by Paul J. Dejillas, Ph.D.
Right after the big bang, time immediately began; space also began to expand rapidly outward and in all directions, carrying along with it all the once virtual particles that were tightly packed in the womb of the initial singularity, but are now real physical matter or elements. Chaotically and frantically spreading throughout space, these elements unavoidably started colliding with each other and combining into nuclei of several elements. The formation of the first lightest chemical elements in the Cosmos—hydrogen, helium, and lithium—immediately began. All these elements, including, quarks, leptons, strings, were already swarming all over the expanding space of the Cosmos in less than a millisecond (10-43 seconds according to Max Planck’s reckoning, and that’s 43 zeros to the left, or .00000000000000000000000000000000000000000001, an inconceivably short period of time).
Then, in another micro-second (between 10-32 and 10-6 seconds), the Cosmos became an incensed hot soup of electrons, quarks, and leptons; quarks of several varieties collide with each others to form protons and neutrons. But by then, the expanding Cosmos was still very hot, 108oC, for the electrons and nucleus to combine into atoms. So within three minutes after that fiery eruption, the expanding Cosmos was swarmed with ‘non-condensible’ gases of hydrogen and helium as well as dust particles of hydrogen and helium nuclei. It was only after around 300,000 years, when the temperature cooled down to 10,000oC, that electrons clumped with protons and neutrons to form the first lightest elements of hydrogen and helium atoms.
But while the big bang only produced the lightest elements; nonetheless, it is said that these elements were the first building blocks of more than 98 percent of the known matter in the Cosmos. All other elements heavier than lithium were produced much later, in the interior of giant Stars, which were formed more than one billion years later. These light elements traveled freely into the expanding space and, through a series of inevitable collisions, combinations, and aggregations, these cosmic dusts of different particles formed larger and heavier molecules that eventually led to the formation of giant molecular clouds, also called nebulae (from the Latin word “Nebula” for “cloud). The formation of molecules from atoms is precipitated by the tug-and-war relationship between thermal pressure and gravitational forces.
Gravity works to pull gas and dust particles in space to become more tightly packed. But the temperature of these particles also plays an important role. The more warm the particles, the more they exert outward pressure overcoming the clumping pressures of gravity. But the cooler the temperature, the more the force of gravity prevails over thermal pressure. In this condition, the more clumps or fusions are formed, converting hydrogen nuclei into helium nuclei. This process eventually leads to the formation of a proto-star (a small stellar entity or a star at its infant stage) and, finally, to the primeval, full-flown star. Molecular clouds, therefore, according to Physicist Fred Adams, are stellar factories that manufacture stars and their accompanying planets (2002:34).
Whatever it was, about 14.5 billion years ago, or so the story goes, this primeval hot substance suddenly erupted into a fiery explosion. And the once tiny singularity expanded, unleashing as if out of nowhere. And in that fiery explosion, space and time began, and immediately inflated outward in all conceivable directions. And as suddenly as it erupted, space became swarmed with all kinds of particles, like quarks, leptons, gluons, strings, and all other miniature elements, produced by the mysterious singularity.
And, for another tiny fraction of a second, the flaming remnants, through a process of attraction, chance, and accidents, collided with each other, with some combining with others, to form relatively more complex particles of protons, neutrons, and electrons. Then, as the story unfolds, these tiny elements continued to collide with each other, with some, joining others to form more complex, but still relatively simple chemical elements of hydrogen and helium, while electrons combined with the already clumped nuclei of protons and neutrons, to produce the proverbial atom.
For the next 300,000 years, when the Cosmos began to cool down, several other larger combinations of atoms, mostly helium and hydrogen, continued to be formed by the millions and billions. After one billion years of frenzied cosmic activities, giant clouds began to form. This formation would later give way, to the appearance of the first stars and galaxies in the young Cosmos. By then, the cosmic temperature really dropped down, to allow the formation of heavier and sturdier elements inside the womb of stars. To this day, the Cosmos continues to expand farther and farther away, at the speed of light. And it is still stretching farther outwards into the farthest reaches of our horizons. 0In the process of its inflation, the Cosmos continues to create new stars and galaxies.
Then, after many billions of years, the Cosmos witnessed the formation of our own stellar system,0now known to consist of 11 major celestial bodies, that include the Sun, Moon, and the nine (now eight) planets: Mercury, Venus, our very own Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and the farthest from the Sun, Pluto. Sharing the space of our heavenly bodies, are the lesser-sized celestial objects, like the satellites, meteors, and asteroids, that are known to congregate in an area in space, known as the Asteroid Belt, and located between Mars and Jupiter. Our own galaxy is known, to be only a tiny part of a larger stellar system, the Milky Way, which is also known to be populated, by around 200 billion stars. And the entire Cosmos houses billions of galaxies that are continually created in the expanding space.
