Wildly improbable conspiracy theories about Hurricanes Helene and Milton have spread largely unchecked on social media. The storms were engineered to clear the way for lithium mining. They were sent to help the Democrats in next month’s election. They were formed by weather-controlling lasers. The claims persist despite attempts by scientists and government officials to debunk them with evidence. They survive all calls to reason. The falsehoods, which have been circulating on X, TikTok, YouTube and other platforms, can resemble the conspiracy theories that plague modern American politics. Prominent figures are pushing them, citing unrelated, misleading or outdated evidence. But...