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| POSSEDUTO (se manca la collocazione vai al documento contenente) | |
| Accesso online: | versione digitale |
| Autore principale: | Maffioli, Cesare S., 1946-
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| Titolo: | La ragione del vacuo : why and how galileo measure the resistance of vacuum / Cesare S. Maffioli. |
| Abstract: | In Two New Sciences the argument of vacuum is used to explain both the limited ability to raise water by suction and the cohesion of bodies. Not only are these aspects correlated in Galileo's book but the value of the resistance of vacuum, which could be found by measuring the maximal lift of water by suction, constitutes a standard of measurement for evaluating the cohesion of solids. In this article I address two questions. One concerns the role of this measurement in the evolution of Galileo's theory of matter. When Galileo realized that the resistance of vacuum is much smaller than the force of cohesion of solids, he abandoned the view that this force is due to exquisite contacts between the tiny particles of matter and attributed it to the resistance to dilatation of the minute vacua that are interspersed in the solid bodies. Another question concerns Galileo's way of establishing that the value of the resistance of vacuum is equal to the weight of a column of water of 18 braccia (about 10.5 m) high. It is my contention that Galileo did not obtain this value from the practice of suction lift pumps but from a series of experiments performed in Genoa by Baliani, who wished to understand why a siphon of about 20.8 m high did not work. By analyzing the data sent to Galileo and the original drawing attached to Balianì‰s letter of 27 July 1630 I argue that the Genoese siphon was the real source of Galileo's 18 braccia |
| Visionato in: | IMSS |
| In: |  Galilaeana A. 8 (2011), p. 73-104 |
| Discipline: | Meccanica dei fluidi--Persone. |
| Persone: | Galilei, Galileo, 1564-1642--Fisica. Baliani, Giovanni Battista, 1582-1666. Galilei, Galileo e Baliani, G.B. |
| Sudd. cronologiche: | Secolo XVII. |
| 000001011613 |
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