Friday, January 30, 2009

The weirdest, bug-eyed bug

kw: animals, fossils

This is the trilobite Erbenochile, surely the creature with the weirdest eyes ever. These fossils are found in Morocco, Algeria and points between, though only in Morocco have complete, well-preserved specimens been found. This genus is Devonian in age, perhaps 400 million years ago. By this time, Trilobites had been around for more than 100 million years, long enough for all sorts of fantastic types to arise.

Those eyes! They are half-columns of calcite lenses. Their arrangement makes them more sensitive, and they are focused on the surroundings rather than above. These critters must have lived in dimmer surroundings, perhaps muddier or deeper water than most of their kin.

There is much more on this taxonomic family to be found at the Phacopida page of the Virtual Fossil Museum.

When I was a child I wondered how closely the Horseshoe Crab is related to Trilobites. Once I learned that "trilobite" means "having three lobes", and that these "lobes" run from head to the tip of the tail, the difference became obvious. You can see on the fossil image that the lobes, right, left and middle, are fully segmented all the way.

On this living Horseshoe Crab (Limulus), what look like lobes are ornaments on the shell, which is only partly separated by spiracles for bringing water from above to the gills, which lie within the shell. Trilobite lobes were articulated, and the side lobes could move relative to the central lobe. This animal's shell articulates only between the large front and smaller back sections, plus the tail spike.

Trilobites belong to their own taxonomic Class, Trilobita, while Limulus belongs to Class Merostomata, which means "legs around the mouth". The legs radiate from the middle of the Horseshoe Crab's forebody, while a Trilobite's legs arise all along the body. Ancestral horseshoe crabs, and their Class-mates the Eurypterids, lived alongside Trilobites in Carboniferous and Permian times. Both these Classes are members of the Subphylum Chelicerata, which includes spiders and scorpions.

None of these animals is that closely related to modern crabs, which are in the Subphylum Crustacea. Strangely, the little pill bugs and sowbugs, which look a little like tiny trilobites, are crustaceans. Is this starting to sound like "Who's on First?" The last half-billion years has seen plenty of surprising animals come and go. The trilobites are a favorite of mine, and I'm sorry they are found only as fossils.

Thursday, January 29, 2009

Snow day, sequel

kw: weather, snow, ice

The radio shows this morning are full of talk about the snowstorm yesterday morning. It seems the President's girls also had the day off, and people are echoing his "learn from Chicago" ribbing. I'd be tempted to join in, but really, this isn't New England. Washington, DC was built on a subtropical swamp. It is just far enough north that it gets at least some snow most winters.

I've been there a few times in winter, and the problem is just its mid-Atlantic location. It is cold enough to get snow, but not cold enough to keep snow in solid form. Snow in the mid-Atlantic region quickly turns to slush, which is much more treacherous. The icy rain that fell on yesterday's snow made it that much worse.

A couple hours north of DC, where I live, I could get around by taking it slow. I knew before I started that I'd be late at work, and decided that was OK. The troubles on the roads were caused by people's impatience. It seems the most impatient people have a blind spot about weather. They don't plan ahead so as to have extra time, so they get twice as impatient with the slower drivers (like me) who did. I'm glad I didn't get rear-ended, but then, I drove at a time with less traffic, on the better-kept roads.

A reminder to everyone driving a four-wheel-drive vehicle: it is easier to get into trouble, because you have a false sense of security. Every vehicle has four-wheel stopping, so you actually have no advantage, there.

Wednesday, January 28, 2009

Snow day

kw: weather, snow, ice

For the schoolkids in the area, today was a snow day. Only one or two companies called the day off, and a few others started late. The rest kept their usual schedules. People in this area mostly seem to do OK, but some need to learn how to drive on snow or ice.

In 1978 I moved from California to South Dakota, where I lived eight years. There, snow is treated as a sediment, like a slightly evil form of sand. Most places, the road surface is left a bit knobbly, and the snow bonds to it when it is warmer (above 0°F), and just loosely packs into the crevices when it is cold. When it is -20°F (-29°C) or colder, it is too cold to snow much, so the typical blizzard will blow in with a half inch (about a cm) of powder, which will blow from here to there until the next thaw.

When I moved to Oklahoma, I soon became the designated winter driver in my carpool. Now, in the Delaware Valley, I don't carpool, or I'd probably also be the main winter driver. There is something to be said for having this attitude: snow is something you pack down and drive on.

Now, Ice is another matter. I've had one auto accident since my teen years, and it was caused by ice. This morning's ice is a good deal more risky than the snow, but fortunately, the main roads I drive on to get to work are all free of ice. They had enough traffic during the overnight storm to keep them from icing up badly. My main problem was keeping fresh ice from forming on my windshield. It sure is nice living only three miles from work. I could just poke along without making myself too late. This hasn't been bad for the first real winter storm of the season.

Tuesday, January 27, 2009

Data miners, light your lamps

kw: book reviews, nonfiction, internet, behavior

PPC means 'pay per click', but to Bill Tancer (I think it rhymes with dancer), it also means, 'porn, pills, and casinos', some of the biggest categories of internet searches. Porn searches top the list of all searches…or at least, they used to. This may be changing.

In the UK at least, social networking searches have surpassed them (Image from Hitwise.com's blog site). The author of Click: Unexpected Insights for Business and Life, Bill Tancer is one of seven Hitwise bloggers, and the company's lead analyst (& general manager of global analysis).

Hitwise purveys competitive intelligence of all sorts, gleaned from a massive, continually growing database of internet searches, clicks and click-throughs. For most of us, a spate of activity on the Web starts with a Search, or several-many. Then we Click on some of the results. A Click-through is a trace: for each Click (URL clicked upon) it is the URL that preceded it and the one that follows. These can be chained for more complex analyses. With the right software and the amalgamated searches, etc. for ten million Web users, you can learn a lot.

The author takes us down a few of the paths he has followed, to find out why searches containing the words "prom dress" spike in January rather than later in the Spring; why the popularity of a certain lady wrestler didn't translate into a win on Dancing with the Stars; or how the internet has become many people's psychotherapist.

To take up the first item: One large segment of "prom dress" searchers is composed of affluent, fashion-conscious girls, and many fashion magazines (on-line and off) publish their initial prom fashions in mid-December…and these girls don't wait. The girls who are more likely to buy a department store dress tend to begin searching in April, and are less avid searchers.

Yearly trends clearly show what people are resolving, each New Years' Day, what diets are most popular when we need to get rid of some of that Thanksgiving lard we pack on, and when young minds begin to think of June weddings (it isn't June).

But the data have social correlations also. This chart, of clicks on charitable websites, shows an interesting trend compared to the Dow-Jones index. Whether this mainly represents people who think more charity will be needed, or people hoping to find help, is left unstated in the blog post this comes from.

But this isn't a review of the blog, but the book. The author supports his contention that Click data can reveal trends that polling never will. This is because we're not afraid of the search engine. It won't pass judgment on us. We ask things we really want to know, from "how to kiss" to "why am I sad" to "where is Tom Cruise today". You may tell a telephone pollster, "I don't gamble," and the number of people who might admit that is indeed very small; but a large proportion of us spend more time on casinos.com and similar sites than the poll would predict.

The author often begins a public appearance by saying, "I love data", or, "I've always loved data". The audience may titter, but quite a number of people whisper later, "So do I." Data are the roots of information, and information is power. The author quotes John Batelle, who said it best,
This information represents, in aggregate form, a place holder for the intentions of humankind—a massive database of desires, needs, wants, and likes that can be discovered, subpoenaed, archived, tracked, and exploited to all sorts of ends.
Just by the way, folks, there may be a constitutional right of privacy, but the real thing is now that much harder to attain. I enjoyed the book, but the implications are unsettling.

