Abstract
ON May 1, a public lecture was delivered at Oxford by Dr. J. K. Fotheringham, reader in ancient astronomy and chronology in the University, on the rotation of the earth. Dr. Fotheringham spoke of the importance of the fact of rotation in regard to such practical matters as the alternation of day and night, the march of the seasons, the tides, and the measurement of time. Some of the Greeks, perhaps including Plato, held the Pythagorean view that the earth and not the sky rotated; but in either case the rotation was generally held to be uniform. The fact of precession was known to Hipparchus, but may be an older discovery. A further disturbance of uniformity, namely, nutation, with a period of 19 years, was determined by Bradley at Oxford. Since his time, further changes have been measured, such as a shifting of the position of the pole in relation to the earth's figure; this has a period of 15 months and may affect latitude to the extent of two-fifths of a second of arc. A change in the speed of rotation is no doubt a real physical fact, “the day is getting longer by one second in many thousand years”. The apparent acceleration of the sun is modified by that of the moon. Fresh facts bearing upon this have been collected by Dr. Fotheringham and others, but their full explanation awaits further research.
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Rotation of the Earth. Nature 133, 679 (1934). https://doi.org/10.1038/133679b0
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DOI: https://doi.org/10.1038/133679b0