The Fermi Paradox

1. The Fermi Paradox • If we are not unique in developing a technological society in the galaxy… • Where is everybody? • The simple premises that lead to the Fermi Paradox are based on the ‘Copernican Principle’ or equivalently ─ ‘The Principle of Mediocrity’: • Planets are common • Earth–like planets are likely to be common • Life is likely on them • Intelligence emerged on Earth and we are not special • Therefore, many civilizations should exist… So if they exist, where are they?

2. Implications of N = RcivL Suppose Rciv =1/yr then N = L. If L = 1000 yrs then N = 1000 We previously estimated that Rciv =10-3/yr and L = 106yrs then we also get N = 1000 • In case (1), Rciv =1 and N = 1000 … thus there are 1000 operationally intelligent civilizations NOW, but about 1010 civilizations emerged since the Milky Way began! • … and even in case (2), which leads to the same conclusion that N = 1000 NOW, about 107 civilizations emerged during the Milky Way’s lifetime! • In either case, that’s a lot of technologically proficient civilizations … why hasn’t at least 1 of them figured out how to colonize the entire galaxy ? • In other words, ‘Why haven’t they been here or …

3. Why Aren’t They Here NOW? Assume a technologically advanced civilization sends out colonists to 2 nearby stars (~10 LY away) at 0.10 c…The trip takes 100 years … assume it takes about 400 years to get established …then they send out 2 sets of colonists … the number of colonies grows exponentially Colonization expands away from home planet at the rate of 10 LY per 500 years … or about 0.02 LY / year The galaxy is ~100,000 LY across … it would take ≈ 5 million years to colonize every possible habitat in galaxy! So … Where Are They???? Instead of ‘colonists’… send self-replicating robot probes!

4. In the “Coral Model” of galactic colonization, if we assume that colonizing ships can travel at 0.10c, then we might expect all of the habitable planets in the galaxy to be colonized within about ____ years. > 10 billion 1 billion ≈ 10 < 100 ≈5 million

5. Solutions to Paradox? • There are only 4 conceivable types of hypotheses that can be proposed to ‘escape’ the Fermi Paradox … 1. ‘Physical’ Explanations • Interstellar spaceflight is just not feasible!

6. ─ Counterpoint Point • Interstellar spaceflight is physically impossible! • Voyager (v ~ 10-4 c) exists! • No known principle of physics or engineering rules out interstellar spaceflight! • Fusion rockets (0.1 c) look do-able! • Antimatter rockets (0.9 c) … a maybe!

7. ─ Counterpoint Point • Longer life span? • Human lifetime is too short for interstellar space travel! • Suspended animation? • If we have only fusion rocket s (v~ 0.1 c) … • Antimatter rockets (v~0.9 c)? Arrive ε-Eridani Leave Earth

8. ─ Counterpoint Point • Humans are unlikely to withstand the hazards of interstellar travel. Earth’s magnetic field protects us from harmful radiation! • The human body deteriorates in space! • Bone and muscle mass loss. • Cardiovascular system deterioration. • Effects upon immune system. Shielding can protect spaceships against radiation and impacts. Send robots and/or embryos and/or sperm and egg cells!

9. Solutions to Paradox? 2. ‘Temporal’ Explanations • ET is actively exploring the galaxy but hasn’t had enough time to get here yet. • The Milky Way is 100,000 LY across and Earth is 2/3 out from its center … • Earth is at most 80,000 LY from ET. Even if ET traveled at 0.1 c, flight time < 1 million years!

10. Counterpoint • Actually, we’ve already dealt ‘temporal’ explanations a crushing blow! It would take ET’ on the order of 1- 10 Myr to ‘get here’, which is 10-4 – 10-3 the lifetime of the Milky Way Galaxy! ET ‘himself’ colonizes ET colonizes with ‘Von Neumann’ robots – self-constructing machines ET colonizes with ‘sperm and egg’ cells to be fertilized and cared for by robots.

11. Counterpoint • The implication is clear: • the first technological civilization with the ability and the inclination to colonize the galaxy could have done so before any competitors even had a chance to evolve. • In principle, this could have happened billions of years ago, when Earth was inhabited solely by microorganisms and was wide open to interference from outside. • Yet no physical artifact, no chemical traces, no obvious biological influence indicates that it has ever been intruded upon.

12. Which of the following best expresses the “Fermi Paradox?” Why are we here? Who are we? Where are we? Where is everybody? What are they?

