Snowflakes. These intricate, whimsical crystals are a staple of magical wintry scenes, but how big can they really get? Well, according to the Guinness World Record keepers, the "largest snowflake" ever recorded was a whopping 15 inches in diameter. It was spotted near Missoula, Montana in 1887. But Kenneth Libbrecht, a physicist at Caltech, has long been skeptical of that record. So he set out to find what makes a snowflake a snowflake and whether that 1887 record is scientifically possible. You can read more about what he discovered here. (encore)Want to share the snowflakes you've spotted this winter? Email us a photo at shortwave@npr.org.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy