DAWN.COM

Today's Paper | November 14, 2024

Published 15 Aug, 2015 07:05am

Astronomy: Astronomical parlance continues

HERE I am still in one piece after a long illness which almost broke me in two pieces! The longing for one’s nation’s children keeps one going to the extent that the bond never really snaps.

Here we shall continue where we left off some time back, from the letter B onward. Every single letter of the alphabet presents some important and vital aspect of astronomy. Some of it is related to pure astronomy while the rest is in close consort with science of the skies, that having to do with life on the Earth, or its origin. To know this well is to know astronomy well.

Bacteria: The smallest and simplest living organism around. Viruses are yet smaller but exist on the borderline between living matter and nonliving matter, and are therefore not considered an organism. Bacteria, often called germs, are single-called microorganisms without organised nuclei ( plural of nucleus) although microorganism refers to any kind of microscopic life. Bacteria are neither plants nor animals, but fall into the category called, monera.

Bacteria DNA is scattered within the cell rather than contained in discreet nuclei as in animal and plant cells. Most bacteria are harmless to humans, and animals, working as the chief agents of organic decay. Some others are parasites and work as agents of disease that we often confront. These are treatable with antibiotics, while the virus-based ailments are not. Others, such as E (.scherichia) coli live in intestines and are needed to help in digestion.

Beta particles: It is a high-speed electron or positron emitted during radioactive decay. A beta ray is a stream of beta particles, and one of three types of electromagnetic radiation. The other two are alpha and gamma particles.

Big Bang: So much has been, and will be said about it. It is the accepted standard model for the origin of the universe. This theory maintains that the universe began when a single point of infinitely dense and infinitely hot matter exploded spontaneously. Curiously, some scientists think that it was as big as only a molecule, densely packed and hot, both of them on unearthly scale, while the others hold that “the atom” was as big as the Solar System is wide. Interesting, isn’t it? Out of the debris of this explosion, all of the galaxies, quasars, stars and planets were formed.

This event is also called a Singularity and it is believed to have occurred some 15-18 billion years ago. Time began at the Big Bang. So did the distance. The American astronomer, Edwin P. Hubble’s discovery in 1929 that the universe was continuously expanding and that all galaxies were drawing away from one another, led to the logical conclusion that once the outward expansion was somehow reversed all galaxies and all the rest of the matter would come scurrying, converging to the same point. In short, the universe would have a beginning, albeit a cataclysmic, violent one. Hence the Big Bang.

This is agreed to by many of the world’s leading scientists, like Stephen Hawking (1970) but there are many others who are bitterly opposed to the conclusion. With strong reasons, though. Hawking’s ideas are based on Albert Einstein’s General Theory of Relativity (1915), and his own mathematical genius. (For better understanding, read A Brief History of Time by S. Hawking).

The Big Crunch: The Big Bang in reverse! Although the BB is the generally accepted theory for the beginning of the universe, there is no generally accepted theory for its end. The universe may go on expanding forever, becoming emptier, colder, bigger and deader. This is called the Open Universe Theory.

If the Big Crunch is the fate of the universe (for some horrendous thing must happen in the end), the end of time will be billions of years in the future, because the universe should take as long to collapse as it did to expand, which is such a long and agonising process that it has been continuing over the past at least 16 billion years coming to a dead halt nowhere in the next three to four billion years before it contracts again. However, there will be a time when the universe comes to a dead stop, before it moves again (inward). What will happen then is the big question.

We shall learn what happens then. Keep your fingers crossed until the moment that day arrives and I try to provide you with the answer soon enough! Meanwhile, take a good care of yourself and sleep soundly for nothing untoward is going to happen in the next couple of billion years or so!

Read Comments

Pakistan ‘may withdraw’ from Champions Trophy after India refuse to cross the border Next Story