Tuesday, December 31, 2013

The organic and inorganic


Back in the blissful, healthful, snow-and-ice-free tropics, and, as usual, everything artificial, technological, modern and convenient has borne the assault (and salt) of moisture, sun, rust, mildew and termites. It's not as bad as I make it sound, but it remains a fact that technology and the tropics are incompatible.

Only one thing has prospered in our absence: the organic. The sea lettuce, sea grape, love vine, and coco plum have burgeoned, threatening to overwhelm the property.

Jared Diamond, the Durants, Michael Adas, and others have written books trying to explain why technological civilization developed in temperate climates. Well, duh…

They should start with the first, pre-human revolution, one that occurred in the tropics where sunshine is most plentiful. Green plants! Green plants took billions of years to perfect their mastery of solar energy, creeping only reluctantly, one might suppose, north and south into more sun-starved temperate realms.

When the Industrial Revolution occurred in the north, it was powered by all that stored up solar energy –- as coal -– buried in the ground when northern continents were in more clement zones.

Meanwhile, why so little technological innovation in the tropics? Live here and you'll know. Why invent electronics when the humidity and salty air provides built-in obsolescence? Why invent something as simple as a hinge, for God's sake, when it's only going to rust?

Sure, the sunshine, warmth and balmy breezes feel good on my 77-year-old bones, but they don't do much to feed my innovative get-up-and-go. Who needs modern civilization when you're lolling under a shady palm, pace Jared Diamond? But it would be nice to have a cold beer, and right now I'm dealing with a fridge that's on the blink. That may be another reason technological civilization didn't develop in the tropics: Nothing inorganic lasts long enough to make the effort worthwhile.

Monday, December 30, 2013

Pumpkins and velvet cushions


Last evening, just at sunset, the sky in the east, over the sea, was filled with a towering cumulous cloud of Maxfield Parrish rose and gold, struck through with a short arc of vivid rainbow. We stood on the terrace, transfixed, wondering what we had done to deserve so rich a gift.

Thoreau famously wrote: "The cost of a thing is the amount of what I will call life which is required to be exchanged for it." This cloud castle, this spectral palace, was free. Not only did we not exchange life for it, our store of life was augmented.

Thoreau is someone to admire, but a hard prophet to follow. Not many of us are willing to live alone in the woods, sponging off the neighbors. Like Thoreau, I would rather sit on a pumpkin than a velvet cushion, but I'd rather sit on a cotton cushion than a pumpkin.

Life has been a negotiation between things and –- well, life. Lots of cotton cushions, but never at the expense of selling my happiness for velvet. I've got my Timex and never wanted a Rolex. Thoreau, no doubt, told the time by the shadows of the pines.

I'm not poor-mouthing. I have far more things than most people in the world, far more than necessary, so many in fact that as I get older they are becoming increasingly burdensome. But I don't recall ever exchanging what Thoreau called life for what I have. Good luck, I suppose. And to top it all off, the eternal physical laws of reflection and refraction contrive for our benefit an evening sky of such cottony magnificence not to be exchanged for all the velvet in the world.

Sunday, December 29, 2013

The indirect object


Click to enlarge Anne's Sunday illumination.

Saturday, December 28, 2013

Vital dust -- a Saturday reprise


That's what Nobel Prize-winning biologist Christian de Duve titled his book on the origin and evolution of life: Vital Dust His title reminds us that we live in a sea of invisible spores swimming on the wind. We breathe these seeds of life in and out with every breath. Rusts. Smuts. Molds. Mildews. Mosses. Mushrooms. Ferns.

Given the quantity and variety of airborne reproductive germs, it might seem likely that our lungs would become gardens of foreign organisms -- the invasion of the body snatchers. But that's not quite the way it works. Most airborne spores must alight in a highly specific environment if they are to bear fruit.

Consider, for example, the cedar-apple rust. Here is a photograph I took yesterday of a mysterious apparition on a cedar tree along my Path -- the tentacled fruiting bodies of cedar apple rust, caused by the fungus Gymnosporangium jumiperi-virginianae.


The life cycle of this curious organism "starts" in the springtime, on an apple tree. Small yellow dots develop on the underside of the leaves shortly after the tree comes into bloom. The yellow spots gradually enlarge and become orange. In late summer, small tubes grow on the lower leaf surface near the orange spots, and brown spots may develop on fruit.

