Joby Aviation (NYSE:JOBY) just made its boldest move yet, and it has nothing to do with flying you to the airport. On August 11, the air taxi developer said it would acquire defense technology company Resonant Sciences for about $500 million, split between roughly $450 million in cash and $50 million in stock. The deal hands Joby a dedicated defense business built around radio-frequency and mission systems for national-security customers. Investors did not celebrate. Shares fell 6.5% in premarket trading.Bu ...