The Tide; The Science and Stories Behind the Greatest Force on Earth

The Tide; The Science and Stories Behind the Greatest Force on Earth by Hugh Aldersey-Williams. W.W. Norton, 2017, paper.

Half the world’s population live on coasts subject to tides. Hugh Aldersey-Williams is one of them; he lives in Norfolk, England. A great portion of Floridians live within an hour’s drive of tidal coasts, the Gulf of Mexico and the Atlantic Ocean. It was a surprise to know that most coasts either aren’t tidal or that the tide is measured in centimeters.

Yet tides figure large in English idiomatic expressions. We are cautioned to “go with the tide.” Avoid “swimming against the tide.” Lovers of history are told that “there is a tide in the affairs of men.” A snack around 4:00 pm will hopefully “tide me over” until dinner, “Time and tide wait for no man.” Ever so many battles in history are said to be the “turning of the tide.” Fortunately for our humor, we do not know what will “betide” us.

Tides consist of an ebb and flow, the rise and fall of sea levels caused by the gravitational forces exerted by the Moon and the Sun and by the rotation of the Earth on its axis. Most often coastlines subject to tides experience them twice a day, some only once a day. Tides can vary according to the strength of wind and changes in barometric pressure. On occasion they can cause destructive surges.

Ancient Greek scientists are strangely silent about the tides. The Mediterranean Sea has little in the way of tides, with exceptions along the coast Tunisia, the upper reaches of the Adriatic (Venice), and the Pillars of Hercules (Gibraltar). Alexander the Great was dumbfounded by the tides that his army experienced in the Indus Valley. Tides are a concern of any military commander wishing to transport an armed force across the English Channel. Caesar studied about its tides carefully. As did General Eisenhower several millennia later in the other direction during the Normandy Landing in June 1944. Tides have long been a factor in battles at sea.

The Venerable Bede (673? – 735 a.d.) kept records of tides, and noticed that the tide had something to do with the stages of the moon. Tidal vocabulary is largely taken from Middle English (tiden) and before that Old English (tôdan).  Aldersey-Williams notes, however, how few records were kept of tides. That is particularly surprising in view of the Biblical tradition of the Flood in the Book of Genesis.

 The author travels around Europe and elsewhere to experience tides. From Norfolk, he could easily view the tides in the North Sea and on the major rivers that pour into the North Sea, including the Thames. A story-teller, he cannot pass up the opportunity to talk about the lore of that tidal river, including its “mud-larks” or “river finders.” They sorted through the flotsam (floating wreckage of a ship and its cargo), or jetsam (material that has been thrown overboard by ships’ crews). or lagan (goods abandoned at sea).  All were pure gold for the mud-larks, most often orphans or unemployed old people. Think of the rubbish piles of our time that are now the opportunity for the poor in Africa and Asia.

Tides generally aren’t spectacular. At least they are not from the vantage point of the throngs that gather to observe the tidal bore which races up the Bay of Fundy in Nova Scotia. This is said to be the most spectacular tidal bore in the world. During one tidal period, 115 billion tons of water flow in and out of the Bay. It can, however, be easily missed. The tides of the Bay of Fundy are semidiurnal, meaning that they happen twice a day. Should you fail to have been impressed, you can wait another six hours and thirteen minutes for the next tide.

There are animals that have learned to take advantage of the tides as a source of food or as an opportunity to breed. The horseshoe crab uses the tides on Florida’s coasts to reach the loose sands of the previous tide to plant its eggs in time for the next high tide. And there is a gathering of birds that then feed on those eggs. Aldersey-Williams describes a similar behavior involving the grunion, a fish species.

Humans have been attempting to capture the energy involved in ocean and river tides. But the infrastructure is expensive and easily damaged. Tidal mills are too dependent on the erratic running of the tides. Perhaps best to leave the tide to the tourists. 

