The Turning Point

As the rising sun rose in the east, its gentle rays illuminated and warmed a landscape that would be easily recognizable to any human plucked from past ages. Stately old-growth trees mingled with younger lower-story conifers in forests that marched across the countryside for as far as the eye could see. Cool, deep blue lakes and verdant meadows bristling with birds and other arboreal creatures added a vocal tone color to the landscape. This was not the industrially ravaged world of a millennium ago, but a rejuvenated planet tailored by humankind to maximize its beauty while at the same time providing habitation. It was also a planet deep within the grip of unseen changes that permeated every atom, every molecule and every mote of matter.

Since the sun had dawned upon the long-ago era of the 20th century, scientists had written about these times, though they could not fully imagine all of the adjustments that would need to be made while Earth's magnetic field underwent its final changes. Declining curves of magnetism on innumerable charts scrabbled in the past centuries, followed the relentless downward fall of Earth's magnetic field. The decline was punctuated by a number of false stops and even a few episodes of recovery, but the changes always resolved themselves into a subsequent decline. By 4590 A.D. the field reached a level of barely 8% of its strength in the 20th century. Gone was the reassuring main field, which had steered compass needles and animal migrations for millennia. As the main field relentlessly declined, the irregular magnetism of the crust became more important in defining the total field. A compass taken on a trip from Greater New York to San Francisco would swing wildly as dozens of magnetic surface features pulled and tugged at it.

So, here we find ourselves in the year 4687 A.D. with a field whose decline seems to at long last have bottomed-out for the last 97 years with no noticeable effort to regain its previous state of grandeur.

In the wake of this centuries-old decline, the world and human civilization seem to have continued relatively unscathed, though there have been some temporary losses. Mostly these losses were from animal species that were not able to adapt to their loss of a reliable magnetic compass. Few whale species were affected, since they navigate the murky deep waters by sensing differences in the magnetic zones they were traveling amongst. These zones, controlled by crustal fields frozen into the rock, remained unchanged during the decline. Some species of birds that traveled migratory paths near coastal areas were not so fortunate. Migratory paths had been honed for thousands of years to maximize travel distances while minimizing the stresses upon the birds. As their magnetic compasses became less reliable, their paths became torturous journeys with many direction changes, and only the hardiest and adaptable birds survived. But they did survive, and grow in numbers as competing neighbors failed to make the 10,000 kilometer migratory loops from summer to winter havens. Meanwhile, at the smallest scales of the biosphere, bacteria that used the main field's North-South orientation to sense up and down were subjected to evolutionary pressures to devise new navigation rules. Thanks to the normal variation of traits within large populations, though 95% of a population became extinct, the survivors adapted to the new orientations, survived and flourished. Eventually, the local crustal fields became the controlling influence, and further speciation of the bacteria ensued. Each geographic region controlled by a fixed field orientation, spawned its own biota of these ubiquitous soil bacteria.

The remaining effects of losing the main field were more nuisances than being of any critical impact, at least to the average human that walked the landscape. Ancient fables of pole reversals and geological chaos never played themselves out as any grade school student could tell you. Magnetism is a powerful force on the human scale, but it can't compete with the gravity and inertia of an entire world spinning through space. Volcanic activity continued to be regulated by convection currents in the mantle, which were wholly unaffected by magnetic forces. There were no ruptures of crustal plates. Coastal flooding and inundations of populous cities were caused by the far more complex machinations of global warming beginning in the 22nd century. But by the 26th century, the biosphere and climate systems were largely under control by multi-national corporations under constant guidance provided by vast networks of sensors, which dotted the landscape every 10 miles. Greenhouse gases were once again stabilized to conform to human desires for optimizing land use. The ice caps which had reached their minimum area in the 22nd century had reformed by the 25th century. Oceans ceased their expansion and flooding abated.

But what of the mutagenic effects of cosmic rays and solar gamma rays flooding the atmosphere during the decline of our planetary shield? This was perhaps the least important consequence of the reversal. The thickness of the atmosphere was vastly more effective in absorbing gamma and cosmic rays than non-scientists had ever considered. High-flying passenger aircraft had been well-shielded by the middle of the 21st century in response to the occasional, vigorous solar storm event. The effect of the cosmic ray influx was limited to the increased production of carbon-14 radioisotopes, which were ingested by the biomass, producing barely a detectable signature in the global DNA of the biosphere.

The other major potential impact had to do with human technology, especially satellites orbiting Earth. By the mid-21st century, nearly all information was relayed by fiber optic cables, making our entire global communication and entertainment network completely invulnerable to any space events. The only satellites orbiting Earth were in place for scientific or military purposes. Thanks to a major revolution in launch vehicle design in the late 21st century, the cost of including adequate radiation shielding in all satellite designs became an insignificant added cost to the price of a satellite.

So, were there any significant impacts to humans or their way of life? Practically none. The average person would not even know that the field had all but vanished. Navigation was accomplished, not by antiquated and unreliable compasses, but by a global network of transmitters covering the entire planetary surface. Ocean navigation was achieved through inertial guidance systems. This network originally had its genesis in the ancient cellular phones, and quickly evolved into a navigation system by the end of the 21st century.

During the last magnetic reversal, no humans had any idea about the invisible forces that were battling for supremacy as they walked forests and savannas. By the time the next reversal began, humans had through the natural course of their technological evolution, also made themselves immune from the effects of this process. The only casualty, it seemed, was a sublime phenomenon that had graced the polar skies for thousands of years. Gone, at least for now, were the ghostly and awe-inspiring lights of the aurora borealis and aurora australis. Without a space-girding magnetic field, there could be no invisible tail of magnetic energy flowing out beyond the Earth. There could be no dance of particles flowing back along this tail into the polar regions, lighting the night skies with sheets and curtains of light. Instead, only a faint diffuse red-green glow of color, devoid of detail, greeted the eye during times of solar unrest.

For most of humanity, losing the Northern Lights was of only passing interest. But the impacts upon northern populations were felt in a deep and powerful way. Without aurora and the songs of the northern lights dancing in the sky, there was no longer beauty and mystery in the ice-covered Arctic to offset the drudgery of living there. Eventually, the tundra and Arctic became depopulated and devoid of human activity as legions of humans abandoned their traditional homelands in favor of more welcoming and warmer latitudes - but promising, some day, to return when the Northern Lights again danced in the skies

Story written by Sten Odenwald

Copyright (C) 2003

The Astronomy Cafe

(www.astronomycafe.net)