Erling Kagge is one of the most accomplished explorers of our time. He has trekked to both the North and South Poles alone. Here are two quotes from his TedX talk about silence, Another Lecture on Nothing. He had plenty of time for contemplative silence in his solo adventures.

 

When faced with greatness, you become silent, and if you wish to understand greatness, a good way to start is by being silent

And

I tend to think about silence as a practical method for uncovering some answers about the intriguing puzzle that is your Self.

Full talk here, p.c. Twitter