It's a good thing the diverse people of Hawaii have managed to live together peacefully — it's not easy to leave. The state is called the most isolated population center in the world — some 2,390 miles from the U.S. and nearly 4,000 miles from Japan. While its remoteness can make Hawaii an ordeal to visit (flights from Los Angeles take 5½ hours), it's a boon for scientists. Hawaii is home to one of the largest clusters of telescopes and observatories in the world, taking advantage of the area's low levels of air and light pollution. Last month the summit of Mauna Kea, on Hawaii's Big Island, was chosen as the site for the world's largest telescope — expected to be completed in 2018 with a price tag of more than $1 billion.