Critical thinking - needed now more than ever!

kw: book reviews, nonfiction, critical thinking, psychology, sociology

As I write this, a Kangaroo Court is being conducted in a Congressional committee, to hear "testimony" from a convicted perjurer. Such testimony is intended to, at the very least, embarrass the President of the United States; hopefully, to convince a larger segment of the public that said President is a liar, bigot, and general bad guy; even possibly ("Please, please!", you can almost hear them begging), to gather material that will allow Articles of Impeachment to be drawn up. P.T. Barnum would be proud (Google the two words Barnum and sucker).

So, mini-quiz:

1. Do you know what verse in the Bible states, "Money is the root of all evil."?
2. Do you believe the Moon landings of 1969-1972 were faked?
3. Do you expect part of California to "fall into the ocean"?

My analysis (feel free to disagree):

1. First Timothy 6:10 states, in the King James Version, "For the love of money is the root of all evil: which while some coveted after, they have erred from the faith, and pierced themselves through with many sorrows." Note that it is "love of money" not just "money". The New International Version, usually more accurate in colloquial English, renders the first phrase, "For the love of money is a root of all kinds of evil." Here it is "all kinds of evil", not just "all evil." Big difference.
2. If you believe NASA faked the Moon landings, you're in good company if you're British (52% of Britons think so), but only 7% of Americans think the landings were faked. U.S. Government hype about the Moon program is definitely worth taking with a grain of salt, but in my view, it would be harder to fake than to actually do it!
3. This was a popular belief 40-50 years ago, when everyone was waiting for a "big one" earthquake on the San Andreas Fault. In the half-century since, there have been several "nearly big one" earthquakes, which seem to have relieved the geological strain…for now. But, the S.A. Fault moves sideways, not up and down. The western side is creeping northward. If you wait long enough (40 million years), Los Angeles and San Francisco will be "sister cities", right across the Fault from one another. After a further 100 million years or so, the L.A. area will begin to descend beneath Alaska somewhere along the Aleutian Trench. That's when it will "fall" into the ocean.

Item #1 above is in the "everybody knows" category, at least for Americans brought up in a nominally Christian environment. But what most of "everybody" knows, isn't what was really written by the apostle Paul. Item #2 is a "grand conspiracy" belief. Those who believe it, can't be convinced into not believing it. And #3 takes advantage of general ignorance of geology (which direction the fault moves) and our small time horizon. It isn't just that we only live a century or less; most of us get impatient waiting for the microwave oven to heat a cup of water to make instant coffee! Even H.G. Wells's Time Machine only takes the fellow 800,000 years into the future (except for one scene, at an unknown remove, when the Sun is becoming a red giant).

When I was in college, I took a course in the English department, but it really belonged in the Philosophy department. We read articles in lots of journals of all kinds. We were to figure out what was the bias of the article, and by reading editorials or other articles in the same journal, what was the bias of the journal as a whole. So, the Wall Street Journal was, and still is, quite conservative, while Commonweal was and is liberal, bordering on progressive, and with a Roman Catholic viewpoint. There were five or six others. Near the end of the course we were to read editorials from several local and near-local newspapers, plus the New York Times. It was obvious to all of us that, without exception, the papers were exclusively left-wing. This was in the 1960's! Looking back and comparing with editorials in the local papers now, those would be considered hide-bound conservative (Jack Kennedy was fondly looked upon as a liberal, but today would be to the right of nearly everyone in Congress).

This points up two things. Firstly, I don't think any American college still has such a course in Critical Thinking. That wasn't its title, but it should have been. Secondly, baselines have shifted. Creeping leftism is one kind of "moving goal posts" trend. The fallacy of Moving Goal Posts is one matter taken up by the authors of The Skeptic's Guide to the Universe: How to Know What's Really Real in a World Increasingly Full of Fake, Dr. Steven Novella with Bob Novella, Cara Santa Maria, Jay Novella, and Evan Bernstein.

