But one of Roberts' most notable achievements was human - when he moved from MIT to Caltech, he brought with him Caltech's first female graduate student, Dorothy Semenow.
Roberts certainly played an important role in admitting the institute's first woman, but Semenow's transition would likely have not been possible without the intervention of one of the world's greatest scientists, Linus Pauling, who was then chairman of Caltech's chemistry department. Here's what Roberts says in his autobiography about Pauling's stamp on this historic change:
"Caltech, unlike MIT, did not admit women as students, although there were a few female postdoctoral fellows. I talked to Linus about Dorothy and her strong desire to come to Caltech. To my surprise, he showed immediate interest. He told me that the question of admitting women had been raised not many years earlier, and that the faculty had voted not to change. Furthermore, he said that the Institute's trustees had taken note of the faculty action and had endorsed it. But he said he wanted to try again with a specific case, and asked that Dorothy submit an application as soon as possible.
I wasn't on hand and had no idea what happened at Caltech during the decision-making process. It was certainly to the credit of both Caltech and Linus that the matter was settled by the end of the academic year, including approval by the trustees. There were stories that I had said I would not come if Dorothy was not admitted. That was not true. I only presented the case and others carried the ball, but it was wonderful to be associated with an institution that could act so quickly to change a very strong tradition."
It is certainly to Roberts' credit that he pressed for the change. It is also to his credit that he admits at the end that his role in the whole affair was not as gallant as the New York Times and others think it was. At Caltech Semenow did very strong work validating one of Roberts' key contributions to chemistry, the discovery of benzyne which is a very unusual benzene double with a triple bond. After an academic career in which she also acquired a PhD in psychology, she now seems to be advancing chemical education through games.
Interestingly, I found a reference to Dr. Semenow in a 1953 Caltech publication which seems to be some kind of monthly campus newsletter. After acknowledging her admission, the newsletter curiously says the following:
"This gallant action is not, however, an open invitation to the ladies. It applies only to "women of exceptional ability who give promise of great scientific contributions." And, before she can enroll, a woman must get the approval of the academic division in which she intends to work, as well as that of the Committee on Graduate Study.' With such hurdles as these, it is hardly likely that the campus will ever be swarming with female students. Most admissions of women, in fact, will probably involve the use of unique or outstanding research facilities here."
Yes, that charming second paragraph does seem to put a dent into the unprecedented event which it heralds, reassuring its readers not to worry about the campus "swarming" with the ladies (who understandably would of course distract all the gents). In fact, until 1967, Caltech's catalog proclaimed that female students would be admitted, "but only in exceptional cases". Now I am willing to cut Caltech some slack here - it was 1953 after all - but it does show how far they still had to go even after Semenow moved there from the more egalitarian MIT.
How times have changed. Today Caltech has about 30% female graduate students, and while there clearly can be an improvement in this number, it was Dorothy Semenow, Jack Roberts and Linus Pauling who blazed that trail.