Troglodyte fantasy

 kw: generated images, ai experiments, caves, cave dwellings, underground living

I have been experimenting with image generation "AI" software for just over two years, having first tried out Dall-E2 on November 11, 2022. I frequently use the software to produce various kinds of backgrounds for Zoom meetings, to use with a green screen. Some are forest glades, some are mountain scenes, some are desert scenes, some are views of alien planets, and some that are intended for "business"  sessions are laboratories or offices.

I had the idea to make images of an office in a cave. I love caves. Preferred vacation destinations are places such as Carlsbad Caverns, Mammoth Cave, Luray Caves and the several caves along the Blue Ridge Parkway. I had several art generators produce hundreds of images, and kept about thirty of them. Two are standouts:

This is from Leonardo AI, using the Preset "Illustrative Albedo" and Style "Stylized Illustration", which produced this colorful result. It's a bit fanciful, which appealed to me.

To see an image full size, click on it. Click next to the image to return to this page.

This is from ImageFX (in Google Labs), which does things differently, having an option to choose from numerous adjectives, which then are appended to the prompt. I appended "Cinematic". This looks more like a natural, though dry, cave (I wouldn't want an office in a drippy, living cave!).

A week or two later I decided to generate the rest of the rooms of a cave dwelling, one I might like to live in.

The original prompt for the Cave Office was an extra-long 50-word prompt, about 275 characters. Several of the art generators put the first 32 characters of the prompt in the file name, in addition to the name of the program and, often, the "seed" number (The seed is supposed to allow you to regenerate an image and then modify it in a later session). I keep a text file of long prompts so I can re-use them. This helps with product comparisons. I change the file name to a prompt identifier plus a program ID, the date, and a serial number.

I eventually prepared twelve more "Trog" series prompts, ranging from 17 to 48 words. Note that most of these programs take in no more than 77 "tokens" (an unusual number...), and a "token" can be a word, a syllable, or a punctuation-space combination, so I don't let prompts go much beyond 50 words.

Is Troglodyte a new word to you? It means a person or animal that lives underground. In old literature it was used in a derogatory way to refer to, for example, underground-dwelling "dwarves".

I won't dig deeper into the technicalities. Here I want to showcase the different rooms I dreamed up, and the way each of these two programs responded to the prompt. I present them four rooms at a time, and each "room" is my favorite from 4, or 8, or more images offered up by the art generator. I start with all the Leonardo AI offerings:

Clockwise from upper left: 

• Entryway. An arch has been built into the cave mouth, and case of shelves full of pots stands nearby. I asked for a coat closet; this is the only "closet" I was offered! Note that this combination of product and its presets has every room adjacent to a skylight or a cave exit.
• Living Room. The floor is paved. I'd have asked for Grow Lights for the houseplants if I'd realized the program would create some.
• Kitchen, complete with a window to outside. The prompt included "refrigerator" but none was offered.
• Formal Dining Room with a chandelier. The pool is a bonus.

• Sitting Room and Library. It takes a dry cave to be a safe place to shelve books.
• TV Room. I debated asking for theater-style seating, but opted for this look instead.
• Office. The original cave room, which inspired all the others.
• Game Room. What's a grand home without a billiards table and some board games?

• Hallway to Bedrooms. This was as close as I could come, in the Leonardo offerings. The floor is close to natural. I asked for wall sconces, and got lots of them.
• Master Bedroom. I asked for a canopy bed, but never received one.
• Utility Room and Laundry. The most natural floor of all the rooms. The tool bench is minimal. Though no stairs are evident, this is clearly a "basement" area.
• Walk-in Closet. This is intended to be attached to the Master Bedroom. One presumes the view is from an archway in the bedroom.

OK, let's compare the ImageFX offerings, in the same order:

As before, clockwise from top left:

• Entryway. Here, the entry is apparently around a bend. Coat closets and a chair make it inviting.
• Living Room.
• Kitchen. Complete with refrigerator! IFX is more compliant to details in the prompt.
• Formal Dining Room with chandelier. The buffet off to the side, with warming pans, is a nice touch.

