Jugglers, magicians and orators: the role of emotions in the art of improvisation

La capacità oratoria di persuadere ricorrendo ai mezzi patetici propri del teatro è, nel mondo antico, motivo di discussione. Il diverbio riguarda la tensione fra verità e finzione, per cui l’attore recita una parte, mentre l’oratore deve raccontare fatti reali. La credibilità di un discorso dipende, dunque, dal grado di coinvolgimento emotivo, ovvero dalla capacità dell’oratore di apparire realmente convinto delle proprie tesi. In questo senso riveste un importante ruolo la tecnica immedesimativa tipica della recitazione che, grazie alla circolarità delle emozioni, permette di attivare un rapporto empatico con il pubblico. In particolare, nei manuali di retorica, laddove si intende chiarire con quali espedienti ottenere questo risultato, si ricorre all’exemplum di attori talmente commossi dalla propria parte da rimanerne scossi. L’influsso del teatro sull’oratoria, però, non si limita all’ambito propriamente performativo, ma si allarga anche ad altri settori, arrivando addirittura a condizionare l’inventio e le tecniche di composizione di un’orazione. In questo senso è emblematico il caso di Galba, raccontato nel Brutus ciceroniano (§§ 87-88): questi si immedesimava a tal punto nelle vicende da farle proprie, un procedimento analogo a quello degli attori, che “si calano” nella parte prima di andare in scena, ma soprattutto dello scrittore, che si immedesima nei protagonisti delle storie da lui create. Il contributo intende, quindi, indagare le reciproche interazioni fra passione estemporanea e acquisizione di una tecnica nell’arte dell’improvvisazione: se, infatti, recenti studi hanno messo in luce la pianificazione di una strategia comunicativa già nel momento compositivo, resta ancora da chiarire quanto la tecnica recitativa abbia influito su tali acquisizioni.   Jugglers, magicians and orators: the role of emotions in the art of improvisation One of the aspects that the art of rhetoric and acting share is the acquisition of a technique based on identification. In rhetoric manuals, whenever the modes in which the speaker can start using the technique need to be addressed and clarified, examples of actors deeply moved and shaken by their own roles are pointed out: it is a recurring topos, which highlights the reciprocity between the two artes. Through mental projections of narrated events, also known as visiones, the speaker filters the events through the eye of imagination and emotionally identifies with them: thanks to the intentional control of emotions, the speaker appears to be truly involved in the matter and gains credibility. However, the planning of emotions concerns not only the performance itself but also the inventio, the initial conception of a speech. From the analysis of the sources it is evident that improvisation and the instrumental use of the various adfectus result from a long learning process too and that in oratory nothing is left to extemporaneity. While performing, the speaker unconsciously implements a whole series of techniques that have been previously assimilated through memorization and exercise and that concern both the contents and the ways to successfully communicate them

Exploiting Sentinel-1 amplitude data for glacier surface velocity field measurements. Feasibility demonstration on baltoro glacier

The leading idea of this work is to continuously retrieve glaciers surface velocity through SAR imagery, in particular using the amplitude data from the new ESA satellite sensor Sentinel-1 imagery. These imagery key aspects are the free access policy, the very short revisit time (down to 6 days with the launch of the Sentinel-1B satellite) and the high amplitude resolution (up to 5 m). In order to verify the reliability of the proposed approach, a first experiment has been performed using Sentinel-1 imagery acquired over the Karakoram mountain range (North Pakistan) and Baltoro and other three glaciers have been investigated. During this study, a stack of 11 images acquired in the period from October 2014 to September 2015 has been used in order to investigate the potentialities of the Sentinel-1 SAR sensor to retrieve the glacier surface velocity every month. The aim of this test was to measure the glacier surface velocity between each subsequent pair, in order to produce a time series of the surface velocity fields along the investigated period. The necessary co-registration procedure between the images has been performed and subsequently the glaciers areas have been sampled using a regular grid with a 250 × 250 meters posting. Finally the surface velocity field has been estimated, for each image pair, using a template matching procedure, and an outlier filtering procedure based on the signal to noise ratio values has been applied, in order to exclude from the analysis unreliable points. The achieved velocity values range from 10 to 25 meters/month and they are coherent to those obtained in previous studies carried out on the same glaciers and the results highlight that it is possible to have a continuous update of the glacier surface velocity field through free Sentinel-1 imagery, that could be very useful to investigate the seasonal effects on the glaciers fluid-dynamics