Available online
Description
The programme, recorded on location at Foxcombe Hall, Oxford, examines the design of sundials by use of mathematical models.
The programme, recorded on location at Foxcombe Hall, Oxford, examines the design of sundials by use of mathematical models.
| Module code and title: | TM281, Modelling by mathematics |
|---|---|
| Item code: | TM281; 03 |
| First transmission date: | 17-04-1977 |
| Published: | 1977 |
| Rights Statement: | |
| Restrictions on use: | |
| Duration: | 00:24:00 |
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| Producer: | Philip Ashby |
| Contributors: | Keith Attenborough; Bob Tunnicliffe |
| Publisher: | BBC Open University |
| Keyword(s): | Geometry; Solar system; Sundial |
| Footage description: | Bob Tunnicliffe, standing next to a sundial, introduces the programme. He also briefly holds up a portable sundial. Keith Attenborough, with a sundial, points out its component parts. He then lists those aspects of sundials which will be explained with mathematical models in the programme. Using still shots of the sun in the sky during various times of the day and also a large model set up on the lawn at Foxcombe Hall showing the earth in orbit about the sun Attenborough explains the principles upon which sundials are based. Bob Tunnicliffe explains the difference between the sidereal day and the solar day. He uses a diagram to help make his points. Attenborough adjusts his model of the earth orbit about the sun to take account of the fact that summer days are longer than winter days. Attenborough goes on, with the aid of a cutaway model of the earth, to explain why the style of the sundial is inclined at an angle, this being an angle parallel to the earth's spin axis. Bob Tunnicliffe explains how the style angle of the sundial can be calculated for any particular latitude. He uses a diagram, to which he adds data, to help make his points. Tunnicliffe goes on to explain how the latitude at which the sun dial operates is calculated. Again he uses a diagram to help make his points. Keith Attenborough uses a cylindrical model to explain how a sundial is calibrated. He does this for both horizontal and vertical sundials. Bob Tunnicliffe and Keith Attenborough look at several portable sundials. They point out some of the features of each. Bob Tunnicliffe explains why the time indicated on a sundial in fast or slow, against a clock, depending on the time of year. He goes on to show how the corrections for this are applied. |
| Master spool number: | 6HT/72315 |
| Production number: | 00525_5287 |
| Videofinder number: | 769 |
| Available to public: | no |
