In this paper, some conceptual issues are addressed in order to make sense of what string theory is supposed to tell us about spacetime. The dualities in string theory are used as a starting point for our argumentation. We explore the consequences of a standard view towards these dualities, namely that the dual descriptions represent the same physical situation. Given this view, one has to understand string theory in a manner such that what counts as physical spacetime is based only (...) on the shared physical content—or common core—of the dual descriptions. In general such a spatiotemporal picture does not have to agree with, or be similar to, any of the ones suggested by naïve readings of the dual descriptions. However, in certain regimes or limits, one or the other of the initial dual descriptions may give a good effective description of physical spacetime. (shrink)

日本初の“日英対訳版”登場!今こそ日本精神の源流を学ぶ時。「武士道」は、人類最高の指導理念です。本書は「武士道」の全てが分かる珠玉の一冊。ぜひ、世界の人々に「日本精神」を知って欲しい。.

A collection of essays discussing the philosophy and foundations of quantum gravity. Written by leading philosophers and physicists in the field, chapters cover the important conceptual questions in the search for a quantum theory of gravity, and the current state of understanding among philosophers and physicists.

String theory promises to be able to provide us with a working theory of quantum gravity and a unified description of all fundamental forces. In string theory there are so called ‘dualities’; i.e. different theoretical formulations that are physically equivalent. In this article these dualities are investigated from a philosophical point of view. Semantic and epistemic questions relating to the problem of underdetermination of theories by data and the debate on realism concerning scientific theories are discussed. Depending on ones views (...) on semantic issues and realism different interpretations are possible of the dualities. (shrink)

人間存在の総体性の回復、人称的対立における和解と統合の試み。日々の風景、断想、聖書研究等も収録。.

String theory has been the dominating research field in theoretical physics during the last decades. Despite the considerable time elapse, no new testable predictions have been derived by string theorists and it is understandable that doubts have been voiced. Some people have argued that it is time to give up since testability is wanting. But the majority has not been convinced and they continue to believe that string theory is the right way to go. This situation is interesting for philosophy (...) of science since it highlights several of our central issues. In this paper we will discuss string theory from a number of different perspectives in general methodology. We will also relate the realism/antirealism debate to the current status of string theory. Our goal is two-fold; both to take a look at string theory from philosophical perspectives and to use string theory as a test case for some philosophical issues. (shrink)

The Correspondence of Tiglath-pileser III and Sargon II from Calah/Nimrud. By Mikko Luukko. State Archives of Assyria, vol. 19. Helsinki: Neo-Assyrian Text Corpus Project, 2012. Pp. lxxiv + 287, 3 plts., illus. $89.50.

The modeling of black holes is an important desideratum for any quantum theory of gravity. Not only is a classical black hole metric sought, but also agreement with the laws of black hole thermodynamics. In this paper, we describe how these goals are achieved in string theory. We review black hole thermodynamics, and then explicate the general stringy derivation of classical spacetimes, the construction of a simple black hole solution, and the derivation of its entropy. With that in hand, we (...) address some important philosophical and conceptual questions: the confirmatory value of the derivation, the bearing of the model on recent discussions of the so-called ‘information paradox’, and the implications of the model for the nature of space. (shrink)

This is a nontechnical overview of how various approaches to quantum gravity suggest modifications to the way we conceptualize space and time. A theory of quantum gravity is needed to reconcile quantum physics with general relativity, our best theory for gravity. The most popular approaches to quantum gravity are string theory and loop quantum gravity. So far, no approach has been empirically successful, and there is no commonly accepted theory. Thus, the conclusions presented here are tentative. Many approaches suggest that (...) space and time—or perhaps, it is better to talk about spacetime—might not be fundamental. Various views on how to think about time in quantum gravity are briefly presented. (shrink)

In referring to biographies of Edison as examples, the following are shown: the image of a scientist or an engineer in biographies has dramatically changed over time; the images produced anew in each period fitted well to the social milieu of the day; biographies therefore acquired a large readership and contributed to informing to the public of the value of science and technology and the necessity of promoting them. It is also pointed out that a new image of scientist or (...) engineer is to be created which is surely attractive to people today if we expect biographies to remain effective in promoting public understanding of science as before. (shrink)