Oklo for half an hour

How we know…

How can we possibly know, two billion years later, that the fission in Oklo lasted half an hour at a time and then stopped for a few hours? That seems completely absurd. Nobody was there; nobody could see; do scientists just make these things up for breakfast?

Well, we were not there, and we can’t figure out all the details of what happened, but the reason for thinking it worked this way is completely logical and it has to do with the isotopes of xenon which are left in aluminum phosphate crystals in these deposits. You can read about it for yourself if you want to work through all the ideas more thoroughly, but here is the main scheme:

Xenon is a noble gas, an unreactive element like helium, and it has several isotopes that are produced at different points during the normal breakdowns of radioactive uranium and its various “daughter” elements.

Note: When uranium breaks down it does not become a different isotope of uranium, but a different element altogether, depending on how it breaks. The daughter elements can be identified as uranium breakdown products because each element has one isotope that is, you might say, its own “original,” and a few others that come at the end of various breakdown paths.

As scientists were looking over the material in Oklo, they were surprised to find that the several xenon isotopes commonly found after nuclear fission were found here in very different proportions from the norm; in particular, there wasn’t enough xenon-136 or xenon-134. Where could they be? How come the others were dominant?

After some consideration, researchers realized that the missing xenon isotopes were the daughter isotopes of elements that are soluble in water. Perhaps some of these isotopes (radioactive tellurium and iodine) had been carried away by water seeping through the sandstones around the uranium. Perhaps some had been carried away before they broke down into xenon. This water was certainly present for the fission because it is important to the fission itself, but it boils away when things get hot, and then the fission stops. So apparently it works like this:

1. Fission begins,
2. Radioactive tellurium and then radioactive iodine are produced, as well as other elements.
3. These two elements quickly produce xenon-136 and xenon-134 but since they are water-soluble, they are partly off-site by the time these xenons turn up.
4. The water heats and boils away.
5. Fission stops.
6. Other xenon isotopes are produced as things begin to cool, and some are produced very much later, when everything is stone cold.
7. Aluminum phosphate crystallizes out during the cooling and locks the later xenon isotopes (or their radioactive parents) in its crystals. (Otherwise they would float away.)
8. When things are cool enough, the water seeps back in.
9. Fission begins again.

Half an hour of fission and a few hours of crystal formation are what it would take to have part of the xenon-136 and xenon-134 missing while xenon-132, -131, and -129 are locked in the aluminum phosphate.

Something like that. Totally unexpected, complicated, but tidy.

Nice detective work, eh?

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The Oklo Reactor

The Oklo reactor is not in Japan. It is not in Denmark, in case you think it sounds like a Scandinavian name. Over its lifetime, it generated probably 15,000 megawatt-years of energy, about what you’d expect from 6 tons of Uranium-235, a four-year supply for a large reactor, or alternatively, the power supply for a few toasters for a few hundred million years.

Uranium has several different isotopes, mainly Uranium-238, which breaks down with a half-life of a few billions years, and Uranium-235 which is much more radioactive, breaking down at least 6 times faster. Odd that just three missing neutrons make such a difference, for that is all that distinguishes the two forms, but it has another effect as well:  the nucleus of a uranium-235 atom is unstable and apt to split if it is disturbed. All it takes is one wandering neutron, which might come from the natural radioactivity of either isotope or one of its breakdown products, and bam! — the uranium-235 can suddenly break into a couple of smaller unstable atoms, which may break down again, and their breakdowns yet again. Some of these breakdowns throw off neutrons, which, if there’s more uranium-235 in the area, can set off yet more chains of breakdown. All this breaking up is called fission and it can make the neighborhood quite hot if there’s enough of it. Interestingly, because the rate at which this series of decays takes place, the proportions of the fission-formed elements can tell us how long it’s been since the uranium-235 underwent a fission reaction.

At Oklo, it was 2 billion years ago. It was a rather lazy event, probably lasting half an hour at a time, cooling for few hours, and then continuing. And yes, it went on for maybe 200 million years.

Thus, the Oklo reactor was a natural event, and it produced its heat and died down again before men walked on the earth, before dinosaurs walked on the earth, before the shellfish left their households in the soil of Italy, and even before the trilobites who swam around for 250 million years and then died, leaving the sea to the fishes. All the animals we know go back maybe half a billion years, but the blue-green algae go back 3 billion years, and they were there to see Oklo. (Well, they didn’t have eyes.)

Where from, and why then?

