This article is about the history of science and technology in modern Japan.
Science
In the natural sciences, the number of Japanese winners of the Nobel Prize has been second only to the United States in the 21st century, for contributions made in the 20th century. On the list of countries by research and development spending, Japan is third on the list, behind the United States and China.
Chemistry Frontier Molecular Orbital Theory In 1952, Kenichi Fukui published a paper in the Journal of Chemical Physics titled "A molecular theory of reactivity in aromatic hydrocarbons." He later received the 1981 Nobel Prize in Chemistry for his investigations into the mechanisms of chemical reactions, with his prize-winning work focused on the role of frontier orbitals in chemical reactions, specifically that molecules share loosely bonded electrons which occupy the frontier orbitals, that is the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO).
Chirally catalyzed hydrogenation Ryōji Noyori was awarded the 2001 Nobel Prize in Chemistry for his "work on chirally catalyzed hydrogenation reactions" in 1968.
Proteins and enzymes In the 1960s and 1970s, green fluorescent proteins (GFP), along with the separate luminescent protein aequorin (an enzyme that catalyzes the breakdown of luciferin, releasing light), was first purified from Aequorea victoria and its properties studied by Osamu Shimomura. He was awarded the 2008 Nobel Prize in Chemistry "for the discovery and development of the green fluorescent protein, GFP".
Koichi Tanaka was awarded the 2003 Nobel Prize in Chemistry for the development of soft laser desorption, "methods for identification and structure analyses of biological macromolecules" and for "soft desorption ionisation methods for mass spectrometric analyses of biological macromolecules". In 1987, he demonstrated that laser pulses could blast apart large protein molecules so that ions in gaseous form are produced.
Conductive polymers Hideki Shirakawa was awarded the 2000 Nobel Prize in Chemistry "for the discovery and development of conductive polymers".
Mathematics In the 1930s, while studying switching circuits, NEC engineer Akira Nakashima independently discovered Boolean algebra, which he was unaware of until 1938. In a series of papers published from 1934 to 1936, he formulated a two-valued Boolean algebra as a way to analyze and design circuits by algebraic means in terms of logic gates. (3+207+1 pages) 10:00 min
Medicine In a landmark series of experiments beginning in 1976, Susumu Tonegawa showed that genetic material can rearrange itself to form the vast array of available antibodies. He later received the 1987 Nobel Prize in Physiology or Medicine "for his discovery of the genetic principle for generation of antibody diversity."
Physics Particle physics Hideki Yukawa predicted the existence of mesons in 1934, for which he later received the 1949 Nobel Prize in Physics. Yoichiro Nambu was awarded the 2008 Nobel Prize in Physics for his 1960 discovery of the mechanism of spontaneous broken symmetry in subatomic physics, related at first to the strong interaction's chiral symmetry (chiral symmetry breaking) and later to the electroweak interaction and Higgs mechanism.
The bottom quark is a product in almost all top quark decays, and is a frequent decay product for the Higgs boson. The bottom quark was theorized in 1973 by physicists Makoto Kobayashi and Toshihide Maskawa to explain CP violation. Toshihide Maskawa and Makoto Kobayashi's 1973 article, "CP Violation in the Renormalizable Theory of Weak Interaction", is the fourth most cited high energy physics paper of all time as of 2010. They discovered the origin of the explicit breaking of CP symmetry in the weak interactions. The Cabibbo–Kobayashi–Maskawa matrix, which defines the mixing parameters between quarks, was the result of this work. Kobayashi and Maskawa were awarded the 2008 Nobel Prize in Physics "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature."
Quantum physics Leo Esaki was awarded the 1 Nobel Prize in Physics for the discovery of electron tunneling (quantum tunnelling) in the 1950s. The tunnel diode (Esaki diode) was invented in August 1957 by Leo Esaki, Yuriko Kurose and Takashi Suzuki when they were working at Tokyo Tsushin Kogyo, now Sony.
Shin'ichirō Tomonaga was awarded the 1965 Nobel Prize in Physics for his "fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles".
Astrophysics Masatoshi Koshiba was awarded the 2002 Nobel Prize in Physics "for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos" in the 1980s. He conducted pioneering work on solar neutrino detection, and Koshiba's work also resulted in the first real-time observation of neutrinos from the SN 1987A supernova. These efforts marked the beginning of neutrino astronomy.
Psychology The Rashomon effect is where the same event is given contradictory interpretations by different individuals involved. The concept originates from Akira Kurosawa's 1950 film Rashomon, where a murder is described in four mutually contradictory ways by its four witnesses.
