Related papers: Galileo's Double Star: The Experiment That "Proved…
Work published in Sky and Telescope in 2004 discusses Galileo's observations of the star Mizar. These observations raise questions regarding Galileo's assumptions about the universe and the conclusions he drew from his observations. Galileo…
The question of annual stellar parallax is usually viewed as having been a "win-win situation" for seventeenth-century astronomers who subscribed to the Copernican view of universe in which the Earth orbits the Sun and the Sun is one of…
Galileo Galilei believed that stars were distant suns whose sizes, measured via his telescope, were a direct indication of distance -- fainter stars (appearing smaller in the telescope) were farther away than brighter ones. Galileo argued…
The recent paper published in European Journal of Physics [1] aimed to demonstrate the kinematical and dynamical equivalence of heliocentric and geocentric systems. The work is performed in the Neo-Tychonian system, with key assumption that…
The Copernican Principle (which says the Earth and sun are not unique) should have observational consequences and thus be testable. Galileo Galilei thought he could measure the true angular diameters of stars with his telescope; according…
Galileo determined distances to stars based on the assumption that stars were suns, the apparent sizes of stars as seen through his telescope, and basic geometry. However, the apparent sizes that he measured were the result of diffraction…
Galileo's realization that nature is not scale invariant, motivating his subsequent discovery of scaling laws, is traced to two lectures he gave on the geography of Dante's Inferno.
What can physics students learn about science from those scientists who got the answers wrong? Students encounter little science history, and what they have encountered typically portrays scientists as The People with the Right Answers. But…
During the 17th century the idea of an orbiting and rotating Earth became increasingly popular, but opponents of this view continued to point out that the theory had observable consequences that had never, in fact, been observed. Why, for…
Throughout the early history of Science the heliocentric world model was refused because it contradicted the thoughts of Aristotle and the medieval "Impetus" theory of movement. Even Galileo's sky observations did not lead to any acceptance…
The objective reality of the Earth's motion about the Sun was finally proven observationally by Bradley (1727) when he correctly explained the ~20'' annual, elliptical motions of stars as being due to aberration of starlight caused by the…
The Italian Jesuit astronomer Giovanni Battista (Giambattista) Riccioli constructed a powerful, thoroughly scientific argument in favor of geocentrism - an argument based on telescopic observations of stars. This paper contains a rendition…
The Giornata Sesta about the Force of Percussion is a relatively less known Chapter from the Galileo's masterpiece "Discourse about Two New Sciences". It was first published lately (1718), long after the first edition of the Two New…
Galileo's support to the Copernican theory was decisive for the revolutionary astronomical discoveries he achieved in 1610. We trace the origins of Galileo's conversion to the Copernican theory, discussing in particular the "Dialogo de…
Astronomers in the early 17th century misunderstood the images of stars that they saw in their telescopes. For this reason, the data a skilled observer of that time acquired via telescopic observation of the heavens appeared to support a…
The Italian astronomer Giovanni Battista Riccioli is commonly credited with performing the first precise experiments to determine the acceleration of a freely falling body. Riccioli has been discussed by historians of science, sometimes…
Four hundred years after its publication, Galileo's masterpiece Sidereus Nuncius is still a mine of useful information for historians of science and astronomy. In his short book Galileo reports a large amount of data that, despite its age,…
G. B. Riccioli's 1651 Almagestum Novum contains a table of diameters of stars measured by Riccioli and his associates with a telescope. These telescopically measured star diameters are spurious, caused by the diffraction of light waves…
I offer a revisionist interpretation of Galileo's role in the history of science. My overarching thesis is that Galileo lacked technical ability in mathematics, and that this can be seen as directly explaining numerous aspects of his life's…
The aggregate appearance of the naked-eye stars would appear to Galileo to be direct observational support for his ideas about the stars, and indirect observational support for the Copernican theory over the rival Tychonic theory. Brief…