The orange spots release spores that are distributed by the wind. If -- and only if! -- they land on a cedar tree, they germinate and put out tubes that penetrate the tiny leaves. By some chemical magic, these tubes cause the growth of fleshy, reddish-brown galls, called cedar apples, about the size of a grape. The development of the galls and the maturing of the fungus within them require nearly two years from the time of infection.

Then, during wet weather in May, the galls put out the long orange tentacles, slimy and gelatinous, that you see in my photograph. These release spores of a different sort, which make their way by random breezes back to an apple tree. The cedar and the apple are necessary alternate hosts to the fungal parasite. All those spores, at different stages of the fungus's life cycle, wafting back and forth on the wind, utterly dependent upon making a lucky landing on a specific plant.

You'd have to see a cedar tree full of these otherworldly orange-tentacled galls to dream that such a thing could exist. After I had taken my photograph, I stood there on the path shaking my head in astonishment. Vital dust, indeed!


(This post originally appeared in May 2007.)

Friday, December 27, 2013

Sailing to the Moon

It's like fishing in the dark.
Our thoughts are the hooks,
Our hearts the new bait.
And so, China has soft-landed a rover on the Moon. A splendid achievement of which that nation must be very proud. I'm proud too, for humankind.

I think of what Thomas Merton wrote in Thoughts in Solitude, at a time when some far-seeing rocket scientists were considering the real possibility of going to our sister satellite: "What can we gain by sailing to the moon, if we are not able to cross the abyss that separates us from ourselves."

I've read much of what Merton wrote, and at least one biography. Did he succeed in crossing his personal abyss. You tell me.

Certainly he seems to have achieved a degree of self-knowledge that I have not obtained. At seventy-seven I lay awake at night contemplating the abyss, the dark wood, the chasm. What I wouldn't give for the sleep of the just, without the futile worries, the wearisome self-doubt, the hoo-has.

I wonder if the abyss of which Merton speaks in in fact uncrossable. Certainly, consciousness is a mystery yet to be unraveled, and that must include self-consciousness. Are there dimensions of ourselves that are intrinsically beyond our grasp, stirring down there in the opaque pool of the subconscious? Are the dark woods part of our being? Does the abyss rive our very hearts?

Maybe the secret to sleeping the sleep of the just is not to bridge the abyss, but to accept it.
The hook left dangling
In the abyss.


(The quoted lines are from a poem of Charles Simic, "Mystic Life".)

Thursday, December 26, 2013

Binding energy


A week or two ago I wrote about rust. Iron oxide. OK. It's a nuisance where we find it; it can be beautiful on the microscale.

But iron. Let me say a few words about iron, an element so ubiquitous it is inconspicuous, hiding in plain sight.

It's the element that brought us out of the Stone Age (after a brief fling with copper). We are still in the Iron Age. Or should we call it the Steel Age? It's hard to imagine a modern technological world without iron.

The grey eminence. The stalwart foot-soldier. Mister Make-it.

If you take the whole Earth, core and all, iron is the most abundant element. It is the fourth most abundant element in the Earth's crust (after oxygen, silicon and aluminum). Why so much iron in a universe that is mostly hydrogen and helium? Why does Mister 26 stand out?

There's a reason. Iron is the heaviest stable element created by fusion in very large, very hot stars. Remember my diagram not long ago showing how hydrogen is fused into helium in the cores of stars. As the process continues, helium nuclei are fused into ever heavier elements, generating yet more energy. Up to iron. After iron, the game goes the other way; instead of getting energy out, you gotta put energy in.

Here is the detailed explanation from Wikipedia. Read it just for the joy of it.
The process starts with the second largest stable nucleus created by silicon burning, which is calcium. One stable nucleus of calcium fuses with one helium nucleus, creating unstable titanium. Before the titanium decays, it can fuse with another helium nucleus, creating unstable chromium. Before the chromium decays, it can fuse with another helium nucleus, creating unstable iron. Before the iron decays, it can fuse with another helium nucleus, creating unstable nickel-56. Any further fusion of nickel-56 consumes energy instead of producing energy, so after the production of nickel-56, the star does not produce the energy necessary to keep the core from collapsing. Eventually, the nickel-56 decays to unstable cobalt-56, which in turn decays to stable iron-56. When the core of the star collapses, it creates a supernova.
Kablooie!! A big star blows itself apart and feeds iron into the interstellar medium. Out of which new stars are born. Eventually our Sun and its attendant planets.