Monday, January 26, 2009

Hang 'em high?

kw: book reviews, nonfiction, jurisprudence, death penalty, capital punishment, polemics

Spoiler alert: this review contains an outline of the authors' arguments. Let's just dive in. The title and subtitle make it clear the object is contra-capital punishment:
The Top Ten Death Penalty Myths: The Politics of Crime Control, by Rudolph J. Gerber and John M. Johnson. The book is a well-reasoned series of arguments. Each is the subject of a chapter:
  1. Death Penalty History and the Myth of Community Bonding
    • Since colonial times, the venue of a judicial death has moved from the public square to a private, in-prison setting, and the means of death has become less and less painful and degrading.
    • Over the same period, the "community bonding" aspect has given way to a more divisive reality

  2. The Myth of the Rule of Law in Capital Cases
    • Modern forensics, particularly DNA testing, has shown the high rate of erroneous convictions
    • This is driven largely by the prosecutors' drive to 'win at all costs', with which much of society is in general agreement.
    • Both prosecutorial and police misconduct are the natural result

  3. The Myth of Equal Justice
    • The major point, and 90% of the chapter's material, is racial discrimination: sad but true.
    • Social class and gender are more minor biasing effects

  4. The Myth of Deterrence
    • This equals a myth of Rational Perpetrators. In my view, no murderer can be in his or her right mind
    • Required for deterrence: speed plus certainty plus proportionality plus publicity
    • All four requirements are violated

  5. The Myth of Fidelity to the Constitution
    • Two amendments specifically limit the right of the government to "remove life"
    • A long disquisition amounts to saying 'times have changed'

  6. The Myth of Human Execution
    • Methods of execution in the U.S. have shifted from the sword or axe, to the Guillotine, to hanging, to the electric chair, to the gas chamber, to the nearly universal (in 38 States) use of lethal injection.
    • Each method was considered 'humane', and perhaps it is, by comparison with its predecessor
    • All of these methods can be botched, leading to increased suffering by the condemned

  7. The myth of Closure
    • This firstly assumes the victim's family wants revenge or would be comforted by the judicial death
    • The second assumption is that society at large will be similarly comforted

  8. The Myth of Retribution
    • Retribution is not revenge, it is punishment intended to be felt by the perpetrator, so the question is raised, is death without suffering any punishment at all?
    • It is based in lex talionis: 'an eye for an eye' and so forth

  9. The Myth of Effective Crime Control
    • The argument is entirely based on the relative economic costs of prosecuting, appealing and carrying out a judicial death, versus alternatives
    • To the authors, "effective" means "cost-effective"

  10. The Myth of the Dedicated Public Servant
    • The governors and judges who get elected often ride to power upon a 'devotion to death'
    • The public is more and more risk-averse, as shown by these voting records


Why is such great argumentation needed? I am tempted to say, "Methinks thou protesteth too much," but such a stance would ignore the fact that this is the second-most divisive issue in American politics, the most divisive being abortion.

If you boil down the authors' arguments to a sound bite, you get, "Judicial killing is still too cruel, its application is too arbitrary, it is too costly, and it doesn't fulfill its stated goals." My own stance is this: Nine of the arguments are beside the point. One is plain wrong: Death is a deterrent, in two ways. Firstly, the chance that a killer may himself (or rarely, herself) be killed does make at least some people adhere to the proverb, "Don't do something you can't undo." Secondly, the death of a killer completely deters the killer from killing again. This and this alone I consider a justification for a continued right to take a perpetrator's life.

Saturday, January 24, 2009

More art of grief

kw: images, memorials

I was taking a shortcut through northernmost Delaware when I happened on a couple of roadside memorials. I've commented on these before, here. These two are some of the newer ones I've encountered.

Though these memorials are motivated by tragic circumstances, I look on them as examples of folk art by people who do not think of themselves as artists. On this one, the name Cliff can just barely be made out, though the memorial is only two years old. This has the look of being primarily the work of Cliff's children. The setting is intimate, a small, boulder-strewn valley at a tight bend in the road. Fortunately, there is a straight run on both approaches to the bend, and little traffic, so I could get close to the memorial without risking becoming the next victim.

This memorial is on a straight stretch of road. I surmise that the late Pieter fell asleep. Looking away from the road, however, the scene is rather desolate. This meadow is part of a wildlife refuge. I understand that developers want to turn the lands east of the refuge into some kind of mixed mall-plus-residential venture. Most of the non-refuge land is a cornfield. To me, that is already its best use.

I'll forbear to rant, just noting that, if I were king, I'd make it a capital offense to develop land that can grow food. We may not need that much food today, but in the future, we most certainly will.

Back to memorials. Most are as simple as this cross, though few are as well carved. A quick search on Google images for "roadside memorials" yields quite a variety. There are hundreds, perhaps a thousand, recorded among the 5,000+ hits that the search returns.

Friday, January 23, 2009

Male competencies updated

kw: book reviews, nonfiction, handbooks, advice

Let's face it: Guys just love giving instruction or advice. Our most enduring archetype is the Dutch Uncle, providing guidance with a hand on your shoulder (particularly if you are female). A favorite book of my youth was the Boy Scout Handbook. Other "advice for boys" books came and went, but this one was by my side for years and years. Now, there comes along an advice book that could supplant it: The Guide for Guys: An Extremely Useful Manual for Old Boys and Young Men by Michael Powell. My secret title for it: Handbook for Grown-up Scouts.

In Guide for Guys (G4G) we don't find much boy scoutish woodcraft (though it does tell how to build a fire and light it without matches, and how to use a compass, with a compass included). Its seventy short chapters range from "Hold a Baby" and "Smoke a Cigar" to "Defend Yourself in a Fistfight" and "Pitch a Curveball".

The art is retro-fifties, as this clip shows. It may be retro-before that, for this style of drawing began in the late 1800s, when many of the great self-help books were written. The many illustrations cut the word count, so this 200+ page book is a pretty quick read.

I did read it in order, though I don't imagine that is the author's intention. It belongs in the shelf by the phone, or in the workshop, where one can look up its helpful hints as needed. The topics aren't in any special order. The table of contents is the only index.

Were I the author's editor, I might have suggested adding an alphabetical index and grouping topics. For example, "Ballroom Dancing for Guys", "Make Small Talk", "Get the Best Table in a Restaurant" and "Break up with a Woman Tactfully" could form the basis if a "Relations with the Fairer Sex" section, and the "Fistfight" chapter could go with "Survive an Animal Attack" and "Protect Yourself During a Lightning Storm" and others in a "Safety" section. Other section possibilities: Sports, Career, and Pleasures.

But that's another thing about guys. They are seldom that organized.

Thursday, January 22, 2009

Getting used to being two again

kw: musings, empty nest

Every parent goes through it. It is gentler for us than some, because during the college years the youngster doesn't really move out, but just stays away for a few weeks at a time. Our son is just two hours away, and has a car with him, so he can get here at will. Compared to my first two years of college, he visits more than I did. Of course, I didn't have wheels, so a parent had to come for me, but I was just one hour away.

As I recall, my Freshman year I visited home at Thanksgiving, over Christmas break, and for Spring break, until Summer. Then I went back for Summer session. Our son has been home at least monthly from the start. My Sophomore year I was home about the same amount, but that summer we all moved to the West Coast.

Being here without him day-to-day, for 3-4 weeks at a time, we get used to different routines, so that it's a bit of a disruption when he is at home for a day or two. Amazing. It is actually encouraging: whenever he does move out permanently, it won't be too hard to adjust. We had twelve years of being a "single couple" before he was born, and it isn't too hard to remember how to live that way again. One step at a time…

Wednesday, January 21, 2009

The birds in the background

kw: book reviews, nonfiction, natural history, birds

If you live in a city, you may often pass by a scene like this, but do you ever really see it? People who live in the suburbs are more likely to see, because the sight is not an everyday thing. But to a city dweller, the principal reaction to city pigeons is no reaction.

In Superdove: How the Pigeon Took Manhattan…and the World, Courtney Humphries traces the natural and human history that led to this situation. Once they were prime food birds, and in various "fancy" incarnations, they are still show birds. What has caused pigeons to be considered by many as "rats with feathers"? The pigeon population of urban Earth seems to be growing faster than the human population.

The author begins with Darwin—who raised pigeons while researching evolution—and ends in the beginning before that. In between, she traces the history of the domestic Rock Dove (now officially known as the Rock Pigeon) as it pretty much domesticated itself. What makes pigeons so well-adapted to living in human landscapes? Look at a city from a pigeon's point of view: they evolved living in cliffy areas, and our city buildings are big cliffs with plenty of nooks for nesting; they eat mainly grains, and we throw away or spill grain in copious amounts, particularly in and near cities (and many of us throw bread, a grain food, to them whenever possible); a city has relatively few predators; and many humans have an innate "white knight syndrome" that compels them to rescue hurt animals, including pigeons, and nurse them back to health.

Couple all that with a pigeon's territorial instinct, and a pigeon couple and all their offspring will, if sufficient food can be found, multiply to fill any cliffy urban landscape imaginable. They nest on the gargoyles and gingerbread of older architecture, on the struts and supports of air conditioners and signs, in the nooks that can be found even in modern and post-modern architecture, and any place that affords a flat spot an egg won't roll off plus a bit of shelter from the hawk flying above. They are opportunists, possibly second only to humans in that regard.

The pigeons we see in cities are not really wild, they are feral. They are descended from domestic pigeons: prior to the mid-1900s many houses had a dovecote to which the pigeons remained faithful. They were like chickens except that they fed themselves. They are also descended from escapees from the showroom. There are twice as many recognized breed of "fancy" pigeon as there are dog breeds.

