Who is Polar Explorers from Teaching a Stone to Talk and what is their importance?

In "An Expedition to the Pole", Annie discusses the polar explorers from the past who sought to find the North and South Poles. Many of these explorers died on their journey, often from hypothermia, starvation, and other illnesses brought on by the extreme conditions. Annie notes that they explorers died with dignity, often choosing to sacrifice themselves for the sake of their fellow explorers.