Oh, there's more to the story; for example, why the inner planets lost most of their hydrogen and helium. But we'll leave that for another place or another time. Meanwhile, we beat our iron into swords, and plowshares, and automobiles, and skyscrapers. Every one of those atoms churned out in the cores of giant short-lived stars that lived and died in a younger universe before the Earth was born.

Wednesday, December 25, 2013

We meet in the air


Click to enlarge Anne's Christmas illumination.

And very best holiday wishes to all who visit here.

Tuesday, December 24, 2013

Turning woe to weal


I've been sitting on the porch reading Mary Sharratt's novel of Hildegard von Bingen, the 12th-century German mystic/polymath, perhaps the most famous woman in Europe at the time. She is still widely known today. Her writings have been especially embraced by feminists, New Agers, and even environmentalists. Religious naturalists, too, for her pantheistic tendencies.

Perhaps as early as the age of eight. Hildegard was sealed into a cell-like enclosure attached to the abbey church at Disibodenberg, as a companion to the willing anchorite Jutta. A living death as the bride of Christ. For decades, she never moved beyond the confines of that grim tomb, she who as a girl so loved the natural world.

I'll not recount here the story of her escape and long life as a holy woman who spoke truth to authority.

I can, however, relate to her story (quite aside from the fact that her feast day is my birthday). The theology of bodily mortification, fasting, and surrender was still very much alive in the Church of my youth. For a few terrible years I embraced it with a vengeance. And then, like Hildegard, I emerged into the light.

Now I sit here on the porch watching the hummingbird at the feeder. Sip. Swallow. Sip. Swallow. Its wings a whirring canticle of delight. Hildegard would have looked on with fascination too. She was, of course, a theist, as one would expect for someone of her time and place. But her Feminine Divine beat her wings in the hummingbird's tiny frame.
For she is terrible with the terror of the avenging lightning, and gentle with the goodness of the bright sun; and both her terror and her gentleness are incomprehensible to humans…But she is with every one and in everyone, and so beautiful is her secret that no person can know the sweetness with which she sustains people, and spares them in inscrutable mercy.
Sip. Swallow. Sip. Swallow. That racing metabolism. That insatiable thirst for sugar, for that miniscule furnace of respiration.
You cannot look at her face or her garments for the splendor with which she shines.


Monday, December 23, 2013

"In a dark time, the eye begins to see"


Back to clear dark skies. Not as clear or as dark as when we came here 19 years ago, built Starlight House, and settled in for golden years of sky-watching. The airport got lights for nighttime operation. The Queen's Highway got street lights (of the worst kind for light pollution). And the new Four Seasons/Sandals resort, five miles north of our house, is all lit up so their customers couldn't see a star if they wanted to. But by comparison to our home near Boston, our little island is still an oasis of darkness.

Here's a recent APOD (Astronomy Picture of the Day) showing one of the most familiar star configurations in the sky -- Orion's Belt. Three hot blue stars, each vastly more massive than the Sun. That's them running diagonally across the photograph from upper left to lower right (click to enlarge). Nothing else in the photo is visible to the unaided eye.

What a mess of stars! And nebulae where even now stars are being born. There's the famous Horsehead Nebula standing out against the pink glow of hydrogen at lower right. How many stars? Go ahead. Count.

No, just kidding. If you started counting with a magnifying glass you'd be at it all day. And this is just a wee corner of our galaxy.

I'm sure I've mentioned here before that when I used to teach a course called The Universe to general studies students one of my set pieces was to push back the desks and use a one-pound box of salt to make a model of our spiral galaxy on the floor. The students were always dazzled at the number of stars. Then came the kicker. Let's figure out how many boxes of salt we'd need to have the hundreds of billions of stars in the Milky Way. I'd guide the students to a few judicious estimates, averaged for the class. Ten thousand boxes of salt! Sprinkled in a vast spiral as big as the orbit of the Moon. (If a salt grain were proportional to the actual size of a typical star, the grains should be thousands of feet apart.)

As often as I did that demonstration, I was as awe-struck as the students. And now, I lie on the terrace and gaze up into a warm, clear, dark sky, Orion climbing the inky dark in the East, and with a lifetime of practice I fill in the blank spaces with those myriads of stars we see in the APOD photo.

Sunday, December 22, 2013

Young stars


Click to enlarge Anne's Sunday illumination.