To this day, the Cosmos continues to expand and speed farther and farther away from the primal singularity, stretching still beyond the farthest borders, if any, traversing distances indefinitely. In the process, the Cosmos continues to create new stars and galaxies. Our own galaxy is known to be only a tiny part of a larger stellar system, the Milky Way, to which we belong and which is known to be populated, according to latest count, by around 200 billion stars. And the entire Cosmos houses billions of known galaxies that are continually in motion carried along by the expanding space. The “big-bang” story of creation continues to unfold and who knows what new surprises and mysteries are still in store for us.
The Formation of Galaxies
How were the galaxies formed? Why were they created at all? What are their functions? What is our relationship with the galaxies? It took 370 million years, from the time the primal Star appeared, for a galaxy, as big as our Milky Way, to form. The most distant and considered to be the first Galaxy to be formed was discovered only very recently, in 2006. Known as the galaxy IOK-1, this primal Galaxy exhibits an unusually high redshift, of 6.86, corresponding to just 750 million years, after the big bang. This is barely 600 million years, after the primal Star was formed. Today, the number of galaxies known to exist, throughout the entire visible Cosmos, is estimated at more than 100 billion.
A galaxy serves as a depository of heavy metals and elements that were thrown out of the womb of Stars, as a result of supernovae. It is a massive system or cluster, consisting of stars, giant clouds, planets, and other lesser bodies, orbiting “a common center mass,” and bound together by the force of gravity. Because of this force of gravity, heavy nuclei are kept from flying out, into the far reaches of intergalactic space. A galaxy may be elliptical, spiral, and irregulars in shape. Beginning in the 1990s, the Hubble Space Telescope came up with evidence, that there are about 125 billion galaxies in the entire Cosmos.
The majority of the galaxies are organized, into a hierarchy of associations, called galactic clusters, which contain many thousands of galaxies, congregating within an area, and dominated by a single, giant elliptical galaxy. For example, our solar system, the Milky Way Galaxy, is just one galaxy, belonging to a cluster of galaxies, collectively known as the Local Group. The other three known galaxies within this cluster are: the Andromeda Galaxy, in the Northern Hemisphere, which is two million light years away; the Large Magellanic Cloud, in the Southern Hemisphere, which is around 160,000 light years away; and the Small Magellanic Cloud, which is 180,000 light years away.
But clusters and groups of galaxies, can also congregate together an area, to form bigger aggregations, known as superclusters. Superclusters contain tens of thousands of galaxies, which are found in clusters, groups, and at times individually. Under this grouping, the Local Group is known to be part of a much huge, more extended structure, known as the Virgo Supercluster. This is already inconceivably colossal. Even larger scales appear, when galaxies are arranged in, what is called, huge networks.
One of the largest networks ever to be mapped, is the Great Wall, which is more than 500 million light years long, and 200 million light years wide. And future discoveries of even much higher aggrupations, may still come our way. Because, since the occurrence of the big bang, the Cosmos continues to expand infinitely, even as new giant molecular clouds, stars, planets, and galaxies are continually formed.
Within our own Solar System, it is already overwhelming to think, that our Sun is just one of the many billions of Stars, populating the Milky Way galaxy. For all intents and purposes, the Milky Way is in itself already gigantic, with a probable mass of between 750 billion, and one trillion solar masses, and a diameter of about 100,000 light years. Orbiting our Sun, are the nine known planets, including thousands of minor planets, known as the asteroids, that all congregate in our stellar space, between Mars and Jupiter, called the Asteroid Belt. Meteoroids are small rocky bodies, as small as tiny specks of dust, and as big as 10-meter long boulders, orbiting about in space. When they hit the Earth’s atmosphere, they give off streaks of light, known as meteors, or shooting stars. Comets live beyond Neptune, but every 10 years or so, they appear in our skies. Many of our planets are also accompanied by satellites or moons, which orbit around them.
Our Solar System, most astronomers believe, was formed 4.6 billion years ago, developing just like the Stars, from a giant molecular cloud of gas and dust particles, called the solar nebula. Through the interaction of the forces of gravity and thermal pressures, the particles combined to form denser bodies. The material accumulated to our Sun, while other rocky materials combined to form what are called planetisimals, which further clumped together to form the rocky or terrestrial planets.
Those combinations developing at the outer planets, which is much farther from the Sun’s heat, allowed the gaseous particles to freeze into huge balls of frozen gas that eventually formed into what is called, the gaseous giant plants. Thus, it has become traditional among astronomers today, to divide our planets into two groups, except for Pluto, since some astronomers think, that Pluto may not be a major planet at all. The innermost four planets are called terrestrial planets. They include Mercury, Venus, Earth, and Mars; they are small and rocky.
