Rudolph's red nose guides Santa on X-mas

If you always wondered about Robert L. May's Rudolph the Red-Nosed Reindeer, then you should know that his shiny red nose on the foggy Christmas Eve has got many optical benefits.

Researchers from Dartmouth College explain why Rudolph is able to lead Santa and his team of eight tiny reindeer through the thick Arctic fog.

Lead researcher Nathaniel J. Dominy points out that Arctic reindeer can see ultraviolet light, which is invisible to humans and most mammals, a trait that comes especially handy in mid-winter when the sun is low on the horizon and the high scattered light from the atmosphere is mainly bluish and ultraviolet.

In addition, the reflective tissue in reindeer eyes changes from a rich golden color during the summer months to a deep blue color during the winter months. This tissue helps nocturnal animals see in the dark, and a blue one is expected to improve their ability to see blue light. Yet, fog extinguishes blue light more readily than red light, which may make it especially difficult for Santa's reindeer to see blue effectively, never mind fly.

This is where Rudolph's luminescent nose comes into play, as it serves as an excellent fog light for navigating his fellow reindeer.

According to Dominy, Rudolph's nose also poses a problem. Reindeer noses are extremely vascular, which causes them to lose body heat through their noses. A glowing nose could cause excessive heat loss for Rudolph, putting him at risk of hypothermia.

The study is published in the Journal of Frontiers for Young Minds.