Saturday, December 21, 2013

The stages of prayer -- a Saturday reprise


I try not to repeat myself too often here, but some repetition is inevitable. Having published millions of words in books, articles, newspaper columns and blog, I sometimes wonder if I have anything at all left to say. Perhaps now, on the sixth anniversary of this blog, it's time to just shut up.

Previously, here and in When God Is Gone, I quoted the "five stages of prayer" that the poet Samuel Taylor Coleridge jotted down in his journal:

First stage -- the pressure of immediate calamities without earthly aidence makes us cry out to the Invisible.

Second stage -- the dreariness of visible things to a mind beginning to be contemplative -- horrible Solitude.

Third stage -- Repentance & Regret -- & self-inquietude.

Fourth stage -- The celestial delectation that follows ardent prayer.

Fifth stage -- Self-annihilation -- the Soul enters the Holy of Holies.


Which I translated like this:

First stage -- Help!

Second stage -- Here I am!

Third stage -- Oh my God I am heartily sorry for having offended Thee...

Fourth stage -- Gee! -- followed by -- Wow!

Fifth stage -- silent attention.


Which pretty much summarizes my own religious evolution.

I should by now have reached the fifth, silent stage. The essayist Pico Iyer says: "Silence is the tribute that we pay to holiness; we slip off words when we enter a scared place, just as we slip off shoes." But perhaps I'm not there yet. I find myself still saying "Gee!" and "Wow!", which is pretty much all I do on this blog. So I might as well keep doing it for a while longer -- until I find the Holy of Holies.

(This post originally appeared in 2010.)

Friday, December 20, 2013

Take a card. Any card.


I've been blogging here for almost ten years. Imagine each post written on an ordinary playing card. The pile would be nearly a meter tall.

If the thickness of a card represents one day, my life so far would be a stack as tall as the top of the chimney on my two-story house.

All of recorded history? A stack of cards as tall as the tallest man-made structure on Earth, the Burj Khalifa in Dubai.

A stack of cards the age of the Earth would reach to the Moon.

The age of the universe would wrap around the Earth thirty times.

Hold a playing card between your thumb and forefinger: a day in your life. Now think about a pile of cards that would wrap around the Earth thirty times. That's the difference between human time and cosmic time. We're each allotted a deck of cards, each one a tick of cosmic time. We play our cards.

I just played a card. It hardly rippled the cosmos. The trick is to believe it matters locally.

Sunday, December 15, 2013

Excavation


Click to enlarge Anne's Sunday illumination.

Saturday, December 14, 2013

Putting things in bottles -- a Saturday reprise


Summer nights in Tennessee in the 1940s. We kids ran up and down the sloping front lawn chasing fireflies. Lightnin' bugs, we called them. They flickered in the darkness like fluid constellations. We caught them up in our hands and put them in bottles, sometimes two or three dozen to the jar. We thought to make lanterns. Heaven knows what amatory anguish our glass prisons caused the fireflies, all those males -- I assume they were males -- blinking away in close confines, horny as hell in a bioluminescent way. Eventually, of course, we let them go, once we realized their light was useless.

Other creatures, other bottles.

Homemade ant farms. A Mason jar filled with sandy loam scooped up from anthills, ants and all. I don't recall any memorable arthropodal architectural, just a bunch of ants milling about waiting for release. Not so much a farm as a frenzied formicary of frustration.

But -- ah! -- the luna moths. The size of our hands. Plucked from the garage wall and dropped into wide-mouthed jars. Drop-dead gorgeous. Mysteriously sensual. Even a six-year-old knew there was something lush and lascivious about these unwilling prisoners. We kept them in the jars for a day or two -- waiting for what? Something magical and forbidden. Our parents usually talked us into letting them go.

Walking sticks. Chrysalises. Daddy-longlegs. Ladybugs. Newts. Each took their turn in our transparent slammers. I wonder what, if anything, we learned? Maybe a little natural history. Maybe something about biological diversity. Maybe something about freedom, confinement, and the milk of human kindness.

(This post originally appeared in October 2009.)

Friday, December 13, 2013

Happy as kings


In a few days I will make the transition to Exuma, our island in the sun. As usual, I'll be anxious to see what damage we've sustained from the two banes of island existence –- termites and rust.

Who can love termites or rust?

Oh, wait. Have you ever seen a termite up close? I mean, really close? As with a scanning electron microscope (SEM)? Take a look at the creepy-crawlies here. How can one not love even the most insidious insect when you see the astounding complexity of a fly's eye, or a termite's chewing mouth parts. The world is so full of a number of things, I'm sure we should all be as happy as kings. (Who said that? Give me a minute; it'll come to me.)

