The CIA used a futuristic new tool called “Ghost Murmur” to find and rescue the second American airman who was shot down in southern Iran, The Post has learned. The secret technology uses long-range quantum magnetometry to find the electromagnetic fingerprint of a human heartbeat and pairs the data with artificial intelligence software to isolate the signature from background noise, two sources close to the breakthrough said. It was the tool’s first use in the field by the spy agency — and was alluded to Monday afternoon by President Trump and CIA Director John Ratcliffe at a White House briefing. The New York Post is your source for breaking news, news about New York, sports, business, entertainment, opinion, real estate, culture, fashion, and more.