1. Are “they” out there?

2. Fermi’s Paradox  Back in the 1940’s, a group of scientists were discussing extraterrestrial life.  Fermi asked “So? Where is everybody?” What did he mean?What did he mean?

3. Drake Equation  Dr. Frank Drake in 1960 attempted to make a mathematical formula to estimate how many alien civilizations we could possibly make contact with

4. Drake Equation When you put in numbers for all of those, you get 2.3

5. Fermi’s Paradox  Meaning: If there are billions of planets capable of supporting life….  And millions of intelligent species….  Why haven’t any visited Earth?

6. Fermi’s Paradox  He realized that any civilization with modest rocket power and some initiative could colonize the galaxy within a few million years

7. Fermi’s Paradox  Aliens have had more than enough time to colonize the galaxy So, where were they?So, where were they? Question: If OUR civilization is so advanced, where are the other advanced life forms?Question: If OUR civilization is so advanced, where are the other advanced life forms?

8. 3 Types of Civilizations  Type I – Similar to ours. Uses resources of a planet  Type II – Uses resources of it’s solar system / stars  Type III – Uses resources of an entire galaxy. Easy to detect.

9. So???? Where are they?  Perhaps space is too vast to be conquered by living, biological beings…(Do you want to spend your lifetime flying through space?)  Maybe our first encounter will be with self-replicating machines! Idea proposed in the 1950’sIdea proposed in the 1950’s

10. Don’t make me say it again…  Starting to sound redundant. Where, then, are the self replicating machines?Where, then, are the self replicating machines? Why haven’t we made contact with them by now?Why haven’t we made contact with them by now?

11. Solutions to Fermi’s Paradox  I. They are here! They were here and left evidenceThey were here and left evidence  UFO’s, Ancient Astronauts, Alien Artifacts. Problem: No evidence. (Stonehenge not withstanding)Problem: No evidence. (Stonehenge not withstanding) They are us!They are us!  Humans are descendants of aliens Problem: Where are the original aliens?Problem: Where are the original aliens?

12. I. They are here! (Cont.)  Zoo scenario Aliens are keeping us in a well designed zoo, cut off from contact.Aliens are keeping us in a well designed zoo, cut off from contact.  Problem: Can’t test this hypothesis. Only one alien showing his face would break the illusion

13. Solutions to Fermi’s Paradox  II. They exist but have not yet communicated They have not had time to reach usThey have not had time to reach us  Still only travel speed of light Problem: civilizations forming before usProblem: civilizations forming before us They ARE signaling, but we don’t know how to listenThey ARE signaling, but we don’t know how to listen  Exotic signaling methods we don’t know about Problem: If they are so advanced, they should also use “primitive” methods to communicate with usProblem: If they are so advanced, they should also use “primitive” methods to communicate with us

14. Exist but not communicate (cont.)  No desire to communicate Advanced civ. doesn’t want to communicate with “lesser” beingsAdvanced civ. doesn’t want to communicate with “lesser” beings  Problem: Curiosity  Berserkers Killer robots searching the galaxy, so aliens are keeping it on the D.L.Killer robots searching the galaxy, so aliens are keeping it on the D.L.  Problem: Why haven’t berserkers come after us yet?

15. Solutions to Fermi’s Paradox  III. They do not exist We are the first life forms, evolution takes timeWe are the first life forms, evolution takes time  Problem: Sun is average, and young. This view very “American” Planets with right conditions are rarePlanets with right conditions are rare  Planetary systems are rare  Space is a dangerous place  Habitable zones

16. They do not exist (cont.)  Life is rare Life’s Genesis is rareLife’s Genesis is rare Intelligence / tool making rareIntelligence / tool making rare Technology / Science is not an inevitable outcomeTechnology / Science is not an inevitable outcome Urey-Miller experiment

17. They do not exist (cont.)  Catastrophes Civilizations only have a limited lifetime. They are all dead.Civilizations only have a limited lifetime. They are all dead.  Overpopulation  War

18. Fermi’s Paradox Solutions  Basically comes down to 2 possibilites:  1. Life is difficult to start or evolve  2. Advanced civilizations destroy themselves before colonizing space

19. Mission to Mars  Can we buck the trend???  Tune in tomorrow, same Bat-time, same Bat-channel!