text:  Coming back to where we started the show, talking about retail. Yesterday, Kristen Schwab took us inside a UPS warehouse in Louisville, Kentucky, to get a better understanding of how online shopping has transformed the way companies store and ship goods. But what happens at the warehouse is only one piece of the equation. One or two-day shipping often requires air travel, and most major logistics companies have their own airport operations. For UPS, that's Worldport in Louisville.