tragically and not by natural causes, especially for me but certainly for everyone, it hits that much more deeply. because of so much effort that i know we snd in this search for life and universe. and so -- but at least we got to share this universe with him. >> he was on your show twice. >> yeah, yeah. several times. he was a friend of the show. we talked about the science of food and the relationship between culture and what foods you would eat or have the likelihood of eating depending on where you are, what latitude you are on earth, effects, what kind of foods you prefer, how much spice is in it, how much isn't. that's the nature of how we interact with our guests. they're hardly ever scientists as guests. so that gave us the opportunity to experience his life. he has quite a profile. those who only know him from the cnn show, you have to dig a little deeper and you find out