Evolution: 3 billion years ago (The Hadean Eon)
Where were you during the Hadean Eon 4.5 - 3.8 billion years ago? It's a good question, something like the zen koan, "where was your face before you were born?" Yet there is a physical answer. From the moment we consider origins on a cosmic scale, the view of ourselves as a part--a miniscule part--of the universe is thrust upon us. For the very atoms that compose our bodies were created not, of course, when we were conceived, but shortly after the birth of the universe itself.
It is a known astrophysical fact that most stars in the sky are shooting away from each other at tremendous speeds. If we reverse this trend in our minds we come up with the so-called Big Bang, the hypothetical release of all the energy, matter, and antimatter in existence. Like any other look into what Shakespeare called "the dim backward and abysm of time," we must not mistake our best gueses or relatively straight-line extrapolations of present conditions into the past for the literal truth. Slight alterations in the most minor assumptions can lead to major distortions when magnified over the 15,000 million year time span that is the purported age of the present universe. Nonetheless, such extrapolations yield the best picture we have of the cosmos which preceded the evolution of life in the microcosm, as well as of the microcosm and its relentless expansion. Over the first million years of expansion after the Big Bang, the universe cooled from 100 billion degrees Kelvin, as estimated by physicist Steven Weinberg, to about 3000 degrees K, the point at which a single electron and proton could join to create hydrogen, the simplest and most abundant element in the universe. Hydrogen coalesced into supernovae--enormous clouds that over billions of years contracted from cosmic to submicrocosmic densities. Under the sheer force of gravity, the cores of the supernovae became so hot that thermonuclear reactions were fired, creating from hydrogen and various disparate subatomic particles all the heavier elements in the universe that we know today. The richness of hydrogen is in our bodies still--we contain more hydrogen atoms than any other kind--primarily in water. Our bodies of hydrogen mirror a universe of hydrogen...In the cloud of gases destined to become Earth were hydrogen, helium, carbon, nitrogen, oxygen, iron, aluminum, gold, uranium, sulfur, phosphorus, and silicon...all would have cooled and floated about as the aimless detritus of lifeless space were it not for the huge star that formed from the center of the nebula, pulling the hardening smaller bodies into orbit and igniting into a stable, long-lasting burn that bathed its satellites in continuous emanations of light, gas, and energy. At this point, about 4,600 million years ago...the sun ignited.Learn More Take me to the Archean
It is a known astrophysical fact that most stars in the sky are shooting away from each other at tremendous speeds. If we reverse this trend in our minds we come up with the so-called Big Bang, the hypothetical release of all the energy, matter, and antimatter in existence. Like any other look into what Shakespeare called "the dim backward and abysm of time," we must not mistake our best gueses or relatively straight-line extrapolations of present conditions into the past for the literal truth. Slight alterations in the most minor assumptions can lead to major distortions when magnified over the 15,000 million year time span that is the purported age of the present universe. Nonetheless, such extrapolations yield the best picture we have of the cosmos which preceded the evolution of life in the microcosm, as well as of the microcosm and its relentless expansion. Over the first million years of expansion after the Big Bang, the universe cooled from 100 billion degrees Kelvin, as estimated by physicist Steven Weinberg, to about 3000 degrees K, the point at which a single electron and proton could join to create hydrogen, the simplest and most abundant element in the universe. Hydrogen coalesced into supernovae--enormous clouds that over billions of years contracted from cosmic to submicrocosmic densities. Under the sheer force of gravity, the cores of the supernovae became so hot that thermonuclear reactions were fired, creating from hydrogen and various disparate subatomic particles all the heavier elements in the universe that we know today. The richness of hydrogen is in our bodies still--we contain more hydrogen atoms than any other kind--primarily in water. Our bodies of hydrogen mirror a universe of hydrogen...In the cloud of gases destined to become Earth were hydrogen, helium, carbon, nitrogen, oxygen, iron, aluminum, gold, uranium, sulfur, phosphorus, and silicon...all would have cooled and floated about as the aimless detritus of lifeless space were it not for the huge star that formed from the center of the nebula, pulling the hardening smaller bodies into orbit and igniting into a stable, long-lasting burn that bathed its satellites in continuous emanations of light, gas, and energy. At this point, about 4,600 million years ago...the sun ignited.
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