d8a002f75fffdae565033e68b85b8a29.ppt
- Количество слайдов: 36
Extraterrestrial Life, the Population Explosion, and Other Surprises From the Physics of Complex Systems Weldon J. Wilson EQUATIONS Department of Physics University of Central Oklahoma wwilson@uco. edu
OUTLINE q q Complex Systems Methods u Don’t Ignore the Obvious (Try not to be Stupid) u Scale Analysis (Look at Units) u Power-Law Behavior (Make Log Plots) Applications u Life in the Universe u Thinking Computers PHYSICS u Extinction Event Asteroids LECTURES u Population Explosion Conclusions
Bacteria ~10 Billion molecules ~109 Interacting Particles Complexity A Boeing 777 has 150, 000 different components and a total of 30 million subcomponents, some with millions of subparts.
For Complex Systems q. Nonlinear Interactions Key q. Collective Effects Appear q. The Whole = Sum of Parts Need Simple Methods
Don’t Overlook the Obvious! Fox Network
Since 1947 We’ve had 33 U. S. Saucer Crashes! (~1 Every 2 years) 04 -Jul-47 Roswell, NEW MEXICO (4 Bodies) q 13 -Feb-48 Aztec, NEW MEXICO (2 Bodies) q 07 -Jul-48 MEXICO So. of LAREDO TX (1 Body) q 08 -Aug-49 Roswell, NEW MEXICO(2 Bodies) q 10 -Sep-50 Albuquerque, NEW MEXICO (3 Bodies) q 14 -Aug-52 Ely, NEVADA (16 Bodies) q …. q
Since 1965 We’ve Had 13 Boeing 700 Series U. S. Airline Crashes (~1 Every 3 Years) Boeing (1 per 3 years) vs ET (1 per 2 years) q Don’t Get on Flying Saucer (They’re Death Traps) q Boeing has sold over 13, 000 B-777’s alone. q Earth is the OHare International Airport of the Galaxy q
Don’t Overlook the Obvious! FACT A: THERE ARE NO OBVIOUS EXTRATERRESTRIALS ON EARTH NOW AND THERE IS NO OBVIOUS EVIDENCE THERE HAVE BEEN ANY IN THE PAST.
When To Buy Your Next Computer? Or. . . When Computers Become Sentient?
Human Neuron Speed (mere k. Hz)
Will Computers Become Sentient? Moore’s Law Human Brain 100 x 109 Neurons
Baby Picture of the Universe
You are here There are 400 Billion Stars in our Galaxy. How many harbor life?
Where is Everybody? The Players F Edward Teller F F LANL Tech Area LANL Fuller Lodge Cafeteria F Enrico Fermi Edward Teller Herbert York Emil Konopinski Enrico Fermi
The Drake Equation (Fermi) N = Ng * fp * n. L * f. I * f. TC * f. TL • • N = Number of Tech Civilizations in the Galaxy Ng = # stars in Galaxy (4 x 1011) fp = fraction of stars having planets (1. 00) n. L = fraction of planets suitable for life (0. 01) f. L = fraction of suitable planets where life arises (0. 01) f. I = fraction of worlds with life on which intelligent life arises (0. 1) f. TC = fraction with intelligent life where a technical civilization arises (0. 01) f. TL = fraction of a planetary lifetime average technical civilization exists (0. 01)
The Drake Equation N = Ng * fp * n. L * f. I * f. TC * f. TL Putting all this together we find. . . N = (400 x 109) * (1. 0) * (0. 01) = 400 !!! Estimates range from 1 (us) to 400 million.
Maximum Speed Achieved Space Shuttle Automobile Train Horse Plane
SPEED TO COLONIZE SPACE ? Current Technology – Estimated capability 0. 1 c Time to Go 20 parsecs (66 ly) 660 years Time to Go to Nearest Star (4. 3 ly) 43 years Time to Colonize Star 5000 years Assume ~100, 000 years to go out 20 parsecs
TIME TO COLONIZE GALAXY? Assuming 100, 000 years per 20 parsec hop Total Time to Cover Galaxy = 1500 x 100, 000 yrs = 150 million years ! 30 , 00 Distance per hop = 20 parsecs 0 p ars ec s # of hops = (Total Dist)/(Dist per Hop) = (30, 000 parsecs )/(20 parsecs) = 1500 hops
Fermi Paradox Drake Equation 400 ET Civilizations Time To Cover Galaxy 150 Million Years Our Galaxy is 12 to 20 billion years old so. . . Where Is Everybody?
Where is Everybody? q We are the first! q Life is extremely rare in the universe q Cosmic Catastrophes kill off Technological Societies q Technological Societies self-destruct rapidly q We are a protected site (Zoo/Prime Directive) q Others are so far advanced as to ignore us
ut B it! wa THERE’S MORE Expensive searches for ET life are a waste of time and money - if they are there, they would have been here by now. We are the only technological civilization in our Galaxy (or at least the first to arise) and in the long run (~150 million years) will occupy every habitable planet in the Galaxy.
Extinction Event Asteroid Imact How often? Every 100 million years
Meteor Impact Frequency -6 10 Shooting Stars (1 mm) Power Law -3 Frequency (1/yr) 10 Meteorites (1 m) 1 Not Gaussian !! -3 10 Arizona Crater (100 m) -6 10 Ontario Crater (10 km) -9 10 -4 10 1 4 10 Diameter (m) 8 10 12 10
Log-Log plot of Gaussian (Normal) Distribution 0 10 -2 10 -4 10 -6 10 -8 10 -10 10 -2 10 -1 10 0 10 1 10 2 10
Why Power Laws Are So Interesting? q They are “surprising. ” § Central limit theorem suggests we should see mostly normal distributions? They suggest “criticality, ” a major source of “complexity” in physics. q They are ubiquitous. q § Link physics, biology, and engineering. q They imply large (anomalous) events are more likely than previously thought.
Overpopulation ?
This or This
Conclusions q ET probably doesn’t exist but if he does, don’t ride with him (it? ) q By 2020 computers will be smarter than we are q Power-Laws Rule (For Complex Systems) q By 2030 we will know if humans will inherit the Universe or will be making room for someone else q And the Internet/Distance Learning may be replaced by. . .
Multimedia Presentation of the 21 st Century?


