NEW CARLISLE, Indiana — A year ago, it was farmland. Now, the 1,200-acre site near Lake Michigan is home to one of the largest operational AI data centers in the world. It's called Project Rainier, and it's the spot where Amazon is training frontier artificial intelligence models entirely on its own chips.Amazon and its competitors have pledged more than $1 trillion towards AI data center projects that are so ambitious, skeptics wonder if there's enough money, energy and community support to get...