maple chairs have needed such attention.

Here is the first of the maple chairs to be reupholstered next to one that is ready to be done.

Here you can also see the nice woodwork of the backs. We like these chairs, even though I prefer not to sit in them because I am twice as heavy as my wife and I tend to loosen their joints. You can see a hint of the problem in the crossbars that just show below the seats. This post from 2018 shows one of these getting reglued.

Now that all eight chairs have been redone, we have prettier, more comfortable seating for the dining room, the room we use the most.

Science is a universal human skill

 kw: book reviews, nonfiction, science, citizen science

On August 21, 2017, a total solar eclipse crossed the middle of the United States. For those who couldn't travel to the path of totality, a partial eclipse could be seen throughout the country. I was to work at the Delaware Museum of Natural History that day, and the amount of the Sun to be hidden was about 80%, so it was a significant event. At the Museum, we announced and advertised a public Eclipse Day, with a number of telescopes and other devices prepared for the public to join in.

Here we see U.S. Senator Chris Coons looking through binoculars fitted with special filters so he could see the Sun directly and safely. He was one of hundreds of people who came to join the event.

We showed people how to make a "pinhole" with their hand, or by making a small hole in a piece of paper or cardboard, so they could see the shape of the sun projected onto the ground as the Moon crossed in front of it.

People most enjoyed the four telescopes that we set up for projecting the solar image onto screens, as seen in this photo. My own "stovepipe" telescope is in the foreground. Only a little of the Sun was covered at this point. Just behind it a volunteer is adjusting another telescope to move the image back to the center of the screen. The other two telescopes are hidden by the crowd. The picture below was taken near maximum eclipse.

This event shows that people in general are fascinated by nature and natural events. Yet about 9 people in 10 would say, "I am bad at science." That is because they don't know what science is. They don't realize that our life is built around science. The way we learn to interact with people, beginning in infancy, is by observing how others react to us, and by trying different things to see what the reaction will be, and learning to do what gets the reactions we want. Growing up, we learn how to walk around without getting hurt (too much), how to throw a ball, and a great many other skills, by this ordinary process: observe, experiment, categorize, and predict.

What people actually mean is, they are bad at some of the things "professional scientists" do, such as making formal (and often costly) experiments, or publishing articles. If we broaden "publishing" to include gossip and giving advice, though, and also consider how diligent we are to learn things that really interest us, we are all scientists. It's time we acknowledge the fact.

You may have heard the term "citizen science." Perhaps you have stumbled across one of its manifestations, such as Galaxy Zoo, SETI@home, or the Great Sunflower Project (I'll explain what they are in a moment). Equally likely, you may know nothing of these things yet. In either case, a new book should prove quite a treat!

The Field Guide to Citizen Science: How You Can Contribute to Scientific Research and Make a Difference, by Darlene Cavalier, Catherine Hoffman, and Caren Cooper, introduces just the tip of the iceberg of the immense field citizen science has become. For several years I have participated in a number of projects through the Zooniverse interface, which currently includes 78 active projects, all performed online. I got started at Zooniverse through the Galaxy Zoo, for which I viewed galaxy images from the Hubble Space Telescope and reported their shape and other characteristics. Over time I participated in 36 projects, from counting penguins to transcribing labels. The Field Guide introduces the much broader scope of projects of all kinds, about 1,600 of them, available through SciStarter, which was founded by Ms Cavalier.

The bulk of the book describes more than 40 projects. Some are carried out online (including some of the Zooniverse projects); some are done in the home or yard (such as Great Sunflower, for which you plant sunflower seeds and, once they grow up and flower, count the types of bees that visit them); for some you venture out in nature; some are done by day, some by night; and for some you need to get equipment such as a trail camera or a kit the project supplies. The authors also have suggestions for introducing citizen science into schools, libraries and other public venues, such as the eclipse event I described above.

