Earth, origins

Radioisotopes may occur in the earth naturally as primordial radioisotopes, formed when the planet was created, or be produced by natural or artificial processes. Most fast decaying primordial radioisotopes have long disappeared from the planet since the earth originated about 4.5 billion years ago, such isotopes have decayed and reached a final, stable form. The relatively few primordial radioisotopes still extant in the earth today, therefore, decay very slowly. Among these are potassium-40 and some isotopes of uranium, such as uranium-235 and uranium-238, which are of use for dating archaeologically related minerals and rocks (see Textboxes 15 and 16). 

What is the origin of biological chirality and how did it successfully propagate itself to dominance The riddle is at once intriguing, central, and profound. It has been persuasively argued and is now widely accepted that homochirality of biopolymers is essential for the existence of life, and that life would be impossible in its absence. [4] Thus the solution to the riddle of terrestrial homochirality may well be intimately related to how life on Earth originated. 

Cameron AGW (1979) From nucleosynthesis to the birth of the Earth origin of the planets and of the Earth. In The rediscovery of the Earth. Motz L (ed) Van Nostrand Reinhold New York, p 51-58 Chen CH, Nakada S, Shieh YN, DePaolo DJ (1999) The Sr, Nd and O isotopic studies of the 1991-1995 eruption at Unzen. Japan J Vole Geothermal Res 89 243-253 (1999)... 

Having shown that the earth originally called ceria was composed of ail insoluble portion, ceria, and a soluble portion, lanthana, Mosander investigated yttria in a similar manner (7). In 1843 he showed that yttria from which all the ceria, lanthana, and didymia have been removed contains at least three other earths. These are a colorless oxide, for... 

Do you accept the view that life on Earth originated from inanimate matter without any contribution from transcendent power ... 

Craig, J.R., Vaughan, D.J. and Skinner, B.J. (2001) Resources of the Earth Origin, Use, and Environmental Impact, Prentice Hall, Upper Saddle River, NJ, p. 520. 

R. M. De Graaf and A. W. Schwartz (2000). Reduction and activation of phosphate on the primitive earth. Origin Life Evol. Biosph., 30, 405-410. 

OBSERVATIONAL EVIDENCE AND THEORETICAL CONSTRAINTS PERTAINING TO THE NEBULAR ENVIRONMENT FROM WHICH EARTH ORIGINATED... 

Anders E. and Owen T. (1977) Mars and Earth origin and abundance of volatiles. Science 198, 453-465. 

Boss A. P. (1990) 3D Solar nebula models implications for Earth origin. In Origin ofthe Earth (eds. H. E. Newsom and... 

Origin of the solar system Origin of earth -Origin of the moon -... 

Walker, J. C. G. 1985. Carbon dioxide on the early Earth. Origins of Life and Evolution of the Biosphere, 16, 117-127. 

Perhaps the most important example of a new biochemical pathway generating a global impact was the development of photosynthesis. The atmosphere of Earth originally was reducing. Photosynthesis produces oxygen as a by-product. Oxygen, which is quite toxic, became a major constituent of the atmosphere. This change produced a mass extinction event, yet also provided for the evolution of much more efficient metabolisms. 

A. Keefe and S. L. Miller. Potentially pre-biotic syntheses of condensed phosphates. Origins of Life and Evolution of Biospheres, 26 (1996), 15-25 but see also D. Glindemann, R. M. de Graaf and A. W. Schwartz. Chemical reduction of phosphate on the primitive earth. Origins of Life and Evolution of Biospheres, 29 (1999), 555-61. 

Deamer, D. W. (1986). Role of amphiphilic compounds in the evolution of membrane structure on the early earth. Origins of Life and Evolution of Biospheres, 17, 3-25. 

There are a number of reasons for believing that the Earth originally had a more C02-rich atmosphere than it does today. At a very basic level the simple comparison with its planetary neighbors Mars and Venus shows that they both now have atmospheres with more than 95% C02 (Table 5.4). Since it is likely that, in the absence of living organisms and an active tectonic cycle, these planets have retained... 

Earth-Origin. 2. Earth-Internal structure. 3. Geochemistry. 

Although physical and chemical factors were exclusively responsible for affecting the distributions of elements 4.5 Ga ago when the Earth originated (see Chapter 2), this is no longer true. Recent evidence suggests that life originated on Earth over... 

Not only is most of the universe much too hot or too cold for life, but, in addition, the hypothesis that life originated elsewhere introduces a new difficulty that does not arise if life on earth originated on earth we need a mechanism to transfer existing life forms to the earth in a viable form from wherever they originated, so whatever we calculate as the probabihty that life originated anywhere must be multiplied by the very low probability that such a mechanism exists. 

I think a (at least basic) understanding/appreciation for chemistry is essential to really understanding early earth / origins of life, and understanding where we came from is a good reason to study chemistry. ... 

Klabunovs i E.I. and Thiematm W. (2000) The role of quartz in the origin of optical activity on Earth, Origins Life Evol. Biosphere 30, 431-434. 

Klabunovskii E.I. and Thiemann W. (2000) The role of quartz in the origin of optical activity on Earth, Origin Life Evol. Biosphere 30, 431-434. Bonner W.A. (1996) The quest for chirality. Physical origin of homochirality in life, Amer. Inst. Phys. Conf, Santa Monica CA, Febr. 1995, Proceedings, Cline D.B. (ed.). Press Woodbury, N.Y., p. 17-49. Avalos M., Babiano R., Cintas P., Jimenez J.L. and Palacios J.C. (2000) Chiral autocatalysis where stereochemistry meets the origin of life, Chem. Commun. 887-892. 

A3. Organisms on any of the moons of the outer planet (if they exist) are killed or mutated by biological agents of Earth origin. 

Rationale Contamination of an iqr outer planet moon with biological agents of Earth origin could have catastrophically adverse effects on any biological agents indigenous to the icy outer planet moon. 

A6. Organisms of Earth origin are mistaken for organisms indigenous to any of the moons of the outer planet in future missions to study the outer planet s moon. 

Rationale Contamination of a moon of an outer planet with biological agents of Earth origin could lead to a situation in which a future mission discovers the biological agents and falsely concludes that they are indigenous to the moon of the outer planet. 

The differentiated Nonchondrites in Table 18.1 also contain meteorites that originated from Mars and the Moon. These meteorites were ejected as a result of explosive impacts of solid objects (i.e., small asteroids or comets) and went into orbit around the Sun until they were captured by the gravitational field of the Earth. A significant number of the meteorites that have been recovered in Antarctica and in the hot deserts of the Earth originated from Mars, the Moon, and perhaps even from... 

Most of the material on Earth originates from the output of nuclear processes that took place in stars, where the temperature is much too high for individual atoms to exist (and so matter is in the form of plasma, a kind of gas comprising separate nuclei and electrons). After this material was exploded into space, at the end of the star s life cycle, it cooled and formed into more stable combinations of nuclei and electrons sometimes atoms, but often ions or molecules. Very litde of the matter that formed the Earth is in the form of discrete atoms. The formation of the ionic lattice due to ionic bonding does not involve any mysterious electron transfer , and if ionic bonding is taught as suggested here, then there is no reason for students to think in those terms. 

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