Any speculation about the future of our tiny planet would be of immense interest to scientists as well as historians. In the last century, the ideas of a group of “uniformitarians” who had come to realise the great age of the Earth and the fact that geological and evolutionary changes take place imperceptibly over eons of time, had gained an upper hand, leading to a firm belief that man was apparently secure for at least the next few million years.
Such an optimistic viewpoint was obviously in sharp contrast to the prophecies of “catastrophists” who held the view that violent explosions of enormous fury might one day bring about the decay of stars and the solar system, destroying all life as we know. The pessimism of these catastrophists had however been ignored in general.
But recent revelations about the mysterious and sudden extinction of the powerful dinosaurs 60 million years ago which had ages ago after having dominated the earth for 135 million years have once again brought about a necessity to think seriously about the seemingly bleak future of mankind on this planet as well as the precarious position of the earth itself. This in turn has brought to focus the following general possibilities.
All stars have finite lifetimes. When a huge star exhausts all the fuel in its core it begins to collapse. Temperatures of several billion degrees are generated releasing a burst of energy that blasts the star apart. The exploding star is called a Supernova. Such an event takes place throughout the universe including our own galaxy.
The Chinese had apparently recorded the appearance of a Supernova in the year 1054. The Supernova had been so bright that people had been able to see it even in broad daylight a week later. But then it had quickly faded out leaving a glowing print in the sky, in the form of a huge blur of gas which is now called the “Crab, Nebula”because as seen through a telescope with the human eye it resembles a crab.(The Nebula is even now expanding at a rate of 800 miles per second; it stretches across some 35 trillion miles of space).
The estimated distance from the Crab Nebula – is about 6,500 light- years( a light -year is the distance travelled by light at the speed of 18600 miles per second for a whole year . During the last 1054 years there have been only three supernovae in our galaxy, the explosion in 1054 that made the Crab Nebula, Tycho’s Star of 1572 and Kepler’s Star of 1604.
If a Supernova were to explode nearby it would indeed be a spectacular sight for the inhabitants of other solar systems, if such beings do exist. But on this earth we would have only a moment to notice a blinding flash for all life would be destroyed instantaneously were the Supernova less than 60 light years from us.
One famous astronomer in the United States has observed that catastrophes and cataclysms occur regularly in the universe on an astronomical scale. He states that whenever a “quasar” explodes more than a million worlds are obliterated utterly destroying countless forms of life some of them perhaps intelligent. This would come as a shocking revelation to those who believe in a quiet homely universe, designed for the benefit or living organisms, especially human beings.
Indeed the very huge scale of the universe with more than a hundred billion galaxies each containing more than a hundred billion stars, underscores the utter insignificance of events relevant to human events in the Universe.
It has been postulated by a British Physicist that North and South poles have switched places quite often in the past. Such polar reversals would according to him explain the ice ages and animal extinctions, and the presence of mammoths in a frozen condition in the Arctic. (One animal was found in Siberia in a standing position with undigested vegetation in its mouth and stomach). The physicist also attributes the reversal of the earth’s magnetic fields to pole shifts. Geologists have found that magnetism in rocks of different ages does not always point to the present magnetic poles, and that the geo-magnetic field has switched polarity, more, than 400 times in 90 million years. The British physicist believes that these reversals can be explained by the Earth tipping over on its axis 180 degrees.
A complete pole shift could be expected to induce massive tidal waves and several storms, to make continental plates to shift and collide causing volcanic eruptions and throwing up mountain chains rendering whole species extinct. In support of his scientific theories, the British physicist does not hesitate to even resort to evidence based on legend and fable. (There is an old Hopi Indian legend according to which the world with no one to control it went off balance spun round crazily then rolled over twice causing mountains to plunge into seas, and the seas to slosh over the land.
Ancient Egyptian texts and paintings show constellations reversed in the sky and moving in the opposite direction to what they follow now).
He even attempts to explain certain stories in ancient books that tell of the Sun staying in the sky for a longer than usual time by his theory of the earth “rolling over.”) He believes that a large cosmic body passing close to the earth or possibly even hitting the earth might have caused the earth’s axis to shift. In his opinion the force necessary to topple the Earth is not as great as people would probably imagine and that even a comet or some other similarly large body would be able to do that.
Thus the British physicist’s theory of polar shifts attempts to give a unified explanation for such varied phenomena as the ice ages, periods of global volcanic activity, animal extinctions the sudden rise and fall of land masses and magnetic field reversals.
The dust from volcanoes reduces the amount of sunlight reaching the Earth. When the dust and grit and particular matter being discharged into the atmosphere by our machines and factories combine with the dust from volcanoes a shield would be formed against solar radiation gradually lowering the temperature. Thus conditions would in course of time become ripe for a new Ice age.
A worldwide influenza killed 20 million people in 1917. While many epidemiologists have been optimistic that no new disease however deadly has the potential to wipe out the entire human race, the sudden appearance of Covid 19 capable of totally destroying our immunological and pharmacological defences has radically altered man’s perception of the way lethal diseases appear, and spread.
The Earth appears to bear the scars of a number of meteoric collisions. If a meteor no bigger than a mile in diameter were to hit the Earth the damage would be incalculable. In 1908 a meteor hit a spot in Siberia and vaporised everything within a radius of 50 miles including forests and a herd of 500 reindeer. The jolt was recorded in seismographs around the world and produced massive disturbances in the earth’s magnetic field.
One recent near miss with a meteor occurred in 1968 when Icarus an Asteroid about a mile in diameter passed within 4 million miles of the Earth. If its course had changed even by a few degrees it could have collided with the Earth producing as much energy as 500 hundred thousand mega tonnes of TNT i.e. equal to all the energy released by the largest recorded earthquake, squared. Such a blast would flatten everything within a radius of several hundred miles. About a billion tonnes of rocks and soil pulverised into dust would be thrown into the stratosphere where it would act as a gigantic sun shield reducing the solar radiation reaching the earth and almost guaranteeing an Ice age.
It is clear that we are passengers on a planetary spaceship hurtling through the solar system at a great speed, and that we do not have any control over this ship. If another huge object body moving roughly at the same speed collides with our earth the devastation would be unimaginable.
Our galaxy may collide with another, a fairly common occurrence in the universe or we could run into an anti-matter galaxy with disastrous consequences. Or our Sun might get extinguished some time in the future making our planet a cold inhospitable ball of ice. But perhaps there is really no need to feel despondent for long before that date human ingenuity and skill may have developed space technology to such a level that we may have migrated to other Solar systems or space colonies.