Designing Snowflakes

摘要

Snowflakes are growing in Southern California. In the sun-drenched labs of the California Institute of Technology, Ken Libbrecht and his students are busy tinkering with something called a vapor diffusion chamber, which creates a myriad of unusually shaped flakes. Some are tiny, simple hexag-onal prisms; others are complex, beautiful structures that Libbrecht calls "designer snowflakes." Libbrecht, who chairs the physics department at Caltech, has been growing snowflakes for years. Snow is his professional specialty and personal passion. He even has a favorite snowflake pattern: flat plates decorated with ice ridges called sectored plate crystals.