The Inflationary Universe: Alan Guth

Science

 

The Inflationary Universe-The Quest for a New Theory of Cosmic Origins

Alan H Guth

 

There is a bewitching charm in contemplating the origin of universe. I’ve read innumerable books on the subject but the spell the first book cast only gets denser with every new book. Mere size of the universe numbs the senses. Our world, our dreams, our past, our future are all pinioned to earth which is merely a moderate sized planet in a planetary system revolving around one insignificant star, the Sun, which is one among hundred billion such stars in the galaxy Milky Way, in a universe comprising hundred billion other similar galaxies. Now, hundred billion is a huge number. If someone stacked hundred billion sheets of paper, the pile would reach a staggering six thousand miles in space. I can think of only one subject which is as absorbing, sublime and humbling; the origin of complex life forms on earth.

 

Alan Guth, a theoretical physicist was in the vanguard of scientists who grappled with the intricacies of cosmic origins and the physics of the early universe in the latter half of twentieth century. He is known as the inventor of Inflationary theory of cosmic origins. This theory solved many perplexing tangles in the Big Bang model of the origin of Universe. This book is his story of this quest. He intersperses discussion on physics with snippets of his personal life in those days and anecdotes about other physicists he worked with or came to know. Book also depicts the ambition, the anxieties and the not infrequent frustrations of a young scientist working feverishly on the cutting edge of science and the constant worry of being beaten by another person working on the same problems. It reminds me of another superb book on the discovery of the structure of DNA by James Watson.

 

Inflationary theory is not an alternative theory to the Big Bang theory. As Guth writes Big Bang is not really a story of the Bang but of its aftermath. Inflationary theory proposes a phase of explosive inflation of universe soon after its birth, perhaps when universe was 10^-39 seconds old lasting about 10^-30 seconds. In this time interval universe grew in size by a factor of 10²⁵. And after this the theory merges with the standard Big Bang theory. This proposal explained many hitherto inexplicable facets of universe in Big Bang model. Though this book is on Inflationary theory, Guth lays its foundation by explaining the state of cosmology before the inception of inflationary theory. Thus, the book is also an introduction to cosmology for a lay person interested in physics of origins of universe. Guth explains most of the important topics in cosmology; the expanding universe and Einstein’s insistence to deny it initially, the discovery and the far reaching significance of Cosmic Microwave Background Radiation, Nucleogenesis in early universe and the controversies surrounding it, preponderance of particles over antiparticles, the synthesis of modern theory of Particle Physics in 1970s, the birth of Grand Unified theories and off course the Inflationary theory and how it solved the riddles in the Big Bang theory. He completely avoids mathematical equations but does not simplify the explanations to an extent that they start looking like a distorted image of the original. Book is demanding. It demands unbridled curiosity and sincere effort to know and understand the truth. As Guth says in foreword ‘…the book is aimed primarily at the non-scientist with an interest in science…No special knowledge is expected on the part of the reader…Nonetheless, the book is demanding in other ways…that the reader shares with me a vague craving to understand the universe.’ Book goes a long way in satisfying this craving. I only wish I had the time and energy to study higher mathematics so that I could glimpse and perhaps fleetingly experience the sheer ecstasy, as I watched a universe emerge from the seemingly inert mathematics equation on the paper. Lacking such facilities, I take recourse to fantastic books like this. Another such book on the physics of early universe, highly accessible to a non-scientist is Steven Weinberg’s First Three Minutes.