I have to put in a plug for museums: are you a collector? Maybe you collect things that would interest a museum. I work with the seashell (mollusk) collection at the Delaware museum, and I have noticed that more than half the museum's holdings of 2 million shells in more than a quarter-million "lots" (groups of shells of one species collected at one place and time) were donated by private collectors, either during their lifetime as active collaborators, or they were willed to the museum. Whatever museums exist near you, do find out what kinds of items they are interested in receiving for their collections. If you collect seashells, for example, even if you just pick up "a few pretties" every time you go to the shore, it is worthwhile to have a conversation with a curator of mollusks, to find out what kind of data to collect along with the shells, so if/when you later donate them, they will be useful to the museum and researchers that use the collections for scientific purposes. Museums don't hold collections "just so they'll have them", but so historical and ecological study can be done. Not only do I occasionally take in shells I have collected, a month ago I found a recently dead opossum. After making sure it was actually dead, not just fooling, I put it in a bag and drove it right to the museum, where the curator put it in a freezer (all new animal specimens are put through a freeze-thaw-refreeze routine to kill parasites and their eggs).

The great variety of projects offered through SciStarter will have something, probably several somethings, for anyone with any sort of interest. I created a SciStarter account to see how it compares with Zooniverse. Prior to today, I have participated in 36 Zooniverse projects (and made nearly 20,000 classifications), I also have the iNaturalist app on my phone (but it's early days, I have only "collected" 55 observations), and I recently got the Cicada Safari app to use whenever Brood X erupts in my neighborhood (none so far).

When I set up a SciStarter account, I found that in my profile I could link its dashboard to the accounts I have with Zooniverse and iNaturalist. In the Field Guide I found a few projects I may try out, including Fe-BARQ ("Fe" for "feline": describe your pet cat's personality) and Foldit (a kind of game to investigate how a protein molucule folds). In the past I've run the SETI@home "screen saver", which actually works one's computer flat-out, analyzing signals from space in hopes of finding intelligent life elsewhere; I may do so again.

In the Project Finder I entered a few key terms: my state; "animals"; and checked off project types "at home", "on a hike", and "exclusively online". The project types are inclusive, not combined. SciStarter suggested 54 projects. That was just a test. I can go back later and select one or more to try.

Science depends on data. When citizens collect or help sort and categorize data, it helps professional scientists. It can also introduce us to new friends we meet through the projects, friends with common interests. It is worthwhile to get this book and keep it on hand.

Mechanisms of evolutionary saltation

 kw: book reviews, nonfiction, evolution, development, evo-devo, dna, molecular biology

It took Stephen Jay Gould twenty years to write The Structure of Evolutionary Theory. It will take me longer than that to read it. I bought a copy when it was released in 2002, and I am only one-third of the way through it. I intend to read it all.

You may know that Dr. Gould is one originator of the hypothesis of Punctuated Equilibrium: fossils show that species tend to persist almost unchanged for periods of a million years to tens of millions of years, and then undergo rapid change, during which new species arise quickly. His book discusses this matter, and much more, in a historical context. I probably haven't come to the "good bits" yet. But others have, and scientists continue to discover new aspects of genetics and evolution, so I read widely in the field.

A stellar new volume is Some Assembly Required: Decoding Four Billion Years of Life, from Ancient Fossils to DNA, by Neil Shubin, a researcher and professor of Organismal Biology and Anatomy. His book outlines certain events in the history of evolutionary thought and genetic discovery, with an emphasis on a seminal thought expressed by one of his mentors, "Things didn't start when you think they did."

For example, he discusses wings and flight. Flight arose at least four times, in insects, pterosaurs (reptiles), bats (mammals), and birds. In each case, wings didn't appear all at once, but we find that earlier tissues and structures with different functions were co-opted to become wings, in a rather short time span. Furthermore, by digging into the genetics of wing development, he and others have found that the precursors to wings have similar origins in these very different types of animals. I can't do justice to an explanation of this. The book's discussion is brief yet illuminating. Bottom line: structures that could later become wings were developed long ago, for other purposes, and only millions of years later did the new function of "catching air" arise, requiring comparatively modest further development.

