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Dr. Michael Hoskin, Fellow of Churchill College and Lecturer in the History of Science at Cambridge University examines why Galileo, the first astronomer to observe the heavens with a telescope, f...ailed to discredit Tycho's system in which the earth not the sun is at the centre of the universe. He shows why the choice between the dynamical, scriptural, and observational difficulties created by Copernicus and the seductive compromise of Tycho and his fellow travellers, was a crucial step leading to the mathmematical formulation of planetary orbits. Galileo's telescope? The programme takes a critical view of Galileo's observations and puts them into the context of the controversies in hand.
Metadata describing this Open University video programme
Module code and title: AMST283, Science and belief: from Copernicus to Darwin
Item code: AMST283; 02
First transmission date: 27-02-1974
Published: 1974
Rights Statement:
Restrictions on use:
Duration: 00:24:27
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Producer: David Jackson
Contributor: Michael Hoskin
Publisher: BBC Open University
Keyword(s): Astronomy; Copernicus; Planetaria; Ptolemy; Telescopes; Tycho Brahe
Footage description: Michael Hoskin introduces the programme by explaining that Galileo's defence of Copernicanism in his 'Dialogue on the two great world systems' is not a proof of Copernican theories but a disproving of Ptolemy. Compromises such as the Tychonic system were more popular and Galileo's work could not refute them. Captions show this system and Hoskin holds two models of the Copernican and Ptolemaic systems. Opening shots show title page of the 'Dialogue'. Robert Rietty reads part of the title page. He briefly describes the development of the telescope, initially as a toy. Shows an early model and curved glass lenses. He mentions the lengthy gestation of 'De revolutionibus orbitum coelestium', showing the book and planetary tables. Portrait of Copernicus. Overhead view of small planetarium shows planets in motion. Hoskin shows how some planets will appear to move backwards at times, from the earth. Graphics show Venus and Mercury in relation to the sun. He explains how the distance of a planet from the sun can be calculated from the observed duration of its orbit. Graphics show how Copernican system thus derived. Side shot of orrery showing planets in motion. Music. The Copernicans' claims ran counter to the established- Aristotelian cosmos (diagram) and scriptural interpretations. Hoskin describes the opposition and the crucial experiment to prove that the stars did in fact move slightly with the season, as the Copernicans claimed. This failed owing to the impossibility of detecting such small movements by naked-eye observations. As a result many compromise systems developed in the late l6th century. A floor painting and model show the most popular of these: the Tychonic system. In conclusion Hoskin presents a number of extracts from Galileo's writings, mentioning the discovery of moons around Jupiter, the surface of our moon, and the presence of many more stars in the constellations than were visible to the unaided eye. All these discoveries were available to anyone using a telescope. Graphics illustrate this sequence.
Master spool number: 6HT/71123
Production number: 00525_3110
Videofinder number: 3350
Available to public: no