Chaisson, Eric

Chaisson, Eric J., and Steve McMillan. Astronomy Today. 5th ed. Upper Saddle River, N.J. Pearson Prentice Hall, 2004. 

Eric Chaisson and Steve McMillan. (2007). Astronomy A Beginner s Guide to the Universe (5th ed.). Upper Saddle River, NJ Pearson Education. 

The pressure and temperature of the Earth has been so constant that it has created its own scientific puzzle the Faint Young Sun Paradox. Carl Sagan and colleagues pointed out that the equations of stellar evolution show that our sun heats up over time (as accounted for by Eric Chaisson s energy rate density). Four billion years ago the sun gave out only two-thirds the light and heat that it does today. Under that faint sunlight, the oceans should have frozen completely, but the oceans liquid flow is clear from the rocks. So what warmed the oceans ... 

Eric Chaisson s energy rate density, by focusing on the watts of energy flowing through the mass of a system, could measure this flow. A system that is able to retain and increase its watts per kilogram could be favored. The question is how could it ever develop the chemical structures to maintain and improve itself against the random rush and jar of the heat around it. 

Eric Chaisson s measure, and so the energy rate density of life forms would increase, ratcheted up by thousands of similar steps. 

Eric Chaisson argues that each step processes more energy and is more complex than the one that came before. Thirty million years ago, C4 photosynthesis provided maize and sugarcane, with ERDs of about two watts per kilogram or more. This is so much energy that the plant could afford to save it in the form of starch or sucrose. Is it accurate to say this sweetened the planet ... 

With Eric Chaisson s energy rate density (ERD), the contest between brains and galaxies turns out to be no contest at all. The Milky Way processes 50 microwatts per kilogram of energy, while your brain processes 15 watts per kilogram, so by this measure, the brain is thousands of times more complex than our galaxy. If the Milky Way s ERD was a millimeter long, your brain s ERD would be 300 meters. 

Energy rate density (ERD) The amount of energy processed by a system per unit time per unit mass, as used by Eric Chaisson to quantify complexity over time for diverse systems. 

With Eric Chaisson s Energy Rate Density,. .. E. J. Chaisson. Energy rate density. II. Probing further a new complexity metric. 2011. Complexity 17(1), p. 44. DOl 10.1002/ cplx.20373. 

---