School of Science The University of Tokyo 2020 The Frontier of Natural Science What is Science? Science is a study that unravels the mysteries of the universe. It strives to create new knowledge by understanding nature. This begins by approaching nature with a simple question in mind: “Why?” This pamphlet will present some of the activities carried out by the School of Science at the University of Tokyo, which aim to cultivate skilled and knowledgeable members of society through exploring nature. Faculty of Science Graduate 10 undergraduate departments School of Science dedicated to studying science 5 graduate departments dedicated to gaining a deeper understanding of science Mathematics／Information Science Physics／Astronomy Physics／Astronomy Earth and Planetary Physics Earth and Planetary Science Earth and Planetary Environmental Science Chemistry／Biological Sciences Chemistry／Biophysics and Biochemistry Biological Sciences Bioinformatics and Systems Biology Contents The Joy of Unraveling the Mysteries of Nature 01 Explorers of the Field of Science 02 International Programs at the School of Science 04 School of Science as a Global Hub 05 Departments in the Faculty of Science 08 Graduate Departments to Nurture Science 10 History of the School of Science 12 Column A Mountaintop Perch with Views of the Starry Sky 13 Editing: Masatsugu Kayahara Interviews and writing: Masatsugu Kayahara, Jiro Urushihara and Toshihiro Nakamura Photography: Junichi Kaizuka Design: Mitsunobu Hosoyamada and Azusa Suzuki（ Hosoyamada Design Office） Writing and editorial supervision: Office of Communication, School of Science, The University of Tokyo Science seeks to solve the unknown mysteries of nature. It involves finding your own answers to challenging questions that defy solution. You could also say that it is an epic adventure with endless challenges and joys. As such, the School of Science at the University of Tokyo will continuously satisfy your spirit of inquiry and intellectual curiosity. Science is also the cornerstone of the development and prosperity of society. For example, the GPS we use for navigation is based on The Joy of Einstein's theory of relativity, and the semiconductor devices found in computers operate on the principles of quantum mechanics. In this way, scientific discoveries and ideas have dramatically enriched human Unraveling the lives. Mysteries of Nature Through the process of unraveling the mysteries of nature, in the School of Science you can learn to think logically and acquire the skills to solve the problems facing our society. A science-based approach is indispensable for tackling these difficult challenges, including the serious problem of global warming that we face today. I strongly believe that your studies in the School of Science will be a great source of strength for humanity. Dean of the School of Science The University of Tokyo Masahiro Hoshino Masahiro Hoshino graduated from the Department of Geophysics in the School of Science at the University of Tokyo in 1981, and was awarded a Doctor of Science with a major in space physics in 1986. After serving as a researcher at NASA Goddard Space Flight Center and as an associate professor at the Institute of Space and Astronautical Science (ISAS), he has been a professor of the Department of Earth and Planetary Science at the University of Tokyo since 1999. In April 2020, he was appointed to his current position as Dean of the School of Science. 01 01 Explorers of the Field of Science Attracted by the freedom of mathematics Potential to expand into the world of logic The world of mathematics is strictly governed by logic—if it can be proved, any approach is acceptable. Attracted by that freedom, singularities are my daily challenge. Algebraic geometry is a discipline that of an algebraic variety without a Department of Mathematical Engineering bridges algebra, which deals with symbolic singularity can be analyzed by and Information Physics, which teaches expressions, and geometry, which deals differentiation, but this doesn’t work for applied mathematics. with figures. As Professor Takagi describes those with singularities. “I was interested in applied it, “algebraic geometry is the field of study Professor Takagi studies algebraic mathematics, but I was also concerned in which figures are analyzed algebraically.” varieties in the unique world of about whether I could keep up with It is mainly concerned with investigating “characteristic p,” where p is a prime abstract discussions of pure mathematics. the nature of algebraic varieties, special number, in which adding 1 to itself p At that time, I sought advice from types of figures that can be represented by times yields a result of zero. Professor Junkichi Satsuma, who was in polynomials. “Algebraic varieties are classically charge of a class on ordinary differential One thorny problem that arises in the considered in the framework of complex equations, and he recommended that I study of algebraic varieties is that of the numbers.In the world of characteristic p, enter the Department of Mathematics. ‘In