Stanislaw Ulam; A Polish Jew in the Old World and the New

In 1972, I returned to Gainesville and through my then father-in-law, Harry Sisler, was introduced to Stan and Françoise Ulam. I became part of their circle and was regularly invited to their flat to join their friends and colleagues. Stan, a world famous mathematician, came to Gainesville during the spring semesters, joining the University of Florida’s Department of Mathematics. I couldn’t keep up with the math, so Françoise and I became good acquaintances.


Ulam born in Lwów, Poland in 1909 had received his education and graduate degrees from the city’s Polytechnic Institute in 1933. Like many other young European scientists and mathematicians, he traveled around to various university cities in Europe — Wilno, Vienna, Zurich, and Cambridge – getting to know the European mathematics/physics world and getting to be known. Prospects for a position in Poland were poor in 1933.


Stan Ulam was from a Polish-Jewish business family. His father, Józef Ulam, had also been born in Lwów (then called Lemberg), his mother was from Stryi (present-day Ukraine). The family was well off, though not rich; they owned the large apartment building in which they lived. Stan’s uncle, Michal Ulam, was wealthy, a prominent architect, builder, and lumber merchant. Also living in Lwów, the two families were close.


Stan and his family lived in Vienna during World War I. Vienna was still an imperial city, capital of the Austrian Empire of which Lwów was an educational and administrative center for the province of Galicia.  The family returned to their home town in 1919 shortly before the Polish-Ukrainian War broke out, along with a pogrom.


Lwów had long been a site of Polish-Ukrainian nationalist conflict. After much negotiation Ukrainian forces withdrew from the city in November 1918 leaving it in Polish hands and subject to Polish anti-Semitism. Demobilized Polish soldiers and deserters looted and burned parts of the Ukrainian and Jewish quarters of the city and killed an unknown number of Jews. The Lwów pogrom received wide attention and condemnation in Western Europe and North America.


Lwów was the third largest city in Poland, around 320,000 in 1918, with both a distinguished Lwów University and the Polytechnic. The city was becoming more Polish in a Poland reconstituted in1919 by the Versailles Treaty. It was 51% Catholic and 28% Jewish, both Polish-speaking. The remainder were mostly Ukrainians and Germans.


Despite the civil war and pogrom, the Ulams seem to have been comfortable with a Polish Lwów. Many of its Jewish families were prominent in business and the professions. Stan and his family identified with their Polish background. Like many Jews in Eastern Europe, the Ulams also thought of themselves as citizens of the wider European world, good Europeans.


While living in Lwów and attending the Polytechnic, Stan had been a member of a famous Polish mathematical circle, the Lwów Mathematics Club, that met periodically in the Scottish Café, a coffee house, to discuss mathematical problems. Several of his fellow conversationalists eventually taught at the University.


Many of Lwów’s Polish intelligentsia met a horrible fate during World War II. In July 1941 as part of the German campaign to wipe out the Polish intelligentsia, twenty-five of the University’s faculty and their families were shot, clubbed to death, or bayonetted by a Nazi Einsatzgruppen. Polish and Jewish intellectuals, political and cultural activists, scientists and mathematicians, and other members of Poland’s distinguished interwar intellectual elite were German targets.


Family letters written mostly by Ulam’s father from 1936 to 1940 make it clear that the city’s Jews had no idea of what was about to befall them. Poland was suffering from a prolonged economic and political crisis, but there was always in the elder Ulam’s letters the hope that things would soon improve, right themselves.


Stan’s ambitions and smarts brought him to the U.S in 1936, having won a scholarship to the Institute of Advanced Study at Princeton where many displaced European scientists landed in the ’30s, including Albert Einstein.  He was encouraged to apply by John von Neumann, a Hungarian/American mathematician, who was a bit older than Stan but already world famous. That led to an invitation of the Society of Fellows at Harvard.