Another example every school child of my generation learned (do they still?): lungs developed from flotation bladders in fish. Whether the bladder developed a connection to the mouth by accident or for another reason, once that occurred, the already-existing practice many fish had of gulping air when the oxygen supply in the water was low, when combined with a new place to put that air, allowed these fish to survive better. Also, fins in some fish species were modified with "lobes", and these precursors of legs were used to move along the bottom of a lake or stream. "Walking" in this way keeps the animal below the worst of currents that it wants to move against; only later were the "legs" used to move onto and across the land, and eventually they were strengthened into legs strong enough to support amphibian bodies.

The pace of evolutionary development was very slow long ago, but has been accelerated over time with various developments. The first living things were like bacteria, or perhaps their cousins, the archaea. These together are called prokaryotes ("before the nucleus"): a prokaryote cell's DNA is a loosely-wound loop that runs throughout the interior of the cell. After a half billion years of gradual proliferation, some prokaryotes developed photosynthesis. Before that all life was chemosynthetic, using processes such as robbing sulfur from metal sulfides for energy. There are several kinds of photosynthesis; only one, initially, used CO2 and water to produce sugar, with oxygen (O2) as a waste product. Today's cyanobacteria (also called blue-green algae) are descended from O2-producing bacteria that arose about 3,500 million years ago.

At first, all the excess oxygen was used up by oxidizing sulfides into oxides and sulfates. This slowed down after another billion years, and oxygen began accumulating into the atmosphere. From 2,500 million to 1,500 million years ago, during the "boring billion", O2 slowly increased to about 2%. Then things began to change more rapidly. About that time, or perhaps a few hundred million years earlier, more complex cells developed. The DNA was encapsulated inside its own membrane, and at least two events of engulfment happened. Most probably the first "guests" invited into a larger cell (or they were invaders that were subdued and enslaved) were cyanobacteria, which were put to work turning air into sugar, while being kept safe inside the cell. Now they are called chloroplasts. Almost immediately, the second event was the capture of certain small, energy-efficient bacteria that probably looked a lot like E. coli. These became mitochondria. These larger, compound types of cell are called eukaryotes ("good nucleus"). A discussion of this process on pp 195-6 seems to imply that plants have chloroplasts but not mitochondria; not so, they have both. They need both!

Single-celled eukaryotes are still with us, most familiarly in the form of protozoa such as Amoeba and Paramecium. Some time before 1,000 million years ago, molecular mechanisms that were being used to attach to a substrate or to food particles before "swallowing" them, were re-purposed to allow cells to cling together. In the book a lovely discussion of choanoflagellates discusses how this works. The earliest multi-cellular creatures, whether they were proto-plants (with chloroplasts) or proto-animals, had a variety of shapes, but mostly looked quilt-like or mat-like. Some time around 600 million years ago an organizing principle arose. To introduce it, we must look into segmentation.

The prototype of segmented animals is the earthworm. You can see the segments, a lot of them. We vertebrates are segmented also. Our spine expresses the segmentation. Not all animals are segmented; in fact most phyla are not, but all have some kind of body plan. The Homeobox, or HOX, genes are controllers of body plan development. Every animal species has them. The HOX genes are organizers, and represent a kind of meta-control. The simple idea that we have "a gene" for this or that is a big distortion. Even in a simple animal such as a 1mm nematode, there are HOX genes that make the difference between front and rear and so forth. The more complicated sets of HOX genes found in more complex animals arose from reduplication.

Reduplication is a big theme in genetics. The added sets of HOX genes we need are an example. Mutation isn't a matter of creating a new, complex function out of whole cloth. It proceeds by various errors of copying, which will usually just kill the animal, but occasionally are at least mostly harmless, and over time, the odd bit can gain a new function. The most common mutations are single-point changes, such as from an A to a G in the genetic code. But whole segments can be duplicated, particularly during the "crossover" that occurs during the production of eggs and sperm. If an extra set of HOX genes is produced, one set can go its merry way, controlling the body's development, while the other set is modified and can lead to an extra function or body part or even whole section. Again, this isn't usually good for the animal, but it can be.

Segmentation arose by reduplication. In some cases, many identical segments were produced (earthworm). In others, the segments became specialized. The HOX genes control all this. The illustration, from this article at Socratic.org, compares the HOM genes (as they are called for insects) with the multiple sets of HOX genes in humans and mice. The segmentation of the insect's body is emphasized in the drawing.

It may seem strange that we share this organizing principle with fruit flies, mice and everything else. From an evolutionary perspective, it makes sense. The system works, and we can see that it works, for it has produced millions of species of animal.

Now to the matter of saltation, as in this review's title. Saltation is a dirty word to most evolutionists. It has come to mean things like a rabbit suddenly "evolving" into a dog or a horse. That's ludicrous.

In a proper sense, saltation means "jumping", and the concept (if not the term) had to be coped with once Barbara McClintock discovered jumping genes in corn. They have since been found in every species, and certain kinds of them form much of the "junk DNA" found between the genes in our genome. But others have been put to use, and HOX may be an example.

Just by the way, there's a lot less "junk" in our DNA than early reports claimed. Just 2% of it codes for proteins. An additional 2% (perhaps much more) consists of regulatory sequences that control when and how the genes make those proteins, a further 8-10% consists of deactivated viruses, which form a "library" of stuff gathered from everywhere, that can be re-purposed. Some is apparently second- and third-level regulatory stuff. About 2/3 is "palindromic repeats" (such as AATTGCACGTTAA) that consist of head-to-toe copies of "stuff", which at the moment, is at least useful for landmarks used by CRISPER/CAS gene editing.

All these things, and many more discussed in the book, are mechanisms for more rapid evolutionary change, compared to waiting for single-letter mutations to accumulate. Even over millions of years, that process is dreadfully slow. The beauty of these mechanisms, still being discovered, is that they allow big changes to occur without disaster.

The Earth would seem quite full of many species, were there only a few tens of thousands of them. It is astonishing that there are millions! I work in the "shell room" of a museum, and every time I open a cabinet I see something new, just among the mollusks! That room contains specimens for more than 20,000 species...of seashell! Nearly 100,000 are known. It seems that life, having figured out how to spin out new kinds of creatures, is still ramping up. While we may be driving thousands of species to extinction, it is likely that new species are arising even faster. If we attain wisdom enough to let nature alone and "live lightly", we may see even more variety in the multiplicity of life in the future.

The biosphere has used five of its lives

kw: book reviews, nonfiction, geology, geologic history, earth history, mass extinctions

Beginning Geology students have to learn a plethora of new terms, including the geologic ages: Pre-Cambrian, Cambrian, Ordovician, Silurian, Devonian, Carboniferous (in the US, divided into Mississippian and Pennsylvanian), Permian, Triassic, Jurassic, Cretaceous, Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Recent. I remember learning a letter-mnemonic for Cambrian through Recent: COSDMPP-TJC-PEOMPPR. Over time we learned that each such age has characteristics that differ from the others, including different prevalent rock types and different fossils.

Later on we learned that the significant differences from age to age are a result of great revolutions in the kinds of living things, and the transitions are marked by large increases in the rate of extinction. Further, five of these are called "the Big 5" and "the Great Extinctions". Here is a summary of these as shown in a poster prepared by Bud Charles, in use by many web sites that discuss "the Big 5"

The "Death Rate" reported in the diagram is the number of species that were driven to extinction. The percent of the biosphere that was destroyed is a much harder quantity to determine, and I have not found any published estimates. Considering the certain damage to each species that survived any of these events (or periods; some "events" took a million years or more to unfold), it is likely that the actual reduction in the "living biosphere" was 90% or greater for each of these, and may have exceeded 99% for the biggest, the end-Permian mass extinction.