The pigeon is a remarkably malleable animal. The color can be varied from the native gray-with-black-and-purple-accents color scheme to pure white, pure black, a whole range of brown and buff colors, plus blue-gray. The tail feathers can become a fan like a turkey's and the head and neck can become as decorative as a crowned crane. The head can sit atop a tall body, or pop out of the middle of a near-sphere.

All of this variety is the product of about three thousand years of artificial selection. Domestic dogs have been subject to artificial selection for five times as long, but pigeons have responded in an astonishing way by comparison. The size range of dogs trumps that of pigeons, but in all other ways, the variety of pigeons is without compare. All of these amazing breeds come from a smartly turned-out gray and black bird with some iridescence about the neck.

These city birds show the range of their parentage. The one at bottom center is the most similar to the wild Rock Dove. The rest just scratch the surface of the variation of city birds. Though these color and shape varieties are less extreme than their fancy kin, they are quite variable for a bird that can live on its own.

In her last chapter, the author narrates her quest to see truly wild Rock Doves (or Rock Pigeons). She was in for a surprise. They were hard to catch a glimpse of! In the "cliffs of home", wild pigeons have falcons and hawks to contend with. They are skittish and only take a flight longer than from one hole to another when they must travel to a field to forage for seeds or grain. Even the wildest pigeons take advantage of our grain fields, as do many other wild birds. So she did see them, one here, or two there, mostly for less than a second at a time. And this in an area that, her hosts assured her, housed several thousand birds. In a city, the feral birds would mostly be out in plain view. You'd see them all just with a casual glance around.

Throughout, the author makes the point that pigeons, even in cities, are part of nature. For some people, they are the only non-tame animals they'll ever see in any numbers. Feral pigeons live as they do because they can. They are very well suited to city life. Campaigns by various city authorities to eradicate them or reduce their numbers have all failed, with the exception of one scheme that partly succeeds: promoting a city-wide culture that "feeding pigeons hurts pigeons", to the point that most people no longer feed them. In a few Swiss cities where this has been diligently instituted, pigeon numbers have dropped by half or better. They're still able to get food, but this indicates that more than half of what city pigeons eat is provided deliberately by people.

We made the pigeon what it is. For some, pigeons may be pests; for others, near-pets; and for others they are just background noise. But they are the bird best suited to live where we live the most densely. They'll be with us for a long while yet.

Tuesday, January 20, 2009

A different reason to decline

kw: book reviews, nonfiction, evolution, spirituality

I read only the opening chapters of Spiritual Evolution: A Scientific Defense of Faith by George E. Vaillant. The opening chapter has this to say:
Positive emotions—not only compassion, forgiveness, love, and hope but also joy, faith/trust, awe and gratitude—arise from our inborn mammalian capacity for unselfish parental love.
Biologically, this is probably true. However, there seems to be something about the human spirit that is either unique or anomalous. As some preachers say, "You will never see a dog or cat setting up an idol to worship." If worship is no more than a trusting reaction to awe, why is it not found in apes?

Since I agree with most of his premise, I considered it unlikely that I'd gain much from the following 200 preachy pages, and went on to the next book. Stay tuned.

Sunday, January 18, 2009

The quintessential city Park at its most quintessential

kw: book reviews, nonfiction, natural science, naturalists, parks, animals

This book could not have been written twenty or thirty years ago. Oh, many of the same stories might be told, and most of the animal dramas have gone on for many years. But it would be worth your life to be there to observe them. I recall a family friend who attended a family wedding in Cleveland, Ohio in the 1970s. A bunch of us were walking from the restaurant back to the hotel, and someone suggested a shortcut through a park. This friend, who now lived in Manhattan, declined, saying, "I'm from New York. There's no way I'm going through a park after dark!" And in New York, in the 1970s, she was right. Even by day, Central Park could be a death trap.

Things have changed. By 1995 it was quite a bit safer to visit Central Park, even at night. Marie Winn and others have been watching the wildlife in Central Park for a number of years, and by 1995 they began to hazard evening and night visits, particularly to see moths, bats and owls. She records some of these adventures in Central Park in the Dark: More Mysteries of Urban Wildlife. The "more" in the subtitle follows her prior book, Red-Tails in Love, which chronicled the first pair of red-tailed hawks to successfully nest and raise young atop a building near the Park.

When the author began birdwatching in Central Park, more than twenty years ago, she little thought it would lead to midnight moth-watching expeditions, pre-dawn "fly-out" vigils, voyeurism of slug sex, or being bitten by the "rescue fantasy" bug while watching owlets take their lumps as they fledged. Central is a big park. At 843 acres, or about 1.3 square miles, it is big enough to hide the City from you when you are almost anywhere in its midst.

It is also big enough to host quite a variety of wildlife. According to the Central Park Conservancy, more than 240 bird species have been seen here, and about half of these can be found nesting here. There are also several species of bat, quite a few other mammals (not just rats), and perhaps 10,000 species of moth.

It's the moths that brought about the Central Park Mothers (rhymes with Authors), a moth-watching group that, of necessity, had to carry out their activities after dark. There are very few day-flying moths. They began with a sheet and a battery-powered black light, but soon found that bait works best. The Moth Tree, an elm with a mild fungus disease, seeped sweet sap, which attracted moths by the hundreds. Their favorites were the large underwing moths, species with colorful hind wings, usually having big eye spots. These moths flash the eyespots when disturbed, which will startle a predator and give the moth a running head start to escape. Moth stories take up a third of the book.

But the author doesn't just tell animal stories. She has learned a lot of science and lore over the years, and imparts it with relish, using writing that is to be relished. For example, about ring-necked pheasants:
There may have been pheasants in Central Park in the earliest years: an 1878 article in Harper's Monthly mentions a pheasant 'scurrying through the shrubbery' of the Ramble. But an 1886 survey of Central Park bird life did not include pheasants among the 121 species it listed. Perhaps during that period of eight years they all ended up on dinner tables…the pheasant was absent from Central Park until April 30, 1972, when a number of birdwatchers ran into one in the Ramble.
The author has also, at various times, been a member of the Woodlands Advisory Board, a consortium of members of the Conservancy and of the community. After an ill-advised move to remove the hawk nest from atop the nearby building, there was quite an outcry. Since that time, the hawks have been allowed to rebuild their nest, and quite a number of other red-tailed hawks have adopted city skyscraper life. (In a story the author doesn't tell, Peregrine falcons are also to be found nesting atop skyscrapers)

The book's closing chapters chronicle the introduction of screech owls to the Park, ending with a few sightings that indicate their successful integration. The members of the Woodlands Advisory Board originally opposed the project, noting that the owls had been absent from the park since about 1950. A later project by the author indicated, indeed established, that a combination of owl habits and human drivers' habits made screech owls' long-term habitation of the park very unlikely.

Screech owls eat insects, and most of the tastiest ones fly 2-4 feet above ground (very roughly, a meter). The owls begin hunting by dropping from a tree to this level, flattening out their flight path, and swooping along just at the "ideal" altitude to get smacked by cars on one of Central Park's drives. The timing of their earlier disappearance coincides clearly with the era in which cars were first allowed to go faster than 25 mph on Park roads.

But the introduced screech owls, in spite of a high level of auto mortality, have so far reproduced and spread throughout the Park. Maybe they are learning to fly a little higher! In time, this may lead to a new subspecies of screech owl. What it most certainly lead to is a great motivation for subsequent generations to continue watching the birds and beasts of Central Park, by day or by night.

Saturday, January 17, 2009

A living legend passes on

kw: artists

[Scanned from a local newspaper]

Though I've heard about the Wyeths all my life, I hadn't seen any of their art "in person" until I visited the Brandywine River Museum just a few days ago. This morning, I find that the current patriarch of the dynasty has passed on. Seldom does an artist touch the soul of a nation's people the way Andrew Wyeth did.

Though the news article includes an image of his best-known painting, I've added a photo of it here, taken at MOMA. I'd like to have a high-quality scan or photo of this painting, without the error of lighting that MOMA inflicted on it; the artist had already highlighted Christina in painterly fashion; the focused lamp detracts from the view. Click on this image for a wallpaper-size version.

Friday, January 16, 2009

Favorite fortifications - agates that is

kw: rocks, minerals, agates, chalcedony

I was going through some rocks recently, getting a load ready for my tumbler. I've been mostly tumbling jasper that I got at Lavic, California (I posted about Lavic Siding and its wonderful Jasper in March, 2008). But I also have a bit of this and that, different stones of different types, that I've acquired over the years. One thing I am very short of is fortification agate. I made up my mind to acquire some. There is a rock show in Delaware in March, where I'll look for pieces to buy. I'd love to get a piece or two like this one:


This is a Fortification Agate. This sort of pattern is the classic Agate. Some old Aggie marbles were carved from well-formed agates and show patterns like this. This image is a clip, a bit color-brightened, from a photo at Superagates, of a Fairburn Agate, the original Agate. All other fortification agates are compared to Fairburns, with good reason. They're the best.

