As will become a familiar theme in this essay, the rise and fall of species and ecosystems is always primarily an energy issue. The Ediacaran extinction is a good example: Ediacaran fauna either an energy source for early Cambrian predators, ran out of food energy, ran out of the oxygen necessary to power their metabolisms, or lacked some other energy-delivered nutrient. After the extinction events, biomes were often cleared for new species to dominate, which were often descended from species that were marginal ecosystem members before the extinction event. They then enjoyed a of relative energy abundance as their competitors were removed via the extinction event.
Mass spectrometers have been invaluable for assigning dates to various rocks and sedimentary layers, as radioactive isotopes and their daughter isotopes are tested, including , , , and . Also, the ratios of elements in a sample can be determined, which can tell where it originated. Many hypotheses and theories have arisen, fallen, and been called into question or modified by the data derived from those increasingly sophisticated methods, and a few examples should suffice to give an idea of what is being discovered.
Element oxygen essay - Ofnir Engineering
Oxygen is a highly reactive element and is capable of combining with most other elements. It is required by most living organisms and for most forms of combustion. Impurities in molten pig are burned away with streams of high pressure oxygen to produce steel. Oxygen can also be combined with acetylene (C2H2) to produce an extremely hot flame used for welding. Liquid oxygen, when combined with liquid , makes an excellent rocket fuel. Ozone (O3) forms a thin, protective layer around the earth that shields the surface from the sun's ultraviolet radiation. Oxygen is also a component of hundreds of thousands of organic compounds.
Essay: The Presence of Oxygen in Earth’s Atmosphere …
The greatest scientists readily admitted that the theories and data of physics, that hardest of the hard sciences, drew highly limited descriptions of reality, and those scientists were usually, to one extent or another, . If textbook science falls far short of explaining reality, what can be said within its framework that is useful? Plenty. Our industrialized world is based on textbook science and feats such as putting men on the Moon were performed within the parameters of textbook science. With the waning of overspecialization and overreliance on reductionism in the last decades of the 20th century, multidisciplinary works have proliferated and will tend to dominate the references for this essay. I have found them not only very helpful for my own understanding, but they are appropriate references for a generalist essay. I have also avoided scientific terminology when feasible. For example, I use “seafloor” instead of “,” and if a non-specialized term will suffice for a scientific concept, I will often use it.
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In the 1990s, I found the dating issue enthralling and saw it assailed by fringe theorists and by . A couple of decades later, I reached the understanding that, like all sciences, dating has its limitations and the enthusiasm for a new technique can become a little too exuberant, but dating techniques and technologies have greatly improved in my lifetime. Dating the , and using 100,000-year increments to place the dates, may seem a conceit, thinking that scientists can place that event with that precision, but over the years my doubts have diminished. When and can be tested, and the findings support not only Earth’s age previously determined by myriad methods, but also support the prevailing theories for the solar system’s and Moon’s formation, call me impressed. Controversies will persist over various finds and methods used, and scientific fraud certainly occurs, but taken as a whole, those converging lines of independently tested evidence make it increasingly unlikely that the entire enterprise is a mass farce, delusion, or even a conspiracy, as many from the fringes continue to argue. There is still a , and it is not a parody. I have looked into fringe claims for many years and few of them have proven valid; even if many were, their potential importance to the human journey was often minor to trifling. As the story that this essay tells comes closer to today’s humanity, orthodox controversies become more heated and fringe claims proliferate.