The 2018 Winter Olympics in Pyeongchang have been defined by punishing cold and howling winds. But in the ski jump start house, nearly 3,000 feet above sea level, it’s warm and eerily silent. The room is packed with jumpers — brave men preparing to launch themselves some 450 feet through the air — but no one speaks. No one smiles. On the very long, tight elevator ride, there is no banter, just quiet concentration.