Obsidian Hydration - An Inexpensive, but Problematic Dating Technique

Obsidian hydration dating (or OHD) is a scientific dating technique, which uses the understanding of the geochemical nature of the volcanic glass (a silicate) called obsidian  to provide both relative and absolute dates on artifacts. Obsidian outcrops all over the world, and was preferentially used by stone tool makers because it is very easy to work with, it is very sharp when broken, and it comes in a variety of vivid colors, black, orange, red, green and clear. Fast Facts: Obsidian Hydration Dating Obsidian Hydration Dating (OHD) is a scientific dating technique using the unique geochemical nature of volcanic glasses.  The method relies on the measured and predictable growth of a rind that forms on the glass when first exposed to the atmosphere.  Issues are that rind growth is dependent on three factors: ambient temperature, water vapor pressure, and the chemistry of the volcanic glass itself.  Recent improvements in measurement and analytical advances in water absorption promise to resolve some of the issues.   How and Why Obsidian Hydration Dating Works Obsidian contains water trapped in it during its formation. In its natural state, it has a thick rind  formed by the diffusion of the water into the atmosphere when it first cooled—the technical term is hydrated layer. When a fresh surface of obsidian is exposed to the atmosphere, as when it is broken to make a stone tool, more water is absorbed and the rind begins to grow again.  That new rind is visible and can be measured under high-power magnification (40–80x). Prehistoric rinds can vary from less than 1 micron ( µm) to more than 50  µm, depending on the length of time of exposure.  By measuring the thickness one can easily determine if a particular artifact is older than another (relative age). If the rate at which water diffuses into the glass for that particular chunk of obsidian is known (thats the tricky part), you can use OHD to determine the absolute age of objects. The relationship is disarmingly simple: Age DX2, where Age is in years, D is a constant and X is the hydration rind thickness in microns. Defining the Constant Obsidian, natural volcanic glass exhibiting rind, Montgomery Pass, Mineral County, Nevada. John Cancalosi / Oxford Scientific / Getty Images Its nearly a sure bet that everybody who ever made stone tools and knew about obsidian and where to find it, used it: as a glass, it breaks in predictable ways and creates supremely sharp edges. Making stone tools out of raw obsidian breaks the rind and starts the obsidian clock counting. The measurement of rind growth since the break can be done with a piece of equipment that probably already exists in most laboratories. It does sound perfect doesnt it? The problem is, the constant (that sneaky D up there) has to combine at least three other factors that are known to affect the rate of rind growth: temperature, water vapor pressure, and glass chemistry. The local temperature fluctuates daily, seasonally and over longer time scales in every region on the planet. Archaeologists recognize this and started creating an Effective Hydration Temperature (EHT) model to track and account for the effects of temperature on hydration, as a function of annual mean temperature, annual temperature range and diurnal temperature range. Sometimes scholars add in a depth correction factor to account for the temperature of buried artifacts, assuming the underground conditions are significantly different than surface ones–but the effects havent been researched too much as of yet. Water Vapor and Chemistry The effects of variation in water vapor pressure in the climate where an obsidian artifact has been found have not been studied as intensively as the effects of temperature. In general, water vapor varies with elevation, so you can typically assume that water vapor is constant within a site or region. But OHD is troublesome in regions like the Andes mountains of South America, where people brought their obsidian artifacts across enormous changes in altitudes, from the sea level coastal regions to the 4,000-meter (12,000-foot) high mountains and higher. Even more difficult to account for is differential glass chemistry in obsidians. Some obsidians hydrate faster than others, even within the exact same depositional environment. You can source obsidian (that is, identify the natural outcrop where a piece of obsidian was found), and so you can correct for that variation by measuring the rates in the source and using those to create source-specific hydration curves. But, since the amount of water within obsidian can vary even within obsidian nodules from a single source, that content can significantly affect age estimates. Water Structure Research Methodology to adjust the calibrations for the variability in climate is an emergent technology in the 21st century. New methods critically evaluate the depth profiles of hydrogen on the hydrated surfaces using secondary ion mass spectrometry (SIMS) or Fourier transform infrared spectroscopy. The internal structure of the water content in obsidian has been identified as a highly influential variable which controls the rate of water diffusion at ambient temperature. It has also been found that such structures, like water content, vary within the recognized quarry sources.  Ã‚   Coupled with a more precise measuring methodology, the technique has the potential to increase the reliability of OHD, and provide a window into the evaluation of local climatic conditions, in particular paleo-temperature regimes.   