In this paper I draw on Einstein's distinction between “principle” and “constructive” theories to isolate two levels of physical theory that can be found in both classical and (special) relativistic physics. I then argue that when we focus on theoretical explanations in physics, i.e. explanations of physical laws, the two leading views on explanation, Salmon's “bottom-up” view and Kitcher's “top-down” view, accurately describe theoretical explanations for a given level of theory. I arrive at this conclusion through an analysis of explanations (...) of mass—energy equivalence in special relativity. (shrink)

The goal of this research is to know and compare the emotions and reactions to confinement due to the COVID-19 pandemic in children and adolescents with high abilities and community samples. This is a mixed study with an exploratory reach that is descriptive, and which combines survey and qualitative methodologies to examine the emotions and reactions to confinement experiences of children and adolescents aged between 5 and 14 years. An online poll was designed with 46 questions, grouped into three sections: (...) General Data, Reactions to the health contingencies of COVID-19, and Positive and negative emotions. This last section was included the Oros’ positive emotions questionnaire and the scales of the negative effect of the PANAS Schedule positive and negative affect on children and adolescents between 8 and 14 years old. Data were collected online with a convenience sample. Quantitative data were analyzed with the SPSS statistics program and qualitative data with Alceste software. Among the main findings is the fact that there are no significant differences between the groups by ability in terms of reactions and emotions; however, there are differences between age groups and sex. The study discusses the implications for educational intervention in situations like the current pandemic. (shrink)

Interpretations of Einstein’s equation differ primarily concerning whether E = mc2 entails that mass and energy are the same property of physical systems, and hence whether there is any sense in which mass is ever ‘converted’ into energy. In this paper, I examine six interpretations of Einstein’s equation and argue that all but one fail to satisfy a minimal set of conditions that all interpretations of physical theories ought to satisfy. I argue that we should prefer the interpretation of Einstein’s (...) equation that holds that mass and energy are distinct properties of physical systems. This interpretation also carries along the view that while most cases of ‘conversion’ are not genuine examples of mass being ‘converted’ into energy, it is possible that the there are such ‘conversions’ in the sense that a certain amount of energy ‘appears’ and an equivalent of mass ‘disappears’. Finally, I suggest that the interpretation I defend is the only one that does not blur the distinction between what Einstein called ‘principle’ and ‘constructive’ theories. This is philosophically significant because it emphasizes that explanations of Einstein’s equation and the ‘conversion’ of mass and energy must be top‐down explanations. (shrink)

Einstein’s 1935 derivation of mass—energy equivalence is philosophically important because it contains both a criticism of purported demonstrations that proceed by analogy and strong motivations for the definitions of the ‘new’ dynamical quantities. In this paper, I argue that Einstein’s criticism and insights are still relevant today by showing how his derivation goes beyond Friedman’s demonstration of this result in his Foundations of Spacetime ¹heories. Along the way, I isolate three distinct physical claims associated with Einstein’s famous equation that are (...) sometimes not clearly distinguished in philosophical discussions of spacetime theory. (shrink)