Archive for January, 2010

Mr. Mungo Park of Scotland was tall, fair, handsome, hard-working, undemanding, and immensely curious. When, in 1792, he turned up at the Royal Society of London, seeking his fortune, Joseph Banks quickly hired him to go as surgeon on the next trip to Sumatra, in order to see how he would do. When he came back with a top recommendation, Banks offered to send him to Africa, hoping he might find two things: the fabled city of Timbuctu and the source of the Niger River.

Timbuctu had become a fable around 1324, when its Moslem king, Mansa Musa went on pilgrimage to Mecca with such a rich entourage, and scattering such an abundance of gold wherever he traveled, that it was assumed he must live in a city with gilded roofs. Not so, of course; his wealth was the consequence of determined and back-breaking taxation, but the fable took hold.

The Niger River, meantime, has to be one of the strangest river courses in the world. It begins in the highlands Guinea, in the southwestern section of West Africa, only 300 miles from the Atlantic Ocean, yet it travels 2,600 miles to enter that same ocean. It sets out to the north at first, and comes close enough to the Sahara to lose great quantities of water as it bends eastwards around the lower and less steep lands just south of Timbuctu. As it finally turns south, it is joined by the Benue River and heads to the sea, still a long way off. Because the Benue flows in from the east, this confluence is the natural trading post between East and West Africa, and Timbuctu is a relatively important city.

Setting out for Africa

Be that is it may, Mungo wanted to see Africa more than anything, and eagerly set out in 1794, with a good heart and the equipment which seemed important to an English expedition, including: two guns, two compasses, a sextant, a thermometer, a wide-brimmed hat, and an umbrella. He got as far as Pisania before the rains set in, and was cared for by a Dr. Laidley while he dealt with malaria, probably a great good fortune, because else he would have contracted the disease later and, facing it without care, might not have survived.

Survive he did, and ultimately returned with good information, wrote a book, and married his sweetheart. He had stopped short of Timbuctu, however, (he found it next time) and only saw that the river flowed east, as Herodotus had supposed it must. Herodotus, a Greek of the 5th century BC, thought the Niger flowed into the Nile. It does not, as Park learned on a later trip; it continues to curve around to the southeast and then it flows south so that Park thought perhaps it might join the Congo. (It doesn’t do that either.)

It is hard to imagine that people of the 18th century had not improved their understanding of Africa over the information of ancient Greece, but it is a continent of extreme climate barriers, both desert and jungle, and it was culturally dominated by Moslems who were quite hostile to Christian entry. Park’s reports were of inestimable value and interest.

Capsula in the wilderness

But I would like to tell you one charming story which took Europe by storm when his book came out, and which expresses something that lies deep within the heart and the experience of many natural scientists.

Not long after Mungo turned home, he met with Moorish bandits who took everything he had including his horse and his compass, and left him to die. He was half-naked and hungry, 500 miles from the nearest Englishman, wet with the rainy season, and doubtless not far from any number of wild animals… What could he do but lie down and die?

He prayed; nothing happened.

His tired eyes wandered over the ground between his boots, too tattered to be stolen. A tiny moss grew there, with perfectly formed roots, leaves, and capsula, the rarely seen fruiting part of the moss – and his whole attention was captivated. He studied it for a time, full of admiration, and finding such consolation in its beauty, he could not but think that the God who would bring a tiny moss to fruition in the midst of a drizzling wilderness would also care for one made in his own image. He got up and went on, found some shepherds who gave him companionship, and gradually made his way home.

It’s a little like the story of Elijah and the broom tree, really, (1Kings 19:4) but the consolation is in the word of God within creation itself, and that is what makes it so characteristically the story of a believing scientist. Park lived at a time when skepticism was growing in western Europe, when the modern idea of hostility between faith and science was gaining traction year by year and philosopher by philosopher. Yet his story represents such a deep and genuine cry of faith that I think it must outlive all that armchair philosophy to refresh a new generation of scientists. Creation is truly the “other” Word of God.

The Age of Wonder

I owe much of this story to Richard Holmes’ fascinating history of science in the Romantic generation, The Age of Wonder.  I don’t think it made Holmes a believer, but it’s an interesting read.

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Deep Space; Deep Time

William Herschel seems to have been the first person to recognize – the first to state explicitly – that deep space implies deep time. While others mapped the skies as if they were a sparkling dome above the Earth, or, at most, above the solar system, he thought (in 1780) in terms of space stretching out to unimaginable depths – depths that must, based on the estimated speed of light, imply at least 2 million years of time for light to reach us. It was an amazing insight. In that span of time, Herschel believed that stars had been born and died, and that the light now reaching us must often come, like ghosts, from stars that no longer exist.