OK, OK, a termite up close is a thing of beauty. But rust? Rust is rust. A shiny piece of metal –- a handle on the stove, a hinge on the door, the wheels on the terrace loungers - – goes all ugly. More work to do, things to replace.

And just when the sanding and painting and replacing begin to haunt my anticipations, along comes this cover of Science:

Guess what we are looking at? Rust! Iron oxide on painted metal. Up close. SEM close. A patch of surface smaller than the period at the end of this sentence. (Click to enlarge.)

Like an invisibly small rose garden. Those tiny platelets as delicate as petals. Its own astonishing complexity. Its own rare and exquisite beauty.

We stumble around in this world like galoots with other whole universes –- the very big, the very small –- unseen around us. Give the scientific way of knowing this: It has revealed worlds unseen, worlds in which we swim all unawares..

Oh, yeah. Robert Lewis Stevenson. He got that one right.

(I'll be in transition early next week. Back as soon as I can.)

Thursday, December 12, 2013

Pillars of the faith -- Part 2


Let me turn briefly to another essay in Pillar, by John Cavadini, a professor of theology at Notre Dame, the gist of which is that old canard: Science (or "scientific fundamentalism") takes all the mystery out of the world.

He quotes Stephen Hawking's recent book, The Grand Design, to the effect that the true miracle is the power of the human brain to predict and describe the universe we see. In other words, says Cavadini, "once the universe has been disenchanted of illusions, the only thing left to wonder at is the theory that explained them all…[T]he wonder is transferred, as prestige, to the scientists as a cultural elite who can explain everything without ever looking beyond the doors of the College of Science."

This doesn't describe the science I spent my life studying and teaching, or the scientists I have known.

Certainly, science has disenchanted illusions. We no longer believe that comets are signs from God, or that pathogenic diseases are targeted divine scourges, or that fossils on mountaintops are the result of the Flood of Noah, etc. etc. I would hope that my students took a certain amount of pride in the power of the human brain to disenchant illusions, and that some of them carried a healthy skepticism and respect for science into their adult lives.

And mystery? I have often suggested here that the greatest discovery of modern science is the discovery of ignorance, of how little we know -- a thought, by the way, that is hardly unique to me. Scientific knowledge is like an island in an inexhaustible sea of mystery; the larger the island grows, the greater is the shoreline where we encounter mystery. I never discussed religion in my science courses, but I do hope I communicated a sense of reverence and awe in the presence of the astounding wonderfulness of nature.

Wednesday, December 11, 2013

Pillars of the faith


I've spent most of my adult life in the company of men of the Congregation of Holy Cross, a Roman Catholic community of priests and brothers with missions in education and service to the world's poorest. It has been a rewarding association. By my experience, the CSCs are an extraordinary group of men, and I've profited greatly from my friendships.

The congregation puts out a periodic in-house magazine/newsletter called Pillars, and the current issue is devoted to the relationship between religion and science. I can't resist comment.

The theme-setting essay begins, as usual, with reference to the "unfortunate" Galileo affair, then turns to Darwin and evolution (with the mandatory mention of the Catholic monk Gregor Mendel). The Church, we are told, has come to terms with heliocentrism and common descent. Church teaching does not require us to believe in any sort of supernatural suspension of the laws of nature or intrusion into natural processes, argues the author of the essay. God does not act in competition with natural processes, but "in hidden unseen ways within them." What is essential to retain is "our fundamental religious conviction and experience that God is the ultimate source of all things."

Well, fine. One can't argue with that. If that's all there is to it then there can't be much of a conflict between science and faith. I could come home to the Church with only a modest silencing of doubt. But that's not all there is to it. As usual, the author steers clear of real conflicts that are not so easily waved away with the glib assertion that science and religion focus on different aspects of reality.

The Creed, for example, is chockablock with conflicts.

Consider just one aspect of the Creed that would seem to be so fundamental to traditional religion that it's hard to see what is the point without it: personal immortality, with its attendant eternal reward or punishment. Here science and religion are clearly addressing the same aspect of reality, and science has discovered a huge amount about what makes a personal self. If science accounts for anything with even a modest degree of certainty, it is the inseparability of self and the living material body.

And what's the response of the believer? There can be no conflict if immortality is "properly understood," they say, but we are never told what that proper understanding might be. We are also told that God acts in mysterious ways available only to the eyes of faith, which seems to contradict the idea that God only acts through natural processes, not in contradiction to them.

