(CNN) - The four acoustic pings at the center of the search for Malaysia Airlines Flight 370 for the past seven weeks are no longer believed to have come from the plane's black boxes, a U.S. Navy official told CNN.
The acknowledgment came Wednesday as searchers wrapped up the first phase of their effort, having scanned 329 square miles of southern Indian Ocean floor without finding any wreckage from the Boeing 777-200.
Authorities now almost universally believe the pings did not come from the onboard data or cockpit voice recorders, but instead came from some other man-made source unrelated to the jetliner that disappeared on March 8, according to Michael Dean, the Navy's deputy director of ocean engineering.
If the pings had come from the recorders, searchers would have found them, he said.
Dean said "yes" when asked if other countries involved in the search had reached the same conclusions.
Michelle Obama slams the GOP.
It's rare that the first lady gets publicly involved in a political fight. But she has some major beef with House Republicans who want to enable schools to opt out of the nutrition standards that the first lady fought for.
"The last thing we can afford to do right now is play politics with our kids' health," she said. "Now is not the time to roll back everything that we have worked for. Our kids deserve so much better than that."
OutFront, Republican Congressman Robert Aderholt. He's backing the bill that would let cash-strapped schools opt out of the nutrition regulations.
Great TV theme songs stay with you long after the television shows go off the air and the 1960s had a lot of tunes that are now considered all-time classics.
CNN's Jeanne Moos looks back at the best theme songs of the '60s.
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What motivates someone like Santa Barbara college student Elliot Rodger to kill?
Rodger is just one of many troubled young people who commit heinous crimes.
But can kids who kill actually be rehabilitated?
Jean Casarez has this OutFront investigation on the minds of killer teens.
President Barack Obama on Wednesday outlined a foreign policy vision of "might doing right," arguing that modern pragmatism requires both a strong military and the diplomatic tools of alliances and sanctions to exert influence and provide global leadership.
But critics say he sounded a lot more like a man majorly on the defense.
OutFront, CNN Contributor Paul Begala.