The uranium came up from below, nobody knows how far below the crust of the earth, and spread over the edge of the Congo Craton of Africa, to which, incidentally, Brazil was still attached. At this time in the history of the world, the Great Oxygen Event was unfolding, when oxygen first became abundant in the atmosphere, apparently through the action of the blue-green algae, also called blue-green bacteria.

Incidentally, this surplus of oxygen had two very interesting effects:

1.   Oxygen reacted with iron in the water and laid down the banded iron formations which later gave the Bragas of Brazil their living.

2.   By reacting with the greenhouse gas, methane, already in the atmosphere, the new oxygen set off a worldwide glaciation, the Huronian, which very nearly brought life to a dead halt on earth before there were any footed creatures at all to walk its lands.

These amazing events belong to just this one period in earth’s history and they cannot happen again that way.

But the new flush of oxygen in those distant days was important to the uranium, too, because it allowed the formation of uranium oxides, which are water-soluble, and this allowed the uranium to be carried from one place to another. The place where the water dropped it, in Gabon, Africa, became a vast uranium deposit and is now a uranium mine. (Presumably, there are also uranium deposits “in” Brazil, but if so, they are probably 18-20 km underground, and are impossible to mine.)

It was in the context of mining operations in Gabon that the traces of this ancient, natural fission reaction were discovered in 1972, and an effort to understand their origin was slowly launched.

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Fairness in miracles

I have defined miracles, [Jan 9, 2011] but now I would like to talk about them, not as events in themselves, but from the perspective of the believer. In particular, let us think about what belief is required of the hearer compared to the belief required of the observer or of the messenger who tells us about a miracle. For example, let us consider one of the miracles from the life of Jesus, such as His making of the wine of Cana, and compare that with the miracles that the creationist has in mind for, say, the Third Day of Creation. This is the day when, says Genesis, God made the dry (actually the moist) earth and all the grasses and herbs and flowering trees that naturally grow on land.

In the case of the wine of Cana, we and St. John are on the same page and bring the same experience to the story: wine is mostly water, but water is not wine, and good wine is not made quickly even from the best of grapes. Our experience is the same as St. John’s and what he is proposing for our belief is something he must have found hard to believe, or at least most astonishing, himself. He was there, so that helped him, but he did know the unlikelihood of it, which was the precisely the same for him and for us.

But for the Third Day of Creation, the situation is quite different. What we and the author of Genesis bring to this verse of the Bible are very different. Creation itself is astonishing; in that we are the same. But, on a creationist interpretation, what are we to think of grass that must be green without the sun? You may answer that there was light on the first day, but what sort of light was that when there were no stars? Was it electromagnetic radiation like the light we know now? If so, something had to radiate it; what? If not, then was it a spiritual light, not really what we mean by light, but something analogous? And if so then how did it support the activity of chlorophyll in the leaves?

One might imagine that the grass was there but was white until the fourth day when the sun turned up. But that is not so easy, because grass cannot even grow or stand up straight without the energy that is packed up by chlorophyll in the sunshine. You could reply that God could have kept the grass in a mature state, either white or green, whichever he chose, until he made the sun. God can do anything.

Yes, God can do anything, but the question I ask the creationist is: what is being proposed for our belief? That all the green herbs and flowering plants were created in mature but bleached form and then waited for the sun of the fourth day? Or that all were created only as seeds, waiting for the fourth day to sprout? Or that they were created mature and green, but static, only reaching active stature on the fourth day?

Not that it matters, but the point is, what are we talking about? What is it that we are asked to believe? None of the problems I have listed were within the consciousness of the sacred writer. It took him no extra leap of faith to deal these logical consequences of the Genesis sequence, because he was not aware of them. God made the land and its plants: fine. In that case, what he understood himself to be proposing for our act of faith is not the same as what a creationist asks us to believe a few thousand years later. In the case of the wine, it is the same. Even in the case of the Resurrection is it the same, for the deadness of dead bodies is not a new idea; modern medicine does not change it. But for the creationist interpretation of Genesis, it is not clear what is proposed for our belief, and whatever it is, the Genesis author was not conscious of it.

Of course being able to distinguish two types of miracles does not mean one kind did not happen. God can do anything.

But the issue remains: if you cannot tell me what I am supposed to believe, then you cannot fault me for not believing it. I believe that God designed everything with infinite wisdom, and that He is fully aware of every detail of the outworking of even the most law-bound processes. Within Catholic doctrine, that suffices for the Third Day. Whether it took place over a few hundred million years, and whether a good number of animals (such as bees) were actually also created at the same time as the plants they pollinated is of no consequence.

In that interpretation, what is proposed for our belief – that our Father did it all, right to the last apple blossom – is the same for us and for the author of Genesis. Seems only fair.

