The history of quantum field theory (QFT) is one of inconsistencies and attempts at overcoming them. Specifically, Blum’s history of quantum electrodynamics (QED) (ms.) shows that it is one of inconsistencies at high or ultraviolet (UV) energies. While it was known early on that QED also had divergences at low or infrared (IR) energies, IR problems are considered less pathological. Four decades after QED, it was discovered that the theory we now call quantum chromodynamics (QCD) is “asymptotically free”—well-behaved in the UV. Although QCD also bore the worst of QED’s inconsistencies, the Landau pole, asymptotic freedom put worries about the consistency of QFT to rest. The only difference between QED’s and QCD’s Landau poles was that the former lies in the UV and the latter in the IR. Is there a historical explanation for this double standard? A common reaction to QED’s inconsistencies was to reject QFT altogether—call this attitude “Replacement.” A common reaction to QCD was that cleverer ways of looking at or extending RG techniques would prevent a catastrophe in the IR—call this attitude “Refinement.” One goal of my paper is to chart the history of asymptotic freedom, which is undertheorized from the point of view of QFTs (as opposed to a history of the discovery of particles like quarks). Another goal is to compare my historical reconstruction of QCD with Blum’s of QED and draw some philosophical morals about the differences between Replacement and Refinement.

In 1824, Biot detailed the process by which the Biot-Savart's Law was derived in his published work. Biot conducted experiments with both straight and bent wires, and in processing the data from the bent wire experiments, he unnaturally introduced a more complex functional relationship: replacing the rather evident "proportional to $F\frac{2i}{\pi}$" with "proportional to $F\tan \frac{i}{2}$," where $i$ is the angle between the bent wire and the horizontal plane. Upon examination of the relevant literature, it is discovered that prior to Biot's 1824 experiments, contemporary scientists Ampère and Savary had already determined that Biot's experimental data "should be proportional to $F\tan \frac{i}{2}$." Based on Biot's article and Ampère's statements, in conjunction with the debate between Biot and Ampère, it can be inferred that obtaining the correct functional relationship satisfied by the experimental data of the bent wire solely from Biot's experiments would have been nearly impossible. It is highly likely that Biot drew upon Savary's conclusions without acknowledging the contributions of Ampère and Savary.

Computational fluid dynamics (CFD) is a scientific field where digital computers are extensively used to study fluid flows and, as such, one of the subfields of computational science. This paper provides a case study of the emergence process of CFD by focusing on Japan in the 1950s and 1960s. While the term CFD came to be widely used in the late 1980s through a research project organized by researchers in mechanical and aeronautical engineering, a small group of physicists were tackling hydrodynamical problems by numerical methods decades before. Around the 1960s, when the first Computer Center was established at the University of Tokyo, some of the specialists in hydrodynamics began to use digital computers. They were physicists by academic training and had been supervised by Isao Imai, a professor at the University of Tokyo and a leading figure in fluid physics. Although Imai himself didn’t use electronic computers, he encouraged his students, including Mitutosi Kawaguchi and Hideo Takami, to employ the new technology, leading to their pioneering works in CFD. The author argues that two conditions enabled these physicists’ numerical studies. One was a series of research programs hosted by the Institute for Mathematical Sciences that was established in 1963. The other was Imai’s theoretical study on high-speed airflow before the 1950s, where Imai did extensive computation with a desktop “Tiger Calculator” in addition to mathematical analysis. This paper thus proposes a continuous view of the historical development of computational science before and after digital computing.