Organism Earth: The Gaia Theory...

The Gaia Hypothesis:

"The entire range of living matter on Earth from whales to viruses and from oaks to algae could be regarded as constituting a single living entity capable of maintaining the Earth's atmosphere to suit its overall needs and endowed with faculties and powers far beyond those of its constituent parts...A complex entity involving the Earth's biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet."

"To what extent is our collective intelligence also a part of Gaia? Do we as a species constitute a Gaian nervous system and a brain which can consciously anticipate environmental changes?" -James Lovelock (1960s).

"Earth is a perfect planet for life but, according to Gaia theory, this is no coincidence. From the moment life first appeared on Earth it has worked hard to make Earth a more comfortable place to live. Gaia theory suggests that the Earth and its natural cycles can be thought of like a living organism. When one natural cycle starts to go out of kilter other cycles work to bring it back, continually optimising the conditions for life on Earth.

Named after the Greek Earth goddess, Gaia, the theory was developed in the 1960s by scientist Dr James Lovelock. At the time, Lovelock was working for NASA, looking at methods of detecting life on Mars. The theory came about as a way of explaining why the Earth's atmosphere contains high levels of nitrogen and oxygen.

Initially, Gaia theory was ignored, and then later ridiculed by scientists such as Richard Dawkins and Stephen J Gould. However, in recent times stronger evidence for the theory has emerged and Gaia has started to gain support. The theory helps to explain some of the more unusual features of planet Earth, such as why the atmosphere isn't mostly carbon dioxide, and why the oceans aren't more salty.

In its early years Earth's atmosphere was mostly carbon dioxide - the product of multiple volcanic burps. It wasn't until life arrived that the balance began to change. Bacteria produced nitrogen, an inert gas, and photosynthesising plants produced oxygen, a very reactive gas. Ever since that time, about 2,500m years ago, Earth's atmosphere has contained significant amounts of nitrogen and oxygen, supporting life on this planet. The nitrogen helps to keep things stable, preventing oxygen levels from climbing too high and fuelling runaway fires. Meanwhile, the oxygen supports complex life.

Gaia also helps to explain how the oceans are kept in balance. Rivers dissolve salt from rocks and carry it to the ocean, yet ocean salinity has remained at about 3.4% for a very long time. It appears that the salt is removed again when water is cycled through cracks on the ocean floor. This process keeps the oceans' salinity in balance and at a level that most lifeforms can tolerate.

These processes are not thought to be conscious ones, or to favour any one life form over another. Gaia theory simply maintains that Earth's natural cycles work together to keep the Earth healthy and support life on Earth.

Lovelock argues that humans have now pushed Gaia to her limit. In addition to filling the atmosphere with carbon dioxide, we have hacked our way through the "lungs" of the planet (the rainforests) and driven many species to extinction. He thinks we are heading for a very warm world, where only polar regions are comfortable for most life forms. Eventually, he suspects, Gaia will pull things back into check, but it may be too late for the human race.

Feedback Loops:

Feedback loops often appear to keep the planet in balance. One good example of this is the way in which atmospheric carbon dioxide is kept in check. Carbon dioxide is pumped into the atmosphere by volcanoes, and removed by the weathering of rocks (encouraged by bacteria and plant roots in the soil). When it reaches the sea, the dissolved carbon dioxide is used by tiny organisms, known as coccolithophores (algae), to make their shells. When coccolithophores die they release a gas - dimethyl sulphate - which encourages the formation of clouds in the atmosphere.

When atmospheric carbon dioxide levels become too high, coccolithophores get busy, locking up more carbon dioxide in their shells and pumping dimethyl sulphate into the atmosphere when they die - producing clouds which reflect back sunlight and help the Earth to cool. Conversely, if atmospheric carbon dioxide levels become low, coccolithophores reduce their activity. Over the past 200 years mankind has greatly increased atmospheric carbon dioxide levels, and recently there has been evidence that algal blooms in the ocean are increasing. Could Gaia be trying to correct our mistake?

The Gaia Hypothesis has often been described by commentators as one of the most provoking singular ideas to have been put forward in the second half of the 20th Century."

-Kate Ravilious ("Perfect Harmony," Guardian UK, 4.28.2008. Image:-Hieronymus Bosch, Detail from the Triptych: "Garden of Earthly Delights", Museo del Prado, Madrid, 1500 ).

Orson Welles & Howard Koch: On Mars..."Isn't There Anyone On The Air?"

