I.3            From Birth to Planet Earth Men can not remain children forever; they must in the end go out into 'hostile life.' We may call this 'education to reality.'                                      S. Freud (1856-1939)   The investigation of nature is an infinite pasture ground where all may graze, and where the more bite, the longer the grass grows, the sweeter is its flavor, and the more it nourishes.                                                            T. H. Huxley (1822-88)        How and when did the universe start? Observations and measurements to date agree with the Big Bang theory, namely, that the universe, as we know it today, started approximately 14 billion (1 billion = 1,000 million) years ago with a giant cosmic explosion called the Big Bang. It appears that either it always existed, the energy that brought it about, or that it had a purely natural origin.   What was before the Big Bang? Presently nobody knows, but it is speculated that the universe is oscillating. Explosive  expansions are followed by contractions in cycles that last about 80 billion years, ad infinitum.   Where did it all come from? All that is now was prior to the Big Bang energy in a condition of extreme density, a kind of cosmic egg known as a singularity. It was a condition of total collapse of physical laws, matter, forces, and energy. This singularity exploded in the Big Bang and started a chain of events known as the cosmic evolution. After approximately 11 billion years, this evolutionary process would eventually produce a self-replicating organism on Earth. The evolutionary life process took another 3.6 billion years before modern humans appeared and in whom the universe had became conscious of itself.   What happened immediately after the Big Bang? There was a gigantic release of energy that formed matter and with it the four basic forces. Most importantly: 1. Initially there were only photons which are elementary particles that carry electromagnetic energy and have momentum but have no mass or electric charge. In a sense, the universe was initially all light or energy. These packets of energy with no mass moved at the speed of light in temperatures that are hundreds of times hotter than the core of our Sun where hydrogen fusion takes place. 2. Matter emerged as subatomic particles, such as electrons, protons, and neutrons, when at high speeds and temperatures photons collided with each other. This formation of matter or mass from energy can be calculated using Einstein's formula E=mc2, that is, m=E/c2 (mass equals energy divided by the square of the speed of light). 3. Also, the photon collision produces antiparticles such as the positively charged positron, the antiparticle to the negatively charged electron. When the two collide, they annihilate each others matter or mass but set free energy in the form of two photons. This process of energy to matter and vice versa is repeated. It supports the observation that neither matter nor energy can be destroyed or created out of nothing, and it is therefore eternal.  4. These subatomic particles then formed mainly hydrogen and helium. For instance, the hydrogen atom formed when a single proton (+) captured a single electron (-) of equal but opposite charge. It has been calculated that the early universe consisted of about 75% hydrogen and 25% helium. They are the lightest elements and basic building blocks for all other elements as we shall see. 5. At the same time, the four basic forces came into being. Photons were the carriers of electromagnetism. The photon collisions then produced matter or mass and with it the inherent properties of gravitation (and inertia). Finally, the formation of atoms created or captured the strong and weak nuclear force. These forces are basic in the sense that they cannot be explained by any other forces. They are the cause for all observed properties, activities, and various forms of energy in the universe.   How did galaxies, stars, and heavier elements form?  1. The primordial hydrogen and helium gases moved outward in all directions from their point of origin. This expansion is still going on. Instabilities due to gravitational forces caused the formation of separate but still gigantic, many light-years* across, accumulations or clouds. They had sufficient matter to form later on entire clusters of galaxies. However, these very large clouds broke up once more and with sufficient material to form individual galaxies like our Milky Way. Finally, even these accumulations would break up to form stars. *Light travels about 7.5 times the circumference of the Earth in one second. A light-year   is the distance light travels in one year in a vacuum. It is 9,460,000,000,000   km (5,880,000,000,000 mi).   1a. The Milky Way formed about 8,000,000 years ago. It is a spiral galaxy with a main disk of about 100,000 light years in diameter and a thickness at the core of about 1,000 light years. It is composed of more than 200,000,000 stars like our sun. Viewed from the outside it would probably look like its "twin" NGC 7331, which is another spiral galaxy about 46 million light-years away in the constellation Pegasus.   