Putting out the stars and extinguishing the sun.–“Fahrenheit 451,” Ray Bradbury
The first stars were born very long ago, probably when our almost 14-billion-year-old Universe was less than a billion years old. The brilliantly incandescent baby stars illuminated what was once a dismal, dark and murky scene, setting fire to the young Universe with their wonderful glittering light. However, in November 2012, an international team of astronomers published a study in the Monthly Notices of the Royal Astronomical Society, suggesting that almost all of the fiery stars that will ever dwell in our Universe have already been born!
Only a few hundred million years after the inflationary Big Bang birth of our Universe, gravitational attraction had caused dark gas–primarily hydrogen–to collapse and give birth to the first generation of stars. Some astronomers think that the first stars may have burst into existence as dazzlingly and brilliantly as the grand finale of a gigantic fireworks display. According to this scenario, the Universe is thought to have manufactured a substantial fraction of its stars in a powerful, intense, and violent conflagration of star-birth, which ultimately lit up the dark Cosmos. Other astronomers, however, think that the birth of the first stars was more gradual.
All of the stars inhabiting our magnificent, mysterious Universe, are primarily composed of hydrogen, which they burn in their nuclear-fusing hidden hearts. Imagine that very dark and murky era before the first stars caught fire. Opaque clouds, that were primarily made of neutral hydrogen–the lightest of all atomic elements–gather along filaments of invisible, non-atomic dark matter. Dark matter is mysterious stuff, and it is much more abundant than the so-called “ordinary” atomic matter that we are familiar with, and of which we, our planet, the Sun, the moons, all of the other planets, and all of the stars in the Universe, are made. Dark matter, which is composed of some as yet unidentified, exotic, non-atomic particles, that do not interact with light, is invisible. Dark matter makes up approximately 25% of the mass-energy content of the Universe, whereas “normal” atomic matter makes up a paltry 5%. All the rest of the mass-energy content of the Cosmos–70% of it–is composed of a bizarre substance called dark energy, that is even more mysterious than the dark matter. Dark energy is causing our Universe to accelerate in its expansion. 바카라사이트
The dark matter composes the great filaments of the Cosmic Web, on to which the sparkling star-struck galaxies are suspended, shining like incandescent dewdrops on the web of a gigantic, mysterious spider. Some scientists have likened the appearance of the large-scale structure of the great Cosmic Web, dazzling with a myriad of star-fired galaxies, to the appearance of the neurons of the brain.
Imagine how the galaxies of the ancient Universe first lit up, at last, with the fires of a multitude of incandescent stars. The primordial gases, primarily hydrogen, formed tighter and tighter, dense, dark blobs that collapsed under their own gravitational weight, until nuclear-fusing fires started to burn. Imagine with your mind’s eye the heart of the very first baby star in our Universe, glowing in the dark core of a dense glob of pristine hydrogen gas.
Of course, nothing with eyes to see was around to watch the dark galaxies of the ancient Cosmos catch fire with the brilliant light of so many countless, glittering, and beautiful stars.
The bigger the star, the shorter its life. Massive stars live fast and furiously, and die young–at least by star-standards. This is because large stars burn hotter and devour their supply of fuel much more quickly than smaller stars. Some massive stars live “only” a few million years, blowing themselves to pieces in the magnificent conflagration of supernovae explosions. Smaller stars, like our own Sun, live out their main-sequence (hydrogen-burning) lives more slowly and peacefully. Stars that are about the same size as our Sun live for approximately 10 billion years. Some stars that are smaller than our Sun live longer–perhaps for about 15 billion years. Red Dwarf stars are much smaller than our Sun, and they live on the main-sequence for a very long time, peacefully and quietly burning up their supply of fuel. Red Dwarfs are the most abundant stars in the Galaxy, and some of them might live as long as 10 trillion years!
The stars brought our Universe to life. The ancient Universe, dark and murky, knowing not, as yet, the incandescent blasts of starry fires, knew only deuterium (heavy hydrogen), helium, and some wisps of lithium–the only atomic elements manufactured in the inflationary Big Bang inferno. The stars spun out all of the elements heavier than helium in their nuclear-fusing hearts, by way of a process termed stellar nucleosynthesis–spinning ever heavier and heavier elements out of lighter ones in their cores–or in the blasts of supernovae explosions when they died. The stuff of life, the oxygen we breathe, the carbon that is the basis for life as we know it on Earth, the dirt, the sand, the stones, that we walk upon–all were formed by the stars. We are star-dust–starry-stuff come to life.
Billions and billions of years ago, the first star was born in an ancient cradle of darkness, and it took to fire, lighting up the engulfing blackness that surrounded it. Conscious observers, such as we are, are a “way for the Universe to know itself,” as the late Dr. Carl Sagan of Cornell University once said. We are the eyes of the Universe seeing itself.