Читать книгу Apocalypse 2012: An optimist investigates the end of civilization - Lawrence Joseph E. - Страница 23

Hermanus is a picturesque town on South Africa’s southwestern cape. With sheltered coves, this breeding ground for southern right whales is considered the best land-based whale-watching spot in the world.

I had spotted at least ten when Brian, a local bay activist, came over and asked me if I’d like to see the whales closer up. I nodded, and he produced a convoluted instrument, put it to his lips, and blew his own special version of the sound that Gabriel will one day make to signal Judgment Day. After several tortured, bellowing, oddly musical blasts, a half dozen or so whales swam toward us; one, a seventy-tonner by Brian’s reckoning, spouted its hello. He kindly sold me the horn, which he had made out of dried kelp, for forty rand (seven dollars). He then recommended the Shark Lady excursion to me.

“Keep all digits inside the cage,” he advised with a solemn nod.

Brian loves his whales, would rather Jonah’s fate than seeing harm come to them, so I refrained from asking what he thought about the fact that the magnetic field that guides these great whales in their ocean travels from Antarctica to Hermanus and back was weakening. Sooner or later it will dwindle beyond their capacity to sense it. That question was reserved for Pieter Kotze, one of the geophysicists I had come to Hermanus to see.

Kotze is a calm character, a man who fully expects to live a good, long, quiet life. When I visited him at the Magnetic Observatory, a lovely green space on a hill overlooking the bay, the geophysicist hospitably gave me a tour of the quaint laboratories full of state-of-the-art computers analyzing data transmitted from electromagnetic probes buried deep underground. The Earth’s magnetic field originates from the spinning of its molten iron core, which is why the sensors are buried. Kotze asked me if I had any children and what their birthdates were. He then excused himself and after a moment popped back with two seismograph-style readouts of how the Earth’s magnetic field had behaved on the day each child was born.

Kotze’s work is as disturbing as his manner is gentle. He has meticulously chronicled the recent depletion of the Earth’s protective magnetic field. After the tour, he patiently brought me up to speed on what it all means.

We can’t repeal the law of gravity, a good thing, since without also repealing the law of inertia we’d all go flying off the Earth. Neither can we repeal the laws that govern electricity or magnetism. But there’s no law that says the Earth has to have a protective magnetic field shielding us from excessive proton and electron radiation from the Sun that would spur an epidemic of cancers in human beings and many other species, disrupting the global food chain. The glut of solar radiation would also block out cosmic rays, highly energetic particles and waves from outer space that scientists now believe account for much of the cloud formation around the Earth. Clouds, particularly low-lying ones, block out infrared radiation—heat—from the Sun and help keep the Earth’s surface cool.

The Earth’s magnetic field deflects solar radiation and channels it into belts that harmlessly circle our planet’s outer atmosphere. None of our neighboring planets has such a field, at least not nearly to the extent that Earth has currently. In fact our strong, well-functioning magnetic field is not to be taken for granted, particularly because it appears to be in the process of reversing and perhaps diminishing to the point where it will offer little or no defense from the Sun’s depredations.

Traditional geology has it that the Earth’s magnetic field, or magnetosphere, is generated by the spinning of the planet’s core, a mixture of molten and solid iron that essentially acts as a Moon-sized dynamo, creating a giant electromagnetic field that squirts out of the poles, coalesces in the same basic pattern that iron filings do around a bar magnet, and bulges far into the atmosphere. Kotze explained that the interplanetary magnetic field (IMF), essentially the magnetic field that emanates from the Sun, also influences the magnetosphere’s size and shape. Sometimes the IMF energizes the magnetosphere with inputs of solar energy. At other times the IMF presses upon the Earth’s magnetic field, condensing, distorting, and even tearing holes in it.

The anthropocentric point of view of the magnetosphere’s function is that its primary purpose is to prevent potentially lethal incoming solar radiation from reaching the surface of the Earth. There is no scientific reason that our planet should be taking precautions to defend its living organisms. There are, however, valid religious reasons why God might protect His creation in this manner. If nothing else, chalk it up to damn good luck that the Earth has a molten core that for the past 5 billion years has spun a powerfully protective magnetic field thousands of times stronger than those of any of the other inner planets—Mercury, Venus, or Mars. Without that shield, life on Earth would probably never have had a chance to evolve.

The Earth’s magnetosphere channels incoming solar radiation into two belts, known as the Van Allen radiation belts, discovered in 1958 by Explorer I and Explorer II upper-atmosphere research missions, under the direction of the now-legendary James A. Van Allen. The Van Allen belts are wide, ranging in altitude from 10,000 to 65,000 kilometers (6,000 to 40,000 miles), and are densest at about 15,000 kilometers (9,000 miles). The inner belt is composed mostly of protons, and the outer belt is composed mostly of electrons. When these belts reach capacity, radiation spills out, strikes the upper atmosphere, and fluoresces, causing polar auroras. Because the Van Allen radiation belts pose certain hazards for astronauts passing through them, as well as for satellites, several far-fetched proposals have been made for draining them off. The good news is that that will not be necessary if the magnetosphere responsible for channeling charged particles to them ceases to function. The bad news, of course, is that it won’t be just the astronauts who are worried about lethal radiation if we mess with those belts.