Herschel believed this because he perceived that the stars were set in deep space, that they had relative motions. He believed that many of the differences in stars and in starry clusters were differences in the same types of objects seen at different points in a cycle of change, a cycle as definite as the growth of a tree or a child.

This idea of changing stars and an evolving universe was new in the 18th century, but was readily taken up by an intellectual world that was eager to ask unexpected questions and, willing to push against against the notion of a world just 6,000 years old. Nicholas Steno (St. Niels Stenson) and James Hutton had in various ways shown that certain geological forms must be the record of ancient times; now Herschel was taking astronomy into the realm of a very much deeper time.

Today, it is understood that the universe is several billion years old, and that lives of stars – their cycles from first ignition to final cooling — vary considerably. The largest stars are the shortest-lived, perhaps a few million years, while the smallest may be as old as the universe, 13 billion years with as long again to continue. Most stars take so long to burn out that what we see in the sky comes from stars which are still out there; furthermore, we know what is most likely to blow up in the near future – or to have blown up already.

But Herschel was quite right that the presence of light from deep space implies its travel through vast reaches of time. It was a fundamental insight. And the speed of light had been calculated by Huygens as the unimaginable rate of twelve million miles per minute, a very good value, within 10% of the value we presently use. In many ways, Herschel would have been very much at home in today’s world of astronomy.

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Once Joseph Banks was head of the Royal Society, he was the natural contact for anyone who found a promising new scientist. One late night in Bath, when a certain Mr. Watson found William Herschel, the orchestra conductor, standing in a cobbled backstreet looking through his homemade telescope at the most extraordinary view of the Moon ever seen on earth, the news was promptly sent to London. when he discovered Uranus, his reputation was secure.

William and Caroline Herschel, a brother-sister team of astronomers, came to know the skies with a detail that few have matched in all of history. They were born in Hanover and moved to England as musicians, first the brother and, much later, his unhappy little sister. She was, indeed, very little, just over 5’ tall, her face scarred by smallpox, her growth stunted by typhus, and her mother certain she could never be anything but a housemaid. When her adored elder brother brought her to England and arranged for voice lessons, however, she developed a lovely voice; it might have been her living had she not turned to the discovery of comets instead.

At that time, England was governed by King George III, also from Hanover. Over the next ten years, he would provide £4,000 for the construction of the largest and most ambitious telescope of the time. Some considered it one of the 7 wonders of the world, and it became a kind of tourist attraction, visited not only by any astronomer who went to England, but also by Keats, Shelley, Byron, Coleridge, and many other men of letters.

Unfortunately, it was so large that the arrangements to make it maneuverable were barely sufficient and the effects of weather on its mirror were even more troublesome than anticipated. Still, it gave William Herschel a spectacular view of the skies and led to various new discoveries both inside and outside the solar system.

Meantime, Caroline kept busy with a smaller telescope, discovering one comet after another and making a name for herself.

Using a telescope

As anyone who has used binoculars knows, only a tiny fraction of the vastness of the sky is visible through an eyepiece. You go out and see the Dipper, and lift the binoculars to examine it more closely. Pouf! All you see is a few non-descript stars; you have no idea whether they are Dipper stars or just some random collection from nearby. You move the binoculars around to see if you can figure anything out, and the view only becomes more confusing. Someone must explain to you that the way to find a star in the binoculars is to fix on it very steadily and, without moving eyes or head, sweep the binoculars up to your eyes. Ahhh! The second star in the handle, the double star, swims into view. It is beautiful and definite.

With a telescope, however, these problems are multiplied. A stronger magnification yields a better vision of — alas! – an even smaller portion of the sky. A vastly larger telescope will again give a larger portion of the sky, but you can’t just be sweeping it around; it’s too heavy. You need to know what you are looking at. And the Herschels did. They could look at any two-degree segment of the sky – about twice the width of the Moon – and immediately know where they were and the names of all the stars within view. This detailed knowledge of the sky was what enabled them to identify anything unusual. William Herschel had discovered Uranus in the telescope in Bath; it was months before others could verify his discovery, even when he told them exactly where to look.

Other life?

No sooner had Herschel found his excellent view of the Moon, than he became convinced that it had vegetation and must certainly be inhabited. Indeed, he thought all the planets likely to be inhabited, and perhaps all the stars likely to have still more inhabited planets. What a thought! And it was not so badly received as it might have been a hundred years earlier.

