Guest: Dr. Paul Davies. Topics: Interstellar travel, microbiology, cosmology, Mars, and much more. Please direct all comments and questions regarding Space Show programs/guest(s) to the Space Show blog, http://thespaceshow.wordpress.com. Comments and questions should be relevant to the specific Space Show program. Written Transcripts of Space Show programs are a violation of our copyright and are not permitted without prior written consent, even if for your own use. We do not permit the commercial use of Space Show programs or any part thereof, nor do we permit editing, YouTube clips, or clips placed on other private channels & websites. Space Show programs can be quoted, but the quote must be cited or referenced using the proper citation format. Contact The Space Show for further information. In addition, please remember that your Amazon purchases can help support The Space Show/OGLF. See www.onegiantleapfoundation.org/amazon.htm. We welcomed Dr. Paul Davies to this 65 minute discussion about his contribution to the excellent book, "Starship Century: Toward the Grandest Horizon." Other topics included interstellar travel, microbiology, human spaceflight, Mars, ET and much more. We started our discussion with his Afterword in the "Starship Century" book and I asked him about his comments regarding microbes. One quickly learns from reading his Afterword that it is not the propulsion and engineering that presents the greatest challenge to interstellar travel but what happens to essential microbes needed for life in microgravity and the space environment. We learned that even in LEO such microbes can transform and become toxic to life. This is a fascinating microbiology discussion regarding deep space missions to Mars, the Moon, and long interstellar travel. Don't miss what Dr. Davies said about microbes as it opens up an entirely new study in human factors for human spaceflight. Other issues we talked about included planetary contamination, microbial ecosystems, figuring out the minimal needed for sustainability regarding the good microbial environment. Also, what microbes are crucial and those that might be irrelevant for the spaceflight passengers as well as for animals and plants needed for sustaining the mission. Dr. Davies was asked that given microbiology being a bigger challenge than propulsion and engineering, were we close to having propulsion and engineering for interstellar travel. You will appreciate his very "witty" answer to this listener's question. Faster than light travel came up and so did the work being done around the Alcubierre Drive. Dr. Davies had much to say about faster than light travel, the speed of light, physics, and related disciplines. In this discussion, we also talked about both black holes and worm holes. Later, we talked about the possibility of life in the solar system other than on Earth. You might be surprised by some of what Dr. Davies said, including the probabilities that Earth might have been visited over 100 million years ago. Don't jump to conclusions, listen to the discussion first. Helen of Atlanta asked why bother with interstellar travel when we can't even return to the Moon. Again, another terrific response by our guest. More came up on the Fermi Paradox, the need to stay grounded in fundamental science but to have a vision and healthy skepticism. Viking and Gil Levin came up regarding the possibility of life on Mars and the reluctance of NASA to do biological experiments regarding the possibility of life on Mars. A listener asked our guest about ET conspiracy theories and government cover-ups. In closing, Dr. Davies reminded us to have and conduct healthy speculation which means always staying in tune with fundamental science. That is what separates speculation from fantasy, Kool Aid, and La La thinking. As the program was ending, we talked some about his work in cancer research. Make sure you visit his website, http://cosmos.asu.edu. Please post your comments/questions on The Space Show blog. You can reach Dr. Davies through his website or me.