as undermining moral absolutes—in this case, biblical authority. The movement was led in part by an attractive, charismatic sex-symbol and revivalist named Aimee Semple McPherson, the founder of what may have been the first American evangelical megachurch. The 5,300-seat Angelus Temple in Echo Park, Los Angeles, was equipped with radio towers to broadcast her sermons, and McPherson filled it to capacity three times a day, seven days a week. She stressed the “direct-experience” approach to religion, not unlike the empirical spirituality of the Puritans that had been so central to the creation of Western science. Like the Puritans, she considered the mainstream Protestant churches too orthodox—but unlike the Puritans, her complaint was that the mainstream churches were not authoritarian enough.
This revivalist spirit was propelled by the wave of immigration that followed World War I, which many Americans found disconcerting; the recovery from the traumatic flu pandemic of 1918, which had killed millions; and the return of millions more from the war, many of them still with untreated “shell shock,” the condition we now describe as post-traumatic stress disorder. Fueled by new optimism and cheap labor, the stock market boomed. Moral restrictions were loosening and the country needed to blow off some steam. Materialism soared during what F. Scott Fitzgerald called the Jazz Age, a subject he explored in his 1925 novel The Great Gatsby.
But the line between liberalism and running amok depends upon one’s psychological keel, as Gatsby showed. For many, this powerful mix of materialism, diversity, and newfound tolerance was simply too much, and they began to lose their moral bearings—or to feel that other Americans were losing theirs. McPherson was among the latter group. She set about working to bring order to society, and her moral fierceness offered a bulwark in the storm to many.
By the mid-1920s, McPherson had become a household name. She was made an honorary member of police and fire departments across the country, and, at 10,000 members, she ran the largest Christian congregation in the world. She purchased one of the first three radio stations in Los Angeles, and eventually claimed more than 1,300 affiliated churches that preached her “Foursquare Gospel” of literalist Bible interpretation. From this great platform, she took up a campaign against the two most profound evils threatening America at that time: the drinking of alcohol and the teaching of evolution in public schools.
McPherson was not alone in this holy campaign. William Jennings Bryan, the former secretary of state, had been the Democratic candidate for president for a third time in 1908. He had spoken throughout the United States in favor of Prohibition and against the teaching of evolution, which he believed had led to World War I. If we were in fact “descended from a lower order of animals,” he professed, then there was no God and, as a consequence, nothing underpinning society. Like Thomas Hobbes, he felt that, without an absolute authority, society would fall into decay.
Darwin himself had not seen it this way. He had written to John Fordyce about the issue in 1879, saying, “It seems to me absurd to doubt that a man may be an ardent Theist & an evolutionist,” though Darwin himself had by then given up his own Christianity. In 1880, he wrote to the young lawyer Francis McDermott that “I am sorry to have to inform you that I do not believe in the Bible as a divine revelation & therefore not in Jesus Christ as the son of God,” a view that only became known when the letter was sold at auction in 2015.
Following Bryan’s fiery stump speeches warning of the moral decay that teaching evolution would wreak on society, several states passed laws banning the practice. The most notable of these laws was Tennessee’s Butler Act, signed into law on March 21, 1925. By April, the American Civil Liberties Union had recruited a substitute teacher named John Scopes to break the law in Tennessee, after which the organization would pay for his defense to challenge it. On the other side, Bryan was asked to represent the World Christian Fundamentals Association, defending the law at the resulting trial, and, with it, his personal reputation and political future.
McPherson was a strong supporter of Bryan during the trial. He had been her guest at the Angelus Temple and had watched her preach that social Darwinism had corrupted students’ morality. The teaching of evolution was “the greatest triumph of satanic intelligence in 5,931 years of devilish warfare against the Hosts of Heaven. It is poisoning the minds of the children of the nation,” she had said. During the trial, McPherson sent Bryan a telegram, which read, “Ten thousand members of Angelus Temple with her millions of radio church membership send grateful appreciation of your lion hearted championship of the Bible against evolution and throw our hats in the ring with you.” The confrontation at the trial between Bryan and Scopes’s “sophisticated country lawyer” Clarence Darrow, also a Democrat, was the climax of one of the nation’s earliest major scientific-political-religious controversies. Though Darrow lost the case in the Bible Belt state of Tennessee, the accordant publicity turned American public opinion in support of teaching evolution in public schools.
The Vatican stayed out of this debate, partly because its healthy network of parochial schools meant it had little skin in the game—state laws concerning public-school curricula were of little concern. Even today, in Georgia, the joke is, “If you want your kids to learn about evolution, send them to Catholic school, because they won’t learn it in public school.”
The event also marked a curious milestone: Evangelical Protestants and Roman Catholics had now nearly reversed their respective popular positions with regard to science. While Protestants had once embraced it as Catholics had found themselves at odds, now it was Protestants who were rejecting science and Catholics who were beginning to more fully embrace it—a reversal that astronomer Edwin Hubble would soon help to accelerate.
The Largest Scientific Instrument Known to Man
It was into this hothouse climate that the Protestant-raised Hubble, adorned with the cape, cane, and British accent he had acquired while a Rhodes Scholar at Oxford, returned after the war, having traveled Europe and formed friendships with several of its leading astronomers. He arrived at the Carnegie-funded Mount Wilson Observatory outside Pasadena, California, insisting on being called “Major Hubble.” He quickly made enemies among the other scientists with his pompous airs and his self-aggrandizing tall tales. Looking through the great Hooker Telescope—at 101 inches in diameter and weighing more than one hundred tons, it was by far the largest and most powerful scientific instrument in the world—Hubble was able to view the universe with the light-gathering capacity of more than two hundred thousand human eyes.
Despite his propensity for stretching the truth, Hubble was a very strict Baconian observer when it came to science, limiting his statements only to what he observed and what could be strictly concluded from those observations, as John Locke had prescribed. Despite these conservative precautions, or perhaps because of them, what Hubble saw changed humanity’s view of the universe forever—and would further roil the controversy over science’s role in defining the origins of creation. Hubble photographed a small blinking star in the Andromeda nebula that he identified as a Cepheid variable. Like Galileo’s view of Venus, Hubble’s observation of a Cepheid in Andromeda would become iconic in its power.
The Human Computer That Opened the Heavens
Hubble’s work relied heavily on that of another astronomer, Harvard College Observatory’s Henrietta Leavitt, who had in 1912 shown something remarkable about Cepheid variable stars, which change from dim to bright to dim again over a period ranging from a few hours to about a month. Scientists were trying to figure out a way to measure the distance to stars. It was impossible to tell if a star appeared dim because it was far away, or because it didn’t emit as much light, so this was a difficult task.
As a woman, Leavitt was not allowed to be part of the scientific staff; she was a “computer”—one of several women hired merely to identify and catalog stars and calculate light curves for the male scientists. Leavitt began to suspect that there might be a relationship between the brightness of a variable star and the length of its period. She reasoned that all stars in the Small Magellanic Cloud were roughly the same distance from Earth and so their apparent brightness could be compared to one another. She then created a graph showing the maximum luminosity of each Cepheid variable compared to the length of its period, and found that there was indeed a relationship. The longer the period, the brighter the star actually was at maximum luminosity.
Danish