Is the entire planet "back country?" Perhaps enough so that the book Rare Earth should be read by every one facsinated by the idea "where did come from and how did we get here and is anyone else out there"

Rare Earth by Peter D. Ward and Donald Brownlee
“Maybe we really are alone”
I am going to assume that those of you who read books and this part of the forum are probably the best educated and brightest members. The subject matter of this book is about the extremely improbable events leading to higher life form on Planet Earth, if you can refer to an animal who can manipulate a planet for the purposes of over reproducing himself and causing his own extinction as well as that of thousands if not millions of other species, as a higher life form. Ahem…
The book is truly a non-fiction science book not Sci-Fi, and is written in light to medium density science. You do not have to be a biologist or physicist to understand it, but some understanding of astrophysics, chemistry, biology, paleontology, plate tectonics, fusion, evolution, geology, and genes would be helpful.

I paraphrase where needed, otherwise I quote:

All but a minute fraction of the atoms in the Planet Earth and its inhabitants were produced, long before the Earth formed, by an intricate set of astrophysical processes. <gap> During the first half hour (after the Big Bang) conditions existed that produced most of the atoms that are still the building blocks of the stars – mainly hydrogen and helium atoms that make up over 99% of the visible matter in the Universe. It did not produce oxygen, iron, magnesium, or sulfur, the elements that make up over 96% of the mass of our planet and it did not produce carbon. <gap> Carbon formation had to await the formation of red giant stars whose interiors are dense enough to create heavier atoms. Because stars become red giants only in the last 10% of their life time, there was no carbon in the Universe for billions of years. <gap> The elements heavier than Bismuth (the densest non-radioactive element) were produced in stars over ten times more massive than our sun which underwent supernova explosions. <gap> Earths oxygen content is 45% by weight and 85% by volume!!!!!!.
Paraphrased. The sun is quite rare in its abundance of heavy metals, even for its type of star. Without heavy metals the Earth would not have a hot radioactive core to produce plate tectonics and there would be no magnetic field which protects the planet from radiation from space.
Other highlights of the book:
Our moon was actually a heavy metal cored planet the size of Mars that collided with Earth and added its metal core to Earth and then went into orbit around it first at an altitude of only fifteen thousand miles. Tidal forces are moving the Moon away at a few centimeters per year and eventually the moon will escape Earths gravity field. The moon holds the Earth constantly in its minimal tilt which produces mild winters and summers so that the surface has had a very long period of time with constant temperatures for billions of years, with a warm equatorial area where most species live.
The Earth was originally seeded with bacteria from space. Fossil bacteria have been found on the moon and in Martian meteorites. No one knows where they came from but they required a wet world to originate.
It took 2 billion years for bacteria to evolve to blue green algae capable of releasing enough oxygen for other life forms to exist and it took another 2 billion years to create humans. The Cambrian explosion (not a real explosion but the beginning of more complex life forms with mineralized skeletal parts capable of leaving fossils behind) was about 500 million years ago. Since then there have been 15 known mass extinctions, some from asteroids, some from volcanoes and others of unknown causes, but after each there was a period of radiation of species to an ever more complex and increased number. Today there are 3 million to 30 million species on Earth. Today there are hundreds of species becoming extinct every day in what promises to be one of the greatest mass extinctions ever, and it is caused by the presence of humans who are intelligent enough to manipulate the planet and to destroy the habitat of other species for there own purposes.
But I digress, the book is about the extremely rare set of coincidences leading to higher animal life on Earth and explains why there may be no other intelligent life in the Universe, at least at this time.

*****Miscellaneous information pertaining to the subject; Mankind almost became extinct about 70,000 years ago, probably due to the Yellowstone super volcano eruption. Genetic studies indicate that only 40 to 100 human females (and an unknown number of males) survived. In the last 70,000 years, a tick on the geological clock, man has covered the planet like slime in a petri dish and is causing a mass extinction. There are billions of humans and even if 99% of humans vanished tomorrow, by the end of this century, at present rates, they would have replenished that lost percentage. It is ironic that it took billions of years – up to 15 billion in fact to create an intelligent life form that will cause his own extinction and that of millions of other species.
Where did the bacteria in space come from? Where there other equally intelligent and short lived species out there? What are the odds of two intelligent species living at the same time in different solar systems? Why is the Earth so rare? Why couldn’t life evolve on a planet nearer the center of a galaxy or around a binary pair? Read the book for your selves, but be prepared to be saddened by the story of mans very improbable ascension to perhaps the highest pedestal in the Universe, only to destroy his world that was created for him by a set of exceptional events equal to winning the lottery every day for the last 70,000 years.
Jim


Edited by Jimshaw (01/21/10 02:43 PM)
Edit Reason: edited to separate the information below the *** as Miscellaneous information pertaining to the subject; AND to remove an erroneous reference to a particular volcano
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These are my own opinions based on wisdom earned through many wrong decisions. Your mileage may vary.