I have no problem with those who chose to believe in personal immortality against all evidence; I'd like to believe it myself. And I'll be the first to admit that science is amendable and doesn't know everything. But let's not pretend there's no conflict. We either ignore the conflict or we don't.

Tuesday, December 10, 2013

Part II - Philosophy


Take another look at yesterday's diagram (from my Biography of a Planet). It's hard to imagine another half-page of notebook paper that could tell you more about the universe that's worth knowing. So blow it up to poster size and put it on the classroom wall. This is what makes stars burn. This is why the universe is not dark and dead. This is the source of your corn flakes. This is the force that through the green fuse drives the flower.

And you ask: How do we know what's going on at the center of the Sun, 93 million miles away and half-a-million miles down inside that roiling sphere?

1) If not this, then we don't know what.

2) We know this works. This is what happens when a hydrogen bomb explodes. Physicists are working hard to create a controlled version on Earth.

3) The numbers all work out.

4)

5) And the kicker. Back to the diagram. See those two neutrinos I didn't mention before. What happens to them? They have no charge. Hardly any mass. They rarely interact with more ordinary matter. In their staggering (but calculable) numbers they fly up and out of the Sun in every direction, barely impeded by a half-million miles of hydrogen and helium. Eight minutes after their creation, a hurricane of neutrinos intercepts the Earth -- and flies right through. Tillions per second penetrate your body. Nothing stops them. Well, almost nothing. Colossal neutrino detectors deep underground snag a few. A calculable few. A direct "look" at the very heart of the Sun.

And so we know. A collective of human brains has figured it out. Meat against mystery. Neurons versus neutrinos. Synapses versus sunshine. Men and women of every faith, politics and ethnicity have pooled their intelligence to understand whence the grain of sand and the flower in the crannied wall.

Monday, December 09, 2013

Part I -- Physics


The Sun is mostly a big ball of hydrogen, a million miles in diameter, held together by gravity.

A hydrogen atom is a positively charged proton and a negatively charged electron, held together by electrical attraction. The proton (the nucleus of the hydrogen atom) is 2000 times more massive than the electron.

It is so hot at the center of he Sun -- that huge weight crushing down -- that the atomic electrons and protons can't hang together. So instead of atoms, there is a furious sea of electrons and protons careening about.

Two protons approach each other, and what happens? They swerve apart. Particles of the same electrical charge repel. But the hotter it is, the faster they move, and the closer they get before they are repelled. If they get close enough, something dramatic happens.

There is another force in nature, called the strong nuclear force, that holds protons and neutrons together. It is stronger than the electrical force, but has a very short range. If two protons get close enough, instead of being mutually repelled, they are clamped together. This happens at the center of a star where the temperature reaches 10 million degrees.

When two protons bind, one throws off its positive charge as a positron -- an anti-electron -- and becomes a neutron. The positron soon meets its anti-matter partner, an electron, and the two annihilate each other in a flash of energy.

Meanwhile, the proton-neutron pair meets another proton and the strong nuclear force welds them together -- two protons and a neutron. This entity meets another of the same, sheds two protons, and becomes a helium nucleus -- two protons and two neutrons.

Hydrogen into helium. Here is the diagram (from Biography of a Planet).

Now let's do the bookkeeping. Weigh the six protons and two electrons that go into the process. Weigh the helium nucleus and two protons coming out. The latter weigh slightly less than the former. Mass has vanished from the universe. In its place: energy. A lot of energy. E=mc2, where c is the speed of light.

Every second, at its hot core, the Sun converts 657 million tons of hydrogen into 653 million tons of helium, by nuclear fusion. The missing 4 million tons of mass are converted into energy. How much: 4 million tons times the speed of light squared. The energy makes its way to the Sun's surface where it is hurled into space as heat and light. The Earth intercepts about one two-billionth of this energy, or about four pounds worth of the Sun's vanished matter every second. The Sun never misses so slight a fraction of its huge bulk, but for the Earth it is the difference between day and night. And winter and spring.

More tomorrow.

Sunday, December 08, 2013

Radio-flyer


Click to enlarge Anne's Sunday illumination.

Saturday, December 07, 2013

Musing in retirement -- a Saturday reprise


(This post originally appeared in November 2009.)