The authors, three brothers and two associates, are a core group of SGU (see book title), which produces podcasts and other materials on behalf of the New England Skeptical Society. They call themselves and their colleagues "rogue skeptics." Skeptic's Guide first discusses the many ways we can fool ourselves or be fooled by others, presents case studies from their experiences, and shows how to determine (to some degree; nothing is perfect) the veracity of the things we see and hear and read in the media. They have taken on a tall order, and the size of the book (nearly 500 pages) attests to that.

I began to read, with a niggling thought in the back of my mind, "I wonder if they'll make a full-on assault on faith?" I was relieved to find that they do not. They do criticize (rightly) young-earth creationism, anti-evolution beliefs, and the kind of "easy-believism" that attributes favorable coincidences to divine favor. In those areas, I happen to agree with them. Dr. Novella is a physician and educator. He reserved much greater disdain and his best ammunition for anti-vaccination activists and the "AIDS is not from HIV" folks, and most kinds of "alternative" medicine. As to religion, I would not call him an Atheist; that term has been taken over by evangelical anti-theists. I'd call him an honest non-theist. (Hey, Doc, I mean that as a compliment!)

Is it possible to be a Christian skeptic? Particularly for me, a Christian mystic. Let's define terms here: "mystic" means someone who has spiritual experiences; and "skeptic" means someone who withholds belief in claims not properly supported by evidence. The first half of the book points out all the ways that our "experiences" could be fallacious. Well and good. The experiences of me and my fellow believers may not make sense to the SGU folks. They'd say we have false premises. I say we have repeated and reliable experiences and based upon them, we are either crazy, or we are children of God, who know our God by direct experience. However, it is worth taking note that we have finite capacity, which does lead to our brain taking many short cuts with our perceptions. We need to be humble, which is mentioned frequently throughout the book.

So, I am a mystic, but I am also a scientist. I am a retired IT/IS computer scientist, who wrote software for geologists, biologists, chemists and physicists for 40 years. In retirement I work for a natural history museum (part time), where I use my knowledge of the workings of evolution and natural selection daily. I understand Deep Time (millions and billions of years) in a way not many people are equipped to comprehend. As a scientist, I am a skeptic. I am actually quite impressed by an argument the authors make, against the notion of "supernatural" events. If something happens, and it had a physical effect, particularly one that can be measured, it is by definition part of nature. Thus, if there is an entity that we call God, who—as theists believe, by definition—intervenes in the workings of humankind and particularly His believers, that God is part of nature. The Judaeo-Christian understanding of the creator takes that a step further, to say that "real nature", including God, is a lot bigger than the "nature" that human scientists have so far been studying.

I had a colleague at an engineering company where I worked in about 1975, who told me of his belief that God was a "super technologist". Maybe he was right. If what I believe about God is correct, I expect to have the chance to ask Him.

Back to the book. We are bombarded more than ever with "fake news". It is getting easier to fake. Even a century or more ago, some things could be faked. Have you heard of "retouching"? I have a photo from 1914 of a family reunion. I scanned it for my online family tree. In the scan, the oblique light of the scanner made the retouching more evident; I hadn't noticed it before. The photographer actually painted, right on the 8x10 inch print, to make certain of the faces more attractive, particularly one older man who had huge jowls, which are retouched to look more like a more ordinary elderly face. Photoshop was about 75 years in the future! Now such photo-editing can be done very easily and is undetectable without specialized software.

There's one spot in the book where I noticed the authors let an error (made by others) slip past them. On p.88, writing about altering perceptions by the way a fact is presented:

Another example is a survey showing that "62 percent of people disagreed with allowing 'public condemnation of democracy,' but only 46 percent of people agreed that it is right to 'forbid public condemnation of democracy.'" These are, again, the same outcome.

