Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45NSCI 314LIFE IN THE COSMOS19 - LIFETIMES OF TECHNOLOGICAL CIVILIZATIONSDr. Karen Kolehmainen Department of Physics, CSUSBhttp://physics.csusb.edu/~karen/RECALL THAT THE LEAST WELL-KNOWN FACTOR IN THE DRAKE EQUATION IS L = AVERAGE LIFETIME OF A TECHNOLOGICAL CIVILIZATIONESTIMATING L IS IMPORTANT BECAUSE:1. IT ALLOWS US TO USE THE DRAKE EQUATION TO ESTIMATE HOW COMMON EXTRATERRESTRIAL CIVILIZATIONS ARE, AND, 2. EVEN MORE IMPORTANTLY, WE WOULD LIKE TO KNOW HOW LONG WE CAN EXPECT THE HUMAN RACE TO SURVIVE!FACTORS THAT MAY LIMIT THE LIFETIME OF TECHNOLOGICAL CIVILIZATIONS IMPACTS BY ASTEROIDS, COMETS, OR LARGE METEORITES POPULATION GROWTH CLIMATE CHANGE (GLOBAL WARMING)POLLUTIONDISEASEWARLOSS OF INTEREST IN COMMUNICATIONFACTS ABOUT THIS IMPACTMOVING AT 10 to 30 km/SecPASSES THROUGH HOUSE IN 0.01 Sec at 10 km/secENERGY RELEASE = 1 KILOTON BOMBCRATER DIAMETER = 120 FEET (TYPICALLY AT LEAST 10x THE DIAMETER OF THE IMPACTING OBJECT)CRETACEOUS-TERTIARY BOUNDARYBOUNDARY BETWEEN TWO GEOLOGICAL PERIODS 65 MILLION YEARS AGOROCKS DEPOSITED BEFORE THE BOUNDARY CONTAIN DINOSAUR FOSSILSROCKS DEPOSITED AFTER THE BOUNDARY CONTAIN NO DINOSAUR FOSSILSBOUNDARY MARKED BY THE EXTINCTION OF 80% OF LAND AND MARINE ORGANISMS (NOT JUST DINOSAURS)RECOVERY, AS DOCUMENTED IN THE FOSSIL RECORD, TOOK AT LEAST 5,000 YEARSEXTINCTION OF THE LARGE DINOSAURSLUIS & WALTER ALVAREZ DISCOVERED (1980):LARGE EXCESS OF IRIDIUM, A RARE-EARTH ELEMENT,LOCATED IN ROCKS DEPOSITED AT THE CRETACEOUS-TERTIARY BOUNDARY.THIS LAYER HAS BEEN FOUND WORLD-WIDE.IRIDIUM IS KNOWN TO BE PRESENT IN METEORITES AT MUCH HIGHER ABUNDANCES THAN IN EARTH ROCKS.TO SUPPLY THE ESTIMATED AMOUNT OF IRIDIUM WOULD REQUIRE A METEORITE 10 km ACROSS.METEORITE ESTIMATED TO BE 10 km ACROSS (SOMETHING THIS SIZE IS USUALLY THOUGHT OF AS AN ASTEROID)CRATER ESTIMATED TO BE 150-200 km ACROSSPEMEX DISCOVERED A BROAD SUBTERRANEAN ARC OFFSHORE YUCATAN PENINSULA (1978)SUBSEQUENT DISCOVERY OF 180 km CRATER AT CHICXULUB (STRUCTURE IS BURIED)CRATER HAS BEEN DATED AND IS 65 MILLION YEARS OLD99% of Atmosphere Below This LevelAsteroid 10 km across moving at 30 km/secMt. Everest8.7 kmOcean Floor3 kmENERGY OF A MOVING BODYDEPENDS ONLY ON THE MASS (M) AND VELOCITY (V) (BELOW EQUATION CORRECT ONLY IF V<< c)KINETIC ENERGY = (1/2) MV² FOR A 10 km DIAMETER ASTEROIDM = 2 TRILLION METRIC TONS = 2,000,000,000,000,000 kgV = 30 km/s = 30,000 m/s KE = 1024 JOULES OF ENERGY = ONE TRILLION TRILLION JOULES(EQUIVALENT OF 95 DAYS OF SOLAR RADIATION ABSORBED OVER ENTIRE EARTH)ENERGY RELEASE ON IMPACTUPON IMPACT, ALL ENERGY EVENTUALLY TURNS TO HEAT. IMPACT PRODUCED A FIREBALL 200 km ACROSS AND WITH A TEMPERATURE OF 100,000 KRESULTS: GLOBAL EFFECTSFIRESPOSSIBLE TRIGGERING OF EARTHQUAKES POSSIBLE TRIGGERING OF VOLCANIC ERUPTIONSCLIMATE CHANGESEXTINCTION OF MANY LIFE FORMSEFFECTS OF LARGE IMPACTFIRESTORMS ~ DAYS TO WEEKSFIREBALL INDUCED FIRES UP TO SEVERAL THOUSAND KILOMETERS FROM IMPACT SITEGLOBAL FIRES DUE TO SECONDARY IMPACTSIMPACT WINTER ~ 1 