Mr. Marino, the author of the post on the Lens blog, is a 31-year-old architect born in Argentina. In an e-mail interview, he said that the political corruption during the years of dictatorship in his country shaped his thinking: “I started to realize how political corruption operates and how it is the interests of a few in power that really governs our world.”

Image TRUE OR FALSE? Adam Savage, left, and Jamie Hyneman of MythBusters, which spent an episode last year rebutting Moon hoax theories. Credit... Discovery Channel

As he traveled the world  he now lives and works in China  he picked up books contending that the landings were faked and saw documentaries including Mr. Sibrel’s, he said, which paints a dark portrait of political manipulation during the Nixon administration and somehow ties in the Vietnam War, the Titanic and the Tower of Babel before even getting to the supposed photographic evidence of lunar deception.

Mr. Sibrel, who sells his films online, has hounded Apollo astronauts with a Bible, insisting that they swear on camera they had walked on the Moon. He so annoyed Buzz Aldrin in 2002  ambushing him with his Bible and calling him “a coward, and a liar, and a thief”  that Mr. Aldrin punched Mr. Sibrel in the face. Law enforcement officials refused to file charges against Mr. Aldrin, the second man on the Moon.

In an interview, Mr. Sibrel said that his efforts to prove that men never walked on the Moon has cost him dearly. “I have suffered only persecution and financial loss,” he said. “I’ve lost visitation with my son. I’ve been expelled from churches. All because I believe the Moon landings are fraudulent.”

Ted Goertzel, a professor of sociology at Rutgers University who has studied conspiracy theorists, said “there’s a similar kind of logic behind all of these groups, I think.” For the most part, he explained, “They don’t undertake to prove that their view is true” so much as to “find flaws in what the other side is saying.” And so, he said, argument is a matter of accumulation instead of persuasion. “They feel if they’ve got more facts than the other side, that proves they’re right.”

Mark Fenster, a professor at the University of Florida Levin College of Law who has written extensively on conspiracy theories, said he sees similarities between people who argue that the Moon landings never happened and those who insist that the 9/11 attacks were planned by the government and that President Obama’s birth certificate is fake: at the core, he said, is a polarization so profound that people end up with an unshakable belief that those in power “simply can’t be trusted.”

The emergence of the Internet as a communications medium, he noted, makes it possible for once-scattered believers to find one another. “It allows the theory to continue to exist, to continue to be available  it’s not just some old dusty books on the half-price shelf.”