Congress made two startling claims. The first is that “cross-domain transmedium threats to the United States national security are expanding exponentially.” The second is that it wants to distinguish between UFOs that are human in origin and those that are not: “Temporary nonattributed objects, or those that are positively identified as man-made after analysis, will be passed to appropriate offices and should not be considered under the definition as unidentified aerospace-undersea phenomena,” the document states. What does all this jargon mean, though? One key word in the congressional report is “transmedium,” a term the Pentagon has recently adopted for its...