Whether it is true or not that not more than twelve persons in
all the world are able to understand Einstein's Theory, it is
nevertheless a fact that there is a constant demand for information
about this much-debated topic of relativity. The books published on
the subject are so technical that only a person trained in pure
physics and higher mathematics is able to fully understand them. In
order to make a popular explanation of this far-reaching theory
available, the present book is published.
Professor Lorentz is credited by Einstein with sharing the
development of his theory. He is doubtless better able than any
other man—except the author himself—to explain this scientific
discovery.
The publishers wish to acknowledge their indebtedness to the New
York Times, The Review of Reviews andThe
Athenaeum for courteous permission to reprint articles
from their pages. Professor Lorentz's article appeared originally
in The Nieuwe Rotterdamsche Courant of November
19, 1919.