John Wilder Tukey (1915–2000) was one of the most influential statisticians of the 20th century. While he worked simultaneously for Bell Labs and Princeton, he was also a government and corporate consultant. His contributions to statistics were almost too many to mention but included the Stem-and-Leaf Diagram, the Cooley-Tukey Fast Fourier Transforms (algorithms that speed data processing), Tukey’s Paired Comparisons, and citation and permuted indices. Computer technology was an early feature of his work; he was the first to use the word "software" in print and coined words such as "bit" and "linear programming." A prolific writer, his collected papers amount to eight volumes of work. Beyond his scientific work, his collection reveals two hobbies: reading pulp mysteries and science fiction, and square dancing. 

The APS Library holds one of the best collections of Drosophila (small fruit fly) scientists in the world. In addition to Stern, Dobzhansky, and Demerec, the Library has the papers of Hampton Carson, Frances Clayton, Harrison Stalker, and Jack Schultz. The scientist who truly put Drosophila in the forefront of genetics research was Thomas Hunt Morgan. Using Drosophila melanogaster, he conclusively demonstrated that chromosomes carry specific traits, thereby linking Mendelian genetics with Darwinian ideas of natural selection. Morgan’s laboratory at Columbia University became world famous. The APS Library has a small but interesting collection of original Hunt material.

Stanislaw Ulam is not a household name today, but he was significant player in the development of mathematics in the 20th century. A Polish immigrant to the United States, Ulam is known best for two contributions to the development of nuclear technology. The first, the Monte Carlo Method, makes it possible to use random sampling to solve mathematical and physical problems involving large amounts of data and many possible solutions. The Monte Carlo Method can be used to estimate the yield of atomic bombs and is now commonly used in fields such as economics.  

The other contribution is to the development of hydrogen bombs. The basic design for apparently all thermonuclear devices is called the Teller-Ulam design (much about such technology is highly classified, so no one knows for sure), but who contributed what when is still a subject of debate. It is probable that Ulam came up with the idea of separating the fission explosion (used as a trigger) from the fusion explosion, Teller originating the idea that one can compress the fusion fuel with radiation before igniting it. Teller was an enthusiast for the “super” even before the atomic bomb was produced. Teller and Ulam wrote a paper on their theory in March 1951, a paper only known to the public in redacted versions.

One can count on one hand scientists whose work truly changed the world and gave them lasting, now-universal recognition: Galileo, Newton, Einstein—and Charles Darwin. One of the most important natural historians in 19th-century Britain, Charles Darwin provided the first compelling mechanism to account for organismal evolutionary change. Although lacking a coherent model of heredity, Darwin's natural selection has exerted an enormous influence over the biological sciences and since the introduction of Mendelian genetics, had remained the key unifying principle in the discipline.

The APS Library has an important collection of Darwin material. The Valentine Darwin Collection contains 4,800 printed items in many languages. In addition, the Library holds the largest collection of Darwin correspondence outside England. 

The APS Library holds the collections of seven Nobel laureates. Two of those won their Nobel Prize in the same year: 1976. D. Carleton Gajdusek received for the prize for his work in New Guinea on a neurological disease called kuru, spread by ritual cannibalism among the Fore people. Baruch Samuel Blumberg earned his Nobel by discovering the causative agent of hepatitis B and developed a corresponding vaccine. The vaccine was brought into production by Merck & Company through the work of APS Member Maurice Hilleman. Although based at Fox Chase Cancer Center in Philadelphia, Blumberg traveled and lectured extensively. He also served as master of Balliol College, Oxford (from where he had received a Ph.D. in biochemistry on top of his M.D. from Columbia), and as the first director of the NASA Astrobiology Institute. He died while still serving as President of the APS. Blumberg’s journals, some 79 of them, as well as his extensive papers, provide superb documentation of his remarkable career.