 

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Starlight old or new

Here is another piece from Jeannie Fulbright’s Astronomy text in the Apologia series:

“Some people claim that since some stars are billions of light years away, the universe (and therefore the earth) must be billions of years old. After all, they think that the light from those stars had to travel from the star to the earth, and since the light is hitting the earth, it must have had billions of years to travel. They do not understand that God is so wise that He could create things to be exactly as He wants them to be… He could create stars and their light to be fully grown and fully developed … He could create an earth with starlight that was already upon the earth, even starlight from billions of light years away. After all, nothing is impossible for God.

Many believers who accept the Resurrection of Jesus still think the universe is old. I do. I am sure that God has the power and wisdom to create things exactly the way he wants them, but I doubt that he wants them to be deceptive. It’s a matter of honesty, and it is an implicit matter of fatherhood. We are made in his image so we can perceive what he is doing and rejoice in it as sons and daughters admire their fathers.

What is the meaning of astronomy if the things we measure are wrong because God made them to look like something they are not? Why would God make stars far away with a beam of light strung across the whole of space, so that this light appears to travel from that star to our earth, day by day and night by night, when in fact this light was never part of the star at all? Why would God bother to string it out like that instead of just making the universe and letting the stringing take place according to the laws he built into the universe? Was the eternal God in a rush to create an appearance that would turn up by nature’s laws if He just waited? Is He not outside the press of time?

In the end, there are a few things that even God cannot do. He cannot make a beam of light that is both from a star and not from a star in the same sense of “from a star.”  If a beam of light shining upon the earth was never the product of the burning of a star, then it is not starlight no matter how God strings it about.

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Creationist astronomy

Please note: The Astronomy text of the Apologia series was written by Jeannie Fulbright, not by Jay Wile as I had assumed. According to her website, he remains the editor, but not the author. I apologize for this mistake.

The Apologia science series consists of several very accessible science texts, and many home educators use them with pleasure. There are places in this text, however, where the author gets a little preachy and what she says is not helpful for integrating your Catholic faith and your scientific cosmology. Here is an example (brought to my attention by a friend) from page 33-34 of the astronomy text.

“Amazingly, parts of Mercury have no craters. The fact that parts of Mercury are craterless is difficult to understand for those who believe that the solar system is millions or billions of years old. You see, over millions or billions of years, every part of the planet would have gotten hit many, many times by falling asteroids. Scientists know that the chances of some parts of Mercury never getting craters over billions of years is next to impossible. The best explanation for why Mercury has sections with no craters is that the solar system is not millions or billions of years old. However, scientists who want to believe that the solar system is that old have come up with another explanation. They say that the craterless sections are the “new” parts of Mercury.  According to these scientists, the “new” parts of Mercury were formed recently by volcanic eruptions. Since these sections are not very old, they have not had time to be struck by asteroids yet, so they have no craters. Of course, we know that God created the whole planet of Mercury instantly, with only a Word. I also believe that the whole planet is not nearly that old, because I think the Bible tells us that God spoke it into existence only a few thousand years ago.”

In this section, the text proposes a problem, the craterless sections of the planet Mercury. We learn how this is related to the age of Mercury: after billions of years of bombardment by asteroids, Mercury should be cratered all over. Then Fulbright offers the scientific solution — volcanic eruptions, but she offers this as if it were a mere alibi, rather than a conclusion based on the likelihood of volcanism. What do the creationists think that volcanoes will do to the impact craters? Do they have a reason do doubt that there is volcanism on Mercury?

The next line tells us the answer: the creationist has no need to consider the likelihood or the effect of volcanism on Mercury, because the Bible tells us what we need to know, namely that Mercury was created in an instant, “only a few thousand years ago. Presumably that means that it was created with craters printed on its surface, because 6,000 years is not long enough for the bombardment to make them all. And presumably there is no volcanic activity on Mercury, so its effect need not be considered, though neither the spiritual value nor the scientific status of such an opinion is not clear.

Let’s talk about enthymemes.

An enthymeme is an argument which presumes the form of a syllogism such as the famous one:

• All men are mortal.
• Socrates is a man.
• Socrates is mortal.

However, in the enthymeme, one of the first two sentences is missing. So you might just say: Socrates is a man, so Socrates is mortal. You are presuming that everyone knows that all men are mortal, and it’s enough to say that Socrates is a man to know he must be mortal. Alternatively, you might say: All men are mortal, so Socrates is mortal. In this enthymeme, you presume that everyone knows Socrates is a man, a reasonable presumption.

