In honor of the first snow fall of the year in my home town, I present some snow factoids:
Is it true that no two snowflakes are exactly alike?
Yes, say researchers at Caltech. Kenneth Libbrecht, a physicist, has studied the growth of ice crystals in controlled laboratory settings. Ice crystals form around a speck of dust and grow differently depending on the air temperature and humidity. In real life, snowflakes float through the air where temperature and moisture constantly change. Just as no two people have the same developmental history, no two flakes have the same growth history so each is unique.
What causes pink snow?
While it's true that sometimes shadows cast on snow appear to have a pink hue, the bright pink almost reddish tint of "watermelon snow" is a totally different phenomenon. A certain species of algae, Chlamydomonas nivalis, produce a red pigment in addition to the familiar green-tinted chlorophyll produced by plants. This algae thrives in frozen water and when compacted, by stepping on it with a snow boot, the color intensifies. Watermelon snow can be seen in late spring and early summer in old, packed snow at around 10,000-12,000 feet in the Sierra Nevada mountain range in CA. The red tinged carotenoid pigmentation is what gives tomatoes, peppers, lobsters, corals, and shrimp-eating flamingoes their distinctive crimson color. You can see examples of pink snow here.
Snowflake, the Albino Gorilla
Snowflake, the world's only known albino gorilla, lived in the Barcelona Zoo. He was captured from the wild in the 60s in Equatorial Guinea when he was an infant and lived about 40 years in captivity until he died from cancer. He sired 21 offspring and 10 grandchildren, including twins.
Albinism is a recessive genetic trait so both of Snowflake's parents had to have the gene that causes the condition. The gene alters the amino acid tyrosinase which is a necessary building block for the proteins that pigment hair and skin.
Snowflake was not treated any differently by the other gorillas in his community on account of his odd skin and hair color -- a lesson we humans ought to take to heart.