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No. 103: Jan-Feb 1996

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Einstein's nemesis: di herculis

DI Herculis is an 8th-magnitude eclipsing binary about 2,000 light years from earth. These two young blue stars are very close -- only one fifth the distance from earth to our sun. They orbit about a common center of gravity every 10.55 days. So far, no problem!

The puzzle is that, as the two stars swing around one another, the axis of their orbit rotates or precesses too slowly. General relativity predicts a precession of 4.27/century, but for DI Herculis the rate is only 1.05/century. This does not sound like a figure large enough to get excited about, but it deeply troubles astronomers. D. Popper, an astronomer at UCLA, says:

"The observations are pretty clear. I don't think there's any question there's a discrepancy and, frankly, it is an important one and it's unresolved."

Accentuating the challenge to general relativity is the discovery that a second eclipsing binary, AC Camelopardalis, also violates general relativity in the same way. It seems that wherever gravitational fields are extremely strong and space-time, therefore, highly distorted, general relativity fails.

Ironically, it was a very similar sort of astronomical observation that helped make general relativity a pillar of the scientific edifice early in the 20th. century. The orbit of Mercury precesses a bit faster than Newtonian physics predicts. The application of Einstein's general relativity corrected the calculation of Mercury's rate of precession by just the right amount. Now we may need a new theory to correct Einstein -- at least where time-space is sharply bent!

(Naeye, Robert; "Was Einstein Wrong?" Astronomy, 23:54, November 1995)

From Science Frontiers #103, JAN-FEB 1996. 1996-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:


  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987