In The empirical stance, Bas van Fraassen argues for a reconceptualization of empiricism, and a rejection of its traditional rival, speculative metaphysics, as part of a larger and provocative study in epistemology. Central to his account is the notion of voluntarism in epistemology, and a concomitant understanding of the nature of rationality. In this paper I give a critical assessment of thes...

The evolution of Earth's climate on geological timescales is largely driven by variations in the magnitude of total solar irradiance (TSI) and changes in the greenhouse gas content of the atmosphere. Here we show that the slow ∼50 Wm-2 increase in TSI over the last ∼420 million years (an increase of ∼9 Wm-2 of radiative forcing) was almost completely negated by a long-term decline in atmospheri...

We report numerical observation of two new forms of stable localized solutions of the quintic complex Ginzburg-Landau equation. The 6rst form is a stationary zero-velocity solution, which consists of two motionless fronts and a source between them. We call this structure the "composite" pulse. We show that in some range of parameters, a composite pulse can coexist with a plain pulse solution. A...

A growing number of X-ray sources based on the free-electron laser (XFEL) principle are presently under construction or have recently started operation. The intense, ultrashort pulses of these sources will enable new insights in many different fields of science. A key problem is to provide x-ray optical elements capable of collecting the largest possible fraction of the radiation and to focus i...

We postulate a new method of measuring debt which we call the debt burden (DB). We claim that DB reveals the true debt obligations of the fiscal authority by taking the intertemporal debt obligations of the government into account. It is more accurate and more transparent than the currently used methods of assessing debt. DB is calculated on a daily basis and it clearly identifies debt risks. I...