• Sitting Room and Library. I didn't ask for the Oriental rug, but I'm glad it was included.
• TV Room. Here the seating is facing the screen, in an informal arrangement.
• Office. Of all the rooms, this looks the most like the cave is a backdrop rather than integral.
• Game Room.

• Hall to Bedrooms. This is what I had in mind.
• Master Bedroom. With canopy bed! The knitted rug is as I asked for every time; here it is most evident.
• Utility Room and Laundry. A better work bench.
• Walk-in Closet. The central dresser is nice. I had asked for both men's and women's clothing to be shown. IFX did so.
  

The big lesson for me is that tremendous variety is available; it takes lots of experimentation to learn the uses and limitations of each tool. The IFX images tend to be low key. To make a presentable image, I'll raise the lightness with the Gamma tool in IrfanView, which I use to trim an image and add a signature (as any artist would!). I use Upscayl to double the x- and y- pixel count.

If you have a sharp eye, you may note that the aspect ratio of the images differs between the two programs. Both Leonardo AI and ImageFX have various aspect ratios available. I always asked for 16:9, the same as HDTV, which also matches the screens of my computer setup. However, Leonardo AI images, for all its Presets except "Phoenix", yields images that are 1368x768, or 1.78125 or 57:32. ImageFX images are even wider, 1408x768, or 1.8333... or 11:6.

When I make a Zoom background, or a wallpaper for my Screen Saver, I want exactly 16:9, so images must be trimmed. I'll prepare an essay about that later on.

Art generators don't know physics

 kw: generated art, scientific errors, comparisons, stock image websites

Reading a book of science for a popular audience, in a section about the use of spectroscopy to learn the compositions of stars, I encountered this illustration. Can you see what is (dramatically!) wrong with it?

The principle of refraction is this: when light enters a transparent material, such as glass, from the air, at an angle, it is bent closer to a line perpendicular to the material's surface. That means that the beam of white light entering from the left, should be refracted into a narrow spectrum that proceeds down and to the right. Then, when it encounters the other side of the prism, which is at a different angle, it will be bent downward again. 

Here, the first refraction is in the wrong direction. That implies that the glass prism has a refractive index less than 1, which is impossible. But the second refraction has the correct sense, which just adds confusion. This illustration is from Getty Images, a source of much stock artwork and photography. The author of the book in which I saw this image must not have been paying attention.

This is a more accurate illustration; it is from Britannica online. It shows the refraction angles correctly. One small matter is not accurate: Real prisms produce a spectrum with a dispersion angle of less than one degree. This illustration shows the spectrum, at the right, spreading across fifteen degrees. This is OK for the sake of illustration.

I got curious about such illustrations, and investigated a bit. First, I entered the prompt "prism spectrum" in Google Images. I looked through a few hundred images. There were all kinds of results. More than half of them were somewhere between wrong and incredibly wrong!

Not only Getty Images had it wrong; the following sites were consistently wrong or worse:

• Shutterstock
• DepositPhotos
• Pixers
• Freepix
• Pugtree
• Big Stock

The following had it right some of the time:

• Adobe Stock
• iStock
• Vector Stock
• KaiserScience

Finally, these sites had no errors that I found:

• Britannica
• Cyberphysics
• CK12-Foundation
• Dreamstime
• Australia Telescope National Facility
• LabXChange
• Science Photo Gallery
• Hyperphysics
• Urban Pro

Many of the images had the look of generated artwork. So I put various prompts in four image generation products. After much experimentation with the text, the prompt used for these images was

A triangular prism in the center, a narrow light beam from the lower left upwards to halfway up the left side of the prism, continuing as a narrow spectrum across the middle inside the prism, and exiting the prism to descend toward the lower right as a wider spectrum.

Here are the best of each:

Even with very explicit instructions as to the direction of each section of the light beam, these are the best among numerous offerings that were pretty, but nonsensical. None came close.

