Passage 5   
　　They were, by far, the largest and most distant objects that scientists had ever detected: a strip of enormous cosmic clouds some 15 billion light-years from earth. 71) But even more important, it was the farthest that scientists had been able to look into the past, for what they were seeing were the patterns and structures that existed 15 billion years ago. That was just about the moment that the universe was born. What the researchers found was at once both amazing and expected; the US National Aeronautics and Space Administration's Cosmic Background Explorer satellite — Cobe — had discovered landmark evidence that the universe did in fact begin with the primeval explosion that has become known as the Big Bang (the theory that the universe originated in an explosion from a single mass of energy.)
　　72) The existence of the giant clouds was virtually required for the Big Bang, first put forward in the 1920s, to maintain its reign as the dominant explanation of the cosmos. According to the theory, the universe burst into being as a submicroscopic, unimaginable dense knot of pure energy that flew outward in all directions, emitting radiation as it went, condensing into particles and then into atoms of gas. Over billions of years, the gas was compressed by gravity into galaxies, stars, plants and eventually, even humans.   
　　Cobe is designed to see just the biggest structures, but astronomers would like to see much smaller hot spots as well, the seeds of local objects like clusters and superclusters of galaxies. They shouldn't have long to wait. 73) Astrophysicists working with groundbased detectors at the South Pole and balloon-borne instruments are closing in on such structures, and may report their findings soon.
　　74) If the small hot spots look as expected, that will be a triumph for yet another scientific idea, a refinement of the Big Bang called the inflationary universe theory. Inflation says that very early on, the universe expanded in size by more than a trillion trillion trillion trillionfold in much less than a second, propelled by a sort of antigravity. 75) Odd though it sounds, cosmic inflation is a scientifically plausible consequence of some respected ideas in elementary-particle physics, and many astrophysicists have been convinced for the better part of a decade that it is true.
Passage 6  
　　 71) While there are almost as many definitions of history as there are historians, modern practice most closely conforms to one that sees history as the attempt to recreate and explain the significant events of the past. Caught in the web of its own tune and place, each generation of historians determines anew what is significant for it in the past. In this search the evidence found is always incomplete and scattered; it is also frequently partial or partisan. The irony of the historian's craft is that its practitioners always know that their efforts are but contributions to an unending process.   
　　72)  Interest in historical methods has arisen less through external challenge to the validity of history as an intellectual discipline and more from internal quarrels among historians themselves. While history once revered its affinity to literature and philosophy, the emerging social sciences seemed to afford greater opportunities for asking new questions and providing rewarding approaches to an understanding of the past. Social science methodologies had to be adapted to a discipline governed by the primacy of historical sources rather than the imperatives of the contemporary world. 73) During this transfer, traditional historical methods were augmented by additional methodologies designed to interpret the new forms of evidence in the historical study.    　
　　Methodolgy is a term that remains inherently ambiguous in the historical profession. 74) There is no agreement whether methodology refers to the concepts peculiar to historical work in general or to the research techniques appropriate to the various branches of historical inquiry. Historians, especially those so blinded by their research interests that they have been accused of "tunnel method," frequently fall victim to the "technicist fallacy." Also common in the natural sciences, the technicist fallacy mistakenly identifies the discipline as a whole with certain parts of its technical implementation. 75) It applies equally to traditional historians who view history as only the external and internal criticism of sources, and to social science historians who equate their activity with specific techniques.