There are many kinds of fortification agates, for they occur all over the world. Some have larger, coarser patterns, and some are smaller and clearer (the rock above is about two inches, or 5 cm, across). Some are more or less distinct or colorful. I do have a couple of rather insipid agates from the Laguna locality, but I'd hesitate to put up their images; almost a waste of the space.

Agates are nearly pure quartz; the impurities are mineral salts that provide the color. Nearly every color is possible, but earth tones and red-orange are most common. The quartz in an agate is crystalline, not glassy, even though they look like stained glass. They are cryptocrystalline, which just means that the crystals are so small they are hidden from our eyes. The two main types of cryptocrystalline quartz are flint and chalcedony.

In flint, the crystals are blocky and don't have any particular orientation. In chalcedony, the crystals are filamentous, like short fibers. In some forms, the fibers are not oriented in any particular way; they are like felt. Most jasper is composed of felted fibers. When the fibers are oriented, we get agates.

In fortification agates in particular, the fibrous crystals are oriented radially; the bands are formed of crystals that run the short way. In some cases, the crystals are very transparent and when they are just the right range of size, they diffract light. Then thin (2-3 mm), polished slices of the agate show iridescence, and this special kind of fortification agate is called Iris Agate. An example is shown here, in an image from the Flickr account of Rockman836:


The colors don't come from pigments, they come from the light diffracted from the oriented fibers, and the color shift results from the changing orientation of the fibers with respect to the light source. On my monitor this image is very nearly life size, taking for scale the binder clip holding the agate piece. That's quite a large chunk of iris agate. Most of what I have seen has been smaller (of course, I may be mistaking the size of binder clip that was used).

By the way, one would never tumble an iris agate. They need to be cut thin and polished on a flat lap. Other fortification agates can be tumbled, and I have seen rather large agates that were tumbled so their patterns show from all surfaces. Awesome!

Need you ask why I don't go collect my own agates? Compared to jasper, good fortification agate is quite scarce. Many of the classic collecting localities are nearly worked out, and some have become private preserves. If you look at the prices on e-Bay, you'll find that agate isn't really a "semi-precious" stone any more. At current prices, it is as costly as Jade. But buying some will cost me less than a collecting trip, so I'll celebrate oncoming old age by "silver picking" my next acquisitions.

Thursday, January 15, 2009

The biggest moths

kw: moths, lepidoptera

I got a surprise when I stumbled across the information that this is the largest moth in North America. It is the Black Witch, though if the species had been named for the female, it would be called the Brown Witch; there is a significant color difference between the sexes.

The Black Witch, Ascalapha odorata, is the largest North American moth, with a wing span of 11-15 cm (4.4-6 in). It is found throughout the country, though a sightings map at Butterflies and Moths of North America shows it has been seen in scattered locations, coast to coast and from south to north, rather than "just about everywhere". This is probably because it is nocturnal. I suspect it is as widespread as the familiar yellow swallowtail butterfly, which I've seen in every US state I've lived in (seven states).

Prior to this morning, I thought the largest moth in the US was the Ailanthus Silk Moth, Samia cynthia, but its wing span is a trifle less: 10-14 cm (4-5.5 in).

Even if this silk moth were larger, it is not a US native; it was brought here from China in an effort to establish an American silk industry. That didn't work, even though the moth has thrived here. Somehow, the rest of the silk production infrastructure, human and natural, didn't come together the way it has in China.

The Russian thistle comes to mind. It was introduced here long ago, as a forage crop. Somehow, its growth habit in the US led to its popular name, the Tumbleweed. In Eurasia, it doesn't tumble. Nobody knows why.

Back to moths. It's always a pleasure to learn something new and surprising. Having a closeup look at either of these hand-size moths would be a pleasure even greater.

Wednesday, January 14, 2009

A few pix I like

kw: photography, nature, kaleidoscopes

The ice storm we had a month ago was about all the winter we've had so far. This storm had a sharp edge, both for precipitation and for temperature. Half an hour to the north, there was a couple inches of snow. We got sleet followed by ice. Half an hour to the south, just a spattering of rain.

I got outside just as the Sun broke through, backlighting the icy twigs and branches behind my neighbor's house. It is a pity that ice storms are so damaging, because they can sure be pretty. This one was mild, leaving only a thin sheen of ice. I've seen them load trees with an inch of ice all around all the twigs, bringing large limbs crashing down.

Nearly two months prior to the ice storm, the fall leaves were still pretty. I like this one as a reminder of the beauty that led to the cold. I like taking pictures of fall leaves. This is one of just a few I had time to take this year.

When I was a child, my father would load us all into the car and drive up into the mountains as soon as the leaves turned. He would take dozens of pictures of the leaves, and a few of all of us among them. One of my brothers still has some of those old Kodachrome slides.

The "best" leaves are always considered the red and orange ones. I wonder how our perception of fall would be different if fall leaves also came in blues and bright purples. Even among flowers, blue colors are comparatively rare.

On an entirely different note, I happened across this image, and backtracked it to Nikolas Schiller's blog, where a bunch of them may be found along with a host of other pictures of various kinds. The blog writer calls these images "quilts". I call them kaleidoscopes. They are high-resolution aerial imagery of selected cities, sliced on an angle and repeated into an electronic tiling. Very nice. Mr. Schiller sells high-resolution posters of them.

Tuesday, January 13, 2009

Are we normal yet?

kw: climate change, shortsightedness

Early in the book I am currently reading, I found these words:
"If a Black Swallowtail caterpillar turns into a pupa on October 2, it really doesn't matter whether it happens in 1908 or 2008. Black swallowtail caterpillars have been pupating in the same way and at about the same time for eons."
This is followed by a footnote about us being the "last generation to enjoy the timelessness of nature", presumably because of global warming. What rot!

Nature seems timeless to most people because our lives are short compared to geologic and climatic cycles. This era, the last 10,000 to 11,000 years, called the Holocene by archaeologists and geologists, is actually the latest of about twenty interglacial periods of the Pleistocene, the most recent set of Ice Ages. This cold period is somewhat short (only about two million years) and rather less severe than some of the earlier ones.

It actually began in the Pliocene, in which a dozens of warm-cold cycles, each about 50,000 years long, gradually slowed and got more severe, so that by two million years ago the Earth's climate would enter a new icing event every 100,000 years, which would end after 80,000-95,000 years and be followed by five-to-twenty thousand years of interglacial warming. Of the past twenty interglacial periods, some have been cooler than this one, and some have been warmer. Within each, there have been smaller gyrations of a few degrees plus or minus.

The Medieval Warm Period, which peaked about a thousand years ago, was comparable to the pleasant period of 1950-1980. In between, things were cooler by about two degrees, bottoming out with the Little Ice Age that caused so much hardship during the American Revolution and for a couple decades before and after it.

These relatively minor climate cycles have shifted the indicators of Spring and Fall by a month or two, back and forth, and the Swallowtails and other critters have managed to survive. The Black Swallowtail doesn't pupate on a certain calendar date; it doesn't have a calendar. It pupates when two things prompt it: the shortening day and the falling nighttime temperature. During the 1990s, early October was typically the time of the first post-Equinox frost, at least in the New York City area. While a frost can occur before September 21, the caterpillar doesn't seem to get the message until the sun begins to set before 6PM. Caterpillars, as most creatures, do have a diurnal clock that can be quite sensitive.

Just a hint, folks: Fifty million years ago, and also 65 million years ago, there was tropical vegetation growing in Antarctica. There was a freeze in between that was considerably more severe than any Pleistocene event. Think glaciers in Houston. There have been at least two periods in the last billion years that were cold enough that there was sea ice at the equator, and glaciers on all land surfaces. The Pleistocene is comparatively mild!

Now it is true that the climate has warmed by about a degree Celsius (close to 2°F) in my lifetime. It is probably also true that the CO2-induced Greenhouse Effect has been responsible for a quarter to a half of that degree. Seasonal changes are thus occurring earlier in the Spring and later in the Fall than they were 50+ years ago (or even 20+ years ago). If we are paying attention, we are not "enjoying" the timelessness of nature, but the resiliency of nature, for which there is always change.

Monday, January 12, 2009

Sea science

kw: book reviews, nonfiction, oceanography

The Aquarius habitat is presently the only undersea dwelling and research laboratory in operation. Aquarius is owned by NOAA and is operated by the University of North Carolina Wilmington (Aquarius image copyright © 2009, University of North Carolina Wilmington. All rights reserved. Further reproduction prohibited.)

