There are all sorts of resonances around us, in the world, in our culture, and in our technology. A tidal resonance causes the 55 foot tides in the Bay of Fundy. Mechanical and acoustical resonances and their control are at the center of practically every musical instrument that ever existed. Even our voices and speech are based on controlling the resonances in our throat and mouth. Technology is also a heavy user of resonance. All clocks, radios, televisions, and gps navigating systems use electronic resonators at their very core. Doctors use magnetic resonance imaging or MRI to sense the resonances in atomic nuclei to map the insides of their patients. In spite of the great diversity of resonators, they all share many common properties. In this blog, we will delve into their various aspects. It is hoped that this will serve both the students and professionals who would like to understand more about resonators. I hope all will enjoy the animations.

For a list of all topics discussed, scroll down to the very bottom of the blog, or click here.

Origins of Newton's laws of motion

Non-mathematical introduction to relativity

Three types of waves: traveling waves, standing waves and rotating waves new

History of mechanical clocks with animations
Understanding a mechanical clock with animations
includes pendulum, balance wheel, and quartz clocks

Water waves, Fourier analysis

Saturday, March 19, 2011


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History of Mechanical Clocks with Animations

1.9 References on mechanical clocks

There is a wealth of information on clocks and watches at all levels. The sources listed below are but a small sampling of this.

  1. For most items above Wikipedia at has very good material, and a number of nice public domain images for all to use. As always, searches on Google and other search engines produce a wealth of material. Other good sites for free public domain images are, and US government sites such as NASA, NOAA, FWS, etc.
  2. Wikipedia on the verge and foliot escapement.
  3. A site on pocket watches.

Concerning the Longitude problem and Harrison's work:

  1. Wikipedia on the longitude problem at
  2. Wikipedia on John Harrison at
  3. Wikipedia on horology at
  4. Wikipedia on marine chronometer at
  5. Website of the Nautical Maritime Museum and Royal Observatory Greenwich, UK, and have Harrison's actual clocks and these web sites have beautiful pictures of these clocks.
  6. A BBC account of the Harrison story:
  7. Nice account of the longitude problem (under "Board of Longitude at this site"):
  8. American Watch Company web: Specifically see: (This latter link works best with Microsoft internet explorer.)
  9. Added details of Harrison's various clocks:
  10. Also see "Books" below.

General references on clocks and time keeping:

  1. US National Institutes of Standards and Technology (NIST). A walk through time…history of clocks Public domain...nice list of references.
  2. National Watch and Clock Museum, National Association of Watch and Clock Collectors, Columbia, Penn, US.

Great details on escapements and clocks:

  1. A website of an antique watch restorer: .
  2. .
  6. Details of a watch movement.

Great video clips on clocks:

  1., search on "clocks" or try one of the following videos and all the related videos that appear beside the selected one. There is an overwhelming number of videos on the subject. The ones below perhaps most clearly show the internal working of the clocks.
  2. Handmade wooden grandfather clock.
  3. Artistic "Corpus Clock".
  4. Video on Big Ben in London.
  5. Standard pendulum wall clock of 1890 detailing the operation of the escapement in action.
  6. Details of the escapement and gears of a wooden mechanical clock.
  7. A very short video of the inner workings of a modern reproduction of Harrison's grasshopper escapement, a particularly interesting, but seldom used escapement.
  8. A video showing the beauty of mechanical watches.
  9. A skeleton watch, one that is designed to show off its internal parts.
  10. Clock gear cutting.
  11. Making clock gears.
  12. Gears, mechanism, clocks.
  13. Closeup of a standard pendulum escapement in action.
  14. Verge and foliot clock in motion.
  15. John Arnold escapement model.
  16. Very good close up of several watch escapements (if you wait out the first part).
  17. Details of a watch escapement and gear train in motion.
  18. Close up of the escapement of a very large clock for a clock tower.
  19. Another close up of the escapement of a very large clock for a clock tower.
  20. Another close up of the escapement and gears for a very large clock for a clock tower.

Companies that sell antique (and modern) clocks and watches and generally have beautiful images of these:


Details on modeling watch and clock escapements:

  1. 1. Out of Leggos:,


  1. Longitude by Dava Soble is an excellent biography of John Harrison and the history of the longitude prize in Britain. It makes for an entertaining read.
  2. The Illustrated Longitude by Dava Soble and William Andrewes is an beautifully illustrated version of the above book.

Related science fair projects:

  1. Google (i.e. search) on:
    • "mechanical clock science fair project"
    • "pendulum clock science fair project"
    • "balance wheel clock science fair project"
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