Deepak Subedi

When we started to conduct a regular series of popular lectures on Einstein’s life and achievement to mark the World Year of Physics 2005 in connection with Einstein Centenary Year, I was looking for a book which consisted of historical description of Einstein’s monumental work in Physics. To my surprise, I found a book entitled

**written by David Bodanis. After going through the book, I was encouraged to write a review on its praise.***A Biography of World’s Most Famous Equation*The book presents a very good description of the development of basic conservation laws in Physics. The author has skillfully presented the physical theories in extremely simple and interesting way so that readers without the background of Physics and Mathematics can also grasp the theme. The book has been successful to become popular among the

*popular science books*. The*Times*magazine wrote about the book: “with skill and plenty of colorful anecdotes Bodanis traces the intellectual ancestry of E=mc^{2}“.The book is divided into five parts. In the first part, the author introduces the birth of the equation. It gives glimpses of the childhood of the equation which surrounds around 1905 when the three revolutionary papers by Einstein were published. One of these papers was on special theory of relativity which consisted of the ever popular equation.

The second part of the book discusses the development of the law of conservation of energy and highlights the contribution of Michael Faraday

**in this work. It says that Faraday discovered his law of Electromagnetic induction showing a link between electric and magnetic fields which once seemed totally different. An extraordinary vision of energy concept was created by Faraday’s work. It helped to formulate the law of the conservation of energy. The scientific community was more confident that every other form of energy could similarly be shown deeply inter-connected.**In the third part of the book, the author presents a detailed history of the development of the law of conservation of mass. For a long time the concept of mass had been like the concept of energy before Faraday. With his meticulous experiments, Lavoisier showed that matter could convert from one form to another, yet it will not burst in and out of existence. This law of conservation of mass was as much important as Faraday’s work on energy. The substances that fill our universe can be burnt, squeezed or hammered to bits but they won’t disappear. This finding worked as building block for a more general law of conservation which was put forward by Einstein at the beginning of 20

^{th}Century. Einstein later proved in an extraordinary way that there was a link between these two domains. So, a more general law of conservation of mass and energy taken together was formulated. The most remarkable aspect of the discovery was to show that mass and energy are equivalent. It unleashed a secret that tremendous amount of energy can be released from a very small amount of matter.The next part of the book covers period around the second world war when the first experimental results of nuclear fission of heavy elements were reported. In fact these were the experimental evidences to validate the equation.

In the final part of the book, the author switches away from war and describes several areas where the equation has been applied. This period has also been termed as the adulthood of the equation.

I liked this book very much. So far as I know there is also a documentary available based on this book. I recommend this book to anyone who would love to peer into the history of the amazing world of physics.

**Works consulted**

F. Macdonald,

*Albert Einstein*, Orient Longman Limited, Mumbai, 1994.D. Bodanis,

*A Biography of the World’s Most Famous Equation*, Pan Books,<http://www.sparknotes.com/biography/einstein>