what does it mean when the groundhog shows its shadow
Groundhog Day Groundhog Day, (Pennsylvania German: Grund'sau dÃ¥k, Grundsaudaag, Grundsow Dawg, Murmeltiertag; Nova Scotia: Daks Day[1]) is a popular tradition celebrated in the United States and Canada on February 2. It derives from the Pennsylvania Dutch superstition that if a groundhog (Deitsch: Grundsau, Grunddax, Dax) emerging from its burrow on this day sees a shadow due to clear weather, it will retreat to its den and winter will persist for six more weeks, and if it does not see its shadow because of cloudiness, spring will arrive early. While the tradition remains popular in modern times, studies have found no consistent correlation between a groundhog seeing its shadow or not and the subsequent arrival time of spring-like weather.[2]
Shadow The sun casts shadows which change dramatically through the day. The length of a shadow cast on the ground is proportional to the cotangent of the sun's elevation angle—its angle θ relative to the horizon. Near sunrise and sunset, when θ = 0° and cot(θ) = ∞, shadows can be extremely long. If the sun passes directly overhead, then θ = 90°, cot(θ) = 0, and shadows are cast directly underneath objects.