The recent book The Ends of the World: Volcanic Apocalypses, Lethal Oceans, and Our Quest to Understand Earth's Past Mass Extinctions, by Peter Brannen, is a very well-written travelogue through the geologic ages, focusing in some detail on the processes of each of the Big 5. The photo plates show scenery of the existing geology resulting from them. It would have been very beneficial to have a chart such as that above, with even more detail, because more is known now (in 2017, the date of publication), compared to just a few years earlier when the poster was produced.

It would also be useful to have a visual of where these fit in time, such as this diagram from an article in the Washington Post, reproduced here at a small size as allowed by copyright law.

The section on the right labeled "Tertiary" includes all the ages from Paleocene to Recent. The dips and wiggles show how extinctions less severe than the Big 5 have played a part in the transition from each age to the next. Also, the little dip in the middle of the Carboniferous represents a significant change in plant life that accompanied a lesser extinction event, which marks the divide between the Mississippian and Pennsylvanian ages as recognized in the US.

In this diagram, the metric is "number of families", rather than number of species. Look particularly at the end-Permian, where the number of families has dropped by about half, as compared to the number of species, which, as noted above, dropped by 95% to only 5% of its former value. The taxonomic Family is two levels broader than the Species, so if even a single species in a family survived, that is a surviving family. Nonetheless, the end-Permian event is clearly the most severe.

The kinds of things that nature can throw at Earth and its biosphere are described clearly in the book. In many cases, the primary causes may differ, but the critical factor is a great change in global temperature. In the chart above, "rapid global cooling" is mentioned twice, and "rapid global warming" is mentioned twice. In the case of the end-Cretaceous event, it is likely that almost instant world-wide broiling occurred, followed by decades or centuries of "impact winter".

Three of the Big 5 were caused, at least in part, by the eruption of flood basalts, a tame term for the sudden release of 100,000-1 million (or more) cubic miles of lava. Even the end-Cretaceous event, which destroyed all the dinosaurs (except a few that became birds) plus the flying and aquatic reptiles, which "everyone knows" was caused by an asteroid crash 65 million years ago, coincided with the eruption of the Deccan Traps ("Trap" is another word for flood basalt), in India. Enough is known about the Deccan Traps to calculate that if the lava had been evenly spread over the Continental US, it would have been 600 feet deep. That makes the scale of the Yellowstone "supervolcano" a cap pistol by comparison. As big as that was, the Siberian Traps that we think were the primary cause of the end-Permian extinction, 251 million years ago, were as much as ten times larger. The third flood basalt event left remnants in New Jersey (the Palisades) and around the East Coast of the US at the end of the Triassic about 200 million years ago. It was smaller than the Deccan event, but big enough to rate as one of the Big 5.

What can cause volcanism on such a scale? Generally speaking, the splitting of a continent will fill the bill. Prior to about 1966, the continents were thought to be stable and immobile, and all kinds of wild ideas were in vogue at various times to explain the origin of mountains. Plate tectonics was "discovered" in the early 1960's, after being proposed in 1912 by Alfred Wegener, and just when I began to study geology in earnest (1970), this new paradigm changed everything. It was an exciting time to study geology. One offshoot was the study of supercontinents. They seem to form periodically.

The mid-Atlantic Ridge is pushing that ocean's coasts apart at a rate of 2.5 cm/yr., which amounts to 25 km per million years. The Atlantic Ocean's width varies from under 5,000 km to 6,000 km or so, which implies that the breakup of a supercontinent that once included Africa, Europe, and the Americas adjacent to one another along a "seam", occurred beginning about 250 million years ago, and was completed after 200 million years ago. That 250 million-years-ago figure is suspicious. Another "seam" appears to have ruptured at the same time thousands of miles away, and apparently it was the more "active". That would be the source of the Siberian Traps. The 200-million-years-ago figure, relevant to the Equatorial Atlantic, would point the finger at the end-Triassic event that covered much of the eastern US with lava. I think that is enough to make the point.