Obsidian History Obsidians measurable rate of rind growth has been recognized since the 1960s. In 1966, geologists Irving Friedman, Robert L. Smith and William D. Long published the first study, the results of experimental hydration of obsidian from the Valles Mountains of New Mexico. Since that time, significant advancement in the recognized impacts of water vapor, temperature and glass chemistry has been undertaken, identifying and accounting for much of the variation, creating higher resolution techniques to measure the rind and define the diffusion profile, and invent and improved new models for EFH and studies on the mechanism of diffusion. Despite its limitations, obsidian hydration dates are far less expensive than radiocarbon, and it is a standard dating practice in many regions of the world today. Sources Liritzis, Ioannis, and Nikolaos Laskaris. Fifty Years of Obsidian Hydration Dating in Archaeology. Journal of Non-Crystalline Solids 357.10 (2011): 2011–23. Print.Nakazawa, Yuichi. The Significance of Obsidian Hydration Dating in Assessing the Integrity of Holocene Midden, Hokkaido, Northern Japan. Quaternary International 397 (2016): 474–83. Print.Nakazawa, Yuichi, et al. A Systematic Comparison of Obsidian Hydration Measurements: The First Application of Micro-Image with Secondary Ion Mass Spectrometry to the Prehistoric Obsidian. Quaternary International  (2018). Print.Rogers, Alexander K., and Daron Duke. Unreliability of the Induced Obsidian Hydration Method with Abbreviated Hot-Soak Protocols. Journal of Archaeological Science 52 (2014): 428–35. Print.Rogers, Alexander K., and Christopher M. Stevenson. Protocols for Laboratory Hydration of Obsidian, and Their Effect on Hydration Rate Accuracy: A Monte Carlo Simulation Study. Journal of Archaeological Scie nce: Reports 16 (2017): 117–26. Print.Stevenson, Christopher M., Alexander K. Rogers, and Michael D. Glascock. Variability in Obsidian Structural Water Content and Its Importance in the Hydration Dating of Cultural Artifacts. Journal of Archaeological Science: Reports 23 (2019): 231–42. Print.Tripcevich, Nicholas, Jelmer W. Eerkens, and Tim R. Carpenter. Obsidian Hydration at High Elevation: Archaic Quarrying at the Chivay Source, Southern Peru. Journal of Archaeological Science 39.5 (2012): 1360–67. Print.

The Life of Leon Trotsky Essay - 1462 Words

The Life of Leon Trotsky Leon Trotsky is well recognised as one of the greatest Marxists that ever lived. After being arrested, sentenced to exile twice and supporting the Mensheviks, Trotsky was deported to New York Citywhere he was to be a peaceful, productive member of society. Following the removal of the Tsar during the Russian Revolution, Trotsky returned to Russia in May 1917. In August 1917, Trotsky joined the Central Committee of the Bolshevik party whose leader was none other than Vladimir Lenin. Trotsky assumed key roles in the events and policies concerning the Bolshevik Government, which included the Bolshevik Revolution, Treaty of Brest-Litovsk, the Civil War and views on†¦show more content†¦Trotsky marched out of negotiations, however the immediate threat posed by German forces led the Bolsheviks to sign the treaty of Brest-Litovsk and agree to even harsher terms than what was first proposed. Trotsky was the main negotiator at the peace talks, supporting a strategy of no war, no peace. Despite Trotskys actions at negotiations, forcing the Bolshevik government to agree to even harsher terms, Lenin understood Trotskys motivations as a show of loyalty to the Bolshevik Government and allowed him to stay Minister of Foreign Affairs. As the Civil War started, the Bolsheviks passed a declaration announcing the creation of the Red Army, which was Trotskys idea. On the 8th of April, Lenin appointed Trotsky as Minister for War. Shortly after Trotsky introduced conscription and obtained the numbers to overcome the Whites, the Red Army had a total of 3 million men by 1920. Trotskys disciplinary actions paid off with the Red Army being able to launch a counter-attack, driving the enemy back. Thus, with Trotskys other military success of the Bolshevik Revolution and the support from within the Army, Trotsky took on another major feature of his life, the Civil War and successfully created Red Army into victory, as well as consolidating his power by being made Commissar for War. By the mid-1920sShow MoreRelatedThe Russian Revolution And The Soviet Revolution1295 Words   |  6 PagesHowever, many people forget to acknowledge the role played by Leon Trotsky who stood by Lenin s side throughout the Revolution. I believe that Leon Trotsky and his actions during the Russian Revolution were essential to the security of the revolution and therefore his overall impact and status is heroic. Leon Trotsky byname of Lev Davidovich Bronshtein was born in the Ukraine on the 7th of November, 1879. Since a young age, Trotsky had possessed revolutionary ideals and alternative options to theRead MoreRussian Revolution And The Soviet Revolution1238 Words   |  5 PagesHowever, many people forget to acknowledge the role played by Leon Trotsky who stood by Lenin s side throughout the Revolution. I believe that Leon Trotsky and his actions during the Russian Revolution were essential to the security of the revolution and therefore his overall impact and status is heroic. Leon Trotsky byname of Lev Davidovich Bronshtein was born in the Ukraine on the 7th of November, 1879. Since a young age, Trotsky had possessed revolutionary ideals and alternative options to theRead MoreLeon Trotsky s Influence On The Soviet Revolution1496 Words   |  6 Pages Ms. Zbrzeznj Global Perspectives 13 March 2015 Leon Trotsky Leon Trotsky was a man to be reckoned with. Trotsky was a Marxist