Actually, 62+46=108. Either there is a typo there, in the production of this book, or the source contained the typo. Considering the language used in the two statements, I suspect the latter figure was intended to be 38 percent. Now, this does little more than emphasize that I am a pretty good proof-reader. The point they are making is valid. If I say to you, "This chemotherapy is successful 2/3 of the time", it causes quite a different feeling than "1/3 of those who use this chemotherapy find it ineffective."

And I do want to say a word about selective attention. We can't pay attention to everything, so we are, by nature (natural selection, in which I do believe), fitted to discard nearly everything that enters our senses (90%? 99%? anyway, nearly all). Although we have a visual cortex with as many neurons as the entire brain of a gorilla, and it slurps up a 120-megapixel stereo image (about 8 mpx of color info), about 20 times per second, we must discard most of that. There isn't time or space to form lasting memories of everything. We actually "notice" a small number of "things" per minute, but there are upwards of 800 minutes in a waking day. By the end of the day, most of our "minute-memories" are long gone, and we remember only a few. Weeks later, we aren't sure which day we had eggs for breakfast, and which day we had Lucky Charms or Rice Krispies. We will, however, remember the fight we had with our spouse or the scare we got when a semi nearly ran us off the road…but we may not recall just which day it was. Instead, we'll remember what our spouse was wearing or the tree alongside the road that we narrowly missed.

Now, I could go into the techniques for avoiding being faked out by fake news. The book contains so many of them, you'd have to be the kind of specialist that the "rogue skeptics" are, to effectively use more than a handful. So I'll just mention a couple of things.

First, for many things we might encounter, when a viewpoint is presented, we need to ask, "Who benefits?" This principle is behind the phrase "conflict of interest." We are all prone to that! Secondly, when there are conflicting views of an event, it is useful to ask, "Who has the power?" or "Who is paying for this?"

When someone, for example, wishes to run for President, so as to move American toward Socialism, and that same someone has become filthy rich by taking advantage of Capitalism, I just have to say, "Well, his initials are B.S., and that's what he is feeding us!" But, who benefits? Socialism requires totalitarianism. Under the dictum of Marx, "From each according to his ability; to each according to his need," who gets to choose what "his ability" ought to be, and who gets to choose what "his need" is? In every Socialist nation that has been set up, the totalitarians benefit, a whole lot, at the expense of everybody else. Look at the fine suits the current (and I hope outgoing) President of Venezuela wears in his news conferences, compared to the rags worn by the people the Venezuelan troops are gunning down in the streets because they have the temerity to ask for "more". Every "Socialist experiment" has devolved into a kleptocracy.

So, for today's Kangaroo Court, who benefits? Why would Mr. Cohen volunteer to "tell all" to a Congressional committee? There must be a very lucrative book deal in it (as soon as he gets out of prison for perjury). Also, to me this smacks of revenge. That is another kind of benefit, to lots of people. And I would not be at all surprised if there are large behind-the-scenes kickbacks (suitably laundered) from some Congresspersons who are hoping for that "smoking gun" they need to proceed with an impeachment.

My default mode is to get news from numerous sources. It's just kinda hard to get anything but "leftie special", when 90+% of the media are leftists, and I don't have cable so I can't watch The Blaze or Fox. Luckily I can get conservative news from at least one radio station around here, to counterbalance the "radio Leningrad" I hear from the rest of them.

So, Dr. Novella has become a favorite author of mine, at least among the non-theists. The writing in the book is top-notch, and the thinking is clear, or at least a whole lot more clear than almost anything I see in the newspapers these days.

P.S. P.T. Barnum didn't actually say, "There's a sucker born every minute." An associate of his said he built his business on fooling suckers, "…because there's one born every minute." The geek in me just has to add: Today in America, there are 7.3 births each minute, and in Barnum's time it was pretty similar (more births per person though the population was smaller). So, it seems, 6/7 of us aren't suckers! Somehow that seems optimistic…

Nature's got rhythm - it slows down entropy

kw: book reviews, nonfiction, natural history, mathematics, synchronicity, sync

When you view this video, most of the language you hear is Malay. In parts of Asia, and in the Great Smoky Mountains in the U.S., certain species of firefly synchronize their flashing. Why? You'll get part of the answer from reading Sync: How Order Emerges from Chaos in the Universe, Nature, and Daily Life, by Steven Strogatz.