There were at one time seven or eight undersea research habitats in operation, but they are costly and difficult to maintain, and current priorities are elsewhere. The chief scientist for Aquarius, and formerly with the educational organization SEA, Ellen Prager, has written Chasing Science at Sea: Racing Hurricanes, Stalking Sharks, and Living Undersea with Ocean Experts, to convey her enjoyment and the wonder of ocean science.

The author makes a strong case for scientific field work. All natural sciences are based on observations, and nothing observes as thoroughly as a human. For any scientist, the wonder of discovery is powerful motivation; for a scientist in the field, this is coupled with the sheer enjoyment of fieldwork, regardless of the accompanying drudgery and discomfort, or even danger.

Chasing Science is primarily a book of stories. This is no dry tome, but a lively little book, full of anecdotes broadly grouped in a half dozen categories. Some of them are of dangers averted (or not), such as the aggressive sea lions that have occasionally chased the author right out of the water, or the sharks that came to investigate a group of mid-ocean swimmers, or the panic of running out of air sixty feet down, and having to surface quickly, grab an air tank and return to thirty feet to decompress before 'the bends' set in. Dr. Prager tells of a doctor who took an extra blood sample from her while she was saturation diving at Aquarius. Just to prove a point, he took it to the surface in a pressurized container, then released the pressure all at once. The effect was like opening a just-dropped can of soda: ker-fizz, ker-splash!

More of the stories are of the beauties and wonders of the work itself. The author and her science buddies tell stories of swimming amidst a dense pod of curious reef fish, of gathering data that blew away one idea only to replace it with a better one, or of getting so caught up in observing animal behavior that one forgets to sleep for a few days at a time.

Trouble and frustration stories also abound. Equipment gets lost, or storms delay a tightly-scheduled mission. But many a scientist will return from a scientific voyage having endured seasickness, hurricanes, poor sleeping conditions and worse food, and claim stoutly that those are nothing compared to battling the bureaucracy for continued support.

My wife asked, while I was reading the book, why it is so hard to do ocean science. I said, "Because you can't see into it." Astronomy is comparatively easy, because we can see our targets. Yet the amount spent on our four "great observatories", including the Hubble Space Telescope, exceeds all money spent on ocean science for all time, so far. NASA has 25 times the budget of NOAA's ocean science arm.

And this is the author's continued message. Funding for ocean science is declining, even as our need for solid data grows. Coastlines and reefs are being restricted more and more, so that people have ever fewer opportunities to have even the simple pleasure of clambering about a tide pool or snorkeling over shallow corals. Three-quarters of the earth's surface is hidden beneath the opaque screen of one to three miles of ocean water. Nothing compares with real light, reflected off real objects and sea life, entering human eyes unfiltered by video cameras and electronic screens.

I know, I've done geological field work, and nothing beats being there. All the pictures I have taken don't convey to someone else the feelings I had just being there.

Saturday, January 10, 2009

The museum the Wyeths built

kw: museums, paintings, fine art

Today, was free admission day at the Brandywine River Museum, so my wife and I tootled down PA Highway 1 to have a look. All we knew is that it has paintings by members of the Wyeth family. This image, from a published photograph [© A. B. McCoy 1985], is of Old Kris by N.C. Wyeth.

In brief, N.C. is the original Wyeth, mainly an illustrator, who worked from the late 1800s to the early 1940s. He died in 1945. His son Andrew is the currently most famous Wyeth, born in 1917 and still active. Grandson Jamie, born 1946 (and so a year older than I) is the most productive at the moment.

A couple other Wyeth family members also produce art and a piece or two by them are on display. N.C., Andrew and Jamie each have about half a gallery devoted to their work. Also on display is a fine collection of work by Howard Pyle, N.C.'s teacher. Works by other well-known illustrators such as Maxfield Parrish are also shown.

In the non-gallery areas a variety of non-painterly art is on display, such as sculptures large and small, a few carved "wooden Indians", and a large, very ornate Victorian-era doll house. The museum advertises tours led by Victoria Wyeth, but only on weekdays.

I'd called and been told I could not photograph in the galleries, so I didn't bring a camera. It is a pity. In an area where one photography is allowed, three Christmas trees are richly decorated with ornaments made by Museum volunteers, of fanciful animals made from natural materials like thistle and cockle burrs, milkweed pods, gourds, and many other kinds of dried plant material.

On the second floor one gallery is devoted to a delightful model train setup, all O gauge, which is a bit larger than the model train sets that were often given as Christmas gifts to youngsters such as I in the 1950s. Later, HO (half-O) and N (even smaller yet) became more popular, but I've always had a fondness for the larger model sizes.

We had but 90 minutes to spend there, because we could only go late in the day. It was an hour-plus well invested.

Beyond this horizon, everything sets

kw: book reviews, nonfiction, cosmology, black holes

The book took me a long time to finish, and left me puzzled. What, and how, am I to think about these things? Beneath the notice of most of us, an intellectual war has been raging among a small number of physicists, a generally respectful war, carried out with great civility, but concerning the fundamentals of physics and the reality of our Universe.

Of course, scientists cannot be silent about things that deeply move them, so many publications have ensued, but mostly in journals read only by other physicists. A rare popular press article has appeared, say in Scientific American or Popular Science, about universal holograms, or information loss, or variously named "strings", or accelerating cosmological expansion.

As it turns out, the four items mentioned just above are all related, at least to Leonard Susskind and a number of contemporary physicists. In his new book, The Black Hole War: My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics, Dr. Susskind explains the central role of black holes in the controversy, and how they tie together all the important physics concepts of the late 20th and early 21st Centuries.

I won't go into any detail here, because I can't. Not only is the book large, more than 400 pages, but the author has already simplified his arguments a great deal in order to reach a nonmathematical public.

I do just have to express my puzzlement over his discussion that, to an outside observer, an object gets heated as it falls to the event horizon of a black hole, even if it is the only thing in the vicinity. Of course, the now-familiar accretion disk heats incoming stuff by friction. But the observed heating is based on the observation itself:
  • The gravitational redshift approaches infinity for "light" that reaches us from an object that is approaching the event horizon.
  • Let us remember, the event horizon is the point at which gravity stops light entirely. Any electromagnetic energy that originates or reflects from something at or below the event horizon can only proceed inward.
  • Time dilation also approaches infinity in the same manner.
  • For us to see it, the falling object we are watching must be emitting or reflecting radiation that began as much shorter wavelengths than what we detect. Eventually, our "camera" might record an image using visible photons that began their journey to us as gamma rays.
  • These very high-energy photons (gamma rays) imply very high temperature. So the object we are observing must be very hot.
I looked and looked, but never found out what exactly is heating up the object in question, just this circular argument about high-energy photons. Thus, at the moment I counter-contend that for a freely falling object, the only source of heating is tidal friction. Start with a big enough black hole (galactic mass or so), and the tides and heating are minimal. However, suppose the object is not freely falling. Suppose it is a thermometer on a long (and very strong) rope!

Such a thermometer would be heated all right, by the photons hitting it as they freely fall into the black hole. Depending on how close to the event horizon you can get it, the thermometer could be flooded by gamma ray photons that began life as infrared or visible photons, or even the microwave background radiation. But to a freely falling object, the photons seem to have the same energy they had when both they and the object were far from the black hole.

Although I am a science junkie, there is a limit to my understanding. The point of the book is, to me, that science is a very human endeavor. It would be no fun at all were it carried out only by emotionless robots. I am not sure such robots could do science, however, because they'd at least need motivation, and the motivation, "My programmer built in a requirement to 'do science'," is cold comfort indeed.

No, scientists are human, albeit in a few cases, humans who have learned to disagree without being too disagreeable. They hold their views with the same passion that St. Francis and Billy Sunday held theirs, and evangelize with identical fervor.

As a result of the black hole war, new mathematical tools were developed to help "rewire" the brains of a few physicists so they can understand a new paradigm. Boy, I thought particle physics was confusing. Now these guys are operating in realms where the a proton is as big and empty as a galaxy (which is 99.9999% space between stars), compared to a thing called the Planck Mass.

By the way, there is a lot of hope for the LHC (Large Hadron Collider), which will get working again once it is repaired after last year's broken magnet. People fear it will produce tiny black holes that might grow larger and swallow stuff up. Those black holes are the point, and they won't grow. Any black hole that weighs less than a kilogram will evaporate, due to Hawking radiation, in less than 10-22 seconds. It'll make bang somewhat smaller than the bang that created it, but in that slice of a second it ought to produce a ton of data for the scientists to mull over. It just might provide experimental confirmation of some of the things Dr. Susskind has written about.

