The Fitzgerald-Lorentz contraction hypothesis, proposed as an explanation of the Michelson-Morley result, fails to account for the Kennedy-Thorndike result. Hence, Grünbaum argues, the hypothesis has been falsified. However, the contraction hypothesis as formulated by Lorentz is false for the very fundamental reason that it entails a contradiction, namely, the consequence that light waves must have a variable velocity along what by definition is taken to be a rest length. Furthermore, the attempt to resolve this contradiction by coupling the Fitzgerald-Lorentz contraction (...) with the hypothesis that clock rates are a function of velocity, is open to a sound, methodological objection. The Michelson-Morley result is fully satisfied, provided only that the lengths of the interferometer arms, in the longitudinal and transverse positions, are thought to be related to one another in a certain ratio, and this ratio may be interpreted as a contraction in both arms. Since this twofold contraction hypothesis suffices to explain both the Michelson-Morley and the Kennedy-Thorndike results, and since it entails no contradiction, there is no need to correct both the length of rods and the rate of clocks. Therefore, the combined clock-rod hypothesis, and with it the Fitzgerald-Lorentz contraction hypothesis, must be rejected. (shrink)

Written memoranda of conversations, or memcons, provide a near‐contemporaneous record of what was said in conversation, and offer important insights into the activities of high‐profile individuals. We assess the impact of writing a memcon on memory for conversation. Pairs of participants engaged in conversation and were asked to recall the contents of that conversation 1 week later. One participant in each pair memorialized the content of the interaction in a memcon shortly after the conversation. Participants who generated memcons recalled more (...) details of the conversations than participants who did not, but the content of recall was equally and largely accurate for both participants. Remarkably, only 4.7% of the details of the conversation were recalled by both of the partners after a week delay. Contemporaneous note‐taking appears to enhance memory for conversation by increasing the amount of information remembered but not the accuracy of that information. These findings have implications for evaluating the testimony of participants on conversations with major political or legal ramifications. (shrink)

RésuméLe raisonnement selon lequel la simultanéité est relative du point de vue de l'observateur est fondamental dans la Relativité restreinte. Pourtant, l'analyse de ce raisonnement mène aux critiques suivantes:1. Le raisonnement appartient à la physique classique plutǒt qu'à la physique relativiste, en ce qu'il adopte la conception classique de la propagation de la lumière et ignore le principe de la constance de la vitesse de la lumière.2. Il entre en conflit avec l'évidence empirique, car son hypothèse de base et son (...) mode de raisonnement sont presque exactement analogues à ceux qui amenèrent Michelson et Morlay à attendre un résultat positif lors de leur expérience d'interférence.3. Il est logiquement inacceptable, car il repose à la fois sur l'affirmation et sur la négation d'un système de référence privilégié.Bien plus, on montre que l'application correcte des transformations de Lorentz mène non pas à la conclusion que la simultanéité est relative, mais plutǒt à celle qu'elle est absolue.The argument that simultaneity is relative to the viewpoint of an observer, is fundamental to Special Relativity. However, analysis of this argument leads to the following strictures: the argument belongs to classical physics rather than to relativity physics, in that it adheres to the classical view of the propagation of light, and ignores altogether the relativistic principle of the constancy of the velocity of light; the argument conflicts with empirical evidence, in that its basic assumption and mode of reasoning are almost exactly analogous to those which led Michelson and Morley to expect a positive result from their interferometer experiment; the argument is logically untenable, in that it rests on both the affirmation, and the denial, of a privileged frame of reference. Furthermore, it is shown that proper application of the Lorentz transformation, in actually transforming data from one system to another, must lead, not to the conclusion that simultaneity is relative, but rather to the conclusion that it is absolute. (shrink)