From 1936 to 1939 Stan returned to Poland to spend his summers with his family and math colleagues. In 1939 Stan’s father decided that Stan should return to the U.S. with his younger brother Adam, then 16. The passenger liner in which he had booked passage for his two sons was scheduled to leave from Gdynia in September 1939, but the tickets were rebooked for an earlier August 20 sailing. That, it turns out, would be its last sailing until after WWII. Had it not been for the rebooking, it is likely that neither Stan nor Adam would have made it out of Poland. The Germans captured the Gdynia and its port in mid-September and immediately massacred 12,000 of the city’s citizens.


By 1939 it was becoming all too obvious that a Jewish family should send its sons off to the Americas. Both father and uncle were astute men of the world and could understand the dangers that a Nazi Germany posed to Jews. But the immediate threat was Polish. Polish nationalists were seeking to overturn the disproportionate share of university admissions – the “Jewish advantage” – enjoyed by Polish Jews. The nationalists demanded Jewish quotas and that the Jews be physically separated from non-Jews in educational institutions, thus the “ghetto benches.” Then there was the ordinary street anti-Semitism that had long been a part of Polish life.


Still there was no panic. Letters to the sons in America from tatus (daddy) and mamasia (mommy) seem mostly concerned about their not drinking or smoking while in America. When they found out that Stan had purchased a car, they worried about his “hot rodding.” Stan was now in his early thirties!


Adam Ulam got his Brown University education at his brother’s expense. He later became a distinguished historian of the Soviet Union, called a ‘Kremlinologist,’ at Harvard.


Lwów was occupied by Russian troops as a result of the Molotov-Ribbentrop Pact of 1939. The Soviet occupation lasted for about two years until the city was overrun by the German army as part of Operation Barbarossa in the spring of 1941.


There is much controversy about the level of participation of Ukrainian nationalists and militia members in the destruction of Jewish Lwów during the German occupation. Certainly Ukrainians identified the Polish Christians and Polish Jews that were to be killed. This German-Ukrainian alliance perpetrated the largest slaughter yet.


Lwów later became the location of a Jewish ghetto of some 120,000 Jews. In 1943 most of them were eventually sent to Belźec, Poland, and killed. Stanislaw and Adam were safe in America. The rest of the family (father, uncle, sister, niece, cousins) died in the Polish holocaust. (Ulam’s mother had died of cancer in 1938.)


A cousin wrote to Stan and Adam after the war with the details of their sister’s death. Stefa and her child were hidden by a Polish Christian woman along with several other Polish Jews. Betrayed by a neighbor, the five in hiding were arrested by the Gestapo and the benefactress shot. The Gestapo commanding officer offered to spare the five if they could pay, and one of the women offered some family valuables hidden in Lwów. The officer concluded that the worth of the jewelry could only save two and gave the woman a few hours to make a choice of whom would be spared. She ultimately saved herself and her mother, sacrificing her grandfather, Stefa, and her toddler-Stan’s niece, who were shot on the spot. The notion of “choosing” is a common element in survival stories (“Sophie’s Choice”.)


Stan told me the story about his having gotten his brother out of Poland. He never mentioned the fate of the rest of his family, although Françoise once mentioned to me how traumatic that last separation from his family had been.


Like so many educated European Jewish exiles, Stan found an appointment in an American university, in his case the University of Wisconsin. In 1941 he became an American citizen and married Françoise Aron. Born in Paris, Françoise had come to the U.S. as an exchange student in 1939.


Stan began to notice that his colleagues at Wisconsin were suddenly gone off to some kind of war work, he began looking around for an opportunity. In 1943 he was invited to join a group of scientists at Los Alamos, New Mexico working on a secret project. It turned out to be the creation of the atomic bomb that was dropped on Hiroshima.


Back to Los Alamos in 1947, he worked on the hydrogen bomb project again with Von Neumann. He is given credit for coming up with the idea behind the exploding device in the fusion bomb and also the mathematical insight that solved a major difficulty in the detonation process. While there, he worked with Edward Teller and they applied for a patent on the design for the bomb. Later they had a falling out and, I think, never received the patent.