William Herschel, after all, was born in 1738, a contemporary of Benjamin Franklin, (whom he met), a man whose best work was contemporary with the American and French Revolutions. Thus he belonged to the time of intellectual ferment known as the Enlightenment in which reason was elevated at the deliberate expense of faith. His speculations on the likely abundance of life throughout the universe led to immediate speculations about the status of intelligent life beyond Earth: Would it not be fallen? Would it be without redemption? Would Jesus have come to each planet as a member of its intelligent but fallen life? Or did the reality of many worlds show the folly of thinking we are so special that God would come to us?

These speculations were very lively, and they became part of the worldview that eroded the faith of Europe. It is interesting to look at a larger sweep of history and see them in context.

A brief history of cosmology

Before Galileo, whose first telescopic observations took place in 1609, it was thought that the heavens were composed according to a different physics from earth, one based on beautiful spheres of quintessence, wherein only the angels lived. Over the 17th century, however, people gradually got used to the idea that all the stars and planets were governed by the same laws of gravity as our apples and spoons, and when Newton spelled out the math, people were ready to fall into line. The new physics put the Earth into an insignificant position within the Solar system, however, and for some people, this lack of privilege was a problem of faith.

Why? Why should the size or position of our household affect our theology about an infinite God? It was not a problem for everyone.

With Herschel, two hundred years after Galileo, people had become thoroughly used to the idea that the physics was the same throughout the universe, and they were quite ready to think the biology might be the same as well. Again, the question of human importance was raised as the consideration of extra-terrestrial intelligent life suggested new levels of insignificance for mankind. Could God have significant relationships with the inhabitants of so many planets? Surely not! Reason should show us the folly of thinking ourselves significant.

What? Again: surely it is childish to think that God cannot care for us just supposing there are other centers of civilization!

A hundred years later, (three hundred years after Galileo), as the 20th century developed, it was fairly clear that there was no life on other planets within the solar system, but Carl Sagan famously asserted that there must be at least 10,000 inhabited planets in each galaxy, and the number of galaxies was rapidly becoming recognized as vast beyond imagination. There are probably a billion. This — why? — seemed new reason to doubt that God, Who is infinite, could keep track of mere humans or care about them.

Now we are a hundred years later again, four hundred years after Galileo, in the first years of the 21st century. We are used to the idea that the Earth is not in the center of the Solar system; the Solar system is not the center of the Milky Way; and the Milky Way is not the center of the Universe. On the other hand, we have come to recognize that there are no other intelligent inhabitants anywhere in our sector of the Milky Way and that the requirements for intelligent life are such that it cannot be common, and indeed we may be entirely alone in the Universe. An amazing thought, perhaps disquieting, perhaps humbling…  But has this led back to a certainty, even to a suggestion, of God’s providence? No. Rather, in the eyes of the present cosmic fad, it makes us the sheerest of vulnerable accidents, and the cultural despair is final.

So there’s your lesson on the philosophical childishness of those educated only to math and physics without even a dose of logic, let alone serious theology. Real education is education of the whole man, for the whole man always has a cosmology, and if it’s not educated beyond kindergarten, it will not match his other best achievements.

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Ana’s Sundog

After my post about the sundogs, Ana sent me this sundog photo which is nice for the unusual height of the light column, and for the strong white patch at the left which makes it clear how bright the sky is on the outside of a sundog. If you tip your computer so that the colors display more strongly, it looks as if a light wind were blowing through the white part. It’s really not like a rainbow.

Note that the sky is almost clear and the slight background stratus in the lower sky makes no contribution to the parhelion; it is ice crystals suspended in the air that have formed these colors.

Ana's Sundog

Evening sundog visible by an old windmill tower.

Sundog — parhelion; sundogs — parhelia.

By the way, notice also the strong shadows in the foreground. They tell you that the sun is ahead of you and to the right.

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Sundogs, or parhelia, are ice displays in the sky on either side of the sun. They are about 22° from the sun, which is to say that if you reach out your arm, stretch out your fingers, and place your thumb on the sun, then your little finger should lie over the sundog. It looks like a bit of a rainbow.

Parhelion with white tail away from the sun

A striking sundog at the left edge of a dark area towards the sun, with a light white tail going away from the sun.

Actually sundogs are caused by the refraction of light in ice crystals and the red is on the inside, whereas in a rainbow, which is caused by reflection as well as refraction, the colors are reversed so the red is on the outside and the blue on the inside. In a single sundog, you can’t always see which is the inside (towards the sun) and which is the outside, because the display is so short and the curve is not always obvious.

Here are two sundogs at sunset, and if you look closely, you can see a brightness trailing away from the sun and a relative darkness just inside the red part of the display.

