So much has been said in the preambles to my earlier articles on astronomical parlance that we had better begin with the day’s business right away.

Continental drift: Considered a queer concept once, it is now universally accepted as true and happening. The continents and other masses of the Earth are drifting across the surface of the globe. The speed of the drift is only as much as a human nail grows in one year (about 8/10 of an inch).

One look at the map of the world or globe and we notice that the east coast of North and South America fits nearly perfectly with the western coast of the continents of Africa and Europe. Likewise, the island of Madagascar fits perfectly with the East African coast at the western end of Indian Ocean, like the two were once part and parcel of each other.

Indeed if the four continents in reckoning could be joined somehow, they would coalesce into a great land mass of great length and breadth. Many other regions offer a similar example, like they were all a huge jigsaw puzzle. Also, when the submerged shelves of continents are held to account, the fit matches closely.

Its history goes back to about 225 million years. The continents were joined and located at one place since named Pangaea (meaning joined in one mass, in Greek). The dinosaurs had the whole world to themselves. The oldest among the dinosaurs must have roamed on Earth freely.

With time, however, the great landmass broke up into many pieces, and continents and big islands were formed, as they drifted apart. The tug and shove of the underlying magma or other semi-molten rock are responsible. More about it later, in great detail.

Convection current: This explains how heat rises up, cools and sinks again, producing a continuous process of circulation of transfer of heat, whether liquid, gas or solid. All my young friends must have seen their mums boil water at home. How continuously warming water mixes with the layers of the colder one, churning all the while, until all of it attains the desired heat.

Another glaring example in nature’s laborious handiwork is the forever churning atmosphere. How it helps regulate temperatures that is gratefully acknowledged by us humans. It is rivalled only by heat from the interior of the Earth travelling upwards through (thousands of) miles of mantle and crust, diminishing mercifully near the top, contributing significantly to a wonderfully liveable planet.

Nicolaus Copernicus 1473- 1543: What is a man doing in the company of definitions, you’d ask. The fact here is that men like Copernicus, Galileo, Newton, Herschel, Einstine, or Hawking are not merely people, they are in fact, history makers. We have seen that it happen about one person per century approximately.

Polish astronomer, Copernicus, in 1540, proved that the accepted conventional wisdom that the Earth was in the centre (geo-centric) and all planets and stars, even the Sun revolved around it obligingly, was completely wrong. He said no to all that and meticulously proved that the honour instead belonged to the Sun, and that it was Helio-centric system, where the sun provided the sustenance, and all planets revolved around it.

He changed the course of science for all times to come. His tools were observation and mathematics. Men paid heavily for this aberration and many were done to death (remember Giordano Bruno for one). Even Copernicus waited until the end to reveal the newly established truth, for the fear of the clergy. It must be said in all fairness that his discovery was the greatest outcome of human mind until then.

Cosmic rays: It is the radiation that comes to us from deep space. Mainly protons, alpha particles and other atomic nuclei released by millions of stars. Cosmic rays include high energy electrons and photons that enter the atmosphere and cause secondary radiation.

Our planet receives constant bombardment of radiation, which substantiates that the entire universe endures cosmic background radiation composed of photons left over from the Big Bang. It is speculated that every being on Earth (including animals and trees) receives a lot of such rays throughout their lives, perhaps billions of them.

The idea owes its existence to the Russian (actually Ukrainian) scientist George Gamow (Gam-off) 1904-1968. The burly, grizzly fella opined that cosmic rays abound, and scientific evidence also supported his hypotheses that they are a leftover of the mighty Big Bang.

Cosmology: It is the science that deals with the origin, evolution and structure of the universe. It combines astronomy, astro-physics, particle physics and mathematics as a mosaic for better understanding of our universe.

Cosmologists depend heavily on the data provided by astronomers and astro-physicists to reach desired the conclusions.

Cretaceous: Geologic timescale accounting to 65 million years ago to 140 MYA. So that a period 75 million years from the full bloom of dinosaurs to their sudden disappearance can be explained in detail. It is the third and final period of Mesozoic era. The end of this period (65 MYA) led to the flourishing of the mammals and the flowering plants.

Remember that there cannot be an astronomer that has none, or little knowledge of the history of planet Earth, so much so that one branch of science comes entwined with another.

Published in Dawn, Young World, January 16th, 2015