The COSMIC CALENDAR
Feb 26, 2013 11:04:53 GMT
Post by tod2 on Feb 26, 2013 11:04:53 GMT
Many years ago Professor Carl Sagan graced our TV screens with wonderful insights into the universe.
One of the most noteworthy was his 'calendar' setting out the origins of our world since it's inception and to the present day.
You may enjoy what he had to say:
THE COSMIC CALENDAR
To understand the passage of the eons, all of time has been compressed into a single 'Cosmic Year' with the Big Bang on 1st January. Every month here represents a little over a Billion years. The earth didn't form until the Cosmic Year was 2/3 over.
Our understanding of the history of life is very recent, occupying only the last few seconds of December 31st.
What happened on earth may be more or less typical of the evolution of life on many worlds, but in it's details the story of life on earth is probably unique in all the Milky Way Galaxy. The secrets of evolution are time and death. Time for the slow accumulation of favourable mutations, and death to make room for new species.
The earth is about four and a half billion years old. In the Cosmic Calendar it is condensed out of Interstellar gas and dust around September 14th when our world, still heavily battered and cratered from its violent origins, may have looked a little like the moon. We know from the record of ancient rocks that the origin of life happened soon afterwards, around September 25th.
Now, the first living things were not anything so complex as a one cell organism, which already is a highly sophisticated form of life. No, the first stirrings of life were much more humble and happened on the molecular level. In those early days lightning and ultra-violet light from the sun were breaking apart simple hydrogen molecules in the prmitive atmosphere, and the fragments of the molecules were spontaneously reconciling into more and more complex molecules.
The product of this early chemistry disolved in the oceans, forming a kind of 'organic soup' of gradually increasing complexity, until one day, quite by accident a molecule arose which was able to make crude copies of itself using as building blocks other molecules in the 'soup'. This was the ancestor of DNA - the Master Molecule of life on earth.
Four billion years ago the ancestors of DNA were competing for molecular building blocks and leaving crude copies of themselves. There were no preditors - the staff of life was everywhere so the oceans and murky pools that filled the crators were for these molecules
a 'Garden of Eden'
With reproduction, mutation and natural selection the evolution of living molecules was well underway.
Varieties with specilaised functions then joined together making a molecular co-operative - The First Cell'.
The organic soup eventually ate itself up but by this time plants had evolved able to use sunlight to make their own building blocks.
They turned the waters green. A number of one-cell plants joined together. The first multi-cellular organisms. Equally important was the invention, not made until early November, of SEX. It was stumbled upon by the microbes. By December 1st, green plants had released copious amounts of oxygen and nitrogen into the atmosphere.
To Be Continued....
One of the most noteworthy was his 'calendar' setting out the origins of our world since it's inception and to the present day.
You may enjoy what he had to say:
THE COSMIC CALENDAR
To understand the passage of the eons, all of time has been compressed into a single 'Cosmic Year' with the Big Bang on 1st January. Every month here represents a little over a Billion years. The earth didn't form until the Cosmic Year was 2/3 over.
Our understanding of the history of life is very recent, occupying only the last few seconds of December 31st.
What happened on earth may be more or less typical of the evolution of life on many worlds, but in it's details the story of life on earth is probably unique in all the Milky Way Galaxy. The secrets of evolution are time and death. Time for the slow accumulation of favourable mutations, and death to make room for new species.
The earth is about four and a half billion years old. In the Cosmic Calendar it is condensed out of Interstellar gas and dust around September 14th when our world, still heavily battered and cratered from its violent origins, may have looked a little like the moon. We know from the record of ancient rocks that the origin of life happened soon afterwards, around September 25th.
Now, the first living things were not anything so complex as a one cell organism, which already is a highly sophisticated form of life. No, the first stirrings of life were much more humble and happened on the molecular level. In those early days lightning and ultra-violet light from the sun were breaking apart simple hydrogen molecules in the prmitive atmosphere, and the fragments of the molecules were spontaneously reconciling into more and more complex molecules.
The product of this early chemistry disolved in the oceans, forming a kind of 'organic soup' of gradually increasing complexity, until one day, quite by accident a molecule arose which was able to make crude copies of itself using as building blocks other molecules in the 'soup'. This was the ancestor of DNA - the Master Molecule of life on earth.
Four billion years ago the ancestors of DNA were competing for molecular building blocks and leaving crude copies of themselves. There were no preditors - the staff of life was everywhere so the oceans and murky pools that filled the crators were for these molecules
a 'Garden of Eden'
With reproduction, mutation and natural selection the evolution of living molecules was well underway.
Varieties with specilaised functions then joined together making a molecular co-operative - The First Cell'.
The organic soup eventually ate itself up but by this time plants had evolved able to use sunlight to make their own building blocks.
They turned the waters green. A number of one-cell plants joined together. The first multi-cellular organisms. Equally important was the invention, not made until early November, of SEX. It was stumbled upon by the microbes. By December 1st, green plants had released copious amounts of oxygen and nitrogen into the atmosphere.
To Be Continued....
