implications of the search and discovery of life in the universe

Post on 18-Jan-2016

37 Views

Category:

Documents

1 Downloads

Preview:

Click to see full reader

DESCRIPTION

Implications of the Search and Discovery of Life in the Universe. HNRT 228 Bennett & Shostak Epilogue Dr. H.Geller. Issues to be Discussed. Is There Life Elsewhere Is life likely Prospects for finding life In our Solar System Elsewhere in the universe ET and Humans - PowerPoint PPT Presentation

TRANSCRIPT

1

Implications of the Search and Discovery

of Life in the Universe

HNRT 228Bennett &

ShostakEpilogue

Dr. H.Geller

2

Issues to be Discussed

• Is There Life Elsewhere– Is life likely– Prospects for finding life

• In our Solar System• Elsewhere in the universe

• ET and Humans– What impact contact would have?

• Examples from our own past

– Is the search significant?• If life found or not?

3

Remember what is astrobiology?

•Life in the Universe–Origins–Development

–Distribution–Search

4

Life Seems Likely

• What is needed for life?– Right chemical elements– Right environmental conditions

•Especially for liquid water– Right amount of time

•Without heavy meteor bombardment•With right elements and conditions

• Where are these conditions found?– Around individual stars throughout

galaxy

5

Where to look in Solar System?

• Remember likely candidates– Mars

• Perhaps life in past

– Europa• Perhaps life in subsurface ocean

– Titan• Perhaps life in “oceans” beneath cloudy

atmosphere

6

Where to look in galaxy?• Disk region of

galaxy– Population I stars

that have access to heavy elements during formation• Star like our Sun

worked at least once

• Individual stars– F, G, K most likely for

habitable zone over a long enough period

7

How will we view contact?• General public

– Many already believe that ETIs are among us or contacted us in the past or today

– “I told you so” attitude may arise

• Government– Nations to make

treaties with ETIs

• Scientists– Let’s study it

8

Types of Contact• Communications

– Radio waves– Other portions of EM

spectrum

• Artifacts– Remains of space craft– Actual spacecraft

• Face to face– What language would

they speak?

9

Response to Contact• Nine principles

– Seek to verify evidence– Alert other research organizations– Messages to IAU and UN under

Article XI of the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space

– Disseminate detection “promptly, openly, and widely” including the media

10

Response to Contact (cont’d)

• Remaining (of the nine principles)– Release data for confirmation by others– Confirm and monitor more data

recordings– Stop all noise at appropriate frequencies– Do not send a response signal– Advise and consult with other

international organizations as to the procedure for further actions

11

Consider Your Reaction – iClicker Questions

• NEWSFLASH: Scientists Confirm They Have Received Message From Another Intelligent Civilization In The Galaxy– Would you change your religion?

• A Yes• B No• C Not Sure

12

Consider Your Reaction – iClicker Questions

• NEWSFLASH: Scientists Confirm They Have Received Message From Another Intelligent Civilization In The Galaxy– Would you change your nationality?

• A Yes• B No• C Not Sure

13

Consider Your Reaction – iClicker Questions

• NEWSFLASH: Scientists Confirm They Have Received Message From Another Intelligent Civilization In The Galaxy– Would you change your lifestyle?

• A Yes• B No• C Not Sure

14

Consider Your Reaction – iClicker Questions

• NEWSFLASH: Scientists Confirm They Have Received Message From Another Intelligent Civilization In The Galaxy– Would you quit school?

• A Yes• B No• C Not Sure

15

Consider Your Reaction – iClicker Questions

• NEWSFLASH: Scientists Confirm They Have Received Message From Another Intelligent Civilization In The Galaxy– Would you commit suicide?

• A Yes• B No• C Not Sure

16

Explorations of the Universe:Another View

Encyclopedia Galactica

17

“Extraordinary Claims Require Extraordinary

Evidence”- Carl Sagan

18

Close Encounters

• First Kind: Sighting• Second Kind: Physical Evidence• Third Kind: Human-ETI Meeting

19

UFO - California, Novembe

r 1896

20

UFO- England,

March 1909

21

Lessons From Early UFO’s

• Both are exactly what people around 1900 would have expected aircraft to look like

• Consider:– If ETIs are trying to conceal their presence by

using terrestrial-style ships, why are they using searchlights?

• Consider:– If we have effective night-vision devices today,

why would an advanced ETI need searchlights?

• Consider:• people saw a light (Venus, an airplane, a balloon,

etc.?)• and subconsciously added details

22

Near Miss, August 10, 1972

23

1972 Near Miss

• Object was about the size of a bus

• Entered Atmosphere over Utah, travelling north, exited over Canada

• Velocity 15 km/sec• Missed by 58 km

24

Returning to Space

25

Lessons From a Near Miss

• Completely unexpected• Crossed sparsely-inhabited region• Visible a total of 101 seconds • Visible no more than 30 seconds at

any one spot• We have dozens of clear

photographs of this event.

26

The Drake Equation

“A wonderful way to organize our ignorance”

- Jill Tarter

27

The Drake Equation: Another View

Number of Intelligent Civilizations = Number of Stars in the Galaxy (400 billion) x Fraction of Stars with Planets (1/4?) x Number of suitable planets per star (2?) x Fraction of planets where life appears (1/2??) x Fraction of planets with intelligence (???) x Fraction of planets with technology (???) x Fraction of planet’s life with technology (???)