One would think, among the billions of images used to train these programs, there would be some accurate scientific diagrams. However, spectroscopy is a "small market" in the scientific arena. If an author wants good scientific illustrations, it's still, not just "best", but imperative to use a human graphic artist, and to examine the results with a critical scientific eye.

Stepstones to infinity

 kw: book reviews, nonfiction, science, astronomy, space science, popular treatments

My favorite astrophysicist, Neil deGrasse Tyson, published a new book last year in collaboration with Lindsey Nyx Walker, in the Startalk series: To Infinity and Beyond: A Journey of Cosmic Discovery. With apologies to Buzz Lightyear, the title makes it clear this is no scientific treatise.

As one might expect, the book is fun to read, pitched at just the right level for a popular audience, and copiously illustrated. Rather than chapters, the book has four sections, with a subtitle every couple of pages. The sections are titled "Leaving Earth", "Touring the Sun's Backyard", "Into Outer Space", and "To Infinity and Beyond". Broadly speaking, the sections are like layers of an onion, starting at the center.

The second section, on the planets and their satellites and asteroids and other denizens of the solar system, is the longest, as befits the greater knowledge we have "in the Sun's back yard", where at least we have sent instruments to pass by or even orbit the planets and selected objects. The book went to press before the capsule of material returned from Asteroid Bennu was opened, so that's not mentioned. What is mentioned is the quest to colonize Mars, which cannot realistically be done without terraforming it. Engineering solutions, including carpet bombing the polar ice caps with nuclear weapons, have been proposed. Dr. Tyson has this to say:

"In any case, if humanity ever develops enough geoengineering know-how to terraform Mars as our escape plan after we trash Earth, then we should certainly be able to use that intelligence to make Earth livable again and save ourselves from requiring a planet B in the first place." (p. 135)

To which I add a strong, "Amen!"

The fourth section, after treating what we know of the distant cosmos in a general way, gets a bit philosophical. The authors have this to say about "beyond", that is, about the many-worlds interpretation of quantum uncertainty: "The many-worlds solution may not be simple, but it is the simplest explanation for the oddities at quantum scales." I must contend with that:

Consider sunlight shining through an ordinary window. When the light encounters the glass, ~4% is reflected from the outer surface and ~96% passes into the glass. Then about another 4% is reflected from the second surface and the rest, ~92%, continues onward. Interestingly, the light that reflected back into the glass pane is partly reflected and then most passes through. Some smaller and smaller fraction of the original light bounces back and forth inside the glass pane. Glass is not 100% transparent, to soon whatever has not escaped is absorbed. Considering only visible light, sunlight has an intensity of around 500 watts per square meter, or 0.05 watt (50 mw) per square centimeter. Skipping the math, the number of photons of visible light that encounter the glass each second is about 1.4x10¹⁷, or 140 quadrillion (140 million billion). Each photon "decides" whether to reflect or pass through, twice because the glass has two surfaces. According to the many-worlds interpretation, 280 quadrillion entire universes are created every second, because of sunlight shining through one square centimeter of glass. I have a picture window in my family room that has an area of two square meters. On a sunny morning, every second, about 5.6x10²¹ universes spring into existence, along what dimensions we have know way to discern. Five and a half sextillion. Every second.

Folks, that's just silly. Whatever photons and other quanta are, they are doing something we fundamentally don't understand, and interpretations such as many-worlds reveal how immensely far we are from achieving such understanding.

We are like the pilgrim in this famous engraving from an 1888 book by Flammarion, trying to see beyond our own horizon. Our imagination falls short. Newton imagined himself as a beach comber being fascinated by this shell or that pretty pebble, being ignorant of the expanse of the ocean that tossed them up.

All that aside, and aside from a few errata I'll get into shortly, the book is as entertaining as it is comprehensive. I strongly recommend it.