The Core, a Hollywood feature film that Kotze enjoyed but dismissed scientifically, portrays the catastrophe that would happen if the Earth’s core stopped spinning as a dynamo and therefore stopped creating the planet’s electromagnetic field. Of course, for the core to stop spinning, the Earth would have to stop spinning on its axis, which would have even direr consequences, such as wreaking havoc on staples of our existence like the seasons and even day and night. But the film nonetheless introduced the valid notion that our magnetic shield is vital to our existence, and that it just might be getting a bit threadbare.

Scientists are basically clueless as to why the magnetic field is dwindling. Speculation ranges from turbulence in the interplanetary magnetic field to chaotic fluctuations in the fluid dynamics of the Earth’s molten core. It could be haphazard, or strictly cyclical. Kotze confirms, however, that it has all happened before.

There is much jittery speculation about whether or not the dwindling of our planet’s magnetic field means that the poles are about to flip. Compasses that now point north would point south, and vice versa. The first step in a magnetic pole reversal is the weakening of the overall field, such as we are now experiencing. Imagine one sumo wrestler on top of another, pinning him down. Before the bottom wrestler can switch positions and end up on top, there has to be a lot of twisting, wrenching, grasping. For several moments at least, the wrestlers will be side by side, before the reversal is complete. Same idea with the magnetic poles switching their positions, except that instead of moments, this reversal process will take hundreds of years, during which time the Earth will have multiple magnetic poles, and compasses will point north, south, east, west, and all points in between. Birds will get lost; sharks like my frustrated great white will swim aimlessly; frogs, turtles, and salmon will be unable to return to breeding grounds; and polar auroras will flash at the equator. In all likelihood, the weather will get even weirder, with the tangle of magnetic meridians playing hob with the direction and intensity of hurricanes, tornadoes, and other electrical storms.

Studies of ice core samples and sediments extracted from the ocean floor indicate that the magnetic poles last reversed themselves about 780,000 years ago. At that historical depth in the geological record, magnetic rocks and bits that would now face north faced south, and vice versa. For the next thousand or so years, magnetic specimens were found facing in all different directions, before aligning themselves in the north-south pattern that may finally be eroding today.

As to the changes physical again: The Earth will be broken up in the western portion of America. The greater portion of Japan must go into the sea. The upper portion of Europe will be changed in the twinkling of an eye. Land will appear off the east coast of America. There will be upheavals in the Arctic and in the Antarctic that will make for eruptions of volcanoes in the torrid areas, and there will be shifting then of the poles—so that where there has been those of a frigid or the semitropical will become the more tropical, and moss and fern will grow. (italics mine)

EDGAR CAYCE, Reading 3976–15, January 19, 1934

In this reading, given while he was in his “sleep state,” Cayce is said to have channeled the Archangel Halaliel, an enemy of Satan and a companion of Christ. To be sure, his most dramatic predictions have not yet come to pass and, may it please the Lord, never will. However, two important elements, the shifting of the magnetic poles and the Earth growing warmer, are indeed occurring. How, one wonders, could Cayce, lying on a bed in a New York apartment in 1934, know what the best and brightest of our scientists, with their state-of-the-art technology, are just now coming to terms with?

Perhaps it’s just the law of averages. Predict enough different kinds of catastrophe, and odds are that some of them will come true. But in the Hutton Commentaries, an unusually scholarly Web site, geologist William Hutton argues that even small shifts in the location of the magnetic poles can have significant consequences. Hutton points out that there are two basic types of pole shift possible: “In the first mechanism, all the layers of the Earth remain together and the axis and the entire spinning globe tilts relative to the plane of the Earth’s orbit around the Sun,” writes Hutton. He explains that this type of shift results in the north and south poles moving relative only to the position of fixed stars. This would not result in any seismic or volcanic disturbances, since the Earth’s crust, mantle, and core are not moving relative to each other. Unfortunately this is not the type of pole shift we are experiencing, argues Hutton, because the only movement of the poles relative to the Earth in this scenario would be due to the infinitely slow, millimeter-by-millimeter creep of continental drift.

By contrast, the poles appear to be moving far more rapidly, skittering across northern Canada and Antarctica by 20 or 30 kilometers per year, respectively. Hutton believes that we are experiencing what is known as a mantle-slip mechanism, which refers to the slipping of the Earth’s mantle and crust over the liquid core, or over some malleable surface just above the core. This process could easily cause the “wandering pole” syndrome observed with some alarm over the past decade.

“This type of mantle-slip pole shift also causes the pre-shift equator to move over the surface of the Earth,” writes Hutton. “As the pre-shift equator moves into new regions of Earth’s surface, these regions begin to experience changes in centrifugal forces and sea levels. This leads to new distributions of land and sea, and to crustal tectonic movements.” Such movements, Hutton contends, could presage the kind of seismic and volcanic calamities that Cayce predicted.

Kotze, the South African geophysicist, isn’t so sure that a pole reversal is imminent. Neither is Jeremy Bloxham, of Harvard University, who believes that the process may take a millennium or more. Bloxham nonetheless warns that the weakening of the magnetic field, even well short of a complete pole shift, will diminish its shielding effect. We will be much more susceptible to the radiation constantly bombarding our planet from space, much the way that in Star Trek the starship Enterprise was at its most vulnerable when its shields—energy fields that protected the ship—were down. The Enterprise and her crew always managed to escape immolation, disintegration, and all other consequences of the death rays shot at them, because that’s the way television series go. Of course the Earth and her inhabitants come with no such guarantee of a happy ending.