Technology in the Empire of Japan (1868–1945) For the first twenty years in the Meiji era, patents and inventions failed to attract much public attention. From the time of the Russo-Japanese War, largely through the action of the body known as the Imperial Invention Association, invention has been encouraged by the Government. With the outbreak of the First World War, imported manufactured goods were cut off, as was the inflow of foreign technology, and, as a consequence, a number of new industries, especially in the heavy and chemical sectors, were set up. Existing firms also took advantage of the opportunity for technical development and the penetration of new markets. Several such companies were able to overcome the difficulties posed by economic depression and severe international competition. In 1935, at a time Japan experienced state of the art modernization entitled Shōwa Modan, the country ranked only behind the United States and Germany in the number of patents granted.
Agriculture Vertical rice polishing machine The rice polishing machines used today are based on the vertical power-driven the milling machine, which was invented by Riichi Satake (the founder of Satake Corporation ) in 1930. The condition of the rice after milling, the extent of the milling, and damage to the rice grains during the process affects every link in the production chain. Rice could now be polished more efficiently. The abrasive action of the vertical polishing machine reduced the number of broken grains and made polishing more even, making it possible to produce highly polished rice. Unlike the previous horizontal polishing machines, which are used for table rice, the vertical design used gravity to drop the rice through the center chamber, which was outfitted with a center grindstone coated with carborundum. Horizontal polishing machines have the rice grains rub each other, but the vertical Satake type polished the grain with the abrasive center roller to achieve a 40 percent polishing ration, removing 50 percent of the rice grain, revolutionizing the rice milling system and became the standard, resulting in more uniform, finely polished grains that did not chip or crack.
Batteries Dry cell The world's first dry-battery was invented during the Meiji Era. The inventor was . The company Yai founded no longer exists. An award was granted for a dry cell battery by Yai at the 1903 Fifth National Industrial Exhibition () in Osaka, Japan. It seems that his award was given in recognition of the fact that his battery was already being exported to foreign countries.
Reactive lead oxides production method In 1920 Genzo Shimadzu invents a "reactive lead oxides production method". Genzo's invention of the reactive lead powder manufacturing method in 1920 revolutionized the quality and cost of lead powder used in storage batteries. The manufactured lead powder was also used in anti-rust paints, which was even used on the Tokyo Skytree tower completed in 2012. For that invention, Genzo Jr. was selected as one of Japan's ten greatest inventors. He directed the company's efforts toward the development, independently, of a lead-powder production method, which was subsequently named the 'Production Method for Positive Response Lead Powder.' This was a simple and inexpensive method of industrial production, whereby a lump of lead was placed in a revolving iron drum while air was blown in. The ensuing oxidation of the lump of lead, and its breakdown into lead particles by the friction of the revolving drum, produced the positively charged lead powder. In addition to patenting various processes in Japan, Shimadzu registered patents in the major foreign countries. There were enquiries also concerning the implementation of patents for the Shimadzu production method in the US, Britain, Italy, Belgium, Sweden, Canada, Australia and France, attesting to the strong international interest in this technology. At this point, however, Shimadzu became entangled in a patent dispute in the US. In June 1932, the US Supreme Court pronounced its final verdict and established the patent rights for the Shimadzu technology. Following this victory, implementation of patent rights were finalized in the US, Britain, and France; that is, contracts were concluded successively in these countries. A contract for the acquisition by Ost Lurgi of the Shimadzu technology option was signed in Frankfurt am Main on 1 June 1926. Fritz Haber was also present at this meeting. The company, Ost Lurgi located in Berlin, was established in March 1926 as a joint venture of Mitsubishi, Metallgesellschaft and . The initiator of the establishing Ost Lurgi was Fritz Haber, inventor of the Haber Bosch process, who visited Japan in 1924, he thought highly of the standard of Japanese technology and originated a number of proposals for technico-industrial cooperation between Germany and Japan. One of his idealistic proposals gave rise to the establishment contract of Ost Lurgi. The purpose of Ost Lurgi was to transfer Japanese technology to Germany, but negotiations were drawn out, since the parties could not agree on conditions.
Telecommunications Cathode ray tube (CRT) In 1924, Kenjiro Takayanagi began a research program on electronic television. In 1925, he demonstrated a cathode ray tube (CRT) television with thermal electron emission. In 1926, he demonstrated a CRT television with 40-line resolution, the first working example of a fully electronic television receiver. In 1927, he increased the television resolution to 100 lines, which was unrivaled until 1931. In 1928, he was the first to transmit human faces in half-tones on television, influencing the later work of Vladimir K. Zworykin.
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