---------------------------

I have to bring out a few matters where the authors, or a copy editor, ought to have known better:

1. On p. 22, about warming by infrared light, "…once they absorb the various wavelengths of radiation, molecules on Earth's surface are transformed into infrared and are reemitted by the ground." This is a rather dramatic blunder. The molecules are not transformed into infrared! The relevant phrase should read, "…molecules on Earth's surface emit infrared radiation." All the wavelengths of sunlight that reach the ground warm its substance, and it then emits some of this energy as infrared.
2. On p. 119, about the slowing of Earth's rotation, mostly by its interaction with the Moon, it is stated, "After two centuries, days are four milliseconds faster." In this context, the word "faster" is misused. The days are "four milliseconds longer." Gah!
3. On p. 131, "Today, Mars is a frigid tundra." The word "tundra" implies a cold landscape with cold-resistant plant cover. There are no plants on Mars. I don't know what word to use, but the word "tundra" is wrong.
4. On p. 206, on relationships between the intrinsic brightness of stars and their apparent brightness because of their varying distances, "Sirius, the brightest star in our night sky, is smaller than Earth and 8.6 light-years away,…" Siriusly?!?!? As it happens, Sirius is 1.7 times the size of the Sun. Its companion, the white dwarf designated Sirius B, which is much too faint to see without a large telescope, is indeed smaller than Earth.
5. Finally, look carefully at this illustration of a prism producing a spectrum:

This is found on p. 212, where spectroscopy is being discussed. The illustration is from Getty Images. The way the beam of light bends upward as it enters the prism implies that the prism has a refractive index less than 1, which is impossible. Such a material would require the light to go "faster than light" within it.

Compare with this illustration:

This is from Britannica online. It is more correct, showing the light entering being refracted toward the perpendicular to the glass surface as it passes into the prism, and then refracted away from the perpendicular of the second glass surface as it exits. P.S. I was a spectroscopist for a few years…

This illustration isn't totally accurate, however. The best spectroscopic glass disperses the spectrum by a little less than one degree. The spectrum at the right is being dispersed about 15°. However, this bit of scientific license is needed to make the principle more clear.

I put the query "prism spectrum" into a Google Images search. I found that a great many repositories of stock photos have it wrong; only about one-third have it right! Don't Getty and all the others have anyone with scientific understanding on their staffs?

What is the opposite of ennoble?

 kw: book nonreview, philosophical musings

I was sad to find that I could not in good conscience finish reading two books in a row. I wrote a very rare pan of the first book a few days ago. The second one, I won't even mention the title, but only say it was a collection of short stories, one of the many "best of" anthologies. If it does represent the best, the stories are a far cry from the poor-to-middlin' stories of just a few years ago.

Out of about ten stories I attempted to read, I read the entirety of only six. The other four are degrading. The six I did finish had no conclusions worth mentioning. The lead characters got nowhere. Most of them I could call the epitome of people whose lives "don't matter", in recent parlance.

What has happened to authors who might write about a total loser, yet either uplift the loser in some way, or show why not (think of classics such as Grapes of Wrath), or, as a tragedy, make it clear how the person engineered his or her own downfall (Shakespeare was a master of this). Instead, what did I see? Depictions of losers who start nowhere, go nowhere, learn nothing, waste my time as a reader, and leave me feeling sad.

A writer is an entertainer. Do you think "entertainment" should make you feel bad? Where are the entertainers who ennoble their audiences? Even knowing that some of the folks "out there" are total losers, can you give such persons hope that, if a shred of virtue remains, improvement is possible? The writers of this collection apparently assume that such total losers are the norm, so "When in Rome…" I assure you, they are not the norm!

In the realm of one of the best known of Aesop's Fables, the industrious Ant stores provisions for the winter, while the indolent Grasshopper sings away the summer and starves when autumn comes. Aesop stopped his story short. In actuality, all of us Ants wind up taking care of numerous Grasshoppers, so some at least will survive the winters of life. If Ants didn't outnumber Grasshoppers, eventually nobody would survive.

The book of Proverbs in the Bible speaks of someone so indolent he starves because he can't summon the will to bring food to his mouth. The food is available, even within reach. Grasshopper is too kind a word… And I remember a story of a prophet who fell into despair, and wandered into the desert to die. God would have none of it, and sent an angel. How did the angel wake the prophet from slumber? It kicked him in the ribs!

