On a Perceived Expressive Inadequacy of Principia Mathematica

This paper deploys a Cantor-style diagonal argument which indicates that there is more possible mathematical content than there are propositional functions in Russell and Whitehead's Principia Mathematica and similar formal systems. This technical result raises a historical question: "How did Russell, who was himself an expert in diagonal arguments, not see this coming?" It turns out that answering this question requires an appreciation of Russell's understanding of what logic is, and how he construed the relationship between logic and Principia Mathematica

Improving building energy efficiency: case study

The main purpose of this study was to conduct a study for improving energy efficiency of an important building in Rome, the Headquarters of the Italian State Monopoly. The study was conducted by comparing conventional analysis tools with innovative ones, in order to evaluate the possible solutions, both structural and plant, aimed at the use of renewable sources and at energy saving. After making a thermo graphic survey, the first and useful step for a good energy audit, conduct building energy was simulated, at first in steady state by the use of a software widely used at the professional level, then in transient state by the use of TRNSYS, a finite difference method software which is able to simulate more accurately conduct building energy. The next step was to propose possible redevelopment of a structural and energy plant that promotes the building energy rating higher, finding the right balance between the energetic and economic aspect. Among the interventions plant, two possible workarounds have been proposed and designed in detail: - installation of a photovoltaic system; - installation of a solar cooling system. Both solutions lead to a reduction of electricity consumption with a significant impact in economic and environmental term

Hooke's claim on the law of gravity

Based on Galileo's experiments, Newton develops the theory of gravity in his first book Philosophiæ Naturalis Principia Mathematica ("Principia") of 1686. Immediately after, Robert Hooke accused Newton of plagiarism, claiming that he unduly assumed his "notion" of "the rule of the decrease of Gravity, being reciprocally as the squares of the distances from the Center". But, according to Edmond Halley, Hooke agreed that "the demonstration of the curves generated by it" belongs entirely to Newton

Teorie i idee konstruktywistyczne w psychologii

tekst zamieszczony w czasopiśmie "Principia", LVI