Just days before President Obama hosts a nuclear summit in Washington, Iran announced Friday that "its nuclear path is irreversible," a dramatic move, despite the prospect of tough new sanctions. In a ceremony where a choir and musicians performed a specially written nuclear symphony, Iran recently unveiled its homemade nuclear technology, including a new centrifuge - five times faster than the current model. Iran insists it's all for peaceful purposes, but it could also take the country closer to making a bomb. Celebrating Iran's nuclear program in such an elaborate way is of course a public spectacle for Iranians, but it's also a deliberately provocative message to the world, which President Mahmoud Ahmadinejad made crystal clear with words aimed squarely at the U.S., reports CBS News Correspondent Elizabeth Palmer. "Anyone who thinks they can threaten Iranian resolve to carry on with our nuclear program," Ahmadinejad said, "is greatly mistaken."