The Formation of Our Planets
How were our planets born? How do they behave? What role does our Planet Earth play? How important is it to our lives? What ought to be our relationship with our Planet Earth, with Nature, and our environment, in general?
Much of the materials that are contained on planets come from the Star’s interior, which were made available in great abundance, when these were thrown off during stellar explosions into space in the form of gas and dust particles of “various terrestrial materials.” These dust particles include: iron oxides, silicon compounds, water droplets and ice crystals, which were all floating inside the gas. Through collisions of these dust particles, aggregations of larger bodies, which we now call planets were gradually formed. This process of aggregation happens. When a small particle of dust or rock collides with a much larger one, it would evidently bury itself in the body of the larger one, allowing the latter to grow still larger. Then, the newly formed larger lump of mass begins to attract small particles that are passing by its area by the stronger force of its own gravity. This would all the more add more masses into its body.
Gamow, in explaining the formation of the planetary system within the model, states that the interstellar space was then filled with rapidly rotating packets of gas, mostly hydrogen and helium, carrying dust particles of various materials, traveling along its orbital motion around the Sun. Through collisions of these gases and dust particles, smaller particles that collide with much larger ones become buried and embedded into the latter, allowing the larger ones to grow into still larger bodies that eventually give birth to the planets in the Solar system. Weizsäcker was able to show it, according to Gamow, that this must have taken place within a period of about 100 million years for the planets to appear.
How about their orbital path? Why don’t they collide with each others? For sure, collisions did occur but this is because there are so-called “traffic violators” not following their respective lanes or obeying the “traffic rules.” Under the Newtonian law of attraction, continues Gamow, every material body of varying sizes, shapes, and lengths that moves around the Sun is bound to travel in an elliptical orbit. In explaining the Titus-Bode rule, Gamow presented a table showing that the radius of each planetary orbit is roughly twice as large as that of the orbit nearest to it in the direction of the sun. Further collisions are minimized or avoided as these traveling dust particles, described as closed bean-shaped necklaces, rotate with respect to one another at various speeds and distances. Nonetheless, traffic violations continue to happen up there in the Solar system, but, as Gamow says, these only serve to “pulverize” the violators or force them to take a “detour.”
Our Sun played a significant role in the formation of the nine planets. The early solar wind, a stream of hot gases and electrically charged particles coming from the Sun, drove the light elements away from the inner (rocky) planets. But the stronger gravity of the giant outer planets seized more of the planets' hydrogen and helium, and the solar wind was weaker there. In this way, the outer planets kept most of their light elements and wound up with much more mass than Earth. Our nine planets also exhibit differences in size and speed of their revolution around the Sun. Their usual order, if reckoned by their distance outward from the sun, is Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, which, because of its size, was dropped as one of the planets. Planets differ from stars in many ways. Planets, including the Moon, always follow the same path, more or less, through the sky. Planets travel elliptically (in oval-shaped, not in circular motion) around the Sun in paths called orbits at varying speeds and durations:
Mercury, 88 days; Venus, 225 days; Earth, 365 days; Mars, 1.8807 Earth years; Jupiter, 11.8565 Earth years ; Uranus, 84.02 Earth years; Neptune, 164.79 Earth years; and Pluto, 247.92 Earth years.
But the ninth planet Pluto is considered quite eccentric, in the since that its orbit is so elongated that it stays closer to the Sun than does Neptune. However, every material body that is formed in the skies above us—planets, dust particles, small meteorites, asteroids—moves around the Sun in an elliptical orbit in various elongations, depending on its distance from the Sun. Even then, collisions between individual particles are bound to happen, as is the case when small dust particles of rocks and meteors may collide with larger objects like the planets. These collisions are in fact necessary for the formation of new bodies as well as for the sustained growth of young planets.
At some point in time, however, during the year, the planets seem to reverse their direction and, for a while, seem to travel in backward motion. Scientists call this retrograde motion. As they orbit its Parent Star, planets, including the Moon, also rotate on their central axis. And planets rotate at different rates: Earth takes one day to rotate completely on its axis; Jupiter and Saturn spin much faster in just about 10 hours (Earth time), and Venus is much slower in about 243 Earth days. Most planets rotate on the same direction, except for Venus, which rotates in the direction opposite from the direction of its revolution around the Sun. Most astronomers conjectured that several objects from our Solar System must have collided with our planets. Some of these celestial bodies must have been so large that they caused to tip the axis of planets Uranus, Pluto, and Venus.
Nonetheless, from the macro perspective, one observes order and harmony among the various celestial bodies, with the Sun in the center stage even as the movements of the planets, including all those lesser bodies, are choreographed by the force of gravity. And so, there it is, with the appearance of the planets in our Solar System 4.6 billion years ago, the cosmic stage has been slowly set for the appearance of life and Man on Earth millions of years later. But this is another story in itself.#