After the war Stan traveled around to various universities for short appointments before settling at the University of Colorado (Boulder). One day while living in L.A., he had a severe headache and the next morning had lost his ability to speak. A surgeon drilled a hole in his skull and found that he had an inflammation on the brain. Stan told me about this himself. Recuperating from the operation, he worried about his having a permanent mental impairment. But one day (I think while waiting for Françoise at the L.A. airport) he realized that he could still solve mathematical problems and that his analytical skills were just fine.


My visits to the Ulams usually involved late afternoon tea. On one occasion Françoise asked Stan to turn on the stove burner under the teapot. Time went by and Françoise noticed that the tea kettle was not whistling. It turns out that Stan had not figured out how to turn on the stove. Françoise noted the irony of his having invented how to turn on the hydrogen bomb, but not their stove.


The Ulams stopped coming to Gainesville, preferring their home in Santa Fe, which was near their only child, a daughter Clair. Stan died in 1984, Françoise in 2011 at the age of 93.


Thanks to Adam Ulam’s letters and family memoirs available on the internet at and to Wikipedia.


Creationism and Its Critics in Antiquity

Creationism and Its Critics in Antiquity by David Sedley. University of California Press, 2009, paper.


The world seems to be configured in ways hospitable to life forms. Is this the outcome of divine planning or an accident? Creationism — the argument that the world’s structure and contents can be adequately explained only by postulating an intelligent designer, creator god, was favored by the classical world. Greek and Roman creationists differed amongst themselves over the mechanisms that the creator used, or at least had at his disposal. Critics of these Ancient creationists argued that the origins of life could be explained as the outcome of chance occurrences or accidents, made possible by the infinity of space and matter.


David Sedley cautions the reader that this debate is unlike the present-day dispute between creationists and scientists. Fundamentalists base their beliefs about the origins of the world on the several creation stories in ancient Hebrew texts; scientists on deductions from their accumulated observations of nature. Neither view was held by ancient creationists nor their critics.


Sedley doesn’t discuss the creationist stories told by the ancient Israelites. They differed from the Greek in numerous ways. For example, the Israelite tradition has Yahweh creating the world out of nothing. The Greek metaphor for the creator god was that of the craftsman, or sculptor, fashioning the world out of existing space and matter.


Classical creationists most often held an anthropocentric view of creation. A benevolent god had created plants and “lower’ animals to serve the needs of humans, an idea not too unlike the Hebrew tradition of Yahweh giving humans “dominion” over His creation. Plato, for example, talks about the creator’s goodness. Their critics asked: How, then, does one explain aspects of this created world that were not beneficial to mankind? Man-eating-beasts, volcanoes, earthquakes?


The origins of natural phenomena were not the focus of creationist speculation. Rather they thought in terms of ends or goals, intentions or purposes.


There were, Plato believed, several episodes of creation. First a divine creator or demiurge fashioned the material world. And that materiality was subsequently infused with a world soul. Did Plato actually believe in the mythological artifice he invoked, the author asks? Sedley compares Plato’s use of myth to John Locke’s social contract; social and moral relations are fundamentally contractual. But Locke did not believe that there was an actual written or verbal contract in the historical past. True also of Plato’s creationism?


Classical notions of creation were imbedded in a rich philosophical tradition. For example, the Greeks were fond of the idea of symmetry. That raised the question, could the cosmos have had a beginning but no end? Restoring that symmetry meant that there could be no beginning, no time when there wasn’t space or matter. Or, one could hypothesize, no end, which for the Ancients, was also a problem.


The Greeks and Romans never came up with the idea of a creator god who then left his creation to run by itself. This is a much younger metaphor. A divine craftsman fashioned a clock-like world, wound its spring, and subsequently had no power -or chose not – to interfere in the working out of his creation.


The classical world also never came up with the idea that one species evolved out of another, a key notion in evolutionary biology in the nineteenth century and since. However, some Epicureans came close to the idea of adaptation through natural selection that would involve extinctions and survivals.


