Guest: Dr. Douglas Vakoch. Topics: SETI, "Communication With Extraterrestrial Intelligence," interstellar communication efforts. You are invited to comment, ask questions, and discuss the Space Show program/guest(s) on the Space Show blog, http://thespaceshow.wordpress.com. Comments, questions, and any discussion must be relevant and applicable to Space Show programming. Transcripts of Space Show programs are not permitted without prior written consent from The Space Show (even if for personal use) & are a violation of the Space Show copyright. We welcomed the return to The Space Show by the SETI Director of Interstellar Message Composition, Dr. Douglas Vakoch, to talk about his new book "Communication With Extraterrestrial Intelligence." Dr. Vakoch started our discussion by referencing the NASA Astrobiology Science Conference and the 50th anniversary of the first SETI search. Dr. Vakoch then explained that his new book is divided into three parts. Part I focuses on a review of the progress made with SETI and describes new advances in the field. Part 2 carefully examines Active SETI and the issues related to our actively transmitting signals rather than just searching for signals from ET. Part 3 focuses on the issues surrounding Interstellar Message Construction and making sure that we can be understood. This section also looks at ethical issues as well as who would be speaking for us here on Earth. Our guest was asked about the differences in the first searches in 1960 compared to those today. As you will hear, much of the difference lies in computer processing power and the ability to search millions of frequencies instead of one or two. We also talked about searching using radio waves as compared to optical or other methods. Listener Paul asked our guest how SETI would determine that they had reached the point in searches where they could conclude there were no ET signals. Don't miss the answer to this question. When asked about the next search technology beyond optical, Doug suggested it would probably be related to more powerful computer algorithms to process more complicated data. The subject of the WOW signal came up as did SETI@home and locating search antennas on the back side of the Moon or in orbit. Charles was our first caller at the start of the second segment, inquiring about searching among near-earth Asteroids. Randy asked if anything could be inferred by SETI given that while there is much talk about ET having visited Earth, there is no concrete evidence for it. Doug talked about exoplanets and the Kepler Mission and the time it takes for round trip communication at light speed even for a close star system. This brought up the life space of human researchers as compared to what might be a totally different life span situation for ET, especially if ET were computer based or at least very different from humans. John called in wondering if ET could detect a signal from Earth. Doug discussed Earth signal leakage and the one intentional transmission in 1974. You might be surprised by what he said the range of our signals might be plus his noting of the fact that the Earth is actually becoming quieter. We then discussed the issue of Active SETI transmission from Earth. I'm sure you will find our discussion interesting and this part of his book is superb. In the third part of his book, I asked about the Rosetta Stone chapters and understanding ET as well as ET understanding us. We also talked about the possible differences in mathematics between ET and our systems. Toward the end of the program, Doug provided us with an update on SETI, the Allen Telescope Array, the SETI budget situation, their new program SETIstars and more. If you have a comment or question for Dr. Vakoch, please post it on the URL above. You can learn more about SETI at www.seti.org. His book is available now at your favorite bookstore or online book seller and it is in all available formats.