Summary: This week, we run with a team of dogs through 1,000 miles of Alaska's wilderness, then we walk - quickly - down the Appalachian Trail to set a new speed record, and finally, we walk to the edge of a black hole to time travel.
Summary: This week, we run with a team of dogs through 1,000 miles of Alaska's wilderness, then we walk - quickly - down the Appalachian Trail to set a new speed record, and finally, we walk to the edge of a black hole to time travel.