This summer one man has decided to celebrate his 77th birthday by riding his bike 400 miles from Astoria, Oregon, to Crescent City, California. Joe Blumenthal, a cardiologist and instructor at University of California, San Francisco, has been bicycling extreme distances for years, riding 1,000 miles from British Columbia to Point Reyes Station—his hometown—in 2006, 750 miles from Astoria to his home in 2007 and 2010, and 400 miles from the east coast of Vancouver…