revolutionary who played a leading role in the 1905 Revolution, in the eventual Communist Revolution of October 1917, and in the Russian Civil War. Without Trotsky’s impact in the Russian Revolution, the Bolsheviks would have been defeated. His own beliefs on Marxism combined with his intellect made Trotsky a target and influential leader in the Soviets. From hisRead MoreThe Characteristic Of Snowball By George Orwell885 Words   |  4 Pagesimportant characters of the Russian Revolution. There are many characters in this book. A pig named Snowball is one of them who is based on Leon Trotsky. Leon Trotsky was an early leader in communism (ANIMAL FARM). He had control of the Soviet Union. He followed Karl Marx direction who was leader of communist party and also planner of Russian revolution. Trotsky leaded the â€Å"October Revolution,† to get freedom from Czar Nicholas II. On the other hand, Snowball is an early leader in Animalism. He playedRead MoreLeon Trotsky aka Lev Davidovich840 Words   |  3 PagesLeon Trotsky also known as Lev Davidovich Bronstein was born on November 7, 1879. He was born in Yanovka which is now known as Ukraine. When Trotsky was about eight years old his parents sent him to Odessa school, which is a major cultural center of multi-ethnic population. When he started his last year of schooling, which was when his life as a revolutionary began to take shape. It was in Nikolayev at the age of 17; Trotsky started to skip school and was going to talk with political exiles and alsoRead MoreLeon and Snowball Comparison 942 Words   |  4 Pagesgoing. The inspiration for his character was from important revolutionist, Leon Trotsky. Snowball was modeled after him, showing most of his character trails and interest. Most of the people and events that look place throughout Trotsky’s life are also incorporated in Snowball’s life. Orwell’s imagination ran wild as he wrote this memorable story so that he might warn the people of Russia for what was to come. Snowball and Leon are the same in every way from what they believed to their personality.Read MoreSnowball from Animal Farm and Leon Trotskys Roles in the Russian Revolution891 Words   |  4 PagesResearch Question: How was the affect of Leon Trotsky and Snowball? Throughout time, people learned about history from books, websites, articles, and magazines to gain their understandings of History. Leon Trotsky played an important role in the Russian Revolution and so did the character of Snowball from the novel Animal Farm. Their life actions had a positive affect towards history even though their goals were never accomplished. Leon Trotsky Leon Trotsky was the chairman of the Military RevolutionaryRead MoreAnimal Farm by George Orwell Essay876 Words   |  4 Pagesmany different qualities. Animal Farm is an allegory, fable, and a satire. 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Gun control and the Constitution Free Essays

The history of the Second Amendment of the United States Constitution, which guarantees the right of US citizens to â€Å"bear arms† is one of the most complex and controversial of all the developments within constitutional law that have occurred in the last 230 years. In this book Cottrol attempts to bring together most of the major cases on the Second Amendment from the Supreme Court, and also includes various articles on their meaning. One of the most valuable aspects of this book is the fact that Cottrol tackles his subject neither from the perspective of a supporter of the Amendment nor from a gun control advocate. We will write a custom essay sample on Gun control and the Constitution or any similar topic only for you Order Now This balance is a rare achievement in a treatment of an aspect of the law that often inspires resonantly partisan scholarship that fails to offer the true complexity and difficulties involved with balancing the various parties involved with the Second Amendment. The book is divided into two main sections. The first gives copies of the two leading Supreme Court cases, Presser v. Illinois and United States v. Miller, as well as a state case that is now more than a century old but still provides precedence: Aymette v. State of Tennessee. Unlike many other books, Cottrol also provides the full texts of leading laws regarding gun control, such as the Brady Act and the 1986 Farm Owners Protection Act. These enable the reader to compare court cases, with the points of law that are raised within them, as well as the constitutional issues, with the actual laws that are now in place. Over all of them is the simple but actually over-riding language of the Second Amendment. In the second part of the book, Cottrol provides ten law and history scholarly articles which offer a strictly balanced view of the spectrum of views on the Second Amendment. Four out of the ten articles are actually challenging to the idea that the Second Amendment is sacrosanct, while the rest are either historical or pro-Second Amendment in nature. Perhaps the best section of the book is actually the Introduction, an extended contemplation of the various issues involved with gun control from the Revolutionary War on. Cottrol argues that the founding fathers saw that an armed citizenry was a necessity for the defence of political liberty that had only recently been won. However, the idea that America was (and still is) somehow intrinsically different from other countries in its attitude towards gun is merely stated rather than proven. Thus Cottrol argues that â€Å"from the beginning, conditions in colonial America created a very different attitude towards arms and the people† (p. 13). But most European countries had a heavily