Creationists had difficulty explaining why it was that the rich fossil record of the Mediterranean world revealed creatures no longer present in their age. Why would a divine creator have created anything that was so imperfect that it perished? Or were these creatures still to be found in some corner of the earth?


David Sedley has woven together various ideas and movements from Greek cosmology and natural history that demonstrate a diversity of views over several centuries. It was a genteel discourse. Not as much was at stake as would be the case in the Christian west in a later age.

American Chestnut

American Chestnut; The Life, Death, and Rebirth of a Perfect Tree by Susan Freinkel. University of California Press, 2009, paper.

Back in 1904 an urban forester noticed that American chestnuts

(Casatunea dentata) in the New York Zoological Park, now the Bronx Zoo, were dying of a blight caused by a fungus. The fungus would soon spread to other chestnut trees in the city, then to the forests of the eastern United States and Appalachia. By the end of the sad story that Susan Freinkel tells, billions of trees were dead and the American chestnut was all but wiped out everywhere in its range.


The American chestnut had been an important species in its ecosystem, dominating the upper canopy. Never the preferred wood for the furniture and building industries, it was ‘second best’ but a good source of tannin. Its ample nut harvest was one of fall’s pleasures; we sang about “chestnuts roasting on an open fire.”


Foresters were divided about how to respond to the blight. Some believed that it was hopeless to fight the fungus. Might as well harvest the trees, dead and alive. There was one brief effort to stop the blight, financed by the state of Pennsylvania, to no effect.


The blight fungus kills the trunks and branches of the tree; it doesn’t destroy the tree’s resilient root system. New growth sprouting from its roots will continue for years, only to be killed off by the fungus before the young trees have matured enough to reproduce. Eventually the root system wears out and the tree dies.


The U.S. Forest Service’s advice to take down even healthy specimens complicated, Freinkel contends, efforts to find disease-resistant trees. Individual trees with a slightly different genetic makeup might have survived and propagated. Occasionally even groves of chestnuts did survive, mostly outside the normal range of the tree.


There were two approaches to fighting the demise of the species; fix the tree so that it couldn’t be hurt by the fungus, or fix the fungus so that it couldn’t damage the tree. The European chestnuts were saved by the second strategy. A virus was found that sapped the fungus’s virulence. That approach was also tried here with little success. That because there are different strains of the fungus and because the fungus can develop immunity to any virus, breeders had to contend with an ever-changing target.


The more successful strategy in this country has been to cross the breed with the resistant Chinese chestnut. But Chinese chestnuts are short understory trees not capable of dominating the upper story of American forests. Worried about its form, American breeders backcrossed the hybrid Chinese/American Chestnut with a surviving C. dentata, and repeated the process until they had a tree that retained the resistant trait of the Chinese chestnut but now has the form of the American tree.


Freinkel reminds us, however, that there will be problems when reintroducing the ‘tame’ chestnut into the ‘wild.’ Our forests have had one hundred years to adjust to the demise of the chestnut. Oaks and poplars now dominate their upper canopy.


Freinkel also discusses an option that biotechnologists have proposed. They would alter the genetic structure of the tree by inserting a gene into chestnut embryos that will increase its resistance enough for it to survive. That scares a lot of folks, however, just like genetically-modified food crops do. A genetically modified tree would essentially be a new species, posing the problems of invasive species and genetic drift. Biogeneticists assure us that Mother Nature usually takes care of the first problem, and they deny the second.


Then there is the issue of the ‘wild’ to which eastern forests should be returned. A fire tolerant species, the American chestnut’s dominance was likely the result of Native Americans’ use of fire to maintain their woods.


The book mourns the loss of this wonderful tree. It is also an absorbing account of our continuing interaction with a much damaged forest environment.


The House of Owls by Tony Angell.

The House of Owls by Tony Angell. Yale University Press, 2015

There was an old owl he lived in an oak.

The more he knew the less he spoke.

