Nineteenth Century
Kepler did not have a proof of the conjecture, and the next step was taken by Carl Friedrich Gauss (1831), who proved that the Kepler conjecture is true if the spheres have to be arranged in a regular lattice.
This meant that any packing arrangement that disproved the Kepler conjecture would have to be an irregular one. But eliminating all possible irregular arrangements is very difficult, and this is what made the Kepler conjecture so hard to prove. In fact, there are irregular arrangements that are denser than the cubic close packing arrangement over a small enough volume, but any attempt to extend these arrangements to fill a larger volume always reduces their density.
After Gauss, no further progress was made towards proving the Kepler conjecture in the nineteenth century. In 1900 David Hilbert included it in his list of twenty three unsolved problems of mathematics—it forms part of Hilbert's eighteenth problem.
Read more about this topic: Kepler Conjecture
Famous quotes related to nineteenth century:
“When I see that the nineteenth century has crowned the idolatry of Art with the deification of Love, so that every poet is supposed to have pierced to the holy of holies when he has announced that Love is the Supreme, or the Enough, or the All, I feel that Art was safer in the hands of the most fanatical of Cromwell’s major generals than it will be if ever it gets into mine.”
—George Bernard Shaw (1856–1950)
“I delight to come to my bearings,... not to live in this restless, nervous, bustling, trivial Nineteenth Century, but stand or sit thoughtfully while it goes by.”
—Henry David Thoreau (1817–1862)
“The secret point of money and power in America is neither the things that money can buy nor power for power’s sake ... but absolute personal freedom, mobility, privacy. It is the instinct which drove America to the Pacific, all through the nineteenth century, the desire to be able to find a restaurant open in case you want a sandwich, to be a free agent, live by one’s own rules.”
—Joan Didion (b. 1934)
“We have now traced the history of women from Paradise to the nineteenth century and have heard nothing through the long roll of the ages but the clank of their fetters.”
—Jane, Lady Wilde (1821–1896)
“In the nineteenth century ... explanations of who and what women were focused primarily on reproductive events—marriage, children, the empty nest, menopause. You could explain what was happening in a woman’s life, it was believed, if you knew where she was in this reproductive cycle.”
—Grace Baruch (20th century)