WHERE DOES GOLD COME FROM?"by David De Havelland" from his forthcoming book "Gold and Ghosts Volume 5 New South Wales"By faith we understand that the universe was formed at God’s command, so that what is seen was not made out of what was visible. Hebrews 11:3 (NIV)
One of the pleasures of prospecting in the bush is lying back after the fire has died down and gazing into the night sky. Humans have been doing just that for millions of years and to find out where gold originated, we too must peer upwards, past the clouds, beyond the Sun and to the centre of the universe where it all began. The creation of gold is part of a seamless rhythm of life and death, which in human terms is without beginning or end. It’s estimated that within our galaxy, the Milky Way, there are over one hundred billion stars, ranging in mass from a few percent, to a hundred times that of our Sun. Spread over 100,000 light years of space, the stars are so far away that they appear as mere pinpricks of light. Yet on clear, crisp nights, when our atmosphere is free of pollution and moisture, they look almost close enough to touch. They become more than mere twinkles and the sky is ablaze from horizon to horizon with a million beacons of light. It is a sight that is never forgotten and makes it easy to understand why humans have spent so much time gazing into the night sky and why early man viewed cosmic events with trepidation and superstition. As a guide to the immensity of space and time, all of the stars we see at night are doomed. Within ten billion years their fuel will be spent – they will either eventually dim and die a quiet death or be engulfed in a cataclysmic ending, such as being sucked into the vortex of a black hole or turn themselves into supernovae. One by one their once bright lights will be turned off, only to be replaced by the birth of new suns, in other parts of the realm. These births, like our own Sun, are the result of vast clouds of cosmic gas and dust performing an elaborate and intricate dance of amalgamation resulting in the centre condensing and a new proto-sun being born.
Take the time to step outside and look carefully at the night sky. Everything appears serene, calm and never-ending. Yet occasionally the peaceful scene is interrupted when one of those dying stars tears itself apart and explodes with unimaginable fury and it becomes a supernova. What we humans see when this occurs varies from an extra pinpoint of light not seen before or the small expansion of an already visible star. One such event was recorded in 1054 AD, when Chinese and Arab astronomers observed what must have been a staggering blast in the constellation of Cancer the Crab. The intense light glowed for several months and was viewed with awe and fear. To the astrologers, the star's bright light was a bad omen for their ruler Hsin-Tsung – they were right, he died shortly afterwards. Today, all that remains of the cosmic exhibition is a frantically spinning neutron star (now rotating at around 33 times a second) only a fraction of its original size, within the cloud of expanding gas known as the Crab Nebula. This cloud will in turn become a nursery for other infant stars to form. Meaning ‘new’ in Latin, the ‘nova’ seen by Chinese and Arab astronomers was the violent death of old stars and the birth of heavy metals, including gold. All stars start life largely composed of immense balls of compressed gas, mainly hydrogen, the first element produced after the ‘Big Bang’. Clouds of stellar hydrogen condense to form a swirling mass and the inward pressure is held in check by the outward pressure of the compressed gas. The pressure and friction causes incredible heat, resulting in a nuclear reaction at the centre of the mass. Through a complex series of reactions, the hydrogen ignites and a star is born. Over billions of years as the hydrogen is used up, outward pressure falls enough to allow gravity to squeeze the central core even tighter, causing greater pressure and temperature. At around one billion degrees, helium atoms are forged. As this element is devoured in the nuclear furnace, the core continues to contract and increase internal temperatures until the helium nuclei fuse to form carbon atoms. The process continues until further fusion reactions lead to oxygen, neon and other elements materialising. By now the density of the core is around 50,000kg per cubic centimetre (or about 800 tonnes per cubic inch), compared to the Earth’s average density of 5.518 grams per cubic centimetre. With a temperature of around 2 billion degrees, neon fuels a fusion reaction to form silicon - a major component of Earth. As each new element is consumed, so the energy return steadily declines and the star changes, not every ten thousand years or even every year, but first on a monthly, then daily and finally an hourly basis. The last stage is reached when the nuclear reaction produces an iron core - a more stable element without the ability to burn. The core by now is typically 200km across and very dense – it’s estimated that a teaspoon will comprise around a trillion tonnes of matter – six thousand teaspoonfuls (or 30 litres) would weigh as much as the entire mass of Earth. The star, with little nuclear energy remaining to support its own weight, contracts so forcefully under gravity that even atoms are overcome. The trillions and trillions of tonnes of material surrounding the core rushes inwards at tens of thousands of kilometres an hour, colliding with the now solid core. The resulting shock wave, like nothing seen on Earth, travels outwards and is accompanied by a burst of neutrinos formed in the dying moments. The combined energy of the shockwave and neutrinos transform the star’s outer layers into an intense stellar furnace. It is in this environment that heavy elements beyond iron, including gold, are forged in a mad scramble of hyperactive atoms - then the star literally disintegrates. Gold atoms, along with every other element, are blasted into space in a nuclear holocaust beyond anything imaginable. The star will shine with the intensity of ten billion of our Suns - at least for a few days. Fading within weeks, all that remains of the star is a huge cloud of gas and dust containing the elements, including gold, silver, lead and uranium. The cloud is called a nebula and will expand indefinitely, seeking new partners. On its journey through a dark and silent space, the cloud may meet up with another similar nebula. Such clouds are formed at least three times every hundred years in our galaxy alone. Ultimately they will mingle, amalgamate and condense and the seeds of another star system will have germinated to produce a cascade of stellar births. New suns are born. This magical event is taking place right now in the constellation of Orion, located around 1,600 light years from Earth.
It brings new meaning to the prayer, ‘Ashes to ashes, dust to dust’. Our own bodies are composed of material from long dead stars, as is the golden nugget you’ve held in your hands. Let sunlight catch a nugget at the right angle and a brilliant shaft of light will reach out from the gold, a reflection of its birthplace.
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