In 1835 a New York newspaper printed that an astronomer had seen life on the Moon, and the story was made up; the story said that winged man-bats and other creatures lived on the Moon, and that a giant new telescope showed the creatures. It said that astronomer Sir John Herschel was at the Cape of Good Hope with a huge new telescope, and it said it was copied from an Edinburgh paper and then from a science journal, which made it sound real. It was printed in a cheap newspaper and was reprinted by papers around the country. The 1835 stories sold newspapers: the paper's sales and subscriptions rose; a newspaper that makes a big claim can have a reason to make it, such as selling more copies. The paper that printed the Moon story did not issue a full retraction, even many years later, as of November 2026.

In 1917 two cousins in a village in England took photos that seemed to show tiny fairies. Many people looked at those fairy photos and believed they were real, even experts at a camera company, and the photos fooled many people for years. In 1983 the two women who made them admitted they were a hoax, and one of them said she had drawn the fairies and that they were stuck on twigs with hat pins. The fairies in some old photos were paper cut-outs held up with hat pins. It is good to ask why something was made: is it trying to teach you, or to sell you something? To check a claim, look at who wrote it, why, and when; a source should say where its facts came from.

A skull and jaw found in England in 1912 were said to be an early human relative, but the find was a fake: a human skull put with an orangutan jaw. The Piltdown fossils were found in 1911 and 1912 and included part of a skull, a jawbone and a few teeth. A hoax can last when it flatters what people want to be true: the Piltdown find was in Britain, which pleased some British scientists; the skull seemed to match what scientists hoped to find, so many believed it, and scientists wanted to find the first human ancestor in England, and that wish may have made them less careful about Piltdown. Some of the people who looked at Piltdown Man were respected scientists, and they were fooled too.

The Piltdown jawbone was treated with chemicals to look as old as the skull, and its teeth were ground down. In 1912 there were no good dating methods, so the claim could not be checked in the way we can now. The fake fooled scientists for about 40 years before they proved it fake: in 1949 the Natural History Museum had a scientist who was not part of the Piltdown discovery test the jaw and skull with fluorine, and in 1953 tests showed that the jaw was an ape's. The hoax slowed the search for human ancestors, because other fossils did not fit it. Who made the Piltdown fake is not known for sure, as of November 2026. Piltdown was first announced by Charles Dawson on December 18, 1912, to the Geological Society in London.

In 1938 newspapers wrote that many people panicked after a radio play about Martians, but later writers found the panic was much smaller. Stories about the 1938 radio play grew over time: first newspaper items on October 31, 1938, then retellings. Radio had taken away advertising money from newspapers during the Depression, so newspapers had a reason to make radio look untrustworthy. In 1938 about 5,000 homes were asked what radio show they were listening to, and only 2 percent said the Martian play or one like it, while a survey that called 5,000 homes found that 98 percent were listening to something else or nothing. The show was scheduled against a very popular comedy-variety show, and people who study the broadcast disagree about how many were listening: one radio program said about 12 million, while a survey suggested far fewer.

Pictures spread false ideas too; the Lincoln picture composite was made from an 1852 engraving of Calhoun and an 1864 photograph of Lincoln. Vikings did not wear helmets with horns when they fought, and we have no proof that they did. The made-up picture of a Viking in a horned helmet comes from a costume for an opera in 1876, when the first production of Wagner's Ring Cycle used horned helmets in its costumes. That picture has been disproven, but it is still found in modern images. Percival Lowell drew maps of canals on Mars from what he saw at his observatory, and later evidence showed they were optical illusions. Seeing shapes in colors at the limit of what the eye can make out can create illusions.

A conspiracy theory is an idea that a secret plan by powerful people explains an event, and it usually has no solid evidence that anyone can check. Conspiracy theories are not new. They tend to grow where uncertainty, fear or distrust are common; a fraud that is proved with evidence is different from a conspiracy theory: Piltdown was a real hoax that scientists proved with tests. Before you believe something, ask who says it and how they know. Check a second place, because a true fact can be found in more than one good place. If a claim has no clear source, try to find the same fact somewhere else before you trust it. Confirmation bias covers how people search for, interpret and remember information so that it fits what they already believe, and it can create self-fulfilling prophecies.

Words to know

• hoax: deliberate fake
• retraction: public correction
• composite: joined pictures
• conspiracy: secret plot
• bias: leaning one way