Still, he might recognize the disdain for facts so common today. Long before the word “tweet” was associated with anything other than birds, Einstein’s career was nearly derailed by an early form of the disinformation now ubiquitous on social media. In 1920, skeptical scientists who deemed Einstein a crackpot, and his theory of relativity nonsense, joined forces. Their critiques were often laced with antisemitism. In that era, propaganda spread relatively slowly — one person passing it along to a friend who, in turn, would forward it to someone else, with circulation often limited by geography or language.

Einstein was annoyed by the whole endeavor. Curious about the campaign, he went to an anti-relativity event at the Berlin Philharmonic Hall where he saw that anti-Einstein pamphlets were being handed out. Nobody knew it was him. “He thought that these people were actually not very dangerous because they’re so silly and so poorly informed,” said Matthew Stanley, a historian of science and the philosophy of science at New York University and the author of a book on the fight against the theory of relativity. “He thought it’s all faintly ridiculous.”

By 1933, when the Nazis took power in Germany, two strains of falsehoods smeared Einstein far more publicly, and widely: One asserted (incorrectly) that his relativity theory was outright wrong, a threat, as Mr. Stanley put it, “to the very foundations of human knowledge.” The other doubled down on the antisemitism he had experienced early on; this whisper campaign accused Einstein of having stolen the idea from non-Jewish German and Austrian scientists. Like other prominent Jews, Einstein was targeted as an enemy of the state, and a bounty was rumored to have been placed on his head. But by then he wasn’t in Germany, having left to spend time at Caltech in December 1932. Though he returned to Europe in 1933, he left the continent entirely in October 1933.

Einstein received a welcome reception whenever he arrived on the shores of New York City. Carolyn Abraham, author of “Possessing Genius,” a book about the fate of Einstein’s brain, writes that reporters would be in such a rush to board his ship whenever it docked in the United States that some fell into the harbor. For the final two decades of his life, he was one of the most widely respected public figures in the world. Time magazine named him “Person of the Century” in 1999.

Consensus around central figures — like that of an intellectual genius — has withered since Einstein’s death. No longer do we gather around the television in the evening to watch Walter Cronkite deliver the news, nor do all new parents have a copy of Dr. Spock’s baby manual on their bedside tables; today we are drawn to echo chambers where news is bifurcated and TikTok influencers give us health advice. These days you might find skeptics of the sort Einstein first encountered congregating in the same Facebook group, or on Twitter — but now instead of one lowly local meeting, their fake news spirals at warp speed.