As a professor of applied mathematics, Dr. Strogatz has studied sync for most of his career. As a freshly-minted college graduate, he chanced to get a book by Art Winfree (deceased), who became a mentor to him and kick-started his lifelong fascination with synchronicity (sync), and how it is found throughout nature, both in living and nonliving systems.

When our brain forms a lasting memory, a scattering of neurons that reach from end to end of the brain will pulse in sync for a moment. For some reason, memories we aren't destined to hang onto cause a less wide-ranging burst of activity. What little we so far know about this is discussed in Chapter 10, "The Human Side of Sync". The synced fireflies seen in the video above, and theories for the phenomenon, are discussed in the opening chapter, "Fireflies and the Inevitability of Sync." We respond strongly to sync, as evidenced by our love of dance, singing together, and applauding of cheering together. "The Wave" in a sports arena is a traveling sync phenomenon. I've experienced The Wave running around a stadium six or seven times before fading out.

Our "body clock", circadian rhythm, seems to be rooted in a clock that resides in every cell of our body. It typically runs on a 25-hour cycle and is reset by daylight. Experiments with people spending months in "time free" areas like caves or specially built rooms, who were given no clues about what day or time it was (and who frequently went rather crazy), elucidated this chart:

Our body temperature follows a pretty strict daily curve usually peaking at or just below the proverbial 98.6° (actually chosen because it is exactly 37°C, though that is a tad warm) about sundown, and dipping as much as 1.5°F (0.8°C) to a low a few hours before sunrise. BTW, my daily high is seldom above 98°F.

This chart gives support to the siesta habit in some cultures (not only Latino), and to the big spike in "inattentive driving" accidents during the Zombie Zone after midnight.

This chart is averaged. Some people's cycle runs later, some earlier. A friend of mine cannot sleep past 3:00 AM, so he must hit the sack between 7:00 and 8:00 PM to get a full night's rest. Teenagers are frequently "owls", needing to sleep until at least 9:00 AM, even though most high schools start their day more than an hour earlier (taking care of the parents' work day requirements); so our kids are sleepy in class and learn less. This is in part why homeschoolers learn better, on average. Their parents start the learning day later.

Nonliving systems also synchronize. A few centuries ago, Christian Huygens, recuperating from illness, noticed that two clocks hanging on his bedroom wall were ticking in sync. Here, they were in exactly opposite phases: one would tick when the other went tock. There is an episode of  Mythbusters focused on putting hundreds of metronomes on a platform sitting on rollers, showing that, if set to (nearly) the same frequency, they gradually all sync up and tick together. A pair of tiny moons in orbit around Saturn was found to be sharing an orbit in which one almost catches up with the other, then both shift—one a little inward and the other a little outward—so that they move apart and swap velocities so that the formerly slow one will begin to get ahead until it was the one catching up. The two moonlets never touch. I find them similar to Huygens's clocks.

What is going on here? It seems that nature loves sync. A few decades ago I read an essay, based on a physics professor's lecture, called "Nature's Hangups". It illustrated a number of the things that happen in nature to keep everything from just falling to a center and eliminating itself in a big "whooomph". Sync had a lot to do with it. Near the end of Sync, the same principle is mentioned, using an eloquent image of complex systems taking advantage of entropy to form local pockets of decreased entropy, things that we call living beings, crystals, and solar systems. Sync describes the formation of "time crystals", the regular pulse of a natural system, analogous to the regular array of atoms of molecules in a mineral crystal.

