Application To Saturn's Rings
Beginning in the late 1970s, Peter Goldreich, Frank Shu, and others applied density wave theory to the rings of Saturn. Saturn's rings (particularly the A Ring) contain a great many spiral density waves and spiral bending waves excited by Lindblad resonances and vertical resonances (respectively) with Saturn's moons. The physics are largely the same as with galaxies, though spiral waves in Saturn's rings are much more tightly wound (extending a few hundred kilometers at most) due to the very large central mass (Saturn itself) compared to the mass of the disk. The Cassini mission has revealed very small density waves excited by the ring-moons Pan and Atlas and by high-order resonances with the larger moons, as well as waves whose form changes with time due to the varying orbits of Janus and Epimetheus.
Read more about this topic: Density Wave Theory
Famous quotes containing the words application to, application, saturn and/or rings:
“It would be disingenuous, however, not to point out that some things are considered as morally certain, that is, as having sufficient certainty for application to ordinary life, even though they may be uncertain in relation to the absolute power of God.”
—René Descartes (1596–1650)
““Five o’clock tea” is a phrase our “rude forefathers,” even of the last generation, would scarcely have understood, so completely is it a thing of to-day; and yet, so rapid is the March of the Mind, it has already risen into a national institution, and rivals, in its universal application to all ranks and ages, and as a specific for “all the ills that flesh is heir to,” the glorious Magna Charta.”
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)
“From you have I been absent in the spring,
When proud pied April, dressed in all his trim,
Hath put a spirit of youth in every thing,
That heavy Saturn laughed and leaped with him.”
—William Shakespeare (1564–1616)
“You held my hand
and were instant to explain
the three rings of danger.”
—Anne Sexton (1928–1974)