On the occasion of the 100th volume of the Proceedings of the Japan Academy, Series B (PJA-B)

The Proceedings of the Japan Academy (PJA) commenced its publication in 1912 to record the proceedings of regular meetings of the Imperial Academy (now known as the Japan Academy) and to make them accessible to international readers. However, its publication schedule was irregular until volume 2, which began regular annual publications of 10 issues in 1926. It was later divided into the present Series A (mathematics) and Series B (all branches of natural sciences) starting from volume 53 in 1977. Since then, both series have maintained the same volume numbering, and both will reach volume 100 next year.

Reaching the 100th volume is a significant milestone for any academic publication, prompting reflection on the past and planning for active development in the future. It provides us with a valuable opportunity to step away, even briefly, from the busy daily routine of editorial operations and contemplate the fundamental aspects of how influential scientific publications should be. For the Japan Academy, the PJA serves the important purpose of disseminating not only the Japan Academy's activities but also contributions of Japanese scientists to the international scientific community.

Realizing the significance of this momentous occasion, we have decided to commemorate it with a series of publication events. In this inaugural issue of the volume 100 commemoration, we are privileged to feature a special article by Dr. Masanori Iye. It offers an overview of the entire publication history of the PJA. As highlighted in Dr. Iye's article, the PJA-B (originally PJA) publishes articles of diverse nature. Some authors use PJA-B as their primary medium to publish a series of important findings and to advance their field, while others choose PJA-B to swiftly publish their initial critical papers and subsequently report progress through other channels.

We have selected 20–25 articles for reproduction in the 100th volume. These articles describe impactful works conducted in Japan that have made significant contributions to the respective fields. We will reproduce these articles exactly as they were originally published in order to convey their historical significance. Experts in their respective fields will review and evaluate the articles, placing them in its proper historical perspective.

We are commencing the volume 100 commemoration with the publication of this issue prior to the official start of volume 100. We sincerely hope that our readers will enjoy the history and current state of the PJA-B through this commemorative program, which commences now and will continue until the end of next year.

Proceedings of the Imperial Academy, Vol. 1, No. 1 (1912)