Friday, January 09, 2009

A restricted life?

kw: musings, acquaintances

My high school years, the early 1960s, we lived in Sandusky, Ohio, one of the nicer small cities of the time. The man next door had a life story that I found fascinating. At the end of our street, just two blocks from our house, was a small tin shack similar to this railroad model. It really was quite close to the tracks. He said he was born there and grew up there.

On a visit to Sandusky a few years ago, I found that the tracks have been ripped out and the railroad right-of-way is now just a berm. The shack is gone. But the other houses are still there, though many have had updated siding and windows installed.

When our neighbor got into his teens, in the 1880s, he was an apprentice bricklayer and boarded with his master. Later, in business for himself, he prospered so that when he married, he was able to build a house. He married a little late, so it was shortly before the Great War, perhaps 1912.

This house, built in 1928, is similar to my memories of the old house he showed me, right across the street from the tin shack. He lived in the new house until the late 1950s, when his wife died. He said their honeymoon trip to Huron, Ohio, just ten miles East, was the only time he'd been outside Sandusky city limits. My dad offered to take him along on one of our drives, say to Cleveland or somewhere, but he really didn't care to.

After his wife died, to put some of the memories behind him, he bought a different house and sold the first one. The newer house was two blocks from the other one…it was the house next door to us. He was pushing 80 years old by 1965.

Sometimes I think about that. 80 years in a world no more than five miles across. Even today, you can cross the city on foot in about an hour and a half. He was a cheerful old gent, and didn't seem to care that there was a lot more world out there. Some people get a wandering craving, and some don't.

Abe Lincoln said, "People are about as happy as they make up their minds to be." Our neighbor did the things he wanted. What more can you ask for?

Thursday, January 08, 2009

Cooking with black holes

kw: musings, black holes

A book I am about halfway through discusses black holes, and a lot of it has to do with Hawking radiation and the implications of that. See the link just above for a detailed treatment in Wikipedia. A briefer explanation is thus:
  • Richard Feynmen's work on quantum electrodynamics showed that virtual particles are continually created and destroyed, in complementary pairs, everywhere and always. They provide the properties we associate with "the vacuum."
  • Stephen Hawking showed that when a pair of virtual particles gets created just next to the event horizon of a black hole, during the tiny fraction of a second that the particles are physically separated, one may pass through the event horizon.
  • The extreme "strain" on space-time caused by the proximity of the black hole reifies the particles, such that one is captured by the black hole and the other escapes, becoming a particle that is seemingly emitted spontaneously by the black hole's event horizon.
This means that a black hole is a black body, in the physics sense, with a temperature and a perfect black-body thermal spectrum. However, for the black holes we expect to find astronomically, this temperature is very low, and the particles emitted have very low energies. How low? The Wikipedia article I linked above has the equations to figure it out. I made a table to help wrap my mind around the concepts. First, the temperature is extremely low for stellar-mass and larger black holes, but can get rather higher for lighter ones. The table will include a 1kg mass to illustrate how high. I also use "E" notation for large and small numbers: 2e14 means 2•1014.

(I apologize in advance for Blogger's tendency to put too much white space before a table.)
Table: Black Hole Sizes and Radiation Characteristics







ObjectMass, kgTemp, KRadius, mPower, W
Solar mass2E307E-92,9801.5E-32
Earth mass6E240.00240.009 (9mm)1.9E-21
Moon mass7.4E220.191.1E-4 (0.11mm)1.1E-17
Asteroid1E141.4E81.5E-136.1
1 km3 H2O1E121.4E101.5E-1561,000
1 kg11.4E221.5E-226.1E38

We expect black holes produced by natural processes to be the mass of the Sun or heavier. The top row of the table shows that the temperature and thermal output of such an object are too low to measure, particularly when the background temperature of the universe is, at present, about 3K. Even the temperature of a Lunar-mass black hole is in a realm that is difficult to measure, less than 1/5 of a Kelvin (Note, a Kelvin is what a degree of Centigrade size is called when the zero point is absolute zero, called zero Kelvins or 0K).

Should any black holes lighter than the Moon exist, the temperature is higher, and can get very high indeed, as seen by the last three rows of the table. I picked a mass for the asteroid to be about the size of the one that clobbered the Dinosaurs. What does a temperature of 1.4E8 degrees mean? 140 million degrees! Such an object, the mass of a mountain, the size of a proton, radiating 6 watts of mainly gamma rays and x-rays, would be a truly dangerous item. (The x-ray machine used to take a chest x-ray emits about a tenth of a watt of x-rays, but only about a tenth of that passes through your chest. A dental x-ray machine is considerably lower power than that. Six watts of such radiation is a lot!)

Comparing the data in these three rows, the regularities are clear. Temperature is exactly proportional to 1/Mass; radius is proportional to Mass; and total energy output is proportional to the square of 1/Mass.

Back to the radiation emission: A 1-kg black hole radiates so furiously, at a temperature of 14 billion trillion degrees, that all its mass would be emitted in less than 1E-21 second. Black holes in the range of a few kilograms and smaller are simply energy bombs! A 3-megaton thermonuclear weapon converts a gram of mass to energy in a microsecond or so. Imagine the conversion of a number of kilograms in less than a nanosecond.

What is my conclusion? Firstly, as to my title: a black hole that emits sufficient thermal energy to "cook" with, does so with penetrating radiation that would cut right through any lead shielding. Plus, your "stove" would tend to swallow up the food if it is put close enough to be heated!

Secondly, no black holes are currently evaporating, because thermal energy is entering them from the universe at a rate much greater than they emit their own. If the universe really does get stretched out by accelerating cosmic expansion until any large (stellar or galactic) black holes that now exist can begin to evaporate, not much will seem to happen for times so long they are hard to imagine: 1060 to 10100 years. But once a large black hole slowly evaporates down to a few million tons, things go rather faster, and the last ton will "evaporate" explosively. It would be a fatal mistake to be within a light-year or less of such an explosion!

Wednesday, January 07, 2009

Memory Lane by Lake Erie

kw: the past, nostalgia, reminiscences

This is a scene about six blocks from the house I lived in my 9th grade year, in Lakewood, Ohio. It is Clifton & Belle, looking north toward Lakewood Park. This is as close as Google Street View currently comes to the house.

Lakewood Park is the locus of most of my fond memories of Lakewood. When I started 10th grade, I found that the new high school was dominated by youth gangs, with which I was soon in deep trouble, just for refusing to join one. Fortunately, we moved by November, to Sandusky, which move I credit with saving my life.

At Lakewood park I was on the park swim team and learned lifeguarding skills. In the winter, they filled a bermed area with water to freeze, and we all skated there. Skating on any part of nearby Lake Erie was too hazardous, because the lake is in constant motion, being shallow, and the ice breaks unpredictably. Only one person has survived an attempt to walk from Point Pelee, Ontario to Cleveland.

This zoomed-out view of the Street View image shows the controls. It is much clearer and easier to use than Street View was just a couple months ago. The navigation arrows that let you "drive" down a street don't show here, because they fade out of view if you just sit quietly for a moment. A cool feature. Move the mouse, and they appear again.

I can get an overhead view of the nearby house, but I'll wait for a street-level image, whenever the Google folks get around to it.

Tuesday, January 06, 2009

Visual analysis of star mass distribution

kw: analysis, statistical distributions, stars, lognormal, power law

Below I analyze the mass distribution of a couple thousand of the nearest stars. I must first explain what is going on here. It has to do with finding a way to chart a series of data so that they approximate a straight line. This is called linearizing the geodesic.

One of my nerdy obsessions is gathering examples that illustrate the Theory of Breakage. The premise was proven mathematically by Kolmogoroff in 1941 (published in German) and offered to the English-reading public in The Lognormal Distribution by J. Aitchison and J.A.C. Brown in 1957. If you drop a brittle object onto a hard surface so it shatters, then weigh every piece, an analysis would show that the weights of the pieces are distributed lognormally. The analysis of clastic sediments follows lognormal reasoning.

Rather than foist a mathematical proof on you here, I'll support the idea conceptually. The lognormal distribution is based on the normal, or Gaussian, distribution, the famous "bell curve." The relation is thus: If you take the logarithm of a set of items which are distributed lognormally, the resulting distribution will be normal. These six numbers make up a very small normal sequence: 7, 8.4, 9.5, 10.5, 11.6, 13. The mean (and median) value for this distribution is 10. If you add the first and last numbers you get 20, twice the median; so if you add any pair of numbers equally distant from the "gap" between the 9.5 and the 10.5, you get twice the median.

