Are “they” out there?Are “they” out there?

Fermi’s ParadoxFermi’s Paradox

Back in the 1940’s, a Back in the 1940’s, a group of scientists were group of scientists were discussing extraterrestrial discussing extraterrestrial life.life.

Fermi asked “So? Where Fermi asked “So? Where is everybody?”is everybody?”• What did he mean?What did he mean?

Drake EquationDrake Equation

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

Drake EquationDrake Equation

When you put in numbersfor all of those, you get2.3

Fermi’s ParadoxFermi’s Paradox

Meaning:Meaning: If there If there are billions of are billions of planets capable of planets capable of supporting life….supporting life….

And millions of And millions of intelligent intelligent species….species….

Why haven’t any Why haven’t any visited Earth?visited Earth?

Fermi’s ParadoxFermi’s Paradox

He realized that He realized that any civilization any civilization with modest rocket with modest rocket power and some power and some initiative could initiative could colonize the galaxy colonize the galaxy within a few million within a few million yearsyears

Fermi’s ParadoxFermi’s Paradox

Aliens have had more than enough Aliens have had more than enough time to colonize the galaxytime to colonize the galaxy• So, where were they?So, where were they?

• Question: If OUR civilization is so Question: If OUR civilization is so advanced, where are the other advanced, where are the other advanced life forms?advanced life forms?

3 Types of Civilizations3 Types of Civilizations

Type I – Similar to ours. Type I – Similar to ours. Uses resources of a planetUses resources of a planet

Type II – Uses resources of Type II – Uses resources of it’s solar system / starsit’s solar system / stars

Type III – Uses resources of Type III – Uses resources of an entire galaxy. Easy to an entire galaxy. Easy to detect. detect.

So???? Where are they?So???? Where are they? Perhaps space is too Perhaps space is too

vast to be conquered vast to be conquered by living, biological by living, biological beings…(Do you want beings…(Do you want to spend your lifetime to spend your lifetime flying through space?)flying through space?)

Maybe our first Maybe our first encounter will be with encounter will be with self-replicating self-replicating machines!machines!• Idea proposed in the Idea proposed in the

1950’s1950’s

Don’t make me say it again…Don’t make me say it again…

Starting to sound redundant.Starting to sound redundant.• Where, then, are the self replicating Where, then, are the self replicating

machines? machines? • Why haven’t we made contact with Why haven’t we made contact with

them by now?them by now?

Solutions to Fermi’s ParadoxSolutions to Fermi’s Paradox

I. They are here!I. They are here!• They were here and left evidenceThey were here and left evidence

UFO’s, Ancient Astronauts, Alien Artifacts.UFO’s, Ancient Astronauts, Alien Artifacts.• Problem: No evidence. (Stonehenge not Problem: No evidence. (Stonehenge not

withstanding)withstanding)

• They are us!They are us! Humans are descendants of aliensHumans are descendants of aliens

• Problem: Where are the original aliens?Problem: Where are the original aliens?

I. They are here! (Cont.)I. They are here! (Cont.)

Zoo scenarioZoo scenario• Aliens are keeping us in a well designed zoo, Aliens are keeping us in a well designed zoo,

cut off from contact.cut off from contact. Problem: Can’t test this hypothesis. Only one alien Problem: Can’t test this hypothesis. Only one alien

showing his face would break the illusionshowing his face would break the illusion

Solutions to Fermi’s ParadoxSolutions to Fermi’s Paradox

II. They exist but have not yet II. They exist but have not yet communicatedcommunicated• They have not had time to reach usThey have not had time to reach us

Still only travel speed of lightStill only travel speed of light• Problem: civilizations forming before usProblem: civilizations forming before us

• They ARE signaling, but we don’t know They ARE signaling, but we don’t know how to listenhow to listen

Exotic signaling methods we don’t know Exotic signaling methods we don’t know aboutabout

• Problem: If they are so advanced, they should Problem: If they are so advanced, they should also use “primitive” methods to communicate also use “primitive” methods to communicate with uswith us

Exist but not communicate (cont.)Exist but not communicate (cont.)

No desire to communicateNo desire to communicate• Advanced civ. doesn’t want to Advanced civ. doesn’t want to

communicate with “lesser” beingscommunicate with “lesser” beings Problem: CuriosityProblem: Curiosity

BerserkersBerserkers• Killer robots searching the galaxy, so Killer robots searching the galaxy, so

aliens are keeping it on the D.L.aliens are keeping it on the D.L. Problem: Why haven’t berserkers come after Problem: Why haven’t berserkers come after

us yet?us yet?

Solutions to Fermi’s ParadoxSolutions to Fermi’s Paradox

III. They do not existIII. They do not exist• We are the first life forms, evolution We are the first life forms, evolution

takes timetakes time Problem: Sun is average, and young. This Problem: Sun is average, and young. This

view very “American”view very “American”

• Planets with right conditions are rarePlanets with right conditions are rare Planetary systems are rarePlanetary systems are rare Space is a dangerous placeSpace is a dangerous place Habitable zonesHabitable zones

They do not exist (cont.)They do not exist (cont.)

Life is rareLife is rare• Life’s Genesis is rareLife’s Genesis is rare• Intelligence / tool making Intelligence / tool making

rarerare• Technology / Science is Technology / Science is

not an inevitable outcomenot an inevitable outcome

Urey-Miller experiment

They do not exist (cont.)They do not exist (cont.)

CatastrophesCatastrophes• Civilizations only have a limited lifetime. Civilizations only have a limited lifetime.

They are all dead.They are all dead. OverpopulationOverpopulation WarWar

Fermi’s Paradox SolutionsFermi’s Paradox Solutions

Basically comes down Basically comes down to 2 possibilites:to 2 possibilites:

1. Life is difficult to 1. Life is difficult to start or evolvestart or evolve

2. Advanced 2. Advanced civilizations destroy civilizations destroy themselves before themselves before colonizing spacecolonizing space

Mission to MarsMission to Mars

Can we buck the trend???Can we buck the trend???

Tune in tomorrow, same Bat-time, Tune in tomorrow, same Bat-time, same Bat-channel!same Bat-channel!