Journal of Modern Physics, 2011, 2, 587-594 doi:10.4236/jmp.2011.226068 Published Online June 2011 (http://www.SciRP.org/journal/jmp) Copyright © 2011 SciRes. JMP Origin and Evolution of Life Constraints on the Solar Model Karo Michaelian 1 , Oliver Manuel 2 1 Instituto de Física, Universidad Nacional Autónoma de México, Cto. de la Investigación Científica, Cuidad Universitaria, Mexico City, Mexico 2 Associate, Climate & Solar Science Institute, Former Apollo PI for NASA, Cape Girardeau, USA E-mail: karo@fisica.unam.mx, omatumr@yahoo.com Received February 18, 2011; revised April 1, 2011; accepted April 26, 2011 Abstract Life arose as a non-equilibrium thermodynamic process to dissipate the photon potential generated by the hot Sun and cold outer space. Evidence from the geochemical record of the evolutionary history of life on Earth suggests that life originated in a hot aqueous environment dissipating UV light and evolved later to dissipate visible light. This evidence places constraints on models of solar origin and evolution. The standard solar model seems less compatible with the data than does the pulsar centered solar model. Keywords: Pulsar Centered Solar Model (PCS), Standard Solar Model, Origin of Life, Ultraviolet and Temperature Assisted Replication (UVTAR), Constraints on Solar Model 1. Introduction Life is an out of equilibrium, thermodynamic process. As such, its origin, persistence, and evolution are strictly dependent on the dissipation of an external thermody- namic potential (entropy production) and the evolution of this potential in time. By far the most important thermo- dynamic potential which has promoted the existence of life on Earth is the temperature gradient provided by the hot photosphere of the Sun (~5,800 K today) and the cool volume of outer space (2.7 K). Life arose as an en- tropy producing thermodynamic process in response to the Earth being located between the Sun's hot photo- sphere and the cool space environment. The origin and evolution of life on Earth must, therefore, in some way (to be explored below) parallel the origin and evolution of our Sun. The evolutionary history of life on Earth thus provides constraints on models for the origin and evolu- tion of our Sun. Here we show that these constraints yield convincing arguments for distinguishing between competing solar models. 2. Appearance of Life Constraints on Earth’s Solar Environment The most probable first molecules of life, RNA or DNA [1,2], are transparent to visible light. However, in the ultraviolet, in a region centered on 260 nm of width of 100 nm, the aromatic rings of the nucleic acid bases (adenine, thymine, guanine, cytosine, and uracil) absorb light very strongly [3,4]. If RNA and DNA are in water, they dissipate this photon-induced collective electronic excitation energy extremely rapidly (sub pico-second) [5] and efficiently to heat that can be easily absorbed by the water. These molecules when exposed to ultraviolet light are thus very efficient producers of entropy. Therefore, if RNA and DNA were the first molecules of life, and if indeed life arose as a response to dissipating the photon potential generated on Earth by the Sun and outer space, then the solar spectrum in the ultraviolet between about 200 and 300 nm arriving at the surface of the Earth at the beginning of life (~3.8 billion years ago) must have been sufficiently intense for nature to have embarked on a program of constructing uphill, endergonic, organic molecules for the dissipation of these photons. Furthermore, since water is an important solvent for the formation of the nucleic acids from more simple or- ganic molecules such as hydrogen cyanide under electric discharge or UV light sources [6], and since the dissipa- tion of the electronic excitation energy of the nucleic acid bases only occurs efficiently in the presence of liq- uid water (non-radiatively to mainly the vibrational de- grees of freedom of the water molecules), the incident intensity and absorption of sunlight at the surface of the