"ANNOUNCER: I'm speaking from the roof of the Broadcasting Building -- I'm speaking from the roof of the Broadcasting Building, New York City. The bells you hear are ringing to warn the people to evacuate the city as the Martians approach. Estimated in last two hours three million people have moved out along the roads to the north -- Hutchison River Parkway still kept open for motor traffic. Avoid bridges to Long Island -- hopelessly jammed. All communication with Jersey shore closed ten minutes ago. No more defenses. Our army wiped out -- artillery, air force, everything wiped out. This may be the last broadcast. We'll stay here to the end.

People are holding service here below us in the cathedral. Now I look down the harbor, all -- all manner of boats, overloaded with fleeing population, pulling out from docks. Streets are all jammed. Noise in crowds like New Year's Eve in city. Wait a minute, the -- the enemy's now in sight above the Palisades: five -- five great machines. First one is crossing the river. I can see it from here, wading -- wading the Hudson like a man wading through a brook. A bulletin is handed me: Martian cylinders are falling all over the country -- one outside of Buffalo, one in Chicago, St. Louis, seem to be timed and spaced. Now the first machine reaches the shore. He stands watching, looking over the city. His steel, cowlish head is even with the skyscrapers. He waits for the others. They rise like a line of new towers on the city's west side. Now they're lifting their metal hands. This is the end now. Smoke comes out, black smoke, drifting over the city. People in the streets see it now. They're running towards the East River, thousands of them, dropping in like rats. Now the smoke's spreading faster. It's reached Times Square. People are trying to run away from it, but it's no use.

They're -- They're falling like flies. Now the smoke's crossing Sixth Avenue...Fifth Avenue...a hundred yards away...it's -- it's fifty feet....

OPERATOR FOUR: 2X2L calling CQ. 2X2L calling CQ. 2X2L calling CQ. New York. Isn't there anyone on the air? Isn't there anyone on the air? Isn't there anyone...2X2L --

PIERSON: As I set down these notes on paper, I am obsessed by the thought that I may be the last living man on earth. I've been hiding in this empty house near Grover's Mill -- a small island of daylight cut off by the black smoke from the rest of the world. All that happened before the arrival of these monstrous creatures in the world now seems part of another life, a life that has no continuity with the present, furtive existence of the lonely derelict who pencils these words on the back of some astronomical notes bearing the signature of Richard Pierson. I look down at my blackened hands, my torn shoes, my tattered clothes, and I try to connect them with a professor who lives at Princeton, and who on the night of October 20th, glimpsed through his telescope an orange splash of light on a distant planet. My wife, my colleagues, my students, my books, my observatory, my, my world -- where are they? Did they ever exist? Am I Richard Pierson? What day is it? Do days exist without calendars? Does time pass when there are no human hands left to wind the clocks?

In writing down my daily life I tell myself shall preserve human history between the dark covers of this little book that was meant to record the movements of the stars. But to write I must live, and to live, I must eat. I find moldy bread in the kitchen, and an orange not too spoiled to swallow. I keep watch at the window. From time to time I catch sight of a Martian above the black smoke. The smoke still holds the house in its black coil, but at length there's a hissing sound and suddenly I see a Martian mounted on his machine, spraying the air with a jet of steam, as if to dissipate the smoke. I watch in a corner as his huge metal legs nearly brush against the house. Exhausted by terror, I fall asleep."

-Howard Koch ( Radio Adaptation of H.G. Wells classic Sci-Fi novel,"The War Of The Worlds," directed by and starring Orson Welles with the Mercury Theatre On The Air. CBS radio broadcast began at 8:00 PM, Halloween Night, 10.30.1938. Image: "Sunset On Mars," Photograph taken by the Mars Rover on the planet Mars. Mars Rover Exploration Mission, NASA/JPL/Texas A&M/Cornell, 5.19.2005).

THE HOAX: Thousands of people were fooled into believing that Invaders from Mars had landed in New Jersey. They mistakenly believed the show was a factual newscast. "Contemporary newspapers reported that panic ensued, with people fleeing the area, and others thinking they could smell the poison gas or could see the flashes of the lightning in the distance. Studies by unnamed historians "calculated" that some six million heard the CBS broadcast; 1.7 million believed it to be true, and 1.2 million were genuinely frightened. Within a month of the broadcast, there were up to 12,500 newspaper articles about its impact, while Adolf Hitler cited the panic, as "evidence of the decadence and corrupt condition of democracy." -Wikipedia.

Welles's adaptation is arguably the most famous radio dramatic production in history.