A pair of sundogs guards the sun at its setting, January 8, 2010.

A pair of sundogs guards the sun at its setting, January 8, 2010.

Even with only one image, however, a little practice will allow you to distinguish easily between a sundog and a rainbow fragment, even in a photograph. First of all, the sky is darker in the inside (the sunside) of the sundog. But also, though it’s not as clear in the photo as on the ground, look on the blue side of the sundog, and you will see a tail of bluish-white light trailing away. That is the most striking characteristic of a bright sundog. Once I bought a photographic postcard which was titled, “Rainbow over Sage Creek.” In fact, it was a spectacular and unusually tall and brightly-colored sundog with the characteristic white tail. A glance at the shadows on the ground told me that the sun was not at the back of the photographer, as it would be in a rainbow picture, but in front of him, as is always the case with ice displays.

Sundogs are most common at sunrise and sunset. Since they are caused by ice crystals, they are more common in the cold months of the year, but of course it’s pretty cold 6 miles up anyway, so it doesn’t actually have to be winter.

This particular display is also unusual in that, at least for the first photo, there are no clouds at all. It was very windy that day, and there was a lot of powdery snow on the ground, so the air was full of “diamond dust” which was sufficient to form this shining arc. More often, a sundog appears as a bright patch in a wisp of cirrus. The 22° measurement will help you verify that you really are looking at these guardians when their colors are too muted to be sure.

Take a look!

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Tahiti, 1769

In preparation for studying the history of science next semester, I am reading The Age of Wonder by Richard Holmes. It is a study of the Romantic era in science, basically centered between 1769 and 1829. How can science have a Romantic era, given that science is fundamentally a rational pursuit?

Good question!

As I ponder the answers provided in this volume, I am often minded of Chesterton’s words, “When men cease to believe in God, they don’t believe in nothing, they believe in anything.” This volume is, at least in part, the story of men whose religious faith lacked that harmony of philosophical context and personal mysticism which alone is promotes deep satisfaction in the face of life experience. Spiritually shivering and hungry, the Romantics looked into the coldness of the Newtonian universe seeking some reason to affirm human feelings and values and found it a messy business.

Some names in this volume are familiar to me: William and Caroline Herschel, the astronomers; Humphrey Davy and Michael Faraday, the physicists; James Watt and Alessandro Volta obviously concerned with electricity; and our friend Luke Howard, the man who named the clouds.

To Tahiti

But I knew nothing of Joseph Banks, principal character of the opening chapter on the 1769 expedition to the South Pacific to observe the transit of Venus. As our sister planet orbits the Sun, we see it first as an evening star and later as a morning star. When it is close to the Sun, we cannot see it in the glare of sunlight, but now and then this close part of the orbit actually takes Venus directly between ourselves and the Sun so that its dark form is distinctly visible against the bright disk and can be projected onto a suitable background. Such a transit first enabled us to get a good estimate of the true distance from Earth to Sun. Such a transit will take place in 2012. There was one in 1769, and men of science took up their several observation posts well in advance.

Joesph Banks, however, was not an astronomer, but a naturalist, whose energy and interest in all his contacts with the native peoples was almost certainly the reason that this particular expedition succeeded. He was the one who learned some of their language, spent time in their villages, recorded their customs, and generally smoothed several of the misunderstandings which threatened the peace of the contact between two such different cultures.

His avowed intent was to collect all kinds of plant and seeds, which he did; and he hired artists to make drawings of those creatures – fish, birds, insects, and animals, which he could not bring home. He himself recorded the way of life in Tahiti, as far as he was able, and he always meant to write a complete description of his travels, but never quite got to it, leaving his notebooks for others to glean. Meantime, soon after the expedition, he became head of the Royal Society of London, the scientific society of his day, and at the same time he maintained a huge correspondence with naturalists from all over the world. From this vantage point, he had the opportunity to sponsor and introduce new genius into the social fellowship of the men of science, and furthermore, as a man of immense wealth and wide-ranging interests, he personally sponsored and promoted the travels, investigations, and discoveries of many of them. He would have been an interesting man to know, always full of intriguing stories, always aware of the latest discoveries.

But Holmes also presents the human side of these men of science, and it’s an interesting counterpoint.


The beauty, warmth, friendliness, and dancing that characterized the native peoples and customs of the South Seas were already legendary before Joseph Banks got there, and his descriptions make it clear that they were hardly exaggerated. Captain Cook (indeed, the famous Captain Cook led this Venus Transit voyage!) took strong but ineffectual measures to keep his sailors from being drawn too deeply into the Tahitian seductions – not necessarily for moral reasons, but because the health and loyalty of the sailors was necessary for the trip home. In fact, when two sailors refused to leave at the end of their three months’ stay, Banks was the one who defused the situation and got the men unhappily on board.