13. Solutions to Paradox? 3. ‘Sociological’ Explanations • ET has no interest in colonizing or revealing ‘himself’ because … ET sits around and contemplates his navel. ET set Earth aside as a ‘zoo’. ET reveals himself only after we reach ‘high’ technological proficiency. ET obeys a prime directive … do not interfere with primitive life forms. ET’s ‘ethics’ prevent them from ‘contaminating’ space.

14. For whatever reason, ET ‘chooses’ not to be here!

15. Counterpoint It would take only one technological civilization─ for whatever reason ─to embark on a program of galactic colonization! Besides … at some point ET will be forced to colonize … or perish!

16. Solutions to Paradox? 4. ‘Disaster’ Explanations • For whatever reason, ET goes ‘belly up’ before being able to make his presence known. ET blows himself up in a nuclear holocaust. ET fails to solve its population problem … runs out of energy, food, water, etc. ET succombs to environmental and ecological ruin. ET is killed off by some ‘vector- born disease. ET is extinguished by an asteroid impact. ET is killed by the blast or radiation from a nearby supernova explanation. ET is extinguished by a cosmic ‘gamma ray burst’ ET evolves on a relatively short-lived star and its habitable zone passes it by.

17. Counterpoint This hypothesis can be dismissed for the same reason ─ more or less─ as the one we invoked to dismiss all ‘sociological’ hypotheses… All it takes is one and only one technological civilization out of the billions or millions that have emerged during the lifetime of the galaxy to ‘solve their internal problems’ and avoid externally caused disasters to embark on a program of galactic colonization!

18. They Are Here! Atmospheric phenomenon. Hoax … photographs of ‘toy’ UFO’s Russian (???) American (Grumman-Northrup X47B) experimental aircraft!

19. The ‘ET Hypothesis’ … • ~50% of the US public believes that UFO’s (which cannot be attributed to some ‘natural’ phenomenon ─ or hoax) ─ are piloted by Aliens!

20. What Started UFO’s? • June 24, 1947 Kenneth Arnold sights 9, shiny UFO’s flying at 1200 mph near Mt. Rainier. "...Kenneth is not so certain that the strange contraptions are made on this planet.” • The press coins the term ‘Flying Saucers’ and so begins the modern era of UFO sightings! • Arnold’s written statement to the AAF July 12, 1947

21. UFO Sightings Explode! Czaplinek, Poland (1947) Photographer unknown Author Ted Bloechercollected reports of 853 flying disc sightings that year from 140 newspapers from Canada, Washington D.C, and every U.S. state save Montana. This was more UFO reports for 1947 than most researchers ever suspected. Some of these stories were poorly documented or fragmentary, but Bloecher argued that about 250 of the more detailed reports (such as those made by pilots or scientists, multiple eyewitnesses, or backed by photos) made a persuasive case for a genuine mystery.

22. The Lubbock Lights • 1951: Three Texas Tech professors of science and engineering sight 15 – 20 yellowish lights passing from north to south. • One hour later they sight another group of lights moving south in a semi-circular formation. • Near midnight, they sight a 3rd group. • They estimate the altitude of the lights to be 50,000 feet. • They estimate the speed at 5 miles per second! • On following nights, armed with binoculars, they sight more lights! • They are migrating plover whose undersides are lit by newly installed mercury vapor lights in Lubbock. • It is impossible to determine distance, altitude and speed without knowledge of the object’s size!

23. The Roswell Incident - 1947 • The Roswell UFO Incident refers to the recovery of an object that crashed in the general vicinity of Roswell, New Mexico, in June or July 1947, allegedly an extra-terrestrial spacecraft and its alien occupants. • Since the late 1970s the incident has been the subject of intense controversy and of conspiracy theories as to the true nature of the object that crashed. • The United States Armed Forces maintains that what was recovered was debris from an experimental high-altitude surveillance balloon belonging to a classified program named "Mogul“. • However, many UFO proponents maintain that an alien craft was found and its occupants were captured, and that the military then engaged in a cover-up.

24. Aliens in Roswell, N.M. Being probed by aliens!

25. Was God An Astronaut? • Certain structures and artifacts represent a higher technological achievement than was presumed possible at the times they were made. • Von Dänikenattributes their production to either extraterrestrials or humans who were taught by them. • Such artifacts include the Egyptian pyramids, Stonehenge, the Moai of Easter Island, the Piri Reis Medieval Map, allegedly showing the Earth as seen from space ─ and the Nazca lines in Peru─ presumed airfield landing strips.

26. Height of the Great Pyramid von Däniken claimed Egyptians could not have known the distance to Sun and used it to ‘scale’ the height of the Great Pyramid! X 109 = 91,500,000 mi 481.3 ft X 109 = 98,00,000 mi

27. Height of Cathedral in Rouen, France 485 ft x 109 = 92,000,000 mi !

28. Even Better …the Common Bic Ballpoint Pen 14.96 cm x 1012 = 149,600,000 km = 93,000,000 mi ! • Maybe Aliens taught us how to make Bic Ballpoints using the distance to the Sun as the scale factor!

