At the time of Lovecraft’s death in 1937 [the estimate of the universe’s size was] larger than it had been at the time of his birth; with over a hundred million stars in our own galaxy, and many tens or hundreds of millions of other galaxies estimated, and the upper limit on the sun's age raised to five billion years, the universe had expanded by two orders of magnitude in age and nine orders of magnitude in size (as measured by the number of stars) during Lovecraft’s life. That's eleven orders of magnitude in just over four decades. (emphasis in original)
However, Stross provides no support from Lovecraft himself, either in excerpts from his fiction or references to his letters, to give weight to the claim that Lovecraft found the revision of the size of the cosmos to be terrifying.
I respectfully disagree.
Lovecraft himself had been interested in astronomy since his youth, and loved the stars, as he wrote in a letter of January 1, 1915, praising his grandmother for sparking his love of astronomy: “and though she never personally showed me the beauties of the skies, it is to her excellent but somewhat obsolete collection of astronomical books that I owe my affection for celestial science.” He obtained a telescope in 1903 and wrote an astronomy column for a Providence newspaper from 1906 to 1918. More stars were not frightening, merely more to love—and planets, too! He was excited “more than any other happening” at the discovery of Pluto in 1930. On December 3, 1931, he explicitly described new theories of a constantly-expanding cosmos as the “most spectacular of recent astronomical developments.” It should be noted, however, that Lovecraft lacked formal training in physics or higher mathematics and therefore derived most of his ideas from popular summaries.
Instead, Lovecraft explained very clearly where he found cosmic dread in physics, and it was in the relativity theory of Albert Einstein. Not, of course, that he personally expressed revulsion at the idea of relativity; in his letters he wrote that “the general facts of relativity & curved space are unshakable realities, without considering which it will be impossible to form any sort of true conception of the cosmos” (December 20, 1930).
In his fiction, however, Lovecraft depicted Einstein’s theories as disturbing the universe, overthrowing the ordered logic of the Newtonian system, and hurling humanity into insignificance and chaos. In “The Dreams in the Witch-House,” horror emerges because a seventeenth-century witch had somehow mastered “the whole Einsteinian space-time continuum” and could move through fourth-dimensional hyperspace, a theme repeated in “The Trap,” written with Henry S. Whitehead. More troubling was The Shadow Out of Time, where “Dr. Albert Einstein, they said, was rapidly reducing time to the status of a mere dimension.”
More explicit is the horrific Fungi from Yuggoth, the Mi-Go:
The blasphemies which appeared on earth, it was hinted, came from the dark planet Yuggoth, at the rim of the solar system; but this was itself merely the populous outpost of a frightful interstellar race whose ultimate source must lie far outside even the Einsteinian space-time continuum or greatest known cosmos.
For Lovecraft, the cosmos are a canvas on which to paint cosmic fear (consider the opening of “The Call of Cthulhu” in which he describes the insanity that comes from considering reality in its true form)—and he chose fear not because he was plagued by terror of the stars but because terror leads directly to the Burkean sublime, which he saw as a facet of human psychology “coeval with the religious feeling and closely related to many aspects of it,” as he put it in Supernatural Horror in Literature. For Lovecraft, the aliens and the stars and all of space were the closest an atheist could come to religion; this is the same feeling that drives ancient astronaut theories, and it is no coincidence that both Lovecraft and fringe historians lighted on extraterrestrials as substitutes for the gods.
To take a clearer example: Stephen King’s works locate fear primarily in small New England towns. Do we abstract from that the idea that King is actually afraid of small New England towns? No, he loves those towns and uses them as a canvas for his decidedly more earthly and earthy horrors.
So what did Lovecraft actually fear? Sadly, that answer is too obvious: He feared non-white people, miscegenation, and the decline of traditional Anglo-American culture, largely at the hands of non-white immigrants. (This was the same fear that drove many fringe historians to embrace a white paradise in Atlantis or pre-Columbian white colonizers of America like the Mound Builders or Henry Sinclair.) These alien others Lovecraft linked to extraterrestrial others and posited as the primitive recipients of wild, irrational, uncivilized forces that pulsed and throbbed below the surface of civilization. Although this tendency was at its worst in “The Horror at Red Hook,” it is perhaps clearest in “The Call of Cthulhu,” where worshipers of the ancient alien were men of “mixed-blooded, and mentally aberrant type,” joined with “Negroes” and “mulattos.” The “Negroes” and “mulattos” were judged insane, but the one cultist with the most white blood—the “mestizo” Old Castro—is the only one capable of speaking coherently about his noxious beliefs.
Lovecraft’s great sin was identifying the primitive irrational with the non-white (or at least non-Anglo-Saxon) and making racist what could have been universal.