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Published January 26, 1978 | public
Journal Article

Limits to the expansion of Earth, Moon, Mars and Mercury and to changes in the gravitational constant

Abstract

New estimates of the palaeoradius of the Earth for the past 400 Myr from palaeomagnetic data limit possible expansion to less than 0.8%, sufficient to exclude any current theory of Earth expansion. The lunar surface has remained static for 4,000 Myr with possible expansion limited to 0.06%, the martian surface suggests a small possible expansion of 0.6% while the surface of Mercury supports a small contraction. Observations of Mercury, together with reasonable assumptions about its internal structure, indicate that G decreases at a rate of less than 8×10^(−12) yr^(−1), in constant mass cosmologies, and 2.5×10^(−11) yr^(−1) in Dirac's multiplicative creation cosmology.

Additional Information

© 1978 Macmillan Journals Ltd. Received 13 July, accepted November 1977.

Additional details

Created:
August 22, 2023
Modified:
October 26, 2023