This volume of The Collected Papers of Albert Einstein contains the
scientific work Einstein published during the first decade of his
career, and includes some of the most significant achievements of
twentieth-century physics. The first paper was written in 1900 by the
twenty-one-year-old Einstein, newly graduated from the Swiss Federal
Polytechnical School, or ETH, in Zurich and still searching in vain for
a job. The last paper in this volume is the text of an invited lecture
given in 1909 to a major scientific meeting by Einstein after he was
appointed to his first academic post at the University of Zurich. He had
already been recognized as an important theoretical physicist on the
basis of the work reprinted here, particularly the three masterpieces
that appeared in quick succession during 1905, Einstein's year of
miracles. In one of these papers Einstein showed how one could finally
confirm the ancient view that matter is composed of discrete atoms, and
even measure the numbers and masses of these atoms. In a second paper,
which even he referred to as "very revolutionary, " he argued that the
observed properties of thermal radiation suggest that it consists not of
waves, but rather of localized particles of energy which he called
energy quanta. The third and most famous paper set forth the special
theory of relativity, solving some long-standing difficulties, but
requiring a significant change in our understanding of those basic
concepts, space and time.