But the idyllic life of Tahiti, a sexual paradise if ever there was one, had an inevitable cost, which Banks records with horror, but without much personal reflection, considering his own participation in its delights. That is, the young men and women belonged to a kind of club in which children who were conceived were not welcome. If a young mother knew who the father was, and if she persuaded him to accept his fatherhood, they left the group; otherwise, infanticide was her responsibility, and it was matter-of-factly accepted as such…

When Banks returned to England, he was not interested in the sweetheart he had left behind with every intention of marrying on his return. He had a mistress for a while and later married a woman who enjoyed his company and conducted his social responsibilities with aplomb. But if there was, during the Romantic era, a growing separation between science and religion, it was not merely intellectual. Banks’ interest in everything unusual had led him to regard men and (especially) women with that peculiar combination of detached interest and selfish abandon which is bound to cause a religious crisis.

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This past Sunday was the feast of the Three Kings which used to land predictably on January 6th, not a day when everyone went to Church, but the 12th day of Christmas, marking the end of the Christmas celebration. As I listened to the readings, I felt a certain awe about the astronomy of it. Not but that all the stars of all nights belong to God, as I have already said, but because if it really is true that Jesus was born on September 11 of 3 BC, on which evening the Sun shone in the constellation Virgo with the crescent Moon gleaming by its feet, then I must acknowledge that God orders the universe in even more minute detail than I had ever imagined. I have read Revelations 12:1-3 hundreds of times; I know of various interpretations, and I know that truth always has many levels of contact and meaning. Certainly Mary is the Virgin clothed with the Sun, and our miraculous Image of Guadalupe is not the only one with the crescent Moon at her feet. But that is not all.

Wait; I am speaking in riddles. Let me explain.

The zodiac

The constellations are imaginary pictures drawn around the natural, but purely visual, groupings of the stars. As the year goes by, these constellations rise and set with the seasons, and at a given time of each year, the sun stands directly between us and one or another of these twelve. Astrologers, imagining that the stars are fixed in the sky and that the Sun moves through them as it goes round the earth, will say that the Sun sits within one of the constellations.

Not every constellation lies in the path of the sun, however, even its imaginary path. The Big Dipper, for example, is always so far in the northern sky that the path of the sun never passes near its stars. The constellations that lie “in the path of the Sun” are called the zodiac – and many of them are animals of the celestial zoo – a lion, a crab, and so forth, but also the twin boys Castor and Pollux, Virgo the virgin, and so forth.

So in September, the Sun passes through the constellation Virgo.

The Moon also crosses the sky in the same basic path as the Sun’s because it orbits the earth in such a way as to pass through the zodiac; the Moon therefore appears from night to night with different parts of the zodiac in its background. In September, when the Sun is “in” Virgo, the Moon must also be in Virgo part of the time, for the New Moon is always “near” the Sun in the sky. All this is ordinary astronomy; nothing unusual.

Revelations 12:1-3

Now, Rev 12:1-3 says that “a great sign appeared in the heavens, a woman clothed with the sun and the Moon at her feet and on her head was a crown of 12 stars.” This is John’s vision. It never crossed my mind that it might be an astronomical reference to the sky on the night of the birth of Jesus. For one thing, I assumed that every culture had its own names for the constellations, and that Virgo would not be known to St. John anyway.

But Greek and Hebrew culture did intersect, and Virgo was a virgin constellation in both cultures. Therefore it could be that Rev 12:1-3 is actually a description of the starry sky on a particular date.

Indeed, on the 11th day of September in 3 BC, the Sun lay within Virgo, as if illumining the virgin from within, and at her feet, the crescent Moon shone briefly before setting. Furthermore, in 3 BC, September 11 was Rosh Hashanah, the Jewish New Year’s Day that celebrates the creation of the world and the recreation of life after the flood of Noah.

As we have already indicated, it lies within the scriptural time frame for the birth of Jesus, and, as a birthdate for Jesus, it provides an awesome glimpse into the detail and humor of God’s handiwork. It is none of the dates so eagerly offered for his birth by merely superstitious astrologers, but it is its own date, chosen from the creation of the universe as the perfect moment for the birth of Jesus and symbolically recorded in the vision of St. John.

Each detail comes from the hand of God as if it were the main story – no by-products, no mere embellishments; each thing created in its own unexpected perfection. Such were my thoughts for this feast, leading to a deepened sense of providence.

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