so-called singularity. Singularities are however, a “pathological” phenomenon the Department of Mathematical points on algebraic varieties that are “sharp happens, something that isn't seen in the Engineering and Information Physics, or twisted, but not smooth.” The properties case of complex numbers, and this makes students learn the basics of mathematics analysis of figures difficult. The world of at first, and the basics are the same in characteristic p might seem artificial, but both pure and applied mathematics. If it actually has real life implications, as it’s you think you can't keep up with the pure used in encrypted communications on the mathematics in the Department of Internet.” Mathematics, you can go on to the Algebraic geometry is something of a Department of Mathematical Engineering Japanese specialty. Three Japanese and Information Physics in graduate mathematicians have been awarded the school. If you do so, what you learned in Fields Medal, sometimes referred to as the the Department of Mathematics will be Nobel Prize of mathematics, and all three useful.' I followed that advice and entered studied algebraic geometry. Kunihiko the Department of Mathematics, where I Kodaira, the first Japanese to win the soon found my niche in algebraic Fields Medal in 1954, graduated from and geometry.” was later appointed to a professorship in “The attraction of the Department of the Department of Mathematics at the Mathematics is the excellence of its University of Tokyo. The influence of students,” Professor Takagi says. Kodaira still resounds throughout the “We often think of mathematics as a department today. solitary activity, but it’s very important to Professor Takagi says that the freedom discuss your work with others in order to of mathematics appeals to him. get your ideas into shape. There are so “Ultimately, if you can prove something, many wonderful people around me, it’s an you can choose any approach you wish, excellent working environment.” no matter how outrageous. The exciting part is that your thinking is completely unfettered.” He was fascinated by this freedom of Graduate School of Mathematical Sciences thought since he was an elementary Mathematics Professor school student. “What I liked doing at that time was Shunsuke Takagi the kind of math question called a word problem. Although they might have been Shunsuke Takagi graduated from the contrived, I enjoyed thinking about real Department of Mathematics at the University of Tokyo in 2000, completed a doctoral course events in terms of numbers.” in the University’s Graduate School of When he was in high school, his Mathematical Sciences in 2004, and became interest in the application of mathematics an Assistant Professor in the Faculty of Mathematics, Kyushu University. He then to real problems grew, even to the extent served as an Associate Professor there and in of reading an introductory text on the Graduate School of Mathematical operations research. When it came to Sciences at the University of Tokyo before taking his current position at the University choosing his path in higher education, he of Tokyo in 2018. He has also been a visiting had a hard time deciding between the researcher at the University of Michigan and Department of Mathematics and the the Massachusetts Institute of Technology. 02 Explorers of the Field of Science The shape of the universe is changing, There are several models describing Japan with an international collaboration. but it’s difficult for humans to recognize how spiral galaxies may be formed. For Researchers including Egusa use different because our time span is too short example, the density-wave model suggests types of data obtained from different compared to that of the universe. that the overall shape of the spiral is telescopes around the world, depending The shapes of galaxies, which number retained even though individual stars are on their scientific goals. in the trillions, have also changed over moving. In the dynamic spiral arm model, When she was in elementary school, time. Six billion years ago, irregular each arm is repeatedly created and Egusa was drawn to the beauty of space in galaxies with amorphous star distributions destroyed, but the shape as a spiral galaxy an NHK TV science program. She entered accounted for the majority of galaxies in is retained over the long term. the Department of Astronomy as she had the universe, but today, spiral galaxies such Research to date has suggested that hoped, and first came across the spiral as the Milky Way account for more than spiral galaxy morphology cannot be galaxy M99 as a candidate research project 70% of the total population. explained by using just one model. in her fourth year. Then the laboratory How have spiral galaxies been formed Assistant Professor Egusa is therefore head Professor Yoshiaki Sofue (currently during this period? Assistant Professor looking closely at spiral galaxies in an professor emeritus) invited her to take it Fumi Egusa addresses this mystery in her attempt to classify them according to the on as a project, as no-one else had.