It is impossible for describe, do more than salute this extraordinary educator. This man is one of the most brilliant persons I have ever encounted. You can ask him anything abut the Earth, and if he doesn't have an answer, he will point you in the right direction. I had several important conversations with him, each time he was more than willing to to help me figure out my questions and concerns. If you disagree with him, he's ok withg that, as long as you support yourself with facts. He is also one of the best speakers I have ever heard in my life. It is strange, sometimes, walking around with him, I felt as if some spirit of nature were talking to me. I cannot tell you how lucky I feel to have had this professor.