The mid-Atlantic Ridge isn't the fastest. The Pacific Plate is presently being absorbed under Asia at a rate of 8 cm/yr or 80 km/million years. Other plates are moving in other directions, with Africa as an apparent pole of stability. Other plates and their continents show evidence of passing over hot spots in the mantle, such as the one that produced the Hawaiian Islands and the Emperor seamounts, the one currently under Reunion Island, and the one that produced Yellowstone and a chain of calderas stretching at least as far as Idaho. Africa doesn't seem to have any hot spot traces, but it is apparently beginning to rift apart near its eastern margin, in the beginnings of another cycle of continental splitting. 

The crust of the Earth undergoes cycles of continental mash-up into supercontinents, followed by fragmentation. Note that we are in an era of partial fragmentation; Asia occupies about 2/3 of all the continental area of the Earth, and is likely to gather the rest of the continents into one after another 100 million years or so. The Pacific Ocean is shrinking at a rate of about 80 km/million years, so it won't last forever!

Considering this, I wondered if the breakup of earlier supercontinents might be implicated in other big extinctions. Here is a list, summarized from several articles and other documents. Note that Pangaea spans the end-Permian and end-Triassic extinctions. I find it curious that Pannotia came together just after the Deccan Traps erupted, so perhaps continental construction is as effective as continental splitting at producing biosphere-threatening volcanism.

The earlier supercontinents occurred before the Cambrian, which means before easily-found fossils. They could not have been involved in the Big 5. But there were earlier mass extinctions; they are hard to detect, because only bacteria (and archaea) lived then. I suspect a number of Precambrian great extinctions happened. Numerous Precambrian geology specialists are busily working on it.

Atmospheric chemistry is a different driver of extinction. It may be that the biggest mass extinction of all occurred when oxygen began to accumulate in the atmosphere. Photosynthesis began about 3.5 billion years ago. There are several types of photosynthesis, and at first, only one, called "C3", found today in algae and most plants, produced oxygen directly. Other types, such as that used by green sulfur bacteria and purple sulfur bacteria, have other chemical results. For a billion years, none of the oxygen made it to the atmosphere. It was all consumed oxidizing iron and its sulfides, and other reduced materials, forming the great "red beds" and other oxide ore accumulations, for example. About 2.5 billion years ago, most reduced materials had been oxidized, and oxygen began to enter the atmosphere.

We can see from this chart, found in Wikimedia Commons, that a low level of oxygen, in the 3%-5% range, prevailed for more than a billion years, and it seems life kind of stagnated once it got used to that. This era is called the "boring billion." The upward inflection shown here at about 900 million years ago probably occurred a little earlier, maybe at 1.1 billion years. The red and green lines are limits proposed by various workers; the red line is the more probable.

Animals and plants apparently evolved just about a billion years ago, with a metabolism fueled by increasingly abundant oxygen. The big uptick occurred during the Permian, when oxygen probably exceeded 30%, compared to 20% today.

The other significant gas is carbon dioxide, CO2. This is one of numerous diagrams showing the level of CO2 over the past 600 million years. In The Ends of the World it is stated that the primary mechanism for absorbing CO2 is weathering of basaltic rock. However, it is slow, taking place on a scale of 100,000 to a million years. Based on this chart, one would expect that fresh basalt was made available in the mid-Cambrian, all during the Ordovician and Silurian ages, and in the early Carboniferous. That doesn't seem so. Rather, in particular for the Carboniferous age, the huge expansion of forests that produced nearly all the coal in the world occurred. I'll leave it at that because this is a side point.

Apparently, the dip in life's diversity in the mid-Carboniferous that I mentioned earlier happened when CO2 was drawn down to modern levels (between 200-400 ppm), at which point trees, which rely on C3 photosynthesis, have a hard time growing rapidly. At the far right, the CO2 drawdown that trended during the Tertiary (Paleocene until the present) was apparently a result of new types of green photosynthesis, called CAM and C4. Grasses, the main sort of C4 organism, and their relatives are very happy with 200 ppm of CO2 or less, while trees are happiest when CO2 is in the 1,000 ppm range. Experiments with rice plants have found that rice grows best when CO2 is 2,000 ppm.

