The bifurcated conception of perceptual knowledge: a new solution to the basis problem for epistemological disjunctivism

Epistemological disjunctivism says that one can know that p on the rational basis of one’s seeing that p. The basis problem for disjunctivism says that that can’t be since seeing that p entails knowing that p on account of simply being the way in which one knows that p. In defense of their view disjunctivists have rejected the idea that seeing that p is just a way of knowing that p (the SwK thesis). That manoeuvre is familiar. In this paper I explore the prospects for rejecting instead the thought that if the SwK thesis is true then seeing that p can’t be one’s rational basis for perceptual knowledge. I explore two strategies. The first situates disjunctivism within the context of a ‘knowledge-first’ approach that seeks to reverse the traditional understanding of the relationship between perceptual knowledge and justification (or rational support). But I argue that a more interesting strategy situates disjunctivism within a context that accepts a more nuanced understanding of perceptual beliefs. The proposal that I introduce reimagines disjunctivism in light of a bifurcated conception of perceptual knowledge that would see it cleaved along two dimensions. On the picture that results perceptual knowledge at the judgemental level is rationally supported by perceptual knowledge at the merely functional or ‘animal’ level. This supports a form of disjunctivism that I think is currently off the radar: one that’s consistent both with the SwK thesis and a commitment to a traditional reductive account of perceptual knowledge

Transport in a sustainable urban future

Transport is acknowledged as a vital ingredient of any credible strategy for the sustainable city because of the key role it plays in promoting economic development, quality of life and wellbeing. Yet managing urban transport effectively, given its complex and intersecting economic, environmental and social impacts, is also precisely the kind of ‘wicked problem’ that policy makers consistently find hard to resolve (Docherty and Shaw, 2011a; Conklin, 2006; Rittel and Webber, 1973). Many of the reasons for this are longstanding and emanate in particular from the dominance of the private car in meeting the demand for mobility, which has built up over many decades in the developed world, but which is now being reproduced at a much higher pace in the fast growing cities of the Pacific Rim and elsewhere (Newman and Kenworthy, 1999; Lyons and Loo, 2008). Although it has undoubtedly transformed our patterns of travel and consumption, concerns over the limitations and externalities of private car transport – primarily traffic congestion, environmental degradation and social exclusion – have for many years stimulated various initiatives designed to mitigate these externalities (Feitelson and Verhoef, 2001; Knowles et al, 2008). The conflict between the car, long promoted by neoliberal voices as a potent weapon of the free market and individual liberty, and competing visions of a more ‘public’ transport system based on collective modes such as the bus and train, and active travel by walking and cycling, has been played out over many years. Nowhere has this conflict been more intense than in cities, as it is here that the problems such as congestion, poor local air quality and mobility deprivation are often at their most intense (Cahill, 2010; Docherty et al, 2008)

Schemes and estimates for the long-time numerical solution of Maxwell’s equations for Lorentz metamaterials

We consider time domain formulations of Maxwell's equations for the Lorentz model for metamaterials. The field equations are considered in two different forms which have either six or four unknown vector fields. In each case we use arguments tuned to the physical laws to derive data-stability estimates which do not require Gronwall's inequality. The resulting estimates are, in this sense, sharp. We also give fully discrete formulations for each case and extend the sharp data-stability to these. Since the physical problem is linear it follows (and we show this with examples) that this stability property is also reflected in the constants appearing in the a priori error bounds. By removing the exponential growth in time from these estimates we conclude that these schemes can be used with confidence for the long-time numerical simulation of Lorentz metamaterials.This work was supported in part by NSFC Project 11271310, NSF grant DMS-1416742, and a grant from the Simons Foundation (#281296 to Li), in part by scheme 4 London Mathematical Society funding and in part by the Engineering and Physical Sciences Research Council (EP/H011072/1 to Shaw)

Tester automatically checks insulation of individual conductors in multiple-strand cables

Insulation tester checks multiple-strand electrical cables in nuclear rocket reactors. It has both manual and automatic capabilities and can check the insulation of a cable with 200 or more conductors in a few minutes

Research and competition: Best partners

NASA's Microgravity Science and Applications Program is directed toward research in the science and technology of processing materials under conditions of low gravity. The objective is to make a detailed examination of the constraints imposed by gravitational forces on Earth. The program is expected to lead ultimately to the development of new materials and processes in Earth-based commercial applications, adding to this nation's technological base. An important resource that U.S. researchers have readily available to them is the new Microgravity Materials Science Laboratory (MMSL) at NASA Lewis Research Center in Cleveland. A typical scenario for a microgravity materials experiment at Lewis would begin by establishing 1-g baseline data in the MMSL and then proceeding, if it is indicated, to a drop tower or to simulated microgravity conditions in a research aircraft to qualify the project for space flight. A major component of Lewis microgravity materials research work involves the study of metal and alloy solidification fundamentals

How many lone parents are receiving tax credits?

When data on child poverty in 2003/04 were released, the fall in child poverty since 2002/03 was smaller than had been expected. Brewer et al. (2005) identified several reasons that might explain this, one of which was that the Family Resources Survey (FRS) - the data-set from which the Households Below Average Income (HBAI) income series is currently derived - may have been under-recording the number of families receiving tax credits (or the equivalent level of support in out-of-work benefits) and therefore underestimating the incomes of some low-income families with children. Brewer et al. (2006), who analyse what happened to child poverty between 1998/99 and 2004/05, show that estimates of spending on tax credits received by families with children based on the FRS have been getting increasingly inaccurate over time compared with estimates made by HM Revenue & Customs (HMRC), with around £5 billion of spending on tax credits received by families with children going unrecorded by the FRS in 2004/05. However, a detailed comparison of estimates of the number of families with children receiving tax credits (or equivalent in out-of-work benefits) based on the FRS with the equivalent estimates based on the government's administrative data is confounded by the fact that HMRC estimates that the government is paying the child tax credit and the equivalent in out-of-work benefits to more lone parents than official statistics suggest live in the UK

NASA's Aircraft Icing Analysis Program

An overview of the NASA ongoing efforts to develop an aircraft icing analysis capability is presented. Discussions are included of the overall and long term objectives of the program as well as current capabilities and limitations of the various computer codes being developed. Descriptions are given of codes being developed to analyze two and three dimensional trajectories of water droplets, airfoil ice accretion, aerodynamic performance degradation of components and complete aircraft configurations, electrothermal deicer, fluid freezing point depressant antideicer and electro-impulse deicer. The need for bench mark and verification data to support the code development is also discussed, and selected results of experimental programs are presented

Investigation of infrared spectra of atmospheric gases to support stratospheric spectroscopic investigations

Spectroscopic instrumentation and the absorption characteristics of atmospheric gases are discussed in relation to the requirements of spectroscopic stratospheric experiments. Improvement in the spectral resolution, accuracy of the line parameters, and the ranges of atmospheric conditions over which information is to be obtained are among the factors considered. Methods of simultaneously analyzing entire bands containing many lines were developed and applied to the analysis of bands of N20 and CO2. Progress in this analysis is reported