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Applied Optics

Applied Optics


  • Vol. 44, Iss. 27 — Sep. 20, 2005
  • pp: 5759–5762

Turbulent ship wakes: further evidence that the Earth is round

David K. Lynch  »View Author Affiliations

Applied Optics, Vol. 44, Issue 27, pp. 5759-5762 (2005)

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When viewed from the stern, a ship’s turbulent wake appears as a narrow strip of bubble-whitened water converging toward the horizon. The wake does not reach a sharp point on the horizon but has a finite angular width, indicating that the Earth is not flat, but rather round. A simple analysis of the geometry of the observations shows that the radius of the Earth can be estimated using only simple instruments and observations.

© 2005 Optical Society of America

OCIS Codes
(000.2060) General : Education
(010.4450) Atmospheric and oceanic optics : Oceanic optics
(080.0080) Geometric optics : Geometric optics
(280.0280) Remote sensing and sensors : Remote sensing and sensors
(330.5020) Vision, color, and visual optics : Perception psychology
(330.7310) Vision, color, and visual optics : Vision

Original Manuscript: November 22, 2004
Revised Manuscript: March 21, 2005
Manuscript Accepted: March 24, 2005
Published: September 20, 2005

David K. Lynch, "Turbulent ship wakes: further evidence that the Earth is round," Appl. Opt. 44, 5759-5762 (2005)

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  1. D. K. Lynch, W. C. Livingston, “Mountain shadow phenomena,” Appl. Opt. 18, 265–269 (1979). [CrossRef] [PubMed]
  2. P. Gorman, Pythagoras: A Life (Routledge & Kegan Paul, London, 1979).
  3. J. Barnes, ed., The Cambridge Companion to Aristotle (Cambridge University, New York, 1995).
  4. T. L. Heath, A History of Greek Mathematics (2 vols.) (Oxford University, 1921).
  5. N. Bowditch, The American Practical Navigator: An Epitome of Navigation (National Imagery and Mapping Agency, 1995).
  6. A. P. French, “How far away is the horizon,” Am. J. Phys. 50(9) 795–799 (1982). [CrossRef]
  7. http://www.1728.com/cubic.htm and http://www3.telus.net/thothworks/Quad3Deg.html .
  8. C. Bohren, A. Fraser, “At what altitude does the horizon cease to be visible?,” Am. J. Phys. 54, 222 (1986). [CrossRef]
  9. S. Shi, A. Smirnov, I. Celik, “Large-eddy simulations of turbulent wake flows,” in Twenty-Third Symposium on Naval Hydrodynamics (National Academics Press, 2001) pp. 579–598.
  10. E. H. Buller, J. K. E. Tunaley, “The effect of the ships screws on the ship wake and its implication for the radar image of the wake,” Digest 1989 IEEE International Geo-science and Remote Sensing Symposium (IEEE, 1989), pp. 362–365.

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