pultneytooner
23-May-06, 13:25
In the early 1960's, James Lovelock was invited by NASA to participate in the scientific research for evidence of life on Mars. His job was to design instruments, capable of detecting the presence of life, which could be sent on a spacecraft to Mars. This wasn't straightforward, since it was hard to know what to test for: any life forms on Mars may be radically different from those on Earth.
This led him to think about what constitutes life, and how it can be detected. He decided that the most general characteristic of life was that it takes in energy and matter and discards waste products. He also reasoned that organisms would use the planet's atmosphere as a medium for this cyclic exchange, just as we breathe in oxygen and expel carbon dioxide. He speculated that life would therefore leave a detectable chemical signature on the Martian atmosphere. Maybe it could be detected from Earth, so it wouldn't even be necessary to send a spaceship.
To test his idea, he and a colleague, Dian Hitchcock, began to analyse the chemical makeup of Mars, and compare it with that of the Earth. The results showed a strong contrast. The atmosphere of Mars, like Venus, was about 95% carbon dioxide, with some oxygen and no methane. The Earth was 77% nitrogen, 21% oxygen, and a relatively large amount of methane. Mars was chemically dead; all the reactions that were going to take place had already done so. The Earth, however, was far from chemical equilibrium. For example, methane and oxygen will react with each other very easily, and yet they are both present in the atmosphere. Lovelock concluded that for this to be the case the gases must be in constant circulation, and that the pump driving this circulation was life.
Lovelock began to look back at the history of life's interaction with the atmosphere. He noted that about three billion years ago, bacteria and photosynthetic algae started to remove carbon dioxide from the atmosphere, producing oxygen as a waste product. Over enormous time periods, this process changed the chemical content of the atmosphere - to the point where organisms began to suffer from oxygen poisoning! The situation was only relieved with the advent of organisms powered by aerobic consumption.
It was life processes, the cumulative actions of countless organisms, that were controlling the atmosphere. And viewed from outer space, the mass effect of these processes was that the Earth itself appeared as a living entity - especially in comparison with its dead neighbours. Lovelock had a sudden realisation that the Earth could best be described as a kind of super-organism:The earth as a living organism regulating itself to sustain life. Watched a documentary about james lovelock, he said that in destroying the earths ecosystems we are bringing mankind nearer to it's own extinction. He reckons in time we will be back to world war 2 conditions with rationing and people having to grow their own food as other countries will not have enough to export. He said the world, comparing it's lifespan with that of a human would be about 80 y/o, treat it with respect.
This led him to think about what constitutes life, and how it can be detected. He decided that the most general characteristic of life was that it takes in energy and matter and discards waste products. He also reasoned that organisms would use the planet's atmosphere as a medium for this cyclic exchange, just as we breathe in oxygen and expel carbon dioxide. He speculated that life would therefore leave a detectable chemical signature on the Martian atmosphere. Maybe it could be detected from Earth, so it wouldn't even be necessary to send a spaceship.
To test his idea, he and a colleague, Dian Hitchcock, began to analyse the chemical makeup of Mars, and compare it with that of the Earth. The results showed a strong contrast. The atmosphere of Mars, like Venus, was about 95% carbon dioxide, with some oxygen and no methane. The Earth was 77% nitrogen, 21% oxygen, and a relatively large amount of methane. Mars was chemically dead; all the reactions that were going to take place had already done so. The Earth, however, was far from chemical equilibrium. For example, methane and oxygen will react with each other very easily, and yet they are both present in the atmosphere. Lovelock concluded that for this to be the case the gases must be in constant circulation, and that the pump driving this circulation was life.
Lovelock began to look back at the history of life's interaction with the atmosphere. He noted that about three billion years ago, bacteria and photosynthetic algae started to remove carbon dioxide from the atmosphere, producing oxygen as a waste product. Over enormous time periods, this process changed the chemical content of the atmosphere - to the point where organisms began to suffer from oxygen poisoning! The situation was only relieved with the advent of organisms powered by aerobic consumption.
It was life processes, the cumulative actions of countless organisms, that were controlling the atmosphere. And viewed from outer space, the mass effect of these processes was that the Earth itself appeared as a living entity - especially in comparison with its dead neighbours. Lovelock had a sudden realisation that the Earth could best be described as a kind of super-organism:The earth as a living organism regulating itself to sustain life. Watched a documentary about james lovelock, he said that in destroying the earths ecosystems we are bringing mankind nearer to it's own extinction. He reckons in time we will be back to world war 2 conditions with rationing and people having to grow their own food as other countries will not have enough to export. He said the world, comparing it's lifespan with that of a human would be about 80 y/o, treat it with respect.