28

So Where Are They?

• Populations expand exponentially• It would take an exponentially-growing

civilization only a few million years to fill the Galaxy, even at sub-light speeds

• 2 to the 40th power is over a trillion• If it takes 10,000 years for a colony to

achieve interstellar travel, 40 doubling times is only 400,000 years.

• So why aren’t they all around us?– Recall the Fermi Paradox

29

Is There A Problem?• What is ETI psychology?

– How well do we understand humans?– Will ETIs be belligerent or altruistic

• Why did it take us so long to develop technology?– Why did many civilizations never develop

technology?

• Maybe we’re first?– Someone has to be the first civilization in the

galaxy.

• Maybe we’re unique?– But does uniqueness imply solitary?

30

What is Astrosociology?• Simply put, a combination of

astrobiology and sociology– Multidisciplinary science &

humanities course

• “Extraterrestrial Altruism: Evolution and Ethics in the Cosmos” edited by Doug Vakoch of the SETI Institute– Chapter 5 by Dr. Harold Geller

• Harmful ETI Hypothesis Denied: Visiting ETIs Likely Altruists

31

Other Stuff For the Drake Equation

• Jupiter Stabilizes Solar System– Evidence for this with most recent Kepler data

• Jupiter lessens impact bombardment– Evidence for this with models using Kepler data

• Moon stabilizes Earth’s axial tilt– Physics tells us this

• Earth’s magnetic field deflects cosmic rays– This is a fact, and mutations are affected

• Liquid Water Zone is narrow and changes with time as stars brighten– Demonstrated from basic physics

• Center of the Galaxy Deadly?– Amount of x-rays leads us to believe this is true.

32

Communicating With Earth’s ETIs

• Rosetta Stone, 1799• Champollion, 1828• Three Parallel texts, one in Greek• Can we decipher languages with no

parallel texts?

33

CuneiformGeorg Friedrich Grotefend (1775-

1853)

• Wedge-shaped markings in clay• Simple, hence not pictographs• Found literally by the millions• Seem to be mundane records, official

documents, etc.• Probably Semitic language

34

Cuneiform

• Official documents probably had a standard format: “King ---, son of ----”, etc.

• Guess words for “king” and “son”• Create genealogy• Compare with genealogies in other

documents and match format• Assign sound values to letters• Guess many other words from known

Semitic languages

35

Cuneiform

“Empires may rise and empires may fall, but

bureaucrats are the same forever.”

36

Mayan Heiroglyphs• Diego de Landa, 1566• Responsible for destruction of much of

Mayan literature• Left detailed account of Mayans at time of

conquest• Described 64 hieroglyphs, equated 30 with

letters• Later researchers identified 400-800• Once regarded as a type example of a

language lost beyond recovery• Heinrich Berlin, 1958:

-Locality signs• Tatiana Proskouriakoff, 1960

- Ascension and Reign signs

37

Mayan Heiroglyphs

• Yuri Knozorov, 1960• De Landa was too good an observer

to be totally mistaken• His “letters” were really syllables• Positional statistics to analyze syntax• Maya hieroglyphs are now over 85%

decipherable• Maya were not as one-dimensional

as once thought

38

What if we succeed?Some Features of Culture Shock

• Loss of Faith in Beliefs and Institutions• Xenophobia• Over-Dependence, Copying• Nihilism

39

Arthur C. Clarke’s View• The only way to test the limits of the

possible is by going beyond them into the impossible– A Agree B Disagree

• When an elderly but distinguished scientist says something is possible, he is probably right. When he says something is impossible, he is very likely wrong– A Agree B Disagree

• Any sufficiently advanced technology is indistinguishable from magic– A Agree B Disagree

40

Shall We Hide?A Yes B No

• Stephen Hawking believes so– http://www.timesonline.co.uk/tol/news/science/spa

ce/article7107207.ece

• Others have other opinions– http://journalofcosmology.com/Aliens100.html

• At radio frequencies– Earth is brighter than the Sun– Signals now 100 light years out

• ETIs could determine– Length of our day and year– Size of Earth, Distance from Sun– Draw a crude map of Developed World

41

Our Views of ETIs

• Post World-War II– “Savior Model”– “Hostile ETIs” - Eat or Enslave

• Science Source of Fascination and Fear– Winning World War II– Nuclear War

• Similarity with Westerns– We’re the Good Guys– Fighting off Hostile Threats

42

Our Views of ETIs Evolve

• 1960’s: Hostile ETI films and Westerns both decline

• We’re Not Always the Good Guys– Historical Revision of Frontier – “Spaghetti Westerns”-Dark and satirical– Civil Rights Movement– Vietnam

• Star Trek, 1967– Enlightened, Optimistic Future

43

Variations• Humans as Helpers: E.T.• Encounter as Wonder: Close

Encounters of the Third Kind• Encounter as Dreary: Contact• Swashbuckling: Star Wars• Satire: Men In Black• Return to Hostile ETIs

– Star Trek Spinoffs (The Borg, the Dominion)

– Independence Day

44

SETI@Home

http://setiathome.ssl.berkeley.edu/

top related