I'm often asked if I miss teaching, which after more than forty years in the classroom is a reasonable question. The answer, generally, is no. Now that the pension checks appear in the bank each month, I'm happy to spend my time learning rather than teaching. The next question, I suppose, is why learning? Why bother stuffing more stuff into the head when...when it's all going to evaporate soon? Well, because I can't think of anything I'd rather be doing.

But back to teaching: Do I miss it? Only occasionally. Like yesterday morning when the image above was the APOD (Astronomy Picture of the Day): a view of Earth from the third flyby of the European Rosetta spacecraft on its ten-year journey to a rendezvous with Comet Churyumov-Gerasimenko in 2014.

A breathtaking picture. And, as they say, a teachable moment.

I'd love to project this image onto a huge screen in a darkened classroom, and then spend an hour talking about it. Not lecturing. Just asking questions.

For example, the APOD text says we are looking at "a bright crescent phase [of the Earth] featuring the South Pole to the passing rocket ship." Presumably they mean the white mass at the bottom center of the crescent is Antarctica. Can that be right?

Time to get out the 16-inch globe. Where is the Sun? A spotlight will serve. Now let's reproduce the crescent. The flyby was in mid-November; what was the orientation of the Earth relative to the Sun? Can we find the image's time of day on the ESA (European Space Agency) website? Let's sort out exactly what we are looking at.


Here's a closer look at the crescent (click to enlarge the pics). Notice the illuminated cloud tops in the shadow at bottom right. How high are they? Can we work it out? Sure. All we need to know is the diameter of the Earth. A few measurements off the screen and a big sketch on the blackboard will do the trick. This is how Galileo estimated the height of mountains on the Moon.

Etc. Etc.

Some years ago, Eric Hirsch published a A First Dictionary of Cultural Literacy: What Our Children Need to Know, a compendium of core knowledge that he believes kids should acquire by the time they enter junior high school. The chapters on science list 442 terms, from acid to x-ray. It's a good list, but, as Hirsch would surely be the first to acknowledge, a vocabulary is not a sufficient basis for scientific literacy. What is required is a gut feeling for how the world works and our place in it. And a sense of wonder.

That's what I miss about teaching. Give me an image of the crescent Earth looming -- breathtakingly -- in a darkened classroom and I'll do my very best to send a student's imagination hurtling through space into a universe that is deep and vast beyond our present knowing. Once you've caught the virus of wanting to know, the 442 vocabulary terms will come along in their own good time.

Friday, December 06, 2013

Paring the paranormal


The physicists and cosmologists tell us that the universe consists of 5% ordinary matter (the kind of stuff your chair is made of), 27% dark matter (massy stuff of a yet undetermined nature), and 68% dark energy (also yet unidentified). Dark matter and dark energy are hypothesized to exist because of their apparent effects on luminous objects -- stars and galaxies.

Which is to say, most of what is is invisible.

It's sort of like hypothesizing the existence of poltergeists to account for moving candlesticks.

With a difference. Weakly interacting massive particles (WIMPs) and axions -- the two strongest contenders for dark matter -- will only be admitted to the realm of the real if they can be empirically detected. In both cases, this requires a rather heroic experiment. You can be sure that physicists are doing their best to make the supposed culprits reveal themselves. There are reports on the current state of affairs in the 1 November issue of Science.

Some folks would say that the difference between WIMPs and poltergeists are not as great as I make them out to be. OK, the candle moved, but what about the neighbor who reported hearing a spooky sound the same evening, or the "ghost-buster" (reasonable fee) who claims to have captured an aura on his infrared camera?

Do WIMPs and poltergeists then have equal claim on reality? Not quite. Every claim for detection of a WIMP or axion will (has been) subjected to repeated scrutiny. Every claim must be reproducible by believers and skeptics alike. Consensus is the goal. When the WIMP champions concede to the axioners, or vise versa, then we begin to say that nature is revealing the real.

Tentatively. For the time being. And in the meantime, scientists will work to make the bonds that hold experiment and theory together as resilient as possible.

These are constraints that poltergeists have never met.

Thursday, December 05, 2013

Minding my Ps and Qs


Thanks to my friend Bob Goulet for putting me onto two articles in the New Republic by Steven Pinker and Leon Wieseltier, literary editor of the NR. They are well worth reading, here and here.

It is an old battle, between the sciences and the humanities, here fought by two lefties who are equally smart and articulate.

"The worldview that guides the moral and spiritual values of an educated person today is the worldview given to us by science," writes Pinker, and one can feel the hair rise on the humanist's neck.