Enthymemes are a natural way of speaking. Good heavens! if we had to spell out everything we wanted to say all the time, we’d never get anywhere. But when you are constructing a careful argument, enthymemes must be checked. Fulbright writes:

• I believe that the Bible says that God spoke [the planet Mercury] into existence only a few thousand years ago.
• Therefore Mercury is not billions of years old.

If you take out the brown part, it’s very simple. Obviously what is only a few thousand years old cannot be a few billion years old. However, tucked into the first proposition are two further implied claims: that the Bible says something about Mercury and that what Fulbright believes the Bible says really is what it says. Now it goes like this:

• That Mercury is a few thousand years old is what I believe the Bible says.
• (…)
• That Mercury is a few thousand years old is what the Bible really means.

Here is the missing proposition:

• What I (Fulbright) believe the Bible says is what the Bible really means.

Here are the problems with this

1. Fulbright’s opinion is just an opinion. She can have it, but what is her opinion doing posing as an argument in a science text? I do give her credit for admitting (on this occasion, and reluctantly) that it is an opinion.
2. Many serious believers would argue against his opinion. Certainly it is not the only believing opinion.
3. The Bible does not mention Mercury, so whatever it says applies only indirectly to Mercury and does not take into account what scientists see. Of course the Bible cannot list everything, but that is precisely why it is a mistake to view it as a science text. A scientist sees what he sees; shall a theologian tell him to shut his eyes?
4. Why should Fulbright’s opinion be accepted as “the best explanation?” Is she an astronomer, a planetologist, or a simply homeschooling mother with various opinions? I have opinions too, and some are counter-academia, so I understand that; but it’s pretty cheeky to call my opinions “the best,” after dismissing others’ without any scientific explanation.
5. How insulting is it to say that scientists come up with other explanations for what they “want to believe?” Scientists have many good reasons for thinking the solar system is old. What they “want to believe” (for so Christianity once taught them) is that the universe is comprehensible and that, in the end, all the evidence will fit into a consistent interpretation. Otherwise there is no point trying to do science.

Any author who defends a young universe on such terms I call a creationist.

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Evolution defined

Well, I said was going to go on to discuss Wile, and suddenly I realized that I have not defined evolution. I have given this definition so many times, I forgot that I had not done it here. Sorry. Very important.

What is evolution?

Evolution, like creationism, is a word that has gone through a lot of changes, and its many definitions are being used equivocally all the time, which makes for a hopeless situation if you want a conversation to progress.

[To use a word equivocally is to switch from one definition to another without paying attention, so that what you say seems to make sense but is actually trivial or even false. Here’s a famous equivocation:

• A ham sandwich is better than nothing.
• Nothing is better than heaven.
• Therefore a ham sandwich is better than heaven.

The word “nothing” is used in two senses as if they were one.]

So let’s talk about the definitions of evolution and let’s be careful about which one we are using from now on:

1. Evolution means change over time. Hardly anyone objects to such a concept of evolution because we see changes over time all through our lives and the lives of our gardens, apple trees, dogs, and cities.
2. Evolution means vast change over vast amounts of time, including mountain-building and even star formation and even the formation of the universe. This pulls us right off the simple scheme of Genesis 1, and young-earth creationists are not happy.
3. Evolution most often means change in the biological kingdom such that one species (or family, or even phylum) gives birth to another. This does not take place now, but the theory of evolution is the theory that it did happen in the past. This is a definition I accept, and it is the form of evolution that I believe took place. I sometimes call it “single family tree of life.” I say, “I believe in a single family tree of life” and I sidestep the word evolution.
4. A few people believe that evolution proceeds by law and by design, not by accident. I believe that this is so. There is a fascinating little book called Nomogenesis, by Robert Broom, offering the evidence for lawful evolution. John Davison led me to it.
5. A very few of the people who believe that evolution took place believe it is over. I am one; Davison is one; I have good reasons for my position. It is the one position that is so rare that I takes me outside all boxes and everyone has a reason to take a potshot at me; or alternatively, everyone has reason to love me. I wrote a little about it January 31, 2011.
6. For Darwin, the theory of evolution had several other elements:

• • He thought it ongoing in the present, which I do not believe is the case. Young-earth creationists are fierce (rightly and sometimes usefully) about the lack of evidence for genuine contemporary evolution.
  • Darwin thought evolution to be accidental, which I do not believe, and for which there is not and cannot be evidence since it is a philosophical point.
  • He though it due to miniscule mutations (gene mutations for the neo-Darwinists, updating in view of DNA and the genome). This also I believe to be a mistaken idea. See my post last January 22, 2011.
  • Darwin thought Progress was held in place by survival of the fittest, which is either dubious or irrelevant, being either flatly false or a tautology. Creationists are very good at pointing out the tautology.

