Here we have advanced to the alphabet ‘G’, and will soon meet the father of modern science once again. What a delight to see the friend of humanity all over again!

Gaia hypothesis: It is at best unreliable, controversial and largely as yet, thoroughly untested sum of various scientific hypotheses.

With its roots in Greek as well as Hindu mythology, Gaia treats the world as a mother goddess complete with the sum of all organisms, with its availability of water, gases, all kinds of foods, life, rocks, water, flora, fauna, environment, minerals, climate and what not.

In modern times this concept, or group of concepts, has been developed by James Lovelock, a British scientist, drawing on development in many scientific disciplines. His theory postulates the Earth as a living whole. He views it as one great circuit of life from its core to its outer atmosphere. But one can say that it is not entirely original and has its roots dating back in the distant past.

The question of how organisms influence, modify and often control local atmosphere and have cumulative impact on global climate, for instance, it is treated as legitimate by many scientists. The Gaia theory is judged controversial at best, with many loose ends and forever lacking complete adherents. It is not wrong of you to know about it, but like many theories you may reject or accept it only partly or none at all. I, for one, completely reject it. For instance, according to it a fluttering butterfly in the rain forest of Amazon can cause a storm or a twister in Arizona or Texas!

Galaxies: We have dealt with this extensively in the past. These are groups/vast collection of stars bound together gravitationally. There are spiral, elliptical and irregular galaxies. Our Sun belongs to a spiral galaxy, the Milky Way. Some hundred billion galaxies have been spotted, each containing a hundred billion stars, though there are many which contain more or fewer stars. Our galaxy is a medium-size one, about a hundred thousand light years across, peppered with stars and slowly rotating on its axis together with all stars engaged in their own business.

The stars in its spiral arms rotate once about the centre of the galaxy once in at least a hundred million years or so, although some take shorter and some much longer to complete a circuit around the centre. Interestingly, Andromeda galaxy is the most photogenic and beautiful in our neighbourhood, some 2.2 million light years away in the same local group of galaxies where we belong, although there are some smaller ones closer by.

American astronomer, Edwin Hubble (1889-1953) discovered in 1929 that all galaxies were moving away from us. Also, the farther a galaxy is, the faster it is moving away. This led to the conjecture that the universe is expanding and the consequent discovery of the Big Bang, a great burst of energy that took place about 15 billion years ago completing one of the greatest intellectual achievements of 20th century. The present rate of expansion is between five and 10 per cent every one thousand million years. This has of late been denied to reiterate that the rate is instead much higher, the speed having been restrained by the much less understood Dark Matter.

Galileo Galilee (1564-1642): Universally regarded as the father of modern science, he was a great thinker and logician who very nearly paid the price with his life for his discoveries, particularly pertaining to the just-invented telescope (in 1609 by the Dutchman, Lippershey). Galileo made his discovery in 1610 when he trained it at various celestial bodies, especially Jupiter, Moon and the Sun and earned the ire of the church representing the dreaded Inquisition.

He insisted that one could understand the world by observing and understanding how it works. This led to the development of modern physics and changed the world to what it is today. His methodical observation, experiments, and mathematical analyses in physics and astronomy had a profound influence on thinking minds all over, that led to men like Newton to develop Newtonian physics and a lot more in subsequent years (Newton was born in the year that Galilee died, 1642).

To Galileo goes the credit that none of the laws or discoveries made by him have been improved upon or rejected by the scientists who followed him in later centuries, to this day. The great man is always seen sporting a greying beard and a faint smile on his sombre face. We shall forever be in a heavy debt of this man.

General Theory of Relativity: Albert Einstein’s theory on accelerated motion and gravity, General Relativity, is a fundamental concept of nature of space, time and gravity and has changed our concept of how we view the universe. Published in 1915, after his Special Theory of Relativity (1905), this theory holds gravity as a property of space rather than a force between bodies (improving upon Newton). In the presence of matter, space becomes curved and bodies follow the line of least resistance among curves, as in the case of electricity. Gravity, then, is treated as a consequence of the curvature of space induced by the presence of a massive object. More about it later. Meanwhile, God bless and goodbye.

Published in Dawn, Young World, July 2nd, 2016