On Einstein's New Theory^ 



By Leopold Infeld 



Physics Institute, Warsaw, Poland 



In 1905, when our century was still young, Einstein was 26 and 

 a clerk in the Swiss patent office. In that year he wrote a paper 

 that changed the face of science. It contained the basic ideas of 

 Special Eelativity Theory and revolutionized the concepts of space 

 and time. Einstein was the first man on our planet to deduce the 

 relation between mass and energy — a simple but fundamental relation 

 that, 40 years later, led to the discovery and utilization of atomic 

 energy. Thus, 45 years ago, the first Einstein revolution in science 

 was accomplished. 



If Einstein had done nothing since then, his name would live for 

 centuries in the history of science. Yet only 10 years later, around 

 1915, Einstein finished his work on General Eelativity Theory. Here, 

 for the first time since Newton, a new theory of gravitation was formu- 

 lated. This theory explains how the earth attracts the moon, how the 

 planets move around each other; it explains the structure of our 

 universe. As a logical system, Einstein's theory of gravitation is 

 superior to Newton's old theory. Whenever the conclusions of New- 

 ton's and Einstein's theories differ, observation — the supreme judge 

 of all physical theories — seems to favor Einstein's. Thus, 35 years 

 ago, the second Einstein revolution in science was accomplished. 



The characteristic feature of Einstein's genius is his complete in- 

 dependence of mind. He accepts no man's dogma; he thinks for 

 liimself, always and about everything. From 1918 to 1949, for over 

 ,^0 years, he has worked on one of the deepest and most difficult 

 problems in science : to find a theory that would embrace the large- 

 scale phenomena (as his old theory of gravitation did) and, at the 

 same time, the small-scale phenomena concerning the elementary 

 particles of which atoms are built. Many scientists believed (and 

 still believe) that so ambitious a plan can never be realized — that the 



^ Reprinted by permission from the American Scholar, Autumn 1950. At the time this 

 article was written Dr. Infeld was Professor of Applied Mathematics at the University 

 of Toronto. 



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