So, authors, either ennoble your audiences or kick them in the ribs. But don't demean and degrade them or wear them down with depictions of unnaturally clueless folk who are wasting the space they take up.

Mathematics and wokeness don't mix

 kw: book reviews, nonfiction, mathematics, education, polemics

When education becomes indoctrination, genuine learning vanishes. I had high hopes for this book when I saw it: Is Math Real? How Simple Questions Lead Us to Mathematics' Deepest Truths by Eugenia Cheng. As I read, I soon found my thinking sidetracked by hints of lunacy. Then on page 33 the text swerved into a sudden diatribe against white supremacy. Barely a dozen pages later the author, writing of logical reasoning and logical arguments, takes on the "straw man fallacy" (which she retitles the "straw person fallacy") by decrying sundry arguments against the notion of "white privilege". Hmm.

I looked at the profile photo and thought a while. Dr. Cheng is a British-born Chinese, rather young-looking (she's not yet 50, so a generation younger than I am). I lived Jim Crow before she was born; I know genuine white supremacy and white privilege. They hardly exist any more. The constant barrage of accusations regarding these things began during the Obama Presidential campaign in 2007, and continues to this day (it continues despite the fact that this Black activist was elected twice to the Presidency…or maybe because it's him behind the scenes egging it on). Then, along with many other false allegations, they were braided together into "wokeness", which is a slew of anti-white, anti-tradition, anti-family, anti-liberty trends that culminated in "cancel culture."

Muffling my discomfort, I continued reading. In the next chapter a similar tirade erupted, and I had had enough, not even a quarter of the way though the book. Either this math wizard is utterly suborned by leftism, or she's afraid if she doesn't kowtow to woke dictates she'll also get canceled. Either way, she fits the prompt that generated this image: "Defeated female wizard"

Here is my definition of WOKE: Wicked, Obfuscating, Kleptocratic Extortioners. And while we are at it, two of the left's favorite acronyms also belong on the chopping block: DEI = Devilish, Elitist Inversion of truth; and ESG is a total inversion, Environmental mismanagement + Social repression + utter misGovernance.

To be quite clear: Every element of wokeness is evil. The recent election is in part a mandate by a clear majority of the electorate to de-wokify America. Let's laugh the Leftocrats off the stage!!

When I decide not to finish reading a book it is my usual practice to not mention it; just to set it aside and read the next book and review it here. This time I have to pan it. The writing is mediocre but tolerable, the puppyish enthusiasm for topics hardly anyone has heard of is cute but distracting, and while the author's wish to calm the fears of mathophobes is laudable, her methods are off-putting. Far too many times, on rather simple subjects, she urges us to "think really hard about" something or other. Talks about tone deaf! There are many better books about math for those who fear math. This book is most likely to turn math-fearing folks into math-haters.

Is life everywhere or nearly nowhere?

 kw: book reviews, nonfiction, exobiology, astrobiology, seti, exoplanets, origins of life

The title of a recent book by Nathalie A. Cabrol is astonishing: The Secret Life of the Universe: An Astrobiologist's Search for the Origins and Frontiers of Life. Why astonishing? First, let us consider the limits of what is known.

• In our solar system, until recently, only three planets have been considered habitable at least part of the time since the solar system was formed about 4.6 billion years ago (hereafter Ga): Venus, Earth, and Mars. Both Venus and Mars are considered "almost certainly dead", but hints of continued habitability are discovered from time to time.
• Many "ice moons", such as three of the Galilean moons of Jupiter, Europa, Ganymede and Callisto; Enceladus, a moon of Saturn; and Oberon, a moon of Uranus—all appear to have large subsurface oceans of liquid water, or actually brine, which could sustain life.
• Beyond the solar system, thousands of exoplanets have now been detected. A few hundred of these are at an appropriate distance from their host stars to be habitable, at least at present, if not for the long term.
• Most of the exoplanets so far detected and confirmed are less than 5,000 light years from Earth. A handful (so far) are at distances ranging up to 33,000 light years.