Darwinism, with its commitment to accidents and brutality (that’s what survival of the fittest means) as the engines of Progress, is very anti-catechetical. How could a good God make a fundamentally brutal world? This element of Darwin’s thought has always been irreligious in philosophy and in effect, and was certainly the philosophy behind Nazism.

But evolution in my sense is not opposed to our catechism, and it has a charm of its own. Sometimes in speaking of it, I tell an origami story, in which the signature objects in the  story turn up as origami formations, with each form then being folded to the next. Two of the final folds present a golden steeple and a pink rose. The first time I did it, everyone was so surprised by the rose that they burst out clapping. They had not seen it coming; it was fun.

It was fun because it was so clever. Origami is always sort of magical, but an origami story is better magic  — just one piece of paper going through all those changes. As I see it, Creation by the technique of evolution is clever in that way. You just don’t think it’s possible to get from here to there without “changing papers,” without starting over — but it works if the origamist plans it right.

So those are some ideas of evolution, and really the first thing you have to do is find out exactly what your conversation partner has in mind and don’t be slipping from one definition to the next without noticing.

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Creationism

Defining creationism

Defining your terms is the first step in understanding any argument. Like any word with a history, “creationism” has been through several meanings, and is still used several ways, so let’s start with three:

1. Creationism once meant the belief that man has a soul. Darwin’s work suggesting that man is merely a species of primate was then contrasted with the Christian faith that man is God’s special creation, specially in His image, and spiritual in his nature.
2. Creationism later came to mean the belief that God made the world, as opposed to the idea that it is here by accident. New insights into historical geology gradually eroded the specific Biblical sense of creation over a short period of time or in the sequence offered in Genesis 1, leading to a split in how creation was viewed:
   • Creationism may mean the idea that God made the world in 6,000 or 10,000 or 12,000 years, occasionally a little more, but never billions of years, essentially on the Genesis schedule. This is sometimes called “young earth creationism.”
   • Creationism may simply mean the idea that God made the world, on whatever schedule. This is sometimes called “old earth creationism” by Christians who sympathize with the young earth creationists and want to be viewed as believers. It may also be called theological evolutionism, because these believers often retain a serious theology,  even though they see things as happening over a long period of time. However, the theology of old earth creationists is more or less ignored by secularists because it does not affect their system and more or less rejected by young-earthers as a faithless compromise.

The soul-based definition has been fairly well superseded by the issue of God’s work in the universe as a whole. The creationist with the short schedule, is universally called creationist; the creationist with the open schedule goes by various names, but since the schedule is open, he may be ignored unless other issues are involved.

What other issues?

Two principal issues cause the old-earth creationist to define himself in more detail, and put him in or out of the “creationist” i.e. young earth creationist camp: the evolution of the universe and evolution of living forms. There are sub-issues and variations, but that’s what it amounts to.

I myself usually use the term creationist to refer to someone who is a young-earth creationist, someone who more or less completely rejects the standard explanation of fossil formation and its implications, and someone who rejects the Big Bang. The old-earth creationist does not strike me as needing a name, because any serious Christian must believe God made the world, and there is thus no explicit reason for a name. As a scientist, an old-earth creationist does not need to distinguish his scientific ideas from anyone who is not a believer; and while he may want to insist to the young-earth creationist that he is a believer, I don’t notice that it matters. We’re all heretics together to the young-earthers.

Maybe I paint with too broad a brush, but that is my impression, and I have had ample opportunity to form an impression.

I have read a fair number of creationist (young-earth creationist) pieces; they share their arguments to such an extent that the material becomes repetitive, but perspectives do vary. There is a Catholic work called Creation Rediscovered. I am not impressed with either the theology or the science, but it has an imprimatur. This means that holding these ideas is not opposed to Catholic theology. My books on the subject (Creator and Creation, Genesis 1 House of the Covenant, and some other things that are more indirect) also have an imprimatur; so they are not opposed to Catholic theology either. The Church does not have a doctrinal position on the age of the universe; and it does not have a doctrinal position on whether our bodies — or the first human bodies — were derived from other primate stock.

The one issue that is very important in Catholic theology is the unity of truth: truth is one, and there is no proposition that is true in science and false in doctrine or the reverse. No compromise here.

In the light of this definition, I will follow up to explain why I see some curricula as creationist and why I view this as a weakness.

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