Phenomena as disparate as our heartbeat, the swirling of flocks of starlings or schools of fishes, the aforementioned synced fireflies, seizures induced by repetitive flashes (I've been knocked out cold by a rising sweep of bright flashes), and the Kirkwood Gaps in the asteroid belt (orbits in sync with Jupiter), all have related mathematical descriptions, revealing an underlying tendency in nature to sync things up. In later chapters, starting with 7, "Synchronized Chaos", we find that even wildly gyrating "chaotic" systems (in the mathematical sense) can synchronize themselves, which may lead to improved ways to encrypt communications.

Dr. Strogatz is a mathematician. He is also one of the great explainers of recent generations. He manages to discuss and describe many highly mathematical subjects, and make them at least conceptually understandable, without using a single equation. Sync is literally keeping you alive, and his book tells how.

The man in the box is missing

kw: book reviews, nonfiction, artificial intelligence, algorithms, surveillance

Google is spying on you. So are Facebook, Twitter, and nearly every web site that you use. Never mind the NSA and the CIA and their ilk (another 15 of them, just in the US!). Here's the rub, though. Amongst the many "likes" and other clicks you make daily; and if you like to write, as I do, amongst hundreds to thousands of words you generate; and amongst the photos and links and other "stuff" you might send out into the ether, daily: Is there someone who can digest it all, winnow it, and produce a comprehensive picture of just who you are?

Not a someone, but a something. Namely, an algorithm; strictly speaking, in each such case (Google, etc.) a veritable forest of algorithms that analyze (gather, group, parse, summarize, mathematically rotate in n-space) all the data we generate for them and give to them.

What is an algorithm? It is a recipe. A cookbook is filled with descriptions of algorithms that a cook will follow to produce this or that dish. A computer program contains, in specialized language, recipes that the computer will follow to "cook" data to produce "dishes".

Early electronic computers were used to produce tables for predicting the flight of a mortar shell, which made it easier to aim accurately. The ballistics table was the "dish". These days, the "dish" is more likely to be something that an advertiser will use to influence you to buy something, or a political party will use to influence how you vote, or a "nonprofit" group will use to gain your support. Does any of that worry you?

David Sumpter, a professor and applied mathematician, worried about these things, and he had the tools and the standing to do some digging around. How much of this is true, and how effective are these techniques? His intellectual and mathematical journey and the conclusions he drew are described in Outnumbered: From Facebook and Google to fake news and filter-bubbles — the Algorithms that control our lives.

He describes what he found, and, to cut to the chase, while the power of the algorithms is amazing, the results are slender. The algorithms are not much danger. Even the more powerful algorithms we can expect in the next generation or two are unlikely to be much danger, in and of themselves. The true danger is that powerful people believe their results, even when it can be shown that the best algorithm is no more accurate than the informed opinion of an intelligent expert.

Why is that so? I must back up here: we in the computer field rather loosely talk about "putting the intelligence" into a program. But that does not make the program "artificially intelligent." In every case, we embody some aspect of human intelligence in an algorithm that a computer can perform very fast. For example, I know how to perform a Fourier Series analysis, to analyze the frequencies in some kind of signal, such as a snippet of a song or a portion of a digital photo. It takes a lot of calculations (millions of them to analyze 1/100th of a second of audio). Computers can do those calculations so fast that audio spectrum analyzers that run on a smart phone can produce a sound spectrum  in real time (I use one to "see" bird songs). No computer "invented" the Fourier Series analysis, a human did. So, why is it that a knowledgeable person can still outperform a mechanical "understanding" of social cues? Two things: (1) The human mind works in ways that nobody yet has a clue about; and (2) We instantly recognize similarities, which computers don't do well, while computers instantly find tiny differences, which we have a hard time at. (Just by-the-bye, I made a 40-year career exploiting the synergy of mind and machine.)