Milky ways' "twin" NGC 7331 (Photo source: Wikimedia Commons) 2. A first generation of stars formed when smaller hydrogen clouds collapsed due to the forces of gravity. The resulting high pressures and temperatures in the center started a nuclear reaction and with it the life of the star. For a body of hydrogen to "ignite" its mass must be at least 1/8 the mass of our mother star, the Sun, which is considered to be a medium sized star. Some large stars are as much as seven hundred times more massive than our day star. 3. The nuclear reaction in the core of the star is the fusing together of hydrogen atoms to form the next heavier element, helium. The net effect is that four hydrogen atoms form one helium atom. The helium's atomic mass is about 1% less than that of the four hydrogen atoms that formed it. This "loss" is converted into energy according to Einstein's famous formula e=mc2. It is this energy generated in the core of our Sun that radiates and reaches Earth in the form of heat and photons. Stars about equal in mass to that of our Sun cannot fuse anything beyond the sixth lightest element, carbon. the fusing of oxygen, for instance, requires larger stars. See the three Nuclear Fusion Diagrams: 1. Hydrogen to Helium Fusion with Energy Release 2. Helium to Carbon Fusion with Energy Release 3. Helium and Carbon to Oxygen Fusion with Energy Release 4. In stars larger than our Sun this orderly fusion process continues to form elements up to iron (atomic number 26). Heavier element fusion, such as that for silver, gold, lead, and uranium requires much more energy than that is available in the "peaceful" fusion process. 5. Stars at least one hundred times more massive than our Sun "burn" relatively fast. They end their "lives" in a violent explosion, a supernova. The high energies released during this spectacular cataclysm form the heavier elements. The luminosity of the star at that time is a few billion times that of our Sun. The explosion scatters these elements into interstellar space as gigantic clouds called nebula. It is here where simple molecules such as water, carbon monoxide, and hydrocarbons form. 6. The solar system, our Sun and the planets, came into being about 5 billion years ago. At that time the universe was already 10 billion years in the making. Hence, the gigantic,  chemically homogenous cloud that would form the system contained elements from the output of star factories that had existed before it in time. The cloud gradually collapsed to form a rotating disk with the evolving Sun at its core. And just like galaxies and stars formed earlier from gravitational unstableness, the planets formed from and within this disk-shaped nebula. This is supported by the fact that all the planets, except Pluto, orbit the Sun in the same plane. Pluto, now no longer considered a planet, was probably captured by the gravity of the solar system. The Solar System (Photo source: Wikimedia Commons) 7. The proto-Earth changed to make life possible. The magnetosphere formed. It would protect life from incoming, harmful cosmic radiation. The planet was initially very hot due to radioactive decay of some elements such as uranium, thorium, and potassium isotopes. This heated the iron and iron sulfide that permeated the young Earth and allowed it to gravitate into its core displacing lighter matter. The planet's rotation set up electric currents, electrons in motion, in the liquid iron of the core. The resulting magnetic field formed ultimately a protective cavity or bubble around the Earth. After less than a billion years of cooling down and meteorite bombardments that imported large amounts of water and other chemical compounds, the conditions were right for the building of life essential molecules. Vigorous chemical activity took place in heavy clouds fed by volcanoes and penetrated by lightening and solar radiation. In addition, the oceans received organic matter from the land and atmosphere as well as from newly arriving meteorites and comets. Key molecules such as sugars, amino acids, and nucleotides (the basic unit of nucleic acids) formed. These molecules are the building blocks of proteins and nucleic acids, compounds found in most living things. Sequences of nucleotide bases form genes as parts of the DNA and RNA molecules. They direct biological processes and preserve life's operating instructions from one generation to the next. In all living things on Earth--from bacteria, a mere prokaryotic organism, to modern humans--genes direct life, while proteins maintain it. The first prokaryotic cells appeared about 3.500 million years ago. Modern humans appeared only recently, that is, 1/10 of a million years (100,000 years) ago . The first life form were plants. In green plants, the food-making process, photosynthesis, consumed carbon dioxide and released oxygen as a byproduct. This changed the atmosphere over time from almost oxygen free to oxygen rich. Thus it made animal life later on possible. 8. Spaceship Earth moves with a Dizzying Speed. Now there is one outstandingly important fact regarding Spaceship Earth, and that is that no instruction book came with it.                                                 Buckminster Fuller (1895-1983) This natural, self-sufficient ship travels at a high speed around the Sun and together with the rest of the solar system around the center of the Milky Way Galaxy. If we could established a fixed point, an Archimedean point, somewhere in space we would measure: The Earth's rotates just over 1,000 miles per hour at the equator (25,000 miles circumference divided by 24 hours). As we move from the equator towards the poles, the speed diminishes and reaches zero at the center of the axis. The Earth moves around the sun at about 67,000 miles per hour (93 million miles distance from the sun equals a diameter of 186 million miles. Diameter times pi (3.14) and divided first by 365 days and then 24 hours) The Earth moves around the center of the Milky Way at 490,000 miles per hour. That is, together with the solar system, it completes one orbit about every 225 million years. Thus, Earth since its formation 4.6 billion years ago has moved around the Milky Way about 20 times. But had only .0007 of a full orbit since the origin of modern humankind about 160,000 years ago. And the entire Milky Way galaxy moves at 1,350,000 miles per hour relative to the observed location of other nearby galaxies.