Pinker suggests (among other things) that science is characterized by a commitment to two ideals: the world is intelligible, and the acquisition of knowledge is hard. The first principle is essential for science; less so for the humanities. The second principle is sure to drive any humanist up the wall. No wonder Wieseltier comes out swinging.

"Some scientists and some scientizers feel prickly and self-pitying about the humanistic insistence that there is more to the world than science can disclose," growls Wieseltier; "It is not enough for them that the humanities recognize and respect the sciences; they need the humanities to submit to the sciences, and be subsumed by them."

"Sophocles and Tacitus and Augustine and Milton and Gibbon and Keats and Tocqueville and Emerson and Mill and Dickens and Mann and Stevens and Auerbach and Camus and Panofsky and Miłosz" are not made redundant by scientific progress, says Wieseltier. "There are moments when there is nothing more urgent than the defense of what has already been accomplished," he writes.

Ah, this scrap could go on forever. It is probably clear to readers of this blog which contender in the slugfest I lean towards. But I think the best indication of my view is where I sit just now, as I type these words, in my comfy chair in the college library, halfway between the Ps and Qs. Dante and Einstein are equally at hand. I am blissfully unaware of any tension between the sciences and the humanities, and I trust that my posts here have drawn equally from both wells.

Tuesday, December 03, 2013

Who's tops? Whose tops?


Who were the greatest scientists of all time? I've tackled this question before (I'll get to that in a minute), but for the moment let's consider a new book by Steven Skiena and Charles Ward, Who's Bigger: Where Historical Figures Really Rank, as discussed at length in the 1 December Boston Globe.

Skiena and Ward used Wikipedia as their criteria: the length of a person's entry, how often it's viewed, how often edited, and the number of links to that page from the pages of others of significance. That is to say: Who from the past is garnering the most attention at the present?

No. 1: Jesus. No. 2:Napoleon. No. 3: Mohammed. The first scientist pops in at No. 12: Charles Darwin, possibly helped along by being the bugbear of the religious right. Einstein enters at No. 19. And Newton at 21. That does it for scientists in the top 25. Not too shabby.

A few years ago I ranked here seven scientists initially chosen by Boston's Museum of Science. Unlike the Museum, I put Darwin in top place. I wrote:
And, in 1st place, in a stunning upset, turning the museum's ranking on its ear: Charles Darwin. He did not invent or discover evolution. The idea was in the air. Alfred Russell Wallace proposed a theory of biological evolution by natural selection simultaneously with Darwin. However, Darwin not only stated a theory, he marshaled an irresistible display of evidence in its favor, gathered by decades of patient observation, and in so doing established the legitimacy of historical sciences. No other scientific idea has so radically altered our understanding of ourselves. This is the great Darwinian truth: We are not lords of the universe, plunked down into a garden established for our benefit, to be used or despoiled at our pleasure. We are flowers of the garden, inextricably part of the seamless web of life.
Newton wasn't among the Museum's seven, but I was happy to accept Galileo in his place. Einstein made the Museum's list, and didn’t do too bad on mine, although the way we think about ourselves and our place in the world was not dramatically changed by his work.

Earlier, I had hazarded a guess for the greatest American-born scientist. I wonder if Willard Gibbs showed up at all in Skiena and Ward's book? They used both "celebrity" and "gravitas" as criteria. Gibbs was/is all gravitas and no celebrity.

(I'll be away tomorrow.)

Monday, December 02, 2013

Tea


It was certainly one of the saddest episodes in our nation's history; the sacking of Washington by the British in 1814. Most public buildings went up in smoke, including the Capitol and President's House. The north wing of the Capitol housed the Library of Congress, three thousand volumes of history, law and classics meant to help Congress govern wisely and well. Fuel for the conflagration.

The largest personal library in America was Thomas Jefferson's, at Monticello: six thousand volumes. The 71-year-old Jefferson had intended to give the nation his library upon his death. Shocked by the burning of Washington (and in need of cash), he now offered Congress nearly his entire collection for $23,950. Ten wagonloads of books made their way to Washington.

Not everyone in Congress was happy, and not only about the cost. Too many books in foreign languages. Too much philosophy. Too many books of objectionable content, including the works of Voltaire. And who needed all that science that Mister Jefferson had so assiduously collected?

Plus ça change, plus c'est la même chose.

Sunday, December 01, 2013

Outside in


Click to enlarge Anne's Sunday illumination.