So the problem with letting algorithms "do stuff" is that they don't do it any better than we do. This isn't likely to change much in the next few decades. Further, because the data used to "train" the "deep learning" systems in use today (such as for Google Translate) contain lots of human bias, those biases will be reflected in the results produced by the systems. For example, suppose we use the trillions of sentences in Twitter to train a natural-language understanding-and-response system. Is it possible to pre-filter out the trolls, the "hate speech", the bigotry and sexism and this-and-that-phobic utterances? If we don't, the trained system will exhibit the biases and bigotry of the data that went into it. This is a malicious example of "garbage in garbage out."

For most of us, we experience the results of all that spying and calculation in the ads we see online, and even the kinds of results we get from doing a search. I have learned to search for anything meaningful in an Incognito (or inPrivate) window. My wife and I had this experience: a handle on an end table was getting loose. We found that the threads on its screws were getting stripped, probably from being bumped rather hard at some point. We looked online for handle hardware, from various sources. We found something we liked, and ordered handles enough to fix both end tables. Guess what? I got lots of ads for handles, in Google, Facebook, and nearly everywhere else that had banner ads! I got them for a month. I thought of writing to Google, "Dudes, I bought a set of handles the same day. Y'all are way, way too late!" But what's the use? Until they think to check online purchase information, they can't know it.

I did three little experiments. First, in a Firefox Private window, I went to www.google.com and began typing "how to peel", and then I recorded the auto-complete results:

• a mango
• butternut squash
• garlic
• pearl onions
• a kiwi
• an orange
• ginger eggs
• a banana
• tomatoes

When I did the same thing, logged into my Gmail account (on another tab), the first result was

• a pineapple

followed by the next 8 items above, from "mango" to "banana". Yesterday, I happened to look up YouTube videos about peeling pineapples. No surprise there.

Then I did the same process, starting with "best books for". The auto-complete list was:

• young adults
• teens
• 3 year olds
• men
• toddlers
• 2 year olds
• 4 year olds
• men 2018
• babies

When I did the same thing "as myself", I got exactly the same list. Did you notice, as I did, the glaring omission of women or girls? That is funny, because my wife and I use the same account credentials and the same email accounts. Maybe females don't search online for books (but I'd be surprised...)

Then again, in private, I entered the search term "genealogical". The results list, first page, was:

• the definition
• genealogical.com
• www.dictionary.com/browse/genealogical
• www.thefreedictionary.com/genealogical
• delgensoc.org
• [2 "top stories"]
• "How genealogical sleuthing led to suspect in Warwicks joggers death" - The Providence Journal
• "Genealogical Society learns about creating digital family histories" - Community Journal
• www.archive.gov/research/alic/reference/genealogy.html
• www.archive.gov/research/genealogy
• www.ngsgenealogy.org
• - not detailed
• www.newyorkfamilyhistory.org

The page also included a photo-ad from ancestry.com for its software and service. After that, logged in again as myself, I entered "genealogical", with these results:

• [3 ads]
• www.myheritage.com/Genealogy
• www.geneticsdigest.com
• www.genealogy.com
• the definition
• genealogical.com
• en.wikipedia.org/wiki/Genealogy

and then the rest as above, from www.dictionary.com through the rest except the newyorkfamilyhistory one. The photo-ad for ancestry.com was the same. Are these differences significant? Not usually.

The book ends on a slightly melancholy note. Dr. Sumpter found he'd become something of a wet blanket at parties, because when people started grumbling about what Google and FB and others were doing, he had the real info, which was less flashy. Sure, if an algorithm can sell 0.1% more fribble widgets, and if the market for fribble widgets is usually a few million, that 0.1% could be a few thousand more of them being sold. But people want something to be a little scared about. There's nothing scary about fractions of a percent. Even filter-bubbles turn out to be a toothless bugaboo. Nothing pops a bubble quicker than outside info from a source that isn't trying to change your mind, but is just presenting the facts as seen from elsewhere. All of us have more than one source of information. Sooner or later, any bubble we've been in will come up against "real life" from another angle.