YEARGLOBAL CLOUD COVER, ACID RAIN, SALT RAIN, HIGH LEVEL OF DUST, REDUCED TEMPERATUREEXTINCTION OF NUMEROUS LIFE FORMS, ESPECIALLY LARGE ONES MANY PLANTS DIE DUE TO FIRES AND DARKNESSMANY ANIMALS DIE DUE TO INTERRUPTION OF THE FOOD CHAINULTRAVIOLET SPRING ~ 1 - ? YEARSDESTRUCTION OF OZONE LAYERUV INTERRUPTS PHOTOSYNTHESIS UV INCREASES MUTATION RATES, EVEN IN OCEANSFURTHER EXTINCTIONSMASS EXTINCTIONSHUMAN-CAUSEDDINOSURS ETC.SMALLER ASTEROID ?MOST LAND & SEAMOST FISHES MANY INVERT.MARINE SPECIES0400300200100 500MILLIONS OF YEARS AGOASTEROID IMPACTSEARTH-CROSSING ASTEROIDS – ASTEROID’S ORBIT INTERSECTS EARTH’S ORBIT.ONE OF THEM HITS EARTH EVERY 50 TO 100 MILLION YEARS ON THE AVERAGE.ORBITS ARE NOW BEING MAPPED, SHOULD BE DONE IN 10 YEARS. THEN WE WILL BE ABLE TO PREDICT FUTURE IMPACTS.HUMANS MUST THINK ABOUT PROTECTION FROM IMPACTS! BEST METHOD – USE EXPLOSIONS NEAR ASTEROID TO ALTER ITS ORBIT SLIGHTLY. DON’T BLOW IT UP!POPULATION GROWTHTHERE ARE CURRENTLY 6.7 BILLION HUMAN BEINGS ON EARTH.HUMAN POPULATION IS GROWING AT A RATE OF: –1.4% PER YEAR–88 MILLION PER YEAR–7 MILLION PER MONTH–240,000 PER DAY–18,000 DURING OUR CLASS PERIOD TODAYIF YOU ARE 20 YEARS OLD, THE WORLD’S POPULATION HAS GROWN BY 1.8 BILLION SINCE YOU WERE BORN.THE MAJORITY OF ALL HUMAN BEINGS WHO HAVE EVER LIVED ARE ALIVE TODAY!HOW WILL WE FEED EVERYONE? THE EARTH IS NOT INFINITE! IF GROWTH CONTINUES, AT SOME POINT IT WILL BECOME IMPOSSIBLE TO FEED EVERYONE, EVEN IF FOOD IS DISTRIBUTED EQUALLY TO EVERYONE.17 MILLION CHICKENSTHEY EAT 40% OF THE WORLD’S GRAINHUMANS “CONTROL” ABOUT 90% OF ALL LARGE ANIMALS4.3 BILLION LARGE DOMESTICATED ANIMALSIN ADDITION TO FEEDING HUMANS, WE MUST ALSO FEED:BY MORE SENSIBLE USE OF EXISTING RESOURCES (BETTER LAND USE, VEGETARIAN DIETS, DEVELOPMENT OF NEW CROPS), WE CAN DELAY THE PROBLEM, BUT NOT SOLVE IT!POPULATION GROWTHGOVERNED APPROXIMATELY BY “EXPONENTIAL GROWTH” – THIS TERM HAS A PRECISE MATHEMATICAL MEANING.EXPONENTIAL GROWTH OCCURS WHENEVER THE RATE OF GROWTH DEPENDS ON HOW MANY ARE ALREADY THERE - THE MORE PEOPLE ARE ALIVE, THE MORE OF THEM THERE ARE TO REPRODUCE.EXPONENTIAL GROWTH IS CHARACTERIZED BY A “DOUBLING TIME”, i.e., THE TIME NEEDED FOR THE NUMBER TO DOUBLE ALWAYS REMAINS THE SAME.DOUBLING TIMES DOUBLING TIMEExample: You have $5,000 in savings earning 5% per year.You will have $10,000 in 14 years.Example: Inflation is running at 1.5% annually.In 47 years, the average cost of products will have doubled.~~70 % GROWTH RATEExample: The world’s human population is growing at a rate of 1.4% per year. The current population is 6.7 billion.In 50 years the world population will be 13.4 billion.HISTORY OF HUMAN POPULATIONYEAR200AD13001750190019752000DOUBLING TIME (YRS)11004501507550POP.200 M400 M800 M1.6 B3.2 B6.0 BANNUAL GROWTH0.06%0.16%0.47%0.93%1.4%IT TOOK ABOUT 1 MILLION YEARS FOR EARTH’S HUMAN POPULATION TO REACH 1 BILLION . THE NEXT BILLION TOOK ONLY 100 YEARS.THE LAST BILLION TOOK ONLY 12 YEARS.POPULATION GROWTHDOUBLING TIME IS NOT CONSTANT, BUT RATHER DECREASES WITH TIME!THEREFORE,