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The theme of the programme is the usefulness of the mental device of putting one's mind outside the immediate environment so as to 'look in' on it. This idea is introduced at the start of the progr...amme by comparing the swing of a pendulum viewed from a spinning children's roundabout with the view from a fixed position outside of the roundabout. The analogy is made between the spinning roundabout and the spinning earth and between the small pendulum and the Foucault Pendulum. A reconstruction of Foucault's original experiment is shown in St. Paul's Cathedral, London, and the rate of apparent rotation is indicated by the pendulum cutting through a thin wedge of sand. Professor Pentz explaining that in London the rotation is only 12 degrees per hour and not 15 per hour as predicted by the simple roundabout model. The programme carries on the idea by 'looking in' on a studio model of the Earth-Moon system to show the lunar phases. The model is used to show how the Moon's orbit must be inclined to the Earth-Sun plant in order to avoid lunar eclipses each month. Finally, the 'outside' view is widened to take in both the Earth and a more distant planet in the solar system. With the help of another studio model linked to an oscilloscope trace, the phenomenon of retrograde motion is explained.
Metadata describing this Open University video programme
Module code and title: S102, Science: a foundation course
Item code: S102; 01
First transmission date: 07-02-1988
Published: 1988
Rights Statement:
Restrictions on use:
Duration: 00:25:00
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Producer: J. Stratford
Contributors: Mike Pentz; Keith Hodgkinson
Publisher: BBC Open University
Keyword(s): Foucault pendulum; Lunar phases; Lunar eclipse; Retrograde motion
Subject terms: Moon; St. Paul's Cathedral (London)--History--15th century; Foucault's pendulum; Science
Master spool number: HOU5644
Production number: FOUS451F
Videofinder number: 928
Available to public: no