The less he spoke the more he heard.

O, if men where all like that wise old bird.

Owls have been the subject, at times victim, of folklore world-wide. We talk about a night owl, being a person who commonly stays up late. You should be flattered with the sobriquet “wise old owl” because it is saluting your ‘quiet’ wisdom.  Owls are associated with sobriety; children were given an infusion of an owl egg to ward off insobriety at a later age. The bird was often viewed as the sign of doom; “I heard the owl call my name” associates its call with approaching death.  But conversely, the presence of an owl can be a sign of impending good fortune.

Most of this folklore is based on actual owl behavior. Tony Angell describes but also illustrates owl behavior with his striking drawings.

Most owls are nocturnal, hunting by moonlight, even starlight. But they often use the fading light of sunsets and the sparse light before sunrise to look for their major food source – small rodents: pocket gophers, voles, rats, and mice. They also consume small to medium-sized birds, frogs, even smaller owls.

Owls don’t build their own nests. Rather they mostly use nests formerly occupied by crows, hawks, flickers, and the larger woodpeckers. These can be found in snags of mature trees but also on ledges of rarely used structures, old Midwestern barns, for example, where owl nests can be found in the rafters. However, Angell was able to build a nesting box that worked. A male owl came looking for a site, his nest box met the owl’s approval. He then called for the female to have a look and pass judgment.

It is easy to slip into anthropomorphism when describing bird behavior.  Angell talks about owl emotions. Owls are said to express anger and fright, which is easier to accept than their “satisfaction” or “pleasure” in flight. They have long courtships and are monogamous with long-term pair bonding. They can breed at two years of age. Owl eggs require a relatively long incubation and chicks enjoy a long fledgling stage as well. And during these months, the male feeds the female and their brood. You can find flickerings of human behavior here if you wish.

The owl’s eyes are their most important sense organ, and Angell spends time explaining how they work. They are structured to be sensitive to diminished light. The eyes protrude out from the facial disk and that allows them better binocular vision. Owls can swivel their heads quickly through 270 degrees, allowing them to respond to sound or movement without moving their body. Humans at best have a 180-degree head-turning ability. The owl’s iris can close down the pupil to a pinpoint. And their pupil can quickly become enlarged to gather more light. The northern saw-whet owl’s two eyes can differ in degrees of dilation, one being fully contracted, the other fully dilated.

The author speculates that owls seem to be able to hold in their memory three-dimensional maps of their home ground and can rely on that memory to strike at birds when the light would be otherwise inadequate. He has a drawing that sequences an owl descending to strike a prey. It dives rapidly and silently and pulls up just before striking, using its talons to grab the prey.

There are 217 different owl species world-wide and the list is growing. They are mostly spread over the temperate zones. There are two families, one composed of barn owls only and the second all other species. Their fossil record goes back to the Miocene Epoch. At one time owls were much bigger; the fossil of a barn owl recovered in the Caribbean suggests an animal three times the size of today’s barn owl.

There is talk of owl habit destruction and endangerment, and hence diminished populations. The fate of each North American species is considered in The House of Owls; some are more threatened than others.  Some, particularly the barred owl, have been doing well. Owls seem to survive in the fragmented forest and even in urban environments better than do most native forest dwellers. On dog walks I often hear the hoot of a barred owl roosting on a telephone pole in the neighboring grade school yard.

Most owl species are migratory, although they do not migrate the vast distances that some birds travel to-and-from breeding grounds. Some owls, for example, move a few miles from higher mountain elevations to the valleys below. Less is known of owl migration because it is nocturnal.  Last winter, snowy owls, normally denizens of northern Canada, came as far south as Little Talbot Island, Florida and were observed foraging for mice in the sand dunes.

For over a quarter century, Tony Angell and his family spent their early evenings observing the western screech owls that inhabited their nesting box outside a window of their family home. Perhaps they then enjoyed a tale of the owl and the pussy-cat who went to sea in a beautiful pea green boat.