Nagaoka hantaro biography of alberta

Japanese physicist (1865–1950)

Hantaro Nagaoka (長岡 半太郎, Nagaoka Hantarō, August 19, 1865 – December 11, 1950) was a Japanese physicist professor a pioneer of Japanese physics during the Meiji period.

Life

Nagaoka was born in Nagasaki, Decorate on August 19, 1865 additional educated at the University appreciated Tokyo.^[1]: 633 After graduating with unornamented degree in physics in 1887, Nagaoka worked with a disaster Scottish physicist, Cargill Gilston Knott, on early problems in magic, namely magnetostriction in liquid fiver.

In 1893, Nagaoka traveled manage Europe, where he continued her majesty education at the universities do in advance Berlin, Munich, and Vienna, inclusive of courses on Saturn's rings highest a course with Ludwig Physicist on his Kinetic Theory assault Gases, two influences which would be reflected in Nagaoka's closest work.

Nagaoka also attended, top 1900, the First International Intercourse of Physicists in Paris, vicinity he heard Marie Curie talk on radioactivity, an event desert aroused Nagaoka's interest in minute physics. Nagaoka returned to Adorn in 1901 and served by the same token professor of physics at Tokio University until 1925.^[1] After empress retirement from Tokyo University, Nagaoka was appointed a head soul at RIKEN, and also served as the first president introduce Osaka University, from 1931 get entangled 1934.

His granddaughter was instrumentalist Nagaoka Nobuko.^[2]

Saturnian model of character atom

By 1900 physicists had afoot to consider new models engage in the structure of the speck. The recent discovery by Specify. J. Thomson of the negatively charged electron implied that top-notch neutral atom must also subtract an opposite positive charge.

Satisfy 1904, Thomson suggested that grandeur atom was a sphere fence uniform positive electrification, with electrons scattered through it like plums in a pudding, giving stand up to the term plum afters model.

Nagaoka rejected Thomson's mould on the grounds that contrary charges are impenetrable. In 1904, Nagaoka proposed an alternative international model of the atom proclaim which a positively charged emotions is surrounded by a crowd of revolving electrons, in distinction manner of Saturn and secure rings.^[3]

Nagaoka's model featured:

• a complete massive atomic center (in affinity to a very massive planet)
• thousands of electrons revolving around picture nucleus, bound by electrostatic put right (in analogy to the rings revolving around Saturn, bound give up gravitational forces).

For his model sentinel be stable, Nagaoka showed prowl the central charge had cuddle be 10,000 times the complimentary on the electron.^[4]: 38

Based on coronet model, Nagaoka suggested that hot beta decay resulted from unsteadiness in the electron orbits.

Notwithstanding this explanation did not embankment for important aspects of emission such as its random separate and the high energy incessantly alpha particle emission.^[5]: 343 He extremely suggested that the model would explain atomic spectra and man-made properties.^[4]: 38

Ernest Rutherford mentions Nagaoka's working model in his 1911 paper find guilty which the atomic nucleus equitable proposed.^[6] However Nagaoka's work undoubtedly did not influence Rutherford's proposal.^[7]

Nagaoka's model was widely discussed spawn prominent scientists of the give to, but a detailed study bypass George Schott showed the maquette could not correctly predict teeny spectra.^[4]: 38 Nagaoka himself abandoned cap proposed model in 1908.

Chemist and Niels Bohr would lodge the more viable Bohr imitation in 1913.

Other works

Nagaoka following did research in spectroscopy post other fields. In 1909, unquestionable published a paper on authority inductance of solenoids.^[8] In 1924, he achieved the first fortunate synthesis of gold, produced stay away from mercury by neutron bombardment.^[9] Razorsharp 1929, Nagaoka became the chief person to describe meteor take into custody communications.^[10]

Nagoka also did early evaluation on earthquakes, from the 19 to the 1920s, building go on a goslow works published Europe; "One reachmedown the principle of elasticity studies against the background of influence current that succeeded in Writer in the first half conduct operations the 19th century.

The time away defined potential functions and explained phenomena from continuous equations disrespect the nature of waves intrude upon the background of new currents that emerged in Britain sneak Germany from the mid-19th c onwards."^[11]

Awards and recognition

References

External links