Further interesting information is found in the List of Exoplanet Extremes. 

What do these facts imply? As much as we might like to speculate about life (almost certainly bacterial or some analog thereof) on various solar system bodies, the confirmed occurrence of life in the solar system is found only on Earth. N=1.

Outside the solar system, we have partially probed a volume of space totaling about 80 billion cubic light years (considering the thickness of the galactic disk to be 1,000 light years). That's not bad; it is 1% of the volume of the Milky Way galaxy. However our galaxy is one of at least 200 billion, and probably more than a trillion, galaxies in the visible universe. We don't know how much universe lies beyond our visible horizon. Again, in all that space, known life: N=1.

From a numerical standpoint, the data we have relate to between a quintillionth and a quadrillionth of the known universe. That makes the book's title an astonishingly extreme overstatement.

On the other hand: The author, the director of the Carl Sagan center at the SETI institute, presents the principles by which life is likely to have arisen, and the evidence from all around the universe that the right chemistry to kick-start life exist nearly everywhere. This makes the book's title almost banally obvious! Isn't that great?

Rather than survey all of the author's points, I'll focus on a few of interest, that may be little known. Firstly, note that word "Origins" in the book's subtitle. Life may have started on Earth more than once. It may have arisen, been snuffed out, and arisen again, perhaps several times. Earlier incidences of life may not have been totally snuffed out, and still exist alongside "us".

Firstly, consider that the "standard DNA coding table" doesn't apply everywhere. For example, there are variations in the encoding of certain DNA codons (3-base groups) to amino acids (or to Stop) that are found in mitochondria. Various classes of eukaryotic organisms have different mitochondria, as revealed by their coding tables. Other microscopic critters, not all of them bacteria, have alternate coding tables. So far, 30 alternative coding tables are known, with the "standard table" bringing the total to 31. See List of Genetic Codes for more details.

Let's step back and consider the situation. There are 64 possible DNA codons. All known life on Earth uses 20 amino acids (one bacterial genus may use a 21st amino acid; I can't find out much information about it). There are dozens, perhaps hundreds, more possible amino acids. The 64-to-20 conversion involves numerous duplicate codes, which makes for a robust system. Many single-codon variations (micromutations, which are common), make no change in the protein being produced. How many possible coding tables are there? I am good at many kinds of math, but not the details of "permutations and combinations". The best I can figure, the number is at least 48x10³³ (a 35-digit number), but it could actually be an 84-digit number. Either way, it is a lot!

Is it safe to assume that life elsewhere in the universe also uses DNA and RNA and ribosome decoding to produce proteins from some 20 amino acids? Not really. It is not even safe to assume faraway life requires water. Dr. Cabrol mentions "life as we don't know it" from time to time. She considers places like the Saturnian moon Titan, where water ice is a rock and the primary liquid is methane. What kind of life could arise there? Water (our solvent!) is polar, but methane is nonpolar; perhaps the abundance of ammonia, which is polar, could make methane plus ammonia an appropriate solvent for generating life-as-we-don't-know-it.

I am reminded of the Lensman series of space opera novels by E.E. "Doc" Smith from 1948 to 1954. It concerns intergalactic warfare between water/oxygen-based life and methane/chlorine-based life. I am also reminded of what the character Ian Malcolm said in Jurassic Park, "Life will find a way." I am further reminded of Vital Dust by Christian deDuve, who calls life "inevitable" and "a cosmic imperative." There could be a lot of different kinds of life in the universe, and it's unlikely that we could eat any of it, nor that it could eat us!

