FIRST EDITION OFFPRINT, PRESENTATION COPY, of Bohr's first published scientific paper, written while he was a 20-year-old student at Copenhagen University. Inscribed by Bohr in Danish on front wrapper to Poul Heegaard, mathematician and professor at Copenhagen University. In original wrappers. More

FIRST EDITION of Bohr, Kramers, and Clarke’s influential paper that “contained drastic theoretical proposals concerning the interaction of light and matter." Printed simultaneously in German in Zeitschrift fur Physik. More

THE ORIGIN OF STATISTICAL MECHANICS: FIRST EDITIONS, JOURNAL ISSUES, IN ORIGINAL WRAPPERS, OF LUDWIG BOLTZMANN’S ATTEMPTS TO DERIVE THE SECOND LAW OF THERMODYNAMICS FROM THE BASIC PRINCIPLES OF MOLECULAR MECHANICS, AND HIS PROPOSAL OF THE “ERGODIC HYPOTHESIS.”. More

FIRST EDITION OFFPRINT IN ORIGINAL WRAPPERS OF BORN’S NEW MATHEMATICAL DESCRIPTION OF QUANTUM PHYSICS, INCLUDING THE FIRST USE OF THE TERM "QUANTUM MECHANICS." More

FIRST EDITION IN ORIGINAL WRAPPERS of the first experimental evidence of the existence of quarks. More

FIRST EDITION IN ORIGINAL WRAPPERS of Compton’s report providing the data and experimental evidence for the dual wave-particle nature of electromagnetic radiation, later called “the Compton effect”. More

FIRST EDITION IN ORIGINAL WRAPPERS of Dirac’s first major paper; a major achievement in the advancement of the new quantum theory. More

FIRST EDITION IN ORIGINAL WRAPPERS of Dirac’s general transformation theory, his own favorite paper and “the pinnacle of Dirac's development of quantum mechanics,” unifying “all proposed versions of quantum mechanics, as well as giving rise to a continuum of other possible versions” (Richard Dalitz). More

AN EXTRAORDINARY LETTER BY EINSTEIN TO HIS SON OFFERING LIFE ADVICE AND DISCUSSING FREUD, SHAKESPEARE, AND SCHILLER. More

FIRST EDITION IN ORIGINAL WRAPPERS of one of Einstein's major papers on the modification of general relativity and the beginning of his unified field theory. More

FIRST EDITION, FIRST PRINTING, IN ORIGINAL WRAPPERS of Einstein’s paper outlining a thought experiment to suggest that the uncertainty principle requires the acknowledgement of an indeterminate past. More

FIRST EDITION of Feynman’s undergraduate thesis at MIT, “a fundamental discovery” published in The Physical Review when he was just twenty-one. More