I have to tell this story, a bittersweet one. In 1980 the first Chinese students were allowed to come to American colleges. A few years later some Chinese nationals who had relatives in the US were allowed to visit them. A Chinese friend of ours, a man in his seventies, was visited by his sister. For a few days, she said a lot about how good the Chinese system was, how Communism was better than Democracy, and so forth. I understand, of course, that in China, speaking any other way could get a person in trouble. Our friend and his wife didn't argue with her. They just took her along the next time they went to the grocery store, at a Walmart. The dear lady saw the rows and rows of fresh produce, the bread, and everything else, and began to cry. I must have been rather hard for her to return to China a few weeks later.

Will artificial intelligence make the algorithms work any better? Many of them are already being called AI, but it is hyped. It is just the rapid application of human intelligence. Anyway, we may be in a waning cycle of hype about artificial intelligence. Computer software is in no danger of replacing us any time soon. Before there were electronic computers, people had cleverly devised mechanical aids of many kinds to speed up the processes we needed. Napier's Bones were devised in the 1600's to simplify multiplication and division. Slide rules (I still have a few) preceded the pocket calculator by a few generations, and could also perform trigonometric and logarithmic calculations. I have an old copy of Machinery's Handbook, which contains "log tables", in case you need greater accuracy than a slide rule can produce. The first mainframe computer I used was no more accurate than the table of logarithms, it was just faster.

So far, all these things are tools. The algorithms used on our social data are tools used by marketers and propagandists. If we keep ourselves aware of these facts, we'll have better sales resistance, and "fake news" resistance. And we'll also be able to turn the tools back on themselves to our own benefit: sometimes the ads they show us are for something that we really can use, and we didn't even need to go looking for it!

Snowflake specs

kw: observations, convolution, novelty glasses

Someone gave me a pair of "Snowflake Glasses" as a gag gift. Here is how they look. It is kind of intriguing. There are apparently many of these with different light effects.

 I could see that, whatever they did, it would be a diffraction phenomenon. The purple color hints that they use an Ozalid process to make these. That makes sense, because it is capable of very high resolution, and is used for cheap microfilm. I didn't try these while there were Christmas lights up, so when I did, I first looked at the sodium-mercury street light. A very pretty snowflake! You can see a dimmer one radiating from the reflection on the right.

I noticed a little red-green fringing, which I would expect from a diffraction effect. So I decided to try a more broad-spectrum light, as seen next.

This is the light on a neighbor's house. It shines at a side yard. The color fringing is more evident. Each wavelength is diffracted a different amount, with red moving furthest because its wavelength is the longest.

I just had to see what the pattern looked like under a microscope. That's next.

 Diffraction bends light both ways, so only three pattern orientations are needed to make the hexagonal star. This pattern is called a convolution. It is the mathematical inverse of the star pattern that we see when we look through it. The oval with "snow090" is an identifier. The ovals are spaced far apart, so they don't diffract enough light to be visible, and they do it at a very low angle.

The total pattern is made up of tiles that look like they are about 2"x2" in this image. They are small enough that several of them "fit" in the beam of light that enters the pupil of your eye. Thus, no matter what portion of the specs you look through, you see the intended snowflake.

I am not sure of the magnification here. I was using my inspection microscope at 20x, but this is cropped from the middle of a bigger image, so perhaps it is around 50x.

Just for the record, it would be possible to produce such glasses that select just a few light colors (red, green and blue, for example) and diffract them separately so that they all make the same size snowflake, and there are no color fringes. But it has to be done using a different method, and the cost would be much greater. These are intended for looking at Christmas lights, which are single-color.

Animals you never knew about

kw: book reviews, nonfiction, animals

Bestiaries of the past combined natural history, legend, speculation and moral instruction. Based on better science, and including rich commentary instead of crude moralizing, Caspar Henderson has produced The Book of Barely Imagined Beings: A 21st Century Bestiary.

