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Let us invite you to a Brown Bag Seminar by Roman Dimakov
on May 23th, 2024, at 12:50 in room 402

You can also join the seminar online:
https://call.lifesizecloud.com/21194066
Passcode: 3691

Presenter: Roman Dimakov

Title: “Peer Effects and Reception of Innovations in Science: Evidence from the Advent of Quantum Mechanics in 1925-26”

Abstract:
A characteristic of the immediate reception of innovations is that people (and scientists) often tend to find what they are looking for, but also fail to recognize what they are not prepared to see. Prior background, expectations and prejudices can accelerate the reception of scientific innovations for ones but hamper it for the others. What you know and what you are ready to believe might crucially depend on whom you talk to. In economic literature, peer effects have been proved to have a significant effect on socio-economic outcomes of scientists’, including their lifetime career success.
In this paper, I compare the success of scientists (as measured by citations they gather) who adhere to ideologically different scientific theories which deal with the same class of nature phenomena yet, and only one theory often proves to be correct. I use citations as an outcome since citations can be a proxy for recognition of a scientist’s contribution to science by peers.

I consider the historical case of the advent of quantum mechanics of atomic structure and processes by HeisenbergSchrödinger in 1925-26 (a major break-through in science). Prior to the discovery, physicists were naturally divided into two “camps” which were ideologically different in their approaches towards the development of the theory of the atom.
The first camp tried to preserve causality and determinism in the description of atomic processes, which is inherent to classical Newtonian physics. Max Planck, Albert Einstein and Erwin Schrödinger were among the advocates of the approach. The culmination of the approach was the creation of wave mechanics by E. Schrödinger in 1926. The second camp, in contrast, declared the need to abandon causality in the description of atomic processes since they were fundamentally a-causal and not deterministic, as they believed. The advocates of the approach included Werner Heisenberg, Max Born and Niels Bohr. The culmination of the approach was the creation of matrix mechanics by W.
Heisenberg in 1925. The two “camps” were in strong antagonism and competition with each other over some time.
Eventually, the a-causal approach (i.e. matrix mechanics of Heisenberg) won the dominating role in quantum physics and became known as Copenhagen's interpretation of quantum mechanics. The historic outcome commemorates the “death of determinism in quantum physics.” Hence, the case provides an opportunity to study how scientists that belonged to opposing camps reacted to the advent of quantum mechanics and how their reaction influenced their subsequent success in science (citations).

I use novel data on scientific correspondence among physicists in the first half of the twentieth century to determine who was talking to whom via letters, which can be a proxy for modern-day (potentially unobservable) communication of people through the Internet. My preferred empirical strategy is the Difference-in-Difference (with potential specification adjustments in the future). The key identifying assumption is that physicists belonging to different camps exhibited parallel citation patterns in the period prior to the discovery of quantum mechanics (since, according to historians of science, reasons to reject causality in physics were “only incidentally related to developments in their own discipline”). The opposing camps are treated and control groups. The treatment group consists of physicists who were in correspondence with the future founders of matrix mechanics (i.e. the advocates of the a-causal approach - Heisenberg, Born, Bohr, etc.) prior to the discovery. The control group consists of physicists who were not in correspondence with the a-causal camp, but rather were in correspondence with proponents of the usual causal approach, i.e. Schrödinger, de Broglie, Einstein, etc. Hence, the two groups were treated in fact but by different treatments. The main research hypothesis is that scientists who belonged to the camp of the pro-causal approach in quantum mechanics (which eventually failed) exhibited significantly lower number of (weighted) citations after 1925-26 than those scientists who belonged to the camp of the a-causal approach to quantum mechanics.