armed populace in the Eighteenth and Nineteenth centuries compared to today, but have succeeded in developing into modern countries that do not have a generally armed citizenry, with associated much lower crime/murder rates. Cottrol offers an interesting view on a part of the gun control debate that rarely received much attention from either side. That is the fact that during the Nineteenth Century fears of insurrection from slaves (and then freed blacks) and Indians meant that there were outright bans on these groups possessing arms. So the Second Amendment has already been suspended in the past for what are now regarded as spurious reasons: should not similar suspensions be considered in the present day? Cottrol does not explicitly state this, but it is implicit within his own scholarship that he briefly outlines within the Introduction to his book. In one of the most important aspects of the book, Cottrol argues that the â€Å"collective rights† argument over whether the Second Amendment merely guarantees the right to bear arms for a small, trained militia (i. e. an army? ) is moot. He says that if both pro and anti- gun control proponents accepted that there is a right to bear arms guaranteed in the Constitution then a genuinely productive conversation and dialogue could occur within society as to sensible limits to access to that right. Arguing theoretically over whether the â€Å"right† exists or not is a rather futile exercise in sophistry. The more important argument is how the right should be instituted within society: what type of arms should be allowed under the constitution, what limits as to age, criminal history etc, should be placed? The right to bear arms, Cottrol suggests correctly, does not imply the right to bear all arms. For example, fully automatic machine guns have been illegal for ordinary citizens in the United States since the 1930’s. A person cannot but a bazooka, tank or fighter plane and claim that the Second Amendment protects his right to purchase and use it. So the argument, Cottrol suggests, should be on the types of arms that are allowed, not whether they are to be allowed at all. Here Cottrol’s suggestion that Federalist issues be more closely considered is very interesting. He correctly asserts that about 43 states already have laws and/or constitutions that touch in some way or another upon the unfettered right to bear arms. This area of law, full of often contradictory of at least contrasting law, has yet to receive much scholarly attention. Cottrol implies that far more gun control may actually be occurring than those on the national level, arguing over theoretical constitutional matters, seem to understand. State matters may at times conflict with Federal authority, especially considering the existence of state militias versus the federally controlled national guard. Who actually controls national guard units became of great importance during the civil rights movement, when Southern states started to deny the validity of federal laws regarding desegregation. Presidents Eisenhower, Kennedy and Johnson all used federal troops in one way or another to help enforce federal court decisions. Cottrol’s book suggests that the strict constitutional arguments regarding the Second Amendment are in fact a fulcrum for much larger political, social and cultural dilemmas within society. The scholarly articles which support the idea of gun control, and thus the diminishing of Second Amendment rights , often seem to rely upon essentially pragmatic arguments: gun control would lessen the amount and seriousness of violent crime. They imply that a tragic irony is now occurring in which the constitutional amendment designed to protect the country, and to make the citizens safer, have actually made the United States of America one of the most dangerous advanced industrialized countries in the world. The issue of guns and the Second Amendment seems to be rather tangential to the real problems according to Cottrol. He briefly mentions the country that is the most difficult for gun control advocates to explain: Switzerland. The Swiss keep about 650,000 assault weapons in their private homes, making them by far the most armed/per capita population in the world. Yet Switzerland has virtually no violent crime. The country also has virtually no poor people and few if any of the social problems that seem to lead to much of the gun violence in the United States. While Cottrol’s one volume edition of what was previously a large three-volume work is by necessity limited in length, it is a pity that these wider issues surrounding the Second Amendment could not be considered. For example, the Brady Law, named after the Reagan official who was paralyzed by the man who nearly assassinated President Reagan, was designed to stop the type of attack which had occurred there, but in fact does not really begin to tackle the problem. A person who wants to assassinate a President (or to shoot his wife) will find access to deadly weapons in any country in the world, whether it has no gun laws or a plentitude of them. The psychological problems associated with spree killers such as the Columbine killers cannot be tackled by gun control laws, nor can the economic hardship and desperation that seems to lead to much of the black-on-black violence that accounts for a majority of murders. If Cottrol were to write another book on the wider implications of gun control these kinds of matters could be considered. Yet the book might still have a constitutional basis as the US Constitution was not a theoretical document written as some kind of intellectual exercise but rather as a living framework on which a