Photos Show It's True: No Two Snowflakes Alike

　　Starting in October, the U.S. Postal Service will issue a set of four stamps featuring pictures of snowflakes taken by Kenneth Libbrecht, a professor of physics at the California Institute of Technology. For years, Libbrecht has been studying the physics of snowflakes, looking at the different patterns of crystal growth and snowflake formation. These pictures revealed on thing that is there're no similar Snowflakes in the world.