今週は、北京の清華大学で開かれた超弦理論国際会議 Strings 2016 に行ってきました。
中国では１０年前にも、北京で超弦理論国際会議 Strings 2006 が開かれました。その時に比べて若い大学院生の参加者数が圧倒的に増えていて、中国の基礎科学の伸びに強い印象を受けました。
This banquet reminds me of a poem Li Bai of the Tang Dynasty wrote during one of his trips, saying that the hospitality of his host made him forget that he was away from home . Many of us have indeed traveled from faraway places to meet and discuss with each other and learn about latest developments in all areas of string theory.
In these days, there are many conferences and workshops on subareas of string theory, but the String Conference plays a special role in our scientific community. It presents string theory as a unified field, where discoveries in subareas are interconnected. There is something special about sitting through talks in many subareas and appreciating the richness and vibrancy of the field as a whole. Each year, the Strings Conference takes us to a different part of the world and still makes us feel at home, as Li Bai wrote.
I entered the graduate school in Kyoto in 1984, when Michael Green and John Schwarz discovered the anomaly cancellation in the Aspen Center of Physics and triggered the first superstring revolution. That was 7 years before the arXiv was launched, and their preprint took 3 months to travel from Caltech to Kyoto, but it was worth the wait.
I was particularly fascinated by the paper on the Calabi-Yau compactification by Candelas, Horowitz, Strominger and Witten. I think it is the first paper where the term, Calabi-Yau manifold, was used. The paper showed how the intricate structure of the standard model of particle physics can be encoded in the geometry of the Calabi-Yau manifold. I found it beautiful. In that winter, I was asked to report on the paper at a meeting in the Yukawa Institute in Kyoto. I was given 30 minutes to speak, but I could not stop after 2 hours. Eventually, a guard came in and turned off the heat. Fortunately, the director of the Yukawa Institute, Ziro Maki, kindly let us use his office, which had a separate heating system, and we discussed there past midnight. It was very exciting.
In those days in the 80’s, there were not many international conferences that a student from Kyoto can attend, and the first one I attended abroad was in India in 1987. It was there that I realized how important it is to meet each other and to discuss in person since there are knowledge and insight that are difficult to communicate on papers.
The Strings Conference has been an important asset to our scientific community, and I am grateful that our friends in China are hosting it for the second time this year. I am impressed by the number of young Chinese students and their active participation to the conference, showing the vitality and strength of the scientific community here. I and my colleagues in Japan are looking forward to welcoming all of you in Okinawa in 2018.
Theorists are like travelers without a map, and the Strings Conference provides us an oasis to stop by and see how far we have come. As Xin Qiji of the South Song Dynasty wrote in his tribute to the Bodhisattva, there may be countless mountains and hills obstructing our view, but the waters behind them will eventually come through . And we will have a lot of fun finding them out. Thank you.
 李白 「客中行」
 辛棄疾 「菩薩蛮 書江西造口壁」