29. Tomb Lid of Pacal • von Däniken asserts that the Mayan king, Pacal (615 – 695 C.E.), is an ancient astronaut, in a spaceship with foot on pedals, hands on controls and an oxygen tube respirator!

30. Archeological Interpretation Pacal descending into the Mayan underworld. Around the edges are glyphs representing the Sun, the Moon, Venus, and various constellations. Below Pacalis the Mayan water god, who guards the underworld and the unfolded jaws of a serpent, which Pacalis escaping from, ascending towards the world tree. This is a common iconographic representation of the entrance to the underworld. Many examples of this imagery are found throughout Mexico, for example, in the sculptures on Monument 1 "El Rey" and Monument 9 at the Olmec site of Chalcatzingo, Morelos.

31. Nazca ‘Lines’ of Peru • Claim: • The markings are only visible from the air. • Technology to produce these markings was beyond the capabilities of the Nazca Indian culture of 400 – 650 C.E. • Ancient astronauts produced the lines as markers for landing their spacecraft. • Refutation: • They are visible from the surrounding hills. • Joe Nickell of the University of Kentucky reproduced the figures by using tools and technology available to the Nazca people. National Geographic called his work "remarkable in its exactness" when compared to the actual lines! • Current evidence suggests that they were markers to show where the Sun, Moon and other celestial bodies rose and set at certain times of the year. The lines are shallow designs made in the ground by removing the reddish pebbles and uncovering the whitish/grayish ground beneath.

32. So … Are They … or Have They … Been Here? • Many scientists think that it is highly probable that life exists somewhere else in the universe. • Few accept UFOs piloted by aliens or alien visitations. • Photographs are not enough to support the extraordinary claim that aliens have visited the Earth. • Personal accounts are unsupportedand contradictory. • “Evidence” more logically explained by known earthly phenomena. • Many UFO’s were experimental military aircraft according to the release of USAF classified documents. • Many were high altitude ‘balloons’ designed to monitor possible Soviet flights into US airspace during cold war. • No one has provided unequivocal evidence that UFO’s are piloted by aliens or that aliens have visited the Earth! Why? • Explanations used to account for insufficient evidence • The government is hiding the bodies • Scientists/government engaging in a conspiracy/cover-up. • Scientists are biased/can’t be trusted. • ETs have modified people’s minds. • Witnesses abducted and no longer exist..

33. Faulty Logic! • Belief that aliens have visited the Earth in the past and either showed us how to build things beyond our capability or built them themselves is equivalent to finding a piece of carved wood on top of Mount Arawat and assuming that it must be part of Noah’s Ark, which beached there during the flood! • Belief that aliens pilot those UFO’s that haven’t been attributed to some ‘Earthly’ phenomenon is equivalent to believing that all unsolved murders in New York are committed by robots!

34. But the Presence of Evidence Is Evidence of Presence ! The Absence of Evidence Is Not Evidence of Absence … • It’s possible to prove existence but impossible to prove non-existence … so who is holds the ‘burden of proof’ ?

35. Which of the following hypotheses is the most likely solution to the Fermi Paradox? We are alone because life that becomes operationally intelligent is rare—or we are effectively alone because we are among the first intelligent life forms to emerge. No intelligent civilization is interested or able to communicate. We are being watched by galactic civilizations but will not be contacted until we reach a certain high level of technology. All civilizations that reach our level of technology self destruct before achieving the ability to colonize. We have been set aside as a “zoo,” i.e., we are to be left alone.

36. Does ET Exist? Point: The elements that make up life are universal. Complex, carbon-based molecules form easily under conditions that are likely to be ubiquitous. Life on Earth thrives in a wide range of environmental conditions … some that once were thought to be too hostile! Life appeared ‘very quickly’ on Earth therefore supporting the argument that ‘life will find a way’. Counterpoint: Simple life might be ubiquitous … but it took 4 billion years of slow evolutionary change to produce an ET on Earth! It took 8 billion years following the Big Bang for a ‘Sun’ to emerge, which supports the argument that it takes a long time to produce conditions favorable for ET’s! The argument of the Fermi Paradox deals an almost lethal blow to the conclusion that large numbers of ET’s exist! • The simplest solution … we are alone … or at least among the very few ET’s that have only just begun to emerge. • … and if that’s the case … wouldn’t it be tragic for us to ‘screw’ it all up?