History of Theories of Mass Extinction by Meteorite Impact and Alternative Causes

威廉·格伦博士在威尔特博士的指导下承担了这个项目，他在之前的国家科学基金会资助下继续他的研究，这些研究是由化学证据的发现引发的，这些证据表明，在6500万年前的化石记录中，大灭绝时期发生了陨石撞击。这样的灭绝，后来被假定为周期性的，用三个新的天文学假设来解释，它们都是为了周期性地让彗星像雨点一样洒向地球。许多其他的假说也被提出，这些假说涉及生物圈、大气和岩石圈与大灭绝的关系的各个方面。格伦博士制作了一个特定阶段的数据库，其中包括大量关于这些相互竞争的理论发展的辩论参与者的口述历史访谈。这些访谈和其他文献资料有助于理解随着争论的发展，观念是如何形成和改变的。它们还用于评估各种科学模型，并有助于对这些辩论所产生的剧变进行分析和分类。原始史料的采访和收集工作基本完成。格伦博士目前正在完成一项主要调查，调查对象是与争论中的理论相关的9个专业协会的成员。在这笔资助下，他正在分析迄今为止收集到的数据，进行一些有针对性的后续采访，研究这些辩论的“史前”，并准备对这段历史进行最终研究。这些结果一旦发表，将为科学的历史、哲学和社会科学提供重要的原始材料。

Dr. William Glen, who is undertaking this project under the direction of Dr. Weart, is continuing his study, supported under previous NSF grants, of a series of current interdisciplinary debates that were prompted by the discovery of chemical evidence suggesting a meteorite impact at the time of mass extinction in the fossil record 65 million years ago. Such extinctions, subsequently postulated as periodic, were explained by three new alternative astronomical hypotheses, all designed to cyclically shower the earth with comets. A number of additional hypotheses have also been advanced that address various aspects of the biosphere, atmosphere, and lithosphere bearing on mass extinctions. Dr. Glen has produced a stage-specific data base including a large number of oral history interviews of the participants of the debates over the development of these competing theories. These interviews and other documentary data have aided in understanding how perceptions form and alter as arguments evolve. They also serve in assessing various models of science and have lent themselves to the analysis and taxonomy of the upheaval resulting from these debates. The interviewing and collecting of primary historical materials has been essentially completed. Dr. Glen is currently completing a major survey of members of 9 professional societies related to the theories under debate. Under this grant, he is analyzing the data he has collected to date, conducting a few focussed followup interviews, examining the "pre-history" of these debates, and preparing a final study of this history. These results, when published, will provide major source material for the history, philosophy and social science of science.