Post-docs: Linus Carl Pauling FRS (/ˈpɔːlɪŋ/ PAW-ling; February 28, 1901 – August 19, 1994)[4] was an American chemist, biochemist, chemical engineer, peace activist, author, and educator.

[10] In his later years, he promoted nuclear disarmament, as well as orthomolecular medicine, megavitamin therapy,[11] and dietary supplements, especially ascorbic acid (commonly known as Vitamin C).

[17][18] In 1902, after his sister Pauline was born, Pauling's parents decided to move out of Portland to find more affordable and spacious living quarters than their one-room apartment.

[19]: 4  Lucy stayed with her husband's parents in Oswego until Herman brought the family to Salem, where he worked briefly as a traveling salesman for the Skidmore Drug Company.

They approached local dairies offering to perform butterfat samplings at cheap prices but dairymen were wary of trusting two boys with the task, and the business ended in failure.

[7][21][22] Pauling held a number of jobs to earn money for his future college expenses, including working part-time at a grocery store for US$8 per week (equivalent to US$220 in 2023).

[19]: 25 In his first semester, Pauling registered for two courses in chemistry, two in mathematics, mechanical drawing, introduction to mining and use of explosives, modern English prose, gymnastics and military drill.

[19]: 29 In his last two years at school, Pauling became aware of the work of Gilbert N. Lewis and Irving Langmuir on the electronic structure of atoms and their bonding to form molecules.

[41] The two men planned to mount a joint attack on the nature of the chemical bond: apparently Oppenheimer would supply the mathematics and Pauling would interpret the results.

After returning, he built an electron diffraction instrument at Caltech with a student of his, Lawrence Olin Brockway, and used it to study the molecular structure of a large number of chemical substances.

[47][36]: Preface  It is based primarily on his work in this area that he received the Nobel Prize in Chemistry in 1954 "for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances".

[citation needed] In the mid-1930s, Pauling, strongly influenced by the biologically oriented funding priorities of the Rockefeller Foundation's Warren Weaver, decided to strike out into new areas of interest.

[57] It took eleven years for Pauling to explain the problem: his mathematical analysis was correct, but Astbury's pictures were taken in such a way that the protein molecules were tilted from their expected positions.

Pauling later cited several reasons to explain how he had been misled about the structure of DNA, among them misleading density data and the lack of high quality X-ray diffraction photographs.

[64] Along the same lines, with the physicist turned biologist Max Delbrück, he wrote an early paper arguing that DNA replication was likely to be due to complementarity, rather than similarity, as suggested by a few researchers.

[68] His success with sickle cell anemia led Pauling to speculate that a number of other diseases, including mental illnesses such as schizophrenia, might result from flawed genetics.

His project group, which included Joseph B. Koepfli and Dan H. Campbell, developed a possible replacement for human blood plasma in transfusions: polyoxy gelatin (Oxypolygelatin).

In October 1948, Pauling, along with Lee A. DuBridge, William A. Fowler, Max Mason, and Bruce H. Sage, was awarded a Presidential Medal for Merit by President Harry S. Truman.

In November 1945, Pauling spoke to the Independent Citizens Committee of the Arts, Sciences and Professions (ICCASP) on atomic weapons; shortly after, wife Ava and he accepted membership.

[102] On January 15, 1958, Pauling and his wife presented a petition to United Nations Secretary General Dag Hammarskjöld calling for an end to the testing of nuclear weapons.

[102] This group, headed by Barry Commoner, Eric Reiss, M. W. Friedlander and John Fowler, organized a longitudinal study to measure radioactive strontium-90 in the baby teeth of children across North America.

The "Baby Tooth Survey", published by Louise Reiss, demonstrated conclusively in 1961 that above-ground nuclear testing posed significant public health risks in the form of radioactive fallout spread primarily via milk from cows that had ingested contaminated grass.

[106][107][108] The Committee for Nuclear Information is frequently credited for its significant contribution to supporting the test ban,[109] as is the ground-breaking research conducted by Reiss and the "Baby Tooth Survey".

)[111] They described him as "Linus Carl Pauling, who ever since 1946 has campaigned ceaselessly, not only against nuclear weapons tests, not only against the spread of these armaments, not only against their very use, but against all warfare as a means of solving international conflicts.

In 1960, he was ordered to appear before the Senate Internal Security Subcommittee,[114] which termed him "the number one scientific name in virtually every major activity of the Communist peace offensive in this country".

He made speeches, signed protest letters and communicated personally with the North Vietnamese leader, Ho Chi Minh, and gave the lengthy written response to President Johnson.

[citation needed] In 1965, Pauling read Niacin Therapy in Psychiatry by Abram Hoffer and theorized vitamins might have important biochemical effects unrelated to their prevention of associated deficiency diseases.

[158] Linus Carl Jr. (1925–2023) became a psychiatrist;[159] Peter (1931–2003) a crystallographer at University College London;[160] Edward Crellin (1937–1997) a biologist;[161] and Linda Helen (born 1932) married noted Caltech geologist and glaciologist Barclay Kamb.

[68] Pauling's 1951 publication with Robert B. Corey and H. R. Branson, "The Structure of Proteins: Two Hydrogen-Bonded Helical Configurations of the Polypeptide Chain," was a key early finding in the then newly emerging field of molecular biology.

[177][178] His description reads: "A remarkably versatile scientist, structural chemist Linus Pauling (1901–1994) won the 1954 Nobel Prize in Chemistry for determining the nature of the chemical bond linking atoms into molecules.