democratic country could grow. The argument over whether the US Constitution should be regarded as a â€Å"living document† that should be adapted to current circumstances and even changed if necessary, or whether its power lies within a strictly â€Å"originalist† interpretation is at the heart of political debate today. One of the reasons that many of the public have an opinion on the constitutional arguments surround the Second Amendment is that they are, supposedly, simple to explain. Either the Constitution guarantees the right to bear arms or it does not. Cottrol suggests that this is in fact an irrelevant dichotomy: it is how that right is controlled that is at the heart of the matter. In conclusion, Gun Control and the Constitution: Sources and Explanations of the Second Amendment is an excellent book that raises a number of different perspectives on this important part of the US Constitution. Cottrol’s compendium of cases, opinion and scholarship suggests that a balanced approach to the various arguments should be adopted so that both sides can speak to one another rather than at or passed one another. ____________________________________ Works Cited Cottrol, Robert. Gun Control and the Constitution: Sources and Explanations of the Second Amendment. Routledge, New York: 1994. . 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Medicare Essay Example For Students

Medicare Essay The Medicare DebateEssay submitted by UnknownThe U.S. government have denied that Medicare has been going bankrupt. Although the government may say that Medicare has plenty of money it is untrue because it is a fact that Medicare will go bankrupt by the year 2001 as stated by preliminary sources. Medicare is one of the main sources of funding for those people that have no money or very small amount of money. The community service that was done for this research paper is hospital volunteering at John Muir Medical Center. The community service included various jobs that was needed to be done were, Putting items away for nurses, discharging patients, doing paper work, feeding patients, answering phones, and helping patients when they ask for assistance. The floor I worked on was Oncology (The branch of medicine that deals with tumors, including study of their development, diagnosis, treatment, and prevention). This community service has help me gain insight on the Medicare situation bec ause I have asked multiple amount of people that work at John Muir Medical Center. There is a side to be considered about Medicare and Social Security in the government. The vice president of the United States, Al Gore, wrote in a letter stating that social security funds are not being depleted. Gore said that, the allegations to the contrary have been circulated by certain organizations as a money-making scheme for some time. (Gore Letter). Vice President Gore tries to show theses allegations are untrue by explaining how social security works. In this letter, Vice President Gore cleared up the allegations by writing that, When Social Security taxes are collected, they are credited to the Social Security trust funds with government security, perhaps the safest investment in the United States. In history Medicare has experience a few problem regarding its funding. Problems have occurred over the history of Medicare. The major problem and most recent of Medicare is that it is going bankrupt. Medicare is another legacy of Lyndon Baines Johnson Great Society. Spending is obviously out of control. On June 5th the government announced that the Medicare Trust Fund would go broke by the year 2001(nationaldebt). In 1965 when LBJ started Health and Medicare, the Total Federal Spending for the year was $101 Billion. By the year 2000 we will spend over 4 times than amount on Health and Medicare alone, and Medicare will equal the annual spending for Defense(CNN). Under our Constitution, Defense is a specific responsibility of the Federal Government. Medicare is a step-child of our Liberal/Socialists. You might keep this in mind when we get to the point where we have to chose what we CAN do versus what we would LIKE to do. By the year 2002 Medicare will have exceeded defense spending H ealthcare has been a problem for the government as well for it has added to the enormous debt the country already has. Another major problem of Medicare is that the government does not regulate Medicare enough(Medicare). Medicare affects all different aspects of different programs. For instance Medicare affects Social Security (national debt). Social Security has already exceeded Defense spending by almost double. Just like Medicare, Social Security is being abused. Abused meaning that people take advantage of it. It is different from Medicare because less people can use Social Security because it is set aside for the tax payers of this country. The mechanism is similar to depositing money in a bank. As you know, when a bank accepts a deposit. It takes that money and uses it for loans and investments in order to provide a positive return to share holders and interest-bearing accounts. The deposit is credited to an account, and as long as the account has a positive balance, the bank is obligated to honor debits to it. In the same way, the trust funds balances represent and have swerved as financial claims against the government-claims on which the Department of the Treasury has never defaulted. (Gore Letter). This letter written by Al Gore shows the government side of the issue on Social Security. The government does make its point in describing that Social Security is not endanger of losing money or even going bankrupt. According to Al Gore he mentioned that,