Dr. Cabrol points out that planets seem to outnumber stars. Perhaps many stars have no planets, but many more stars have at least one planet, and usually more than one. What proportion of these are rocky (not gaseous like Jupiter, which may have no solid surface) and in the habitable zone of their host stars? Is it a percent or so? Exoplanet data so far indicates between two and three percent. A further constraint is that, as a Main Sequence star heats up during its existence, the shift of the habitable zone shouldn't move beyond the planet in less than 5 billion years or so. This is just based on the fact that life on Earth required about 4.5 billion years to produce us. We are still left with several billion possible planets in our galaxy alone that have the potential to produce life that can become "civilized" and sufficiently technological to send signals via radio or laser or something that we could possibly detect if we are close enough. "Close enough" keeps getting farther away as our own technology improves.

Let's consider that 5 billion year figure. Our Sun is a star of type G2, a little larger than average. Something like 75%-80% of all stars are smaller and lighter. The lighter a star is, the longer it burns hydrogen on the Main Sequence. During that period, it gradually gets hotter and brighter as helium accumulates in the core. I am interested in the larger half of the K series of stars. Their mass is between 0.75 and 0.9 solar masses, and they burn hydrogen for between 17 and 35 billion years, compared to the Sun's expected hydrogen burning life of about 10 billion years. Stars lighter than 0.75 solar mass have even longer "lifetimes," but they are more likely to produce large flares, which can damage or extinguish life from the surfaces of any planets in their habitable zones. So I favor focusing efforts such as SETI (Search for ExtraTerrestrial Intelligence) on stars in the range K5 to G2. Even a G3 star probably would have begun to burn us off its surface by now, as our Sun is expected to do starting about a billion years from now.

The author also considers the Drake Equation, which is a thought experiment that helps us consider the likelihood or prevalence of life in our galaxy (or the universe). It consists of a bunch of factors that are multiplied together to produce N, a possible quantity of detectable civilizations "out there". An important factor is, "How long does civilization Z emit a signal that we could detect, if we are close enough and have sufficient technological sensitivity?" Consider Earth. The first radio transmission that reached beyond "local" was in December 1901. Just about 124 years ago. 

At present, there are a few dozen "clear channel" AM radio stations that emit 50,000 watt signals 24/7, a larger number of FM radio stations of similar or even greater power, and many TV stations, mostly below 10,000 watts. However, more and more of our TV watching is moving to cable (including fiber optics), and digital signals are more efficient, so stations that do broadcast are using lower power. I have an in-attic antenna that presently receives more than 60 digital TV stations, so I don't use (expensive!) cable. Radio is beginning to go digital also. I predict that Earth will be largely "radio silent" before the 200th anniversary of Marconi's transatlantic radio transmission.

If an exo-civilization is typically detectable for only 100-200 years, even without extincting themselves, that cuts a big hole in all our speculations using the Drake equation. I'll have to think more about this…

The last chapter deals at length with our own danger of extincting ourselves. The author considers pollution, particularly CO₂ buildup plus methane buildup, an existential threat; she states clearly that our window of opportunity for ensuring long-term survival is small, a matter of decades at most. I agree in part, but my expectation is not so dire. I won't encroach on her thesis, though.

I will close this part with a hearty recommendation of the book. It is full of great ideas and great information, and very well written. A pleasure!

------------------------------------

If you aren't interested in errata, you can stop here. I ran across a few items, equally the fault of the author and the copy editor, that need to be corrected.

Tidal Locking is mentioned just a few times. It is not clearly explained, and I found this on page 97: "Callisto is tidally locked to Jupiter, orbiting around it in the same amount of time it takes Jupiter to rotate." Not so. Callisto takes 17 days to revolve about Jupiter, while Jupiter takes 10 hours to rotate on its axis. Callisto's rotation period is 17 days, so it always presents the same hemisphere to Jupiter. This is the same in principle as our Moon, which both rotates and revolves in 27.5 days (sidereal periods), so we always see the same hemisphere. In the quoted sentence, the second instance of "Jupiter" should be "Callisto". A second instance where the numbers are correct is on page 141: Pluto and its moon Charon are mutually tidal locked, always facing each other the same way, both rotating and revolving in 153 days.

An egregious typo, minor misspelling of a homonym on page 142: "pour" rather than "pore". To study a document is to pore over it, not "pour."

