Taming the supergravity description of non-BPS D-branes: the D/Dbar solution

We obtain the supergravity solution which describes a bound state of D-string/anti-D-string pairs attached to different fixed planes of an orbifold, in type IIB string theory compactified on T^4/Z_2. For parameters at which the conformal field theory point of view predicts stability, the solution displays a repulson-like singularity. However, we observe that a D-string/anti-D-string pair probe in this background becomes tensionless before reaching the singularity, suggesting a resolution by the enhancon mechanism. Moreover, the force feels by this probe is attractive, in contrast to the repulsive behaviour observed in the non-BPS D-brane description.Comment: 21 pages, Latex, uses JHEP.cls. Substantial revision; in particular, clarification of the two T-dual descriptions in section 2 and improved discussion of the enhancon mechanism in section 4. Published versio

Bible Software

This article is a statement of unbridled praise for the present state of software available for Bible studies, particularly in the use of the Biblical text in its original languages and alphabets. After giving examples of various products related to Bible study, the article turns to descriptions and comparisons of three programs, Gramcord, Logos, and BibleWorks

Intentionalism and pain

Pain may appear to undermine the radically intentionalist view that the phenomenal character of any experience is entirely constituted by its representational content. That appearance is illusory. After categorizing versions of pain intentionalism along two dimensions, I argue that an 'objectivist' and 'non-mentalist' version is the most promising, if it can withstand two objections concerning (a) what we say when in pain, and (b) the distinctiveness of pain. I rebut these objections, in a way available to both opponents of and adherents to the view that experiential content is entirely conceptual

Evaluativist Accounts of Pain's Unpleasantness

Evaluativism is best thought of as a way of enriching a perceptual view of pain to account for pain’s unpleasantness or painfulness. Once it was common for philosophers to contrast pains with perceptual experiences (McGinn 1982; Rorty 1980). It was thought that perceptual experiences were intentional (or content-bearing, or about something), whereas pains were representationally blank. But today many of us reject this contrast. For us, your having a pain in your toe is a matter not of your sensing “pain-ly” or encountering a sense-datum, but of your having an interoceptive experience representing (accurately or inaccurately) that your toe is in a particular experience-independent condition, such as undergoing a certain “disturbance” or being damaged or in danger (Armstrong 1962; Tye 1995). But even if such representational content makes an experience a pain, a further ingredient seems required to make the pain unpleasant. According to evaluativism, the further ingredient is the experience’s possession of evaluative content: its representing the bodily condition as bad for the subject. In this chapter, I elaborate evaluativism, locate it among alternatives, and explain its attractions and challenges

A Study of Two Newly-Discovered Eclipsing Binary Systems

I have observed three newly-discovered variable stars using the 16-inch telescope and CCD at the Valparaiso University Observatory. Of these three variables, two have been verified as binary star systems, where one of the stars passes in front of the other. The third is found to be a pulsating variable, which varies due to a change in its size and temperature. One of the goals of this project has been to further refine the periods of these three variables. From my new data and some previous observations at the Valparaiso University Observatory, I have been able to determine that the brightness of the three systems has varied from 13-55 percent. I have improved upon the determination of the periods of these variables. For the two binary systems, the periods are 0.52 and 1.21 days. For the pulsating variable, the period is 0.32 days. I have formed light curves for each star showing the change of brightness over one cycle. For the two binaries, the light curves are being analyzed to determine the relative sizes and differences in temperature of the two stars in each system. All of this is a part of my senior research project in physics and astronomy

Pains that Don't Hurt

Pain asymbolia is a rare condition caused by brain damage, usually in adulthood. Asymbolics feel pain but appear indifferent to it, and indifferent also to visual and verbal threats. How should we make sense of this? Nikola Grahek thinks asymbolics’ pains are abnormal, lacking a component that make normal pains unpleasant and motivating. Colin Klein thinks that what is abnormal is not asymbolics’ pains, but asymbolics: they have a psychological deficit making them unresponsive to unpleasant pain. I argue that an illuminating account requires elements of both views. Asymbolic pains are indeed abnormal, but they are abnormal because asymbolics are. I agree with Klein that asymbolics are incapable of caring about their bodily integrity; but I argue against him that, if this is to explain not only their indifference to visual and verbal threat, but also their indifference to pain, we must do the following: take asymbolics’ lack of bodily care not as an alternative to, but as an explanation of their pains’ missing a component, and claim that the missing component consists in evaluative content. Asymbolia, I conclude, reveals not only that unpleasant pain is composite, but that its ‘hedomotive component’ is evaluative