Life in the Whispering Cosmos?


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Could there be life on the billions and billions of exoplanets in the whispering cosmos (1)? The Whispering cosmos is the remnant back-body radiation that has expanded and cooled from the hot big bang 13.8 billion years ago. The 4.5 billion year history of our planet is our best data source for life. About 0.8 billions years after the earth was formed, the first prokaryote cells emerged. About two billion years later, they developed photosynthesis that slowly converted the carbon dioxide, CO2, in the earth’s early atmosphere to 20% oxygen. This is much higher than that of our neighboring planets. This enabled the Cambrian explosion of multicellular life 0.54 billion years ago. Dinosaurs needed these higher concentrations to oxidize sugar to generate energy. Harvard biologist Ernst Mayr believed that single celled life may be common in our universe, but intelligence is rare (also on our earth)! Venus had a runaway greenhouse effect. Its dense CO2 atmosphere at 730 K, hot enough to melt lead, is incompatible with life. Might our earth undergo a runaway greenhouse effect similar to Venus? Since the industrial revolution, the increased burning of fossil fuels is raising CO2 levels 300 times faster than the CO2 increase after the Ice Age. REFERENCE (1) Paul H. Carr, “Not with a Bang, but a Whisper,” APS News, Letter, December 2007. PowerPoint available at URL


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Life in the Whispering Cosmos ? Paul H. Carr 1


The Whispering cosmos is the remnant back-body radiation that has expanded and cooled from a hot big bang 13.8 billion years ago. WHISPERING COSMOS “COOLER” THAN BANG Whispering Cosmos Temperature a “cool” 2.725 K. 2


Why does our earth have 21 % oxygen, 0.04% CO2? -Neighboring Venus & Mars are mostly CO2 3


Figure from “ Cosmic Dawn ” by Eric Chaisson Photosynthesis of blue-green algae converted CO 2 to Oxygen Carbon Dioxide, CO 2 Prokaryote Cells Eukaryote Cells 7 4


542 M years Beginning of Multicellular Life. “ The Fossil Record of the Cambrian Explosion ” Keith Miller, PSCF, June 2014 8 Dinosaurs needed higher oxygen concentration to get energy by oxidizing sugar. 5


PROPOSED DEBATE ON LIFE in the UNIVERSE Between Cosmologist, CARL SAGAN (1934 – 1996) Sagan believed many kinds of intelligent life could form, but that the lack of evidence suggests that intelligent beings destroy themselves rather quickly . And Evolutionary biologist, ERNST MAYR (1904 - 2005, Bedford, MA) Mayr believed single cell life in the universe is very likely, but intelligent life very rare (also on Earth) ! 6


Earth Artist concept of likely rocky Exoplanet Kepler 452b, 385 day orbit in habitable zone of star, 20% hotter than our sun, 1400 light-years away. Discovered July 2015 7


Might our earth undergo runaway greenhouse warming similar to Venus? Fossil fuel burning is increasing CO2 concentrations. Temperature and sea level rises correlate with CO2. Temp 730 K, hot enough to melt lead. Pressure 92 bar. Earth Temp 300K Pressure 1 bar 8


At present rate of 2.5 ppm rise per year, humans are increasing CO2 at a  rate 300 times faster than the recovery from the ice age 18,000 -10,000 years ago. CO2 CONCENTRATIONS, HIGHEST (33%) IN 800,000 YRS, COULD REACH ~1000 PPM BY 21OO. Ice Age 9


Our present level of 400 ppm could reach ~ 1000 ppm by 2100. Arctic became ice-free 8 M years ago when CO2 = 300 to 450 ppm. Antarctic melted ~ 40 M years ago, CO2 ~ 700 ppm Earth was ice-free, sea levels 100s meters (~300 ft) higher. Dinosaur Extinction 65M Yr. BP Figure from Dr. James Hansen, NASA GISS 10 THERMAL MAXIMUM

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