Information Mastery, a la Carl Sagan, is a proposed scale of technological advancement. It is mentioned on page 215, where it is stated that Level A represents 106 "unique bits of information" and Level Z represents 1,031 bits. This is a formatting error, compounded by the insertion of the comma. The two numbers ought to be 10⁶, or one million, and 10³¹, or ten million trillion trillion (a 32-digit number). I suspect a dumb copy-paste removed the exponent formatting. Anyway, the concept is fascinating.

Let us consider where we are as a civilization on Sagan's scale. The venerable Encyclopedia Britannica contains about half a million topics in 40 million words. I suspect that Sagan would consider a "unique bit of information" to represent about a paragraph. These half million topics then are each stated in an average of 80 words, which comes to a smallish paragraph. Worldwide, there are several printed encyclopedias, but they overlap. Thousands, nay, millions of articles and books and journals are published yearly. Then there's Wikipedia, which has (today) 62 million pages, and about 1/8 of that is in 6.9 million formal articles. All told, that puts us in the realm of a Level C or Level D civilization.

There are a couple other typos, but they have less import. I'll leave it at that.

SF is as SF does

 kw: book reviews, science fiction, speculative fiction, fantasy, short stories, collections

I use the term "SF" in the title rather than "SciFi" because Lake of Souls: The Collected Short Fiction by Ann Leckie includes three categories: science fiction, speculative fiction, and fantasy.

The opening novelette and title story, "Lake of Souls" sits on the boundary between science fiction and fantasy, as does Ms Leckie. The story is a bildungsroman, a coming-of-age story, of a crablike creature without a name, who embarks on a quest to find the fabled Lake of Souls, where it may obtain a soul and a name. Until obtaining soul and name, these creatures are called by the generic term Spawn.  This Spawn's quest differs from the usual process, where marks that appear on a being's head upon one's final molt can be read as a name. I don't use "he" or "she" for Spawn because the author studiously avoids genderizing it. The science fiction element enters with a human on the planet, the last survivor of a mass murder on his survey ship. He is on a quest of his own, to find the murderer and the communication device he brought to the planet with him. He and his shipmates had been calling Spawn's fellows "lobster dogs", and having met Spawn, he realizes that these beings are sentient, which he must communicate with "home base", and with others because of the political implications of his discovery. I'll leave it at that; I am perilously close to spoiling too much. I should mention in passing that the author is very skilled at imagining and portraying sundry sorts of non-Earthly beings.

Consider a feudal society, right here on Earth. The lords and ladies lived in splendor in their castles and manor houses, cared for by servants and surrounded by serfs who lived in penury and often misery. Aristocrats lived much longer than serfs, and soldiers typically had notoriously short lives because of the aristocratic hobby of warfare. Move that scenario to a planet on which the aristocrats are called the Justified, and live unlimited lives, though they can die, but never of "natural causes". Everyone else, the short-lived, serve the Justified. I should also mention that they are lionlike, and the Justified become many times stronger than the short-lived. This scenario plays out in "The Justified". An episode in mid-story indicates that short-lived can be promoted to Justified. This has implications for a future situation, back here on Earth again, if aging is defeated but that indefinite life extension is too costly for most to afford. In this and in nearly all of Ms Leckie's stories females are dominant.

These stories are from the first third of the book, where we find all the stories one could term "science fiction". The other two sections are taken from the author's world-building series, termed Imperial Reach and The Raven Tower. Both are based on pantheism: people interact with gods of many "sizes", some that are like feudal lords over a domain, and others that have more narrow realms of influence. Like the Justified discussed above, these gods aren't necessarily eternal, but how a god is done away with isn't made clear. They gain strength from being prayed to and sacrificed to, and the most common sacrifice is an ounce or so of one's own blood, spilled on a makeshift altar.

From all of this I conclude that the author is fascinated (obsessed?) with feudalism, with highly structured societies, and with extreme feminism. Also that she would like to be a god. Then again, who wouldn't?