1. Is There Anybody Out There? An Exercise in the Method of ANALYSIS

2. ANALYSIS: The separation of an intellectual or material whole into its constituent parts for individual study. dictionary.com

3. 300 B.C. Speculation of Life Elsewhere Physics – Biology – Chemistry – Sociology – Archeology Theology Lack of information and poor understanding lead us to analysis…

4. FUNDAMENTAL QUESTIONS… 1.What is the likelihood that other Earth-like planets exist? 2.Given an Earth-like planet, what is the likelihood that life would arise there? 3.Given life, What is the likelihood that such life would develop intelligence? 4.Given intelligence, what is the likelihood that technology would be developed by such an intelligence? 5.Given technology, what is the likelihood that intelligent life would contact us or us them? Grounded in Science – Mindful of Uncertainty

5. What is the likelihood that other Earth-like planets exist? Life on Earth is the only life KNOWN to exist…

7. Approximately 400 billion stars…

9. 50% Binary Stars... Sorry, No Planets Only 200 Billion Stars Left!

10. Other stars have planets… How many are Earth-like?

11. High mass stars burn too fast… Low mass stars burn too cold… Only about 10% have the right mass.

13. UNCERTAINTY Optimism V.S. Pessimism

14. Optimistic: All good stars have planets. Pessimistic: Only 10% have planets.

16. Optimistic: All good solar systems have at least one Earth-like planet. Pessimistic: Only 10% have Earth-like planets. EARTH-LIKE?

17. Optimistic: 20 Billion Earth-Like Places Pessimistic: 200 Million Earth-Like Places

18. Given an Earth-like planet, what is the likelihood that life would arise there? Optimistic: Life is certain Pessimistic: Only 10%

19. Optimistic: 20 Billion Planets with Life Pessimistic: 20 Million Planets with Life

20. Given life, what is the likelihood that life would develop intelligence?

21. BIOLOGICAL CONVERGENCE

22. Optimistic: Intelligence is a certainty Pessimistic: 1 in a million

23. Optimistic: 20 Billion Planets with Intelligent Life Pessimistic: 20 Planets with Intelligent Life

24. Given intelligence, what is the likelihood that technology would be developed by such an intelligence? Optimistic: All intelligent life develops the ability to send radio signals Pessimistic: Only 10% develop technology

26. Optimistic: 20 Billion Planets with Intelligent, Technological Life Pessimistic: 2 Planets with Intelligent, Technological Life

27. Given technology, what is the likelihood that intelligent life would contact us or us them? Our estimate shows that we a reasonable suspicion that Intelligent, technological life to develop, or develop in the future, elsewhere in our galaxy.

28. IS THERE ANYBODY OUT THERE?