If one's science experiment or paper is "elegant", it arrives at the answer or explains a problem -- often one that has remained elusive for years -- with clear, insightful form that prompts smiles, admiration and sometimes chagrin from one's colleagues. Einstein's descriptions of matter and energy are perhaps quintessentially elegant, though the description no doubt underplays their significance. Physicist Brian Greene does justice to all his subjects as he eloquently walks through E=mc² and how Einstein's vision for physics described anew the relationships between mass, energy and the formation of the universe, in "That Famous Equation and You", published in yesterday's New York Times.
"But by September, confident in the result, Einstein wrote a three-page supplement to the June paper, publishing perhaps the most profound afterthought in the history of science. A hundred years ago this month, the final equation of his short article gave the world E = mc²."
The equation is well entrenched in our culture, it's faddish even, blithely plastered onto T-shirts and posters and paraphernalia for sale in campus stores. While many people wear the formula across their chests however, they often misconstrue its significance. Greene points out that Einstein actually published about M=E/c² and the paper emphasized the creation of mass from energy that Greene describes via a jousting scenario, not the creation of energy from mass associated with nuclear reactions. The equation describes not just the extraordinary energy reactions but ubiquitous, everyday ones:
"There is nothing you can do, not a move you can make, not a thought you can have, that doesn't tap directly into E = mc². Einstein's equation is constantly at work, providing an unseen hand that shapes the world into its familiar form..."
The theory reoriented how scientists thought about energy and led to Einstein's General Theory of Relativity and then to Einstein's work to derive a "single theory encompassing all of nature's laws".
"For the better part of his last 30 years, Einstein pursued the "unified theory," but it stubbornly remained beyond his grasp. As the years passed, he became increasingly isolated; mainstream physics was concerned with prying apart the atom and paid little attention to Einstein's grandiose quest. In a 1942 letter, Einstein described himself as having become a "a lonely old man who is displayed now and then as a curiosity because he doesn't wear socks."
Today this work continues and it "is no curiosity - it is the driving force for many physicists of my generation", says Greene. Succinctly describing the formation of the universe is not trivial but the task has progressed significantly. Now scientists:
...[have] established beyond any doubt that a fraction of a second after creation (however that happened), the universe was filled with tremendous energy in the form of wildly moving exotic particles and radiation. Within a few minutes, this energy employed E = mc² to transform itself into more familiar matter - the simplest atoms - which, in the course of about a billion years, clumped into planets and stars."
"During the 13 billion years that have followed, stars have used E = mc² to transform their mass back into energy in the form of heat and light; about five billion years ago, our closest star - the sun - began to shine, and the heat and light generated was essential to the formation of life on our planet."
It's good to be reminded of this "unseen hand" that is so often subordinated to some distorted permutation of the "invisible hand". While the latter is used to press us on in our daily chores, when we understand the former we are put in our place and reminded of the relative power of each.
Obviously the excerpts cannot do justice to the article, located here. The author's research is in the area of string theory and he has written a couple of books including the well-reviewed popular science book The Elegant Universe.
