Search arXiv⌕ Search

arXiv · 2204.04001

Galileo Galilei and a forgotten poem on the 1604 supernova

Abstract

In October 1604, when SN1604, the last naked-eye visible supernova in our Galaxy, exploded, Galileo Galilei was the professor of mathematics and astronomy at the University of Padua, teaching the mechanics of planets. He was therefore the figure of reference to whom all the doubts and questions that such an apparition brought with it were addressed. The University of Padua asked Galilei to outline the situation by exposing in three public conferences his point of view in order to answer the many questions that raged among the academic community and the common people. Three conferences that Galilei held almost immediately between November and December in the Aula Magna of the Bo, the central building of the University. A month after Galilei's lectures a treatise on the supernova appeared in Padua. The unknown Antonio Lorenzini, behind whose name it is easy to see the inspiration of Cesare Cremonini, an Aristotelian professor of natural philosophy in Padua, published a booklet entitled Discourse about the new star which debunked the conclusions of Galilei. One month after was published in Padua by the same editor the Dialogo de Cecco di Ronchitti da Bruzene in perpuosito de la stella nuova, a booklet in Paduan dialect replying to Lorenzini. The Dialogo appears in the national edition of Galilei's works and is attributed to Galileo himself with the help of the monk Girolamo Spinelli; it does not appear instead a poem in octaves, by an unknown author (presumably Galilei), published as an appendix to the first edition of 1605, and immediately replaced in the second edition. We publish it here, with a comment.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Alessandro De Angelis. 2023-02-19. Galileo Galilei and a forgotten poem on the 1604 supernova. https://arxiv.org/abs/2204.04001

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

The Price of Removing the Scaffolding: Maxwell wrote something about Ampère that years later would be done to him

In the history of physics, the name scaffolding has been given to whatever served to raise a theory and is afterwards removed because, it is said, it is no longer needed. This article documents, from the originals, what it cost Maxwell's theory when that method was applied to it: what was removed from it, who did it, with what argument, and how over the years it had to be recovered because it was understood that it was needed after all. It also records what Maxwell himself missed in Ampère, what he calls the traces of the scaffolding: the template with which Ampère himself had given shape to his work.

physics.hist-ph↗

Piezoelectricity: A Brief History of its Discovery and Physical Principles Using the Example of Low Quartz

Piezoelectricity is a key phenomenon in solid-state physics and has significant technological relevance. In teaching, however, it is often treated either without a historical context or an explicit link to the microscopic crystal structure, meaning that a crucial level of understanding remains untapped. This study combines the history of the discovery of piezoelectricity with its physical description within a didactically coherent framework. Building on the work of the brothers, Jacques and Pierre Curie (1880 - 1882), it demonstrated how investigations into pyroelectricity led to the identification of polarization induced by mechanical compression in hemihedral crystals such as tourmaline and quartz. The development from early qualitative experiments towards the first quantitative determination of piezoelectric constants is traced in a structured manner. Using low quartz as an example, the microscopic cause of piezoelectricity was attributed to the asymmetric displacements of silicon and oxygen ions within the orthosilicate ion tetrahedral network. This leads to the formation of macroscopic polarization owing to uncompensated dipole moments in the crystal lattice. The direct and reciprocal piezoelectric effects are qualitatively distinguished and discussed in the context of mechanical-electrical coupling. The article is aimed at students in physics and engineering as well as lecturers. It was conceived as a didactic review article (tutorial article) and serves as a structured introduction to the physical and historical foundations of piezoelectricity.

physics.hist-ph↗

$δ$-flatness and its natural extension

What, if anything, makes Minkowski spacetime a privileged local reference geometry in General Relativity? Recent work by \cite{WeatherallFletcher} argues: nothing. In response, I proposed a criterion of ``$δ$-flatness'', which bounds the magnitude of tidal acceleration within a tubular neighborhood by $δ$, and showed that Minkowski uniquely saturates the bound. Here I ask how $δ$-flatness generalises, and distinguish two kinds of extension. Reference-metric generalisations compare physical tidal acceleration with a reference tidal-force term constructed from another metric. Lorentzian signature obstructs every such comparison in which the reference fails to share the lightcones of the physical metric. Criterion modifications instead build the criterion from the physical geometry alone. The space of such modifications is wide, and I focus on those closest to $δ$-flatness, where one bounds the deviation of tidal acceleration from a non-zero target. The minimal candidate, which I call $δ$-MSS, has a singular limit that picks out the maximally symmetric spacetimes (Minkowski, de Sitter, Anti-de Sitter) via Schur's theorem. A restricted variant, which compares $g$ with a conformal rescaling of itself, either collapses to $δ$-MSS or fails to pick out a unique geometry. The chief result is that $δ$-flatness distinguishes Minkowski with no free parameter. $δ$-MSS, a weaker variant, picks out the maximally symmetric family at the cost of an externally supplied scalar.

physics.hist-ph↗