If we take an exponential function of these numbers, we get a lognormal distribution. In this case, let us take 2 to the power of each of the numbers, and divide the resulting series by 100. Then these six numbers form a very small lognormal sequence: 1.29, 3.4, 7.2, 14.5, 30.7, 81.3. As these are lognormally distributed (for they were constructed so), the median is a logmedian, formed by multiplying the extrema and taking the square root: SQRT(1.29*81.3) = 10.2. Again, this works with any pair of numbers equidistant from the "gap" between the 7.2 and the 14.5.

Where a normal distribution is characterized by values clustered about a median value, a lognormal distribution has a cluster on the small side of the median, and a scattering of the largest values, in other words, a heavy tail. In many cases, the largest member of a lognormal sequence is larger than the sum of the rest of the terms.

A bunch of random items that are related by a similar additive process tend to be normally distributed. The Central Limit Theorem, upon which Kolmogoroff's proof is based, states that repeatedly taking the sum of several random numbers produces a normal distribution. Exponentiation turns addition into multiplication, so by the same reasoning, repeatedly taking the product (or the quotient) of several random numbers produces a lognormal distribution. Thus, in nature, additive (and subtractive) processes produce normally distributed values, while multiplicative or divisive processes (exemplified by breakage) produce lognormally distributed values.

I got interested in this subject when I read (I don't recall where) of an alternative hypothesis of breakage, that the resulting pieces might constitute a "scale free" or "power law" distribution. A power law distribution somewhat resembles a lognormal distribution, in that there are many small members and few large ones. However, the quantity of small members is quite a bit greater. A power law sequence is most simply produced by dividing a series of numbers into a constant, but all practical sequences are produced by dividing some power of each member of the series into a constant.

A very small power law sequence, produced by dividing 30 by 6, 5, 4, 3, 2 & 1, is
5, 6, 7.5, 10, 15, 30. Using the generating law to determine the median, we find it is 30/3.5 = 8.57 (The procedure used for a lognormal sequence yields 8.66). The drawback to continuing this series is that it has no finite sum. A power law sequence from a distribution that will converge to a finite sum is found by dividing the 3/2 power of the first six numbers into 30: 2.04, 2.7, 3.8, 5.8, 10.6, 30. This has median 4.6.

While there are software routines that can distinguish whether a sequence is distributed according to a power law or lognormally (and a great many others), there is a simple visual test that I like to administer. The illustrations that follow have larger-sized versions "behind" them, available by clicking. I prepared these using Microsoft Excel, which unfortunately doesn't have a probability axis option for its charting tools, so I use a transformation to linearize a probability axis.

I illustrate the technique here; I generated six sample distributions of 25 members each. Three are power law sequences and three are lognormal sequences. The latter were scaled to have a largest member equal to 10, so we can see their shapes in this chart and the one that follows.

This chart presentation is log-log. On such a chart a power law sequence plots as a straight line. The three blue lines are power law sequences, and the three dark red lines are lognormal sequences with different breadths of distribution (different values of the logvariance). The strong curvature of the red lines indicates that they are far from linearized in this type of chart.

This chart takes a standard normal sequence as the vertical axis; the value "1" means one Standard Deviation from the mean (1σ or "one sigma"). 25 values have probabilities ranging from 0.04 to 0.96, which are from -1.75σ to +1.75σ. The horizontal axis plots the values of the members of the six distributions, and is shown in logarithmic transformation. As before, the blue lines are the power law sequences and the red lines are the lognormal sequences.

Now it is the latter that plot in a straight line on these axes, while the power law sequences plot as distinct curves. This is diagnostic for each type of data; they plot as a straight line on appropriate axes, and as a curve under any other transformation.

Now we can plot the stars' masses. I gathered stellar data from many sources, but I'd like to acknowledge the Nearby Star Observers for their work and for a great collection of links that allowed me to find some of the sources of data I used.

I gathered information on mass where I could, but for most of the stars I used databases that had the stars' spectral and luminosity types, distances and magnitudes, and applied stellar evolution theory to approximate the masses. I eventually had a list of the masses of 2,200 stars out to a distance of 100 light-years. I plotted these, the 688 stars closer than 50 light years, and the 51 stars closer than 25 light years, in log-log coordinates for this chart. Of the 2,200 stars, 1,876 are on the Main Sequence (Class V), and are distributed spectrally as follows:
  • B - 2
  • A - 38
  • F - 50
  • G - 379
  • K - 578
  • M - 829
These accord well with other analyses of the relative number of each type of star. The total list also includes some giants and close to 100 white dwarfs, plus a very few brown dwarfs. For the white dwarfs I did my best to infer the mass of the star when it was younger, because the aim here is to investigate the breakup of the gas-and-dust clouds that formed these stars.

The clear conclusion from this plot is that the data I have are not distributed according to a power law. There are two possible reasons: a great many K- and M-type stars may yet be discovered within 100 light years of Earth, or the actual distribution is not power law.

A lognormal analysis yields much straighter lines. Let us focus on the pinkish line. This set of 688 stars is probably very nearly complete.

A sphere twice the radius of another ought to have eight times as many stars within it, compared to the other. But 2,200/688 = 3.2, so many stars in the 50-100 light-year range are probably not discovered yet, and most of them will be small, dim stars (K and M) and brown dwarfs. On the other hand, 688/51 = 13.5, so there is a dearth of stars in the solar neighborhood. This is known from the literature about the "solar bubble".

What does this chart show us? It indicates to me that the distribution of star mass is most likely lognormal, and if so we can infer a few things. Projecting a straight line through the pink sequence to the 4σ lines indicates that in a complete sample of about 32,000 stars there ought to be a smattering of giants with up to 9 or 10 solar masses, and similar smattering of M9 types and brown dwarfs as small as 0.02 solar masses, about 20 Jupiter masses. Extrapolating wildly to 7σ (almost a trillion stars, close to the probable number in the Galaxy), puts us in a realm in which the heaviest star approaches 100 solar masses and the lightest brown dwarfs are no more than twice the mass of Jupiter. These conclusions seem plausible, so I have considerable confidence in a lognormal distribution of stellar mass.

Monday, January 05, 2009

Words beyond words

kw: musings, words, definitions

Reading Kluge, which I reviewed yesterday, got me thinking about language. While we may have the largest number of words in the English language, there aren't actually enough of them. How else to explain the large number of words with multiple meanings? These are a source of puns, plus plenty of confusion.

One of my favorites is the word display. According to my big desk dictionary (Webster's New Twentieth Century Dictionary, the unabridged Second Edition), the word has:
  • 5 meanings as a transitive Verb (one that takes an object: "…to display a coat of arms…")
  • 2 meanings as an intransitive Verb (no object: "…Picasso displayed last week…")
  • 5 meanings as a Noun ("I brought a display of widgets.")
  • and it can be used as an Adjective ("…a display card…")
This isn't the English word most prolific of meanings. The entries for cover takes up three times the column space, having 20 transitive and 3 intransitive Verbal uses, 9 Noun uses, and at least a dozen separate entries for Adjective uses such as "cover girl".

When we talk about a "word", is display one word or twelve? Is cover really thirty-plus words? It is for reasons such as these that I once proposed to a standards-making group of which I was briefly a part, that a set of unambiguous codes be invented for unique meanings, which would upon completion greatly facilitate automatic translation of documents.

Thus the word word can be a slippery concept. No wonder we need specialists to write the deathly dull, but unambiguous documents that convey agreements, treaties and contracts. It just doesn't come naturally, folks!

Sunday, January 04, 2009

Futile search for a well-ordered mind

kw: book reviews, nonfiction, brain, mind, evolution

If you look up kluge or kludge at freedictionary.com you will get:
  1. A system, especially a computer system, that is constituted of poorly matched elements or of elements originally intended for other applications.
  2. A clumsy or inelegant solution to a problem.
I think that about sums up the "seat-of-the-pants" that typically underlies the creation of a kluge. Psychology professor Gary Marcus thinks the term, particularly its first definition, exactly suits the "design" of, not only the human body, but particularly the brain and mind. He makes his case in Kluge: The Haphazard Construction of the Human Mind.

I suspect the word "haphazard" is an editor's compromise. It doesn't convey a proper sense of the contingency plus ruthless pruning that constitutes evolutionary change. Our thinking and feelings are what they are because creatures that think and feel thus were able to have more offspring than creatures that think and feel differently. That doesn't mean our mind is the best that can be imagined, just that it is the best collection of mental and emotional tools that has so far been produced, based on the mental and emotional tools available to evolutionary processes that shaped our brain from the brain that existed in our chimp-like ancestors a few million years ago.

The author offers a few suggestions as to the origin of our word kluge. The letters KLUGE can be seen on this paper folding machine, of a kind still in use in small print shops. I have seen just the same name, but in a different typeface, proudly displayed on the front of a piece of electrical equipment from the 1940s, that looked like it came right off the set of Frankenstein.

