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The Triangular Binary Clock

Jörg Pretz
  • III. Physikalisches Institut B, RWTH Aachen University
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Published Online: 2016-04-14 | DOI: https://doi.org/10.1515/rmm-2016-0001


A new idea for a binary clock is presented. It displays the time using a triangular array of 15 lamps each representing a certain amount of time. It is shown that such a geometric, triangular arrangement is only possible because our system of time divisions is based on a sexagesimal system in which the num- ber of minutes in 12 hours equals the factorial of a natural number (720 = 6!). An interactive applet allows one to “play” with the clock.

Keywords: binary; clock; time; sexagesimal system


  • [1] Pretz, J. “A different way to read o the time - A new idea for a binary clock”, Journal of Recreational Mathematics, Vol. 35(4), 327{330, arXiv:1006.1373v1 [math.HO], 2006.

  • [2] Neugebauer, O. The Exact Sciences in Antiquity, Barnes & Noble, New York, 1993.

  • [3] Wikipedia article. “Babylonia”: http://en.wikipedia.org/wiki/Babylonia

  • [4] Richard A., Carrigan, Jr. “Decimal time”, American Scientist, 305(78), 66, 1978.

  • [5] Wikipedia article. “Decimal time”: http://en.wikipedia.org/wiki/Decimal_time

About the article

Published Online: 2016-04-14

Published in Print: 2016-03-01

Citation Information: Recreational Mathematics Magazine, ISSN (Online) 2182-1976, DOI: https://doi.org/10.1515/rmm-2016-0001. Export Citation

© 2016. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License. (CC BY-NC-ND 4.0)

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