On April 14, the day it hit the iceberg, the Titanic received seven heavy ice warnings, including one from the Californian less than an hour before the fateful collision. The message said: "We are stopped and surrounded by ice." Titanic sent back a message that said "Shut up. We are busy."
Clarke said people keep looking for additional causes "because if it's nature or God, then we're off the hook, morally and practically."
Yale disaster expert Charles Perrow said he found the mirage theory plausible, especially because cold air played visual tricks that were a factor in a 1979 airplane crash in Antarctica that was originally blamed on pilot error.
Steven Biel, who wrote "Down with the Old Canoe: A Cultural History of the Titanic Disaster," said he understands the search for other reasons.
"There's something appealing about retrospectively gaining control over an event that's centrally about uncertainty and contingency and lack of control," he said.
Seth Borenstein be followed at http://twitter.com/borenbears
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