This study evaluated the ability of a fast spin echo T2 weighted dark blood sequence to characterize significant (>50%) renal artery stenosis compared to conventional angiography. May still refer to the same object and I illustrate my argument drawing upon the early history of electrons. Finally, I examine the conditions under which an evolving representation I then focus on hidden objects, which are supposed to be part of the permanent furniture of the universe,Īnd I discuss their birth and historicity: They emerge when various phenomena coalesce as manifestations of a single hiddenĬause and their representations change over time. Second, we need a pluralistĪccount of scientific objects, a pluralist metaphysics that can do justice to their rich diversity and their various modes
Of science is so rich and variegated that there are no universally valid answers to these questions. Such cases? Do scientific objects evolve over time and in what ways? I put forward and defend two theses: First, the ontology Historicity of the objects of those claims: How and why do new scientific objects appear? What exactly comes into being in The questions I address in this paper revolve around the To historicize the origin and establishment of knowledge claims. The historical variation of scientific knowledge has lent itself to the development of historical epistemology, which attempts The other hand, the historical reconstruction of the careers of those entities may profit from philosophical reflection on On the reality of those entities has a lot to gain by examining historically how they were ntroduced and investigated. On the one hand, philosophical reflection Practice can be enhanced by adopting an integrated historical-cum-philosophical approach. I argue that our understanding of hidden entities and their role in experimental In this paper are entangled with those debates. For this reason, they have figured prominently in recent debates on scientific realism. Their centrality to past scientific practice, however, several of them (e.g., phlogiston, caloric, and the ether) turned out Hidden entities have played a crucial role in the development of the natural sciences. Conversely, I suggest that the history of those entities has important lessons to teach to Issues raised by “hidden entities”, entities that are not accessible to unmediated observation, can enrich the historical In this chapter I investigate the prospects of integrated history and philosophy of science, by examining how philosophical Among those phenomena were a “light which appears about the negative electrode” and a fluorescence in the glass of the tube (, pp. He observed various complex and striking phenomena associated with the discharge. In 1857 Geissler's tubes were employed by Julius Plücker (1801–1868) to study the influence of a magnet on the electrical discharge.
In 1855 the German instrument maker Heinrich Geißler (1815– 1879) manufactured improved vacuum tubes, which made possible the isolation and investigation of cathode rays.
Below a certain pressure the glow assumed a stratified pattern of bright and dark bands.ĭuring the second half of the nineteenth century the discharge of electricity through gases became a topic of intense exploratory experimentation, primarily in Germany. By the middle of the nineteenth century it was known that the passage of electricity through a partly evacuated tube produced a glow in the gas, whose color depended on its chemical composition and its pressure. The latter phenomenon had been studied since the early eighteenth century. The detection of cathode rays was a by-product of the investigation of the discharge of electricity through rarefied gases.