The Flight of the Iguana (15 page)

A Theory with Some Holes in It

Holes are in the news again.

It happens that way, have you noticed? Mankind tootles along nicely for years, even decades, devoting no special attention to the subject until, suddenly, there comes an outbreak of renewed fascination with the ontology and etiology of holes. Yes, holes, like in the ground. Like the opposite of mounds and mountains. When the time comes around in this cycle, new holes begin to appear; neglected holes are discovered belatedly; old holes are reinterpreted in the light of more advanced thinking. We are in such a period now.

The big meteor crater outside of Winslow, Arizona, turns up in a movie called
Starman.
Elsewhere, scientists searching for evidence of a twin star that may orbit in tandem with our sun—bringing cataclysm and mass extinctions upon Earth every twenty-six million years—have begun surveying meteor craters for possible confirmation of such a twenty-six-million-year cycle. In Great Britain a brilliant astrophysicist announces that black holes, those boggling zones of compacted matter and inexorable gravitation, might actually
emit
particles. And the latest: a pair of hole-related stories out of the Soviet Union, long a world leader in the realm of mysterious holes.

The first of these two Soviet specimens, known as the Kola borehole, is presently the planet's deepest and most expensive (and, some would say, most inane) hole. Penetrating, at last report, 7.5 miles down through hard crystalline rock, and only as wide as a pizza, this hole has been drilled from a spot on the Kola Peninsula, an extreme northwestern nub of the Soviet Arctic. Why was it drilled? That's a good question, and one we'll address in due course. The second Soviet hole is not actually new and not actually a hole (two technicalities that need not concern us here), but it has recently gotten fresh scrutiny by those who apply themselves to the contemplation of holes, thanks to certain developments in atomic theory and astrophysics. The non-hole of which I speak is a huge impact crater that was
not
found at the epicenter of devastation left by the so-called Great Siberian Meteor. It was not found at the epicenter, where it should have been, nor anywhere else: a conspicuously and tauntingly absent hole, this one. There were eyewitness accounts of a flaming mass that fell out of the sky, an explosion equivalent to perhaps twenty megatons, 1,500 square miles of pine and birch trees knocked flat by blast wave and scorched by unearthly heat—but no crater. No hole.

Aha, you say, Siberia. The Soviet Arctic and now Siberia. Why do these holish wonders tend to site themselves in such woebegone places? Another good question. Which just goes to prove my point: With so many holes lurking around so mysteriously, so many nagging questions about them (including:
If you dig a hole in the ground and then fill it up with the same dirt, is that hole gone, or just hidden?
and
Why do bakeries sell doughnut holes but not bagel holes?
and of course
How many holes DOES it take to fill the Albert Hall?)
going unanswered, there seemed reason to hope that someone should be at work on a Unified Hole Theory. As far as I can determine, no one is.

So this week I have thrown myself at that challenge, but I tell you truly, the progress has not been encouraging. I've pedaled
my bicycle back and forth repeatedly between the public library and the one at the university. I've tracked down old journal articles and I've read and I've pondered. I've sat in an aluminum lawn chair beneath a tree, scratching my feet. All to little avail. Some intriguing coincidences have revealed themselves to my modest research, but a good Unified Hole Theory still looks as unattainable as the golden fleece or the end of the rainbow or, well, uh, the Holey Grail.

•   •   •

The oil and gas industry drills more than 10,000 wells annually just in the U.S., but most of those holes are of no help to geologists who want to study the layers of crystalline rock in the Earth's crust. They have either been drilled in the wrong place or to the wrong depth for scientific purposes, or the information turned up is kept secret by the individual companies. Consequently, research geologists have begun promoting their own borehole projects as a means of investigating otherwise inaccessible rock.

The Kola borehole (which my wife, the scientist in the family, insists on calling “the world's deepest boring hole”) was started fifteen years ago and is now deeper than any ocean trench or commercially drilled hole on the planet. The Soviets' stated goal is to continue down beyond nine miles, but according to a report last year in the journal
Science,
the going has lately become difficult. What have the Soviets learned from this project? Mainly, it seems, they have learned how to drill deep holes. They have also found some methane gas and mineralized waters at unexpected depths. If anything more has come out of the Kola hole, the Soviets are keeping it quiet. Meanwhile, a group of U.S. geologists are seeking financial support for their own borehole, to be drilled six miles down from a point in the southern Appalachians.
Science
observes soberly: “To start a national drilling program under present funding conditions, scientists must not only designate an exciting hole as first priority, but they must also put
a clear price on it.” The price of the Appalachian hole might be $45 million. The excitement level is anyone's guess.

Compared to these enterprises, the mystery of the Great Siberian Meteor is much more profound, although not nearly so deep.

Whatever this thing was, it came suddenly out of the sky on the morning of June 30, 1908, and crashed into the taiga along the remote headwaters of the Stony Tunguska River, 2,500 miles east of Moscow and a week's journey by reindeer (as the local people figured it) from the nearest village. One farmer in that village later recalled: “There was so much heat that I was no longer able to remain where I was—my shirt almost burned off my back. I saw a huge fireball that covered an enormous part of the sky. I only had a moment to note the size of it. Afterward it became dark, and at the same time I felt an explosion that threw me several feet from the porch.”