Kluge means "clever" in German, but I suspect it is the almost scary look of the machines made by the two Kluge companies that prompted the term, which arose in America at a time that German scientists were involved in major projects such as the Manhattan Project, and probably using Kluge amplifiers and generators in their labs.

However the term came about, to an engineer it means something pretty specific, usually referring to a "breadboard" prototype that operates according to desired specifications, but needs a lot of work to become a production device. For a lot of home-brew builders, such as those ham radio operators who still build their own equipment, getting a kluge working is more of a goal than a process, and once something is working "well enough", the old proverb "If it ain't broke, don't fix it" kicks in. I've shared the microphone with many a friend whose transmitting amplifier was a kluge they'd cobbled together decades before.

In fact, while this image was unlabeled when I found it, it is of an 845 transmitting tube and supporting electronics, and perfectly exemplifies a home-brewed kluge. It is probably a radio amplifier intended to push the limits of legal power (1500 peak input watts) so the operator can "punch through" a signal in noisy conditions.

Does the human mind really match the concept of the kluge? Dr. Marcus makes a pretty strong case that it does. While many people have gotten somewhat used to the idea that we are smart apes, the idea that our smarts are still pretty ape-like is pretty uncomfortable. But consider the brain's construction.

At its base, the brain stem is most similar to the brain of a fish. It is overlaid by a series of additions that can be found in reptiles and amphibians, and the whole is surrounded by two levels of "cortex" ("bark"). The prefrontal cortex, which seems to be the seat of forethought and planning, is much larger in humans than in other mammals. In a pet cat, it is so small that Fluffy probably plans no farther than what she can see. Some philosophers may extol "living in the present", but if you had to become a housecat to really do so, I suspect the "ideal" would not be quite so popular.

In exploring these concepts, the author considers several realms of mental experience. I find three of these of the most interest. Firstly, memory. Do you know who is ROY G BIV? That's the mnemonic (memory helper) to remember the "seven colors" as proposed by Isaac Newton: Red Orange Yellow Green Blue Indigo Violet. How about "Oh, be a fine girl, kiss me"? It is used to teach budding astronomers the order of star spectral types, OBAFGKM, so created for historical reasons (Astronomers take note: that system is a kluge!). Why do we need mnemonics? It is because our memories are kluged up out of machinery needed by semi-predatory hunter-gatherer apes, and before them by half a billion years of brain development in which it was important to remember What and Where good food or good, safe sleeping places might be, but not so much When we found them, or How they might have arisen. For more than half a journalist's "7 W's", an early hominid would answer, "I couldn't care."

So, we remember where we usually park our car, but not necessarily where we parked it this time. I do that from time to time, and wind up going out the wrong door after work, then walking halfway around the building…when I don't first have a qualm that maybe it was stolen! We remember faces, an ancient skill, but not names. Only humans have names, and probably only for the last few tens of thousands of years. That is not enough time for an enhanced name memory skill to evolve. So instead, some people "peg" the name to some physical characteristic of a person's visage, and the rest of us muddle along until sheer repetition drills the name into our skull.

Secondly, there is language. Words can be very ambiguous, and are often used with more ambiguity still. The author reports how Noam Chomsky argues that syntax and semiotics arose to allow us to convey more exact meaning, to transmit information optimally while using less-than-optimal "atoms" (words). This makes some sense to me as a computer engineer: the TCP/IP system that is used for internet communication has two parts, one of which corrects for deficiencies in the other. IP is "Internet Protocol", which is error-prone but fast and simple. It was originally found better to send something two or three times quickly and correct errors by comparison.

Later, TCP, "Transmission Control Protocol" was developed. It takes care of the redundancy needed to send and correct short packets of information using IP, and has produced a system in which a whole digital movie, a gigabyte or two, can be downloaded with no errors in all its billions of bits. Grammar conventions, which differ from language to language, can take care of some of the problems, if we're diligent to apply them. But English is the most klugey of languages, so problems arise most freely here. Perhaps this is why there are so many lawyers in the English-speaking countries. They are trained to write bulletproof contractual language, which most of us find impossible. Not all languages have our problems.

For example, consider the sentence, "Put the book in the box on the table." Most of us would respond by looking first for a book, expecting there to be a box on a nearby table to put it in. Were we to see a book already in a box, and a clear tabletop nearby, we'd suffer only a momentary lurch, then we'd be able to follow through. In Japanese, this particular ambiguity cannot arise. Japanese has a number of grammatical tags called Particles by linguists, or sometimes Postpositions, since they come after the word they modify. Here is the Japanese for the commonly-expected meaning of the sentence above, with Particles in CAPS, followed by a literal translation:

hon O te-buru NO UENI aru hako NI ireru.
book OBJ table POSS UPON exists box IN to enter: enter the book into the box that exists upon the table.

Here is the alternate meaning I had above:

hon GA haiteru hako O te-buru NO UENI oku.
book SUBJ inside box OBJ table POSS UPON to place: place the book that's inside the box upon the table.

My translator (wife) offered a third possible meaning:
hon O hako NI irete te-buru NO UENI oku.
book OBJ box IN to enter table POSS UPON to place: place the book into the box [then] onto the table.

Though Japanese typically uses word order SUBJect OBJect verb, as long as the main verb occurs last, the Particles allow a Japanese to put the words in many different orders and the meaning can be strung together using them. This makes it easiest for an interpreter to translate from any language into Japanese: she keeps the verb in mind if it comes early, translates all other words and adds particles as needed, then appends the verb in an appropriate tense. English word order (the most variable), French, German, Tagalog—all can be accommodated.

Finally, mental illnesses are distressing troubles to which far too many of us are prone. Depression alone, not just brief sadness nor even just grief with a cause, but causeless, grinding, hopeless-feeling depression will affect a quarter or more of us at some time in our lives. For too man of us, it ends that life, leading to suicide. Many others are schizophrenic or bipolar, or otherwise psychotic, and don't even talk about milder neuroses. Where do these come from?

At the core of our brain, we are lizards, instantly reflexive, driven to react quickly on scant clues. Grab food if it's to be found; run from everything else that moves. Our newer brain organs are more deliberative. This causes conflict, and conflict inside our heads can lead to trouble.

I could write a book on Bipolar from the Inside. Maybe I will some day. All of us experience causeless moods. Bright days followed by a tendency to melancholy. But neither is too strong, for most people. The brighter days, we think faster, react faster, are more impulsive, jump to conclusions, and tend to be irritable, though we forgive slights easily. We are more lizardish. Gray days (and I'm speaking only of the inner weather) we brood, introspect, think things through but suffer "analysis paralysis", are easily wounded but suffer in silence, and hold grudges. We are overusing our much-vaunted "human mind". We need a balance of both to be, well, balanced! The lizard quickly sees lots of possibilities and quickly chooses, but the smart ape can sidestep the sudden reaction and override the choice after more deliberation…when it wants to enough.

The author ruminates a time or two about the fallacy of intelligent design. If we were intelligently designed, mightn't we be, well, more intelligent! Better memory, more accurate recall; crisper and more precise language; less (near-zero?) tendency to go off the rails. Not necessarily less complex, but complex in a more robust way.

In contrast to any of the classic kluges or Kluges, a well-designed mechanism can be quite complex yet very robust. The Linotype as patented by Mergenthaler worked so well and so reliably that it was used without any significant modifications for a century. A friend of my ran a small typesetting shop with a Linotype as its main producer well into the 1970s. These lovely beasts were not supplanted until phototypesetting equipment got to be cheaper and more reliable, which took a while. The phototypesetters of the 1970s were lots more klugey than the Linotype. That has changed.

In evolution, contingency is nearly everything. Nature builds on what has come before, and seldom makes large evolutionary leaps. Consider the eye. Eyes have evolved four separate times, at the very least. The two best-developed, focusing eye designs are those found in mollusks such as squids, and those found in vertebrates including humans. It happens that the squid eye is the better design: the focusing mechanism is more robust and less prone to myopia, and and retina is the right way out, with the light-sensing cells on top and the nerves behind.

The vertebrate eye's retina is backwards, with the nerves lying on top of the light sensors. This has three unfortunate consequences: there is a blind spot where the nerves "bundle up" to exit the eye, there is less total sensitivity, and a large amount of brain power is needed to cancel out the shadowing by the nerves so we see a smooth, blue sky as smooth rather than patterned by branching rivers of nerve shadows.

In his last chapter the author outlines thirteen cognitive tools to help overcome the deficiencies of our cross-purposed mind. I find two rules are sufficient, being easier to remember, and capable of doing most of the good:
  • Don't do something you can't undo (like shoplifting or that impulsive murder)
  • Nothing good happens fast (think it over, unless you'll die quicker than that)