Saturnian Model of The Atom
Physicists in 1900 had just begun to consider the structure of the atom. The recent discovery by J. J. Thomson of the negatively charged electron implied that a neutral atom must also contain an opposite positive charge. In 1903 Thomson had suggested that the atom was a sphere of uniform positive electrification, with electrons scattered through it like plums in a pudding, the plum pudding model.
Nagaoka rejected Thomson's model on the ground that opposite charges are impenetrable. He proposed an alternative model in which a positively charged center is surrounded by a number of revolving electrons, in the manner of Saturn and its rings.
In 1904, Nagaoka developed an early planetary model of the atom. Nagaoka's model was based around an analogy to the explanation of the stability of the Saturn rings (the rings are stable because the planet they orbit is very massive). The model made two predictions:
- a very massive nucleus (in analogy to a very massive planet)
- electrons revolving around the nucleus, bound by electrostatic forces (in analogy to the rings revolving around Saturn, bound by gravitational forces).
Both predictions were successfully confirmed by Rutherford (who mentions Nagaoka's model in his 1911 paper in which the nucleus is proposed). However, other details of the model were incorrect. In particular, charged rings would be unstable due to repulsive disruption, which is not the case with Saturn's rings, and Nagaoka himself abandoned it in 1908.
Ernest Rutherford and Niels Bohr presented the more viable Bohr model in 1913.
Read more about this topic: Hantaro Nagaoka
Famous quotes containing the words model and/or atom:
“If the man who paints only the tree, or flower, or other surface he sees before him were an artist, the king of artists would be the photographer. It is for the artist to do something beyond this: in portrait painting to put on canvas something more than the face the model wears for that one day; to paint the man, in short, as well as his features.”
—James Mcneill Whistler (1834–1903)
“One year, I’d completely lost my bearings trying to follow potty training instruction from a psychiatric expert. I was stuck on step on, which stated without an atom of irony: “Before you begin, remove all stubbornness from the child.” . . . I knew it only could have been written by someone whose suit coat was still spotless at the end of the day, not someone who had any hands-on experience with an actual two-year-old.”
—Mary Kay Blakely (20th century)