The author makes much of the gyrations of CO2 that occurred in the past. While he is right in general, he tends to be alarmist. I almost added "polemics" to my labels for this review, but I decided not to. The book may get a little polemical, but it is much more than that, and contains a great amount of interesting and useful information about the worlds that preceded us, particularly how different each one was from what we live in now. For example, we are accustomed to reefs based on hard corals that host mollusks and fishes of many kinds. Permian reef backbones were masses of brachiopods and mollusks, with corals scattered among them, hosting more ammonites than fishes. Cambrian reefs were even more weird, made of piled-up animals that looked like individual coral polyps, lots of brachiopods (they look like cockles, but with much lower metabolism), and the main swimming things were trilobites and nautiloids, which look like straightened out ammonites (both resemble squids with big shells).

I was particularly interested in the analysis of one person cited, who said we are nowhere near a sixth great extinction. He has the numbers to prove it. So it is a little early to call the past century or two the beginning of the Anthropocene age. But we would do well to be wary. The greenhouse effect is real, and it is pretty certain that we are contributing to it. Whether it will lead to catastrophe or instead ameliorate the next ice age is yet to be seen.

How much can we heat the planet if we continue to burn petroleum and coal? As a teen I reproduced the calculations of Arrhenius, the one who first publicized the CO2-induced greenhouse effect. Later, using differential-albedo modeling (such as how sunlight heats something that absorbs visible light better than infrared, or vice versa), I verified something I read: "If we push CO2 so much that we 'close' the 'window' of its absorption bands in the infrared, the maximum warming would be 4°C". Statements about 9°C and even 12°C are not realistic, nor mathematically possible. Now, four degrees is significant. Will it melt Antarctica? Probably not.

We are also not going to push CO2 into the tens of thousands of ppm range, just by burning fossil fuels. Some look at the oxygen in the atmosphere as being entirely "carbon debt". That 20% is 200,000 ppm. CO2 weighs 37.5% more than oxygen does. If we could really extract (and burn) that much carbon from oil and coal fields, the actual mass of the atmosphere would increase 7.5%, and this new, heavier atmosphere would be 25.5% CO2, or 255,000 ppm. We would all have died from anoxia long before that point. But the total extractable carbon in the crust is only a fraction of this, a few percent. Most of the carbon from decaying "stuff" was carried into ocean trenches and is deep in the mantle, perhaps making gigatons of diamonds!

I have a quibble of a different nature: on page 189 it is stated that the asteroid that did in the dinosaurs "put a hole in the ground 20 miles deep—deep enough...to puncture the earth's mantle...". This should state "puncture to the earth's mantle", which begins around 20 miles down, and extends 1,800 miles deep.

On a happier note, the author cites Mark Richards as proposing that the asteroid impact actually triggered the formation of the Deccan Traps. A more modest level of flood vulcanism had begun before the impact, but it took off right at that time. I suggested this to one of my geology professors some 40 years ago, and he was very skeptical. At that time the "impact theory" was accepted, but the location of the crater in Yucatan wasn't yet known. I suggested a possible impact antipodal to India, somewhere in the South Pacific, perhaps 1,200 miles southwest of the Galapagos Islands. Dr. Richards does say that an antipodal arrangement would yield the best "focusing" of the seismic disturbance caused by an impact, but since the asteroid's impact was like a magnitude 11 or 12 earthquake, such focusing was not needed to trigger an ongoing eruption into a mega-event, releasing its pent-up lava over a much shorter interval.

Another significant theme is that all of the Big 5 mass extinctions were multi-factor "perfect storm" sorts of things, with the end-Permian event being the "most perfect". I'll leave that for readers to discover as they enjoy this readable and informative book.