He goes through the alphabet, sometimes in a surprising way, including two "X" chapters. I am endlessly fascinated by natural history, but I'll keep this shorter by just touching on three special animals, and where his riffs upon them take us.

Barrel Sponges include the Giant Barrel Sponge, Xestospongia muta, which can live more than 2,000 years. Sponges were apparently the first animals to reach sizes larger than a few aggregated cells. They are most sophisticated than they look. There are apparently several (perhaps six) kinds of cells with semi-specialized functions, but no tissues as we would consider them. A small sponge can be forced through a sieve and thoroughly disaggregated to loose cells. It will re-form itself as it originally was.

Henderson discusses the concepts of multicellularity at some length, including some ways it goes wrong, as was seen with the Elephant Man, Joseph Merrick, who suffered the continuous growth of portions of his body. It is still quite mysterious how an animal body, whether sponge or starfish or surfer, keeps its parts proportional. From there the riff goes on to the development of life, once the Bacteria and Archaea split, and creatures that we call Eukaryotes, composed of large, nucleated cells were split off from the Archaea (or descended from one of them by engulfing some bacteria and keeping them as "pets" that are now termed mitochondria and chloroplasts). Every visible creature is a Eukaryote, but they (we) are outnumbered (trillions-to-one) and even greatly outweighed by non-Eukaryotes.

Nautilus, a genus of cephalopod (an order that includes octopus, squid, cuttlefish and others). They and their kind, the Ammonites, were the primary predators in the pre-Dinosaur-age oceans. Today, these are rare and getting more rare. Cephalopods have two kinds of appendages, arms and tentacles. A nautilus has 90 slender arms, without suckers on them. An octopus also has only arms, eight of them, but the arms are well equipped with suckers along their entire length. Squids, cuttlefish and some others have both arms and tentacles. The two tentacles are longer than the arms and have a pad at the end with suckers on it, and only there.

I show this image a little bigger than the others to make the eye more visible. Other cephalopods have eyes with lenses, but this eye has a small pupil with no lens. It is like a "pinhole camera", and it makes a very blurry image. That seems to be enough, along with the animal's tactile and chemical senses, to track down its prey and avoid predators.

Venus Girdle (see video below of Cestum veneris) is a surprisingly lovely type of salp. Salps and other "comb jellies" look kind of like jellyfish, but are in a different phylum, the Ctenophora (ten-o-fore-uh); jellyfish, corals and sea anemones are in the phylum Cnidaria. The "comb" of a comb jelly refers to the rows of cilia that it uses for locomotion. Ctenophores are the largest animals to move about primarily using cilia.

Taking off more from the name Venus (goddess of "love", that is, lust), than from the animal itself, Henderson spends a page or so on sex, and the indications that nearly all animals seem to enjoy it. (I would except those females of species in which the male's "member" actually pierces or spears the female's body to deposit its load somewhere inside!). Comb jellies reproduce very fast, so perhaps the Venus association is actually rather apropos. Where their predators are eliminated, they can rapidly take over an ecosystem and turn a large chunk of ocean into a teeming mass of gooey critters.

One other animal has a rather sideways association with sex in its name, Gonodactylus, the Mantis Shrimp. The scientific name arose when the naturalist who described it thought the paired forelimbs, when held at the ready, looked a lot like a pair of testicles, so the name means "gonad hand". However, those "hands" can move faster than any part of any other animal, when the mantis shrimp clobbers its prey, or even causes cavitation (a kind of shock wave) in the water to stun nearby prey. But I was much taken by the description of their eyes. Humans and most primates have three-color vision. The millions of colors we can see are a mix of the sensations caused by light received by three kinds of cells. Mantis shrimp have around ten different color sensitive cells. In the very brightly-colored and visually confusing environment of a coral reef, they can more clearly distinguish color differences that help them pick out what they need to see.

A book like this is great fun to read, and it is equally great fun to learn of the myriads (millions!) of different animals with which we share this planet.