The flash of that explosion was visible four hundred miles away, and the sound carried still farther. Seismographs halfway around the world registered the concussion. In an area of forest fifty miles across, nearly every tree had been broken off or uprooted, all of them laid flat in a neat radial pattern with the trunks pointing back toward an epicenter. No scientific investigator reached this site for years afterward, but when one finally did, he found two especially curious phenomena. First, the explosion had left a number of trees still standing upright almost exactly at, or under, its epicenter. Second, it had produced no crater. No hole.

Eighty years later, scientists are still wondering how to account for this event. The puzzling fact of the standing trees can be explained by assuming that the Tunguska explosion was an air burst, occurring not precisely at ground zero but some several thousand feet directly overhead. A blast wave spreading from that point might have only stripped branches from the trees beneath,
then splashed out in all directions to flatten an area of surrounding forest.

The matter of the missing crater is more complicated. One hypothesis is that the Great Siberian Meteor was not a meteor but a comet. A comet, being a loose conglomeration of dust and ice, might have vaporized explosively as it passed through the atmosphere, leaving no trace of its own mass on the ground. Another suggestion offered quite seriously is that the explosion was nuclear, resulting from a malfunction in the engines of an extraterrestrial spaceship. This idea seems to be favored by some respectable Soviet researchers, including the professor from Tomsk who claimed recently to have found metal fragments from the ship. One pair of American physicists, A. A. Jackson and Michael Ryan, have even proposed that the devastation was caused by a black hole—a tiny one, no bigger than an atom, but containing the compressed mass of a large asteroid. According to their notion, the black hole would have come whistling in at extremely high speed, generating a shock wave by the intensity of its gravitational force. Having struck near the Tunguska River on an angled path, in a moment it would have passed through the Earth, exiting with a huge burst of spray somewhere in the North Atlantic. Check the maritime records for June 30, 1908, Jackson and Ryan suggest, for reports of some outlandish oceanic disturbance.

Obviously that last hypothesis has great attraction, especially for us Unified Hole Theorists. But one further possibility offers still more promise. Maybe the Siberian forest was hit by a gob of antimatter.

•   •   •

Antimatter, physicists tell us, consists of subatomic particles that are opposite but identical in character to the subatomic particles we all know and love. What they mean by “opposite but identical” could take half a book to explain, so let's just say that
one
possible form of oppositeness is an opposite electrical charge.
For instance, the antimatter equivalent to an electron is called a
positron,
having the same exact mass as an electron, plus an equal but opposite charge. Corresponding to a proton is an
antiproton,
again equal in mass, equal but opposite in charge; and so on for neutrinos, pions, the whole subatomic menagerie.

None of these antimatter particles can have a stable existence on Earth. If a proton comes in contact with an antiproton, there is a potent flash of energy as both particles disappear. That phenomenon, matter and antimatter canceling each other violently out of existence, is called
annihilation.
You can see where this is taking us, yes? Another team of scientists have proposed that perhaps the Tunguska region was hit with a piece of antimatter, a hunk of sheer negation flying in from the far end of the universe.

Now comes the part that can give a person a migraine. It seems that two main conceptual models have been put forward to describe the relation between matter and antimatter. The one devised by Richard Feynman, a brilliant and puckish American physicist, invites us to view the positron as “an electron moving backward in time.” By this model, which makes better sense in the context of Einstein's space-time than it does to our intuition, the annihilation event represents, not a terminal instant for two opposite particles, but the point where a single particle reverses direction in time. (Therefore Feynman's model, whatever its value to physics, at least answers the classic conundrum:
How can you be in two places at once, if you're not anywhere at all?)
The other model, conceived by Paul Dirac, describes a positron as “an electron hole.”

According to Dirac, these holes might exist everywhere throughout empty space, but generally they would not be detectable because they are
filled,
each with a complementary electron. Every electron in our world of matter must have some particular level of energy; the electrons stuck in antimatter holes are those with energy levels less than zero. So they can't get out. And when an electron falls into such a hole, that electron disappears in a
burst of surrendered energy. Do you understand that much? Neither do I. So the Tunguska explosion, with its strange lack of a hole, can be explained in terms of this view of antimatter: The hole isn't there now because
the hole itself
is precisely what came flying in from space.

It wasn't very massive, that gob of antimatter, but it had vast energetic potential. When it entered the Earth's atmosphere it was annihilated—along with an equal but opposite amount of the air above central Siberia. Today the hole is invisible for the very good reason that it happens to be presently full. Like the one you might dig in the ground and then fill back up:
Is it gone, or is it just hidden?

What does all this have to do with the Kola borehole? Another good question. I wish I could answer it. But the matrix of scientific logic connecting Tunguska to Kola, in my Unified Hole Theory, is one part of the pudding that hasn't yet set.

On the other hand, bringing in Dirac's model of antimatter
has
helped to shed light on another notable hole: the big open-pit mine that sits in downtown Butte, Montana. This hole is a mile wide and more than a thousand feet deep. In its day, it swallowed away a large portion of the east side of the city. Now the Anaconda Minerals Company has quit mining it, so the thing just remains there, stark, derelict, gaping. It was known to the company as the Berkeley Pit, but a few years ago some imaginative local folk decided that label just didn't do it justice. So they sponsored a little contest: NAME THE PIT. The winning entry was “Mount Nixon.”