Pebble in the Sky

★★<Pebble in the Sky>1950年首次出版，是阿西莫夫的第一本长篇小说单行本，属于“基地宇宙”系列的银河帝国三部曲之三，但是“基地宇宙”系列的《基地（第一部）》的小故事最先是在1942年出现在杂志上，后来才在1951年整合成《基地（第一部）》出版。

★★Publication history:

Pebble in the Sky was originally written in the summer of 1947 under the title "Grow Old with Me" for Startling Stories, whose editor Sam Merwin, Jr. had approached Asimov to write a forty thousand word short novel for the magazine. The title was an adaption of Robert Browning's Rabbi ben Ezra, the first few lines of which (starting "Grow old along with me! / The best is yet to be...") were included in the final novel. It was rejected by Startling Stories on the basis that the magazine's emphasis was more on adventure than science-heavy fiction (despite the editor inviting Asimov to write the latter as an experiment for the magazine), and again by John W. Campbell, Asimov's usual editor. In 1949, Doubleday editor Walter I. Bradbury accepted the story on the suggestion of Frederik Pohl, on the condition it was expanded to seventy thousand words and the title changed to something more science fiction oriented, and it was published in January 1950 as Pebble in the Sky. "Grow Old With Me" was later published in its original form along with other draft stories in The Alternate Asimovs in 1986.

In Before the Golden Age, Asimov wrote that Pebble in the Sky was influenced by the short story "Proxima Centauri" by Murray Leinster.

★★Place in the wider Foundation saga:

▶Chronology

The 50,000-year estimate is at odds with the chronology given in Asimov's later novels, in particular Foundation and Earth and The Caves of Steel. The latter novel indicates that the robot R. Daneel Olivaw was constructed some three thousand years after the founding of New York City. Foundation and Earth, in its concluding scene, establishes that Daneel survives into the Interregnum period, after the First Galactic Empire collapses. He gives his age as (roughly) twenty thousand years. The Galactic Era dating system, to which most of Asimov's Foundation Series adheres, places Foundation and Earth approximately twelve thousand years after the events of Pebble in the Sky. Adding up all the differences, Joseph Schwartz's time displacement ultimately transported him only some eleven millennia into the future.

In Foundation, the Galactic Empire has existed for 12,000 years. Nuclear power is believed to have existed for 50,000 years, even though this is long after the era of Pebble in the Sky.

▶Historical analogy

The obvious historical analogy is between Earth in the book and the historical situation of Judea under the Roman Empire, with the fanatics plotting rebellion against Trantor being modeled upon the Zealots who in 66 AD launched the First Jewish–Roman War which ended with destruction of the Jerusalem Temple, an event of Jewish history. This fits well in the general scheme of Trantor being the equivalent of Rome, and Trantor's later decline in the Foundation Series being the equivalent of Rome's decline centuries after the destruction of Jerusalem. Asimov's position in this ancient historical controversy is clear, with the fanatic rebels being the undoubted villains of the book. It is noteworthy that Joseph Schwartz – the man from the past who ultimately foils the fanatics' plot – is clearly Jewish, and his action in effect saves the people of the future Earth from re-enacting the great tragedy of Schwartz's own people.

▶The fate of Earth

In Foundation and Earth, it is described that the Empire began a restoration of Earth, but that this was subsequently abandoned. There are also descendants of the old population at "Alpha," a planet circling one of the suns of Alpha Centauri. They were settled there by the Empire, which intended to make a whole terraformed world, but which ultimately produced just one large island. Janov Pelorat stated that, if he understood the legends of Alpha correctly, the start of the restoration attempt was right before a period of much larger problems for the Empire. Daneel explains that he had a role in attempting the restoration of Earth's soil and also settling humans at "Alpha," but achieved less than he had wanted. Whether he was personally involved in the actual events of Pebble is not discussed, but strongly implied. It is left open that other refugees from Earth might have settled elsewhere in the universe.