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Crystal structures, the Earth and Dirac's Large Numbers Hypothesis

Naturevolume 257pages115116 (1975) | Download Citation



DIRAC'S Large Numbers Hypothesis assumes that the large, dimensionless numbers obtained from the ratios between fundamental physical constants are related to the age, t, of the Universe1–4. The theory demands two important consequences: that matter be continuously created with time and that the gravitational constant, G, vary with time. To reconcile those demands with Einstein's theory of gravitation two metrics are required. One, the Einstein metric, involves the equations of motion and classical mechanics; the other, the atomic metric, refers to quantum mechanics and laboratory measurements of distances and time as determined by atoms. According to Dirac, the continuous creation of mass requires either of two models—one, called additive creation, assumes that matter is created uniformly throughout space (mostly intergalactic space). The other model is called multiplicative creation. It calls for the creation of matter where matter already exists in proportion to the amount and kind already existing.

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  1. 1

    Dirac, P. A. M., in The Physicist's Conception of Nature (edit, by Mehra, J.), 45 (Reidel, Dordrecht, 1973).

  2. 2

    Dirac, P. A. M., Naturwissenchaften, 60, 529 (1973).

  3. 3

    Dirac, P. A. M., Proc R. Soc., A 338, 439 (1974).

  4. 4

    Dirac, P. A. M., Nature, 139, 323 (1937).

  5. 5

    Dicke, R. H., Science, 138, 653 (1962).

  6. 6

    Hoyle, F., Q. Jl R. astr. Soc., 13, 328 (1972).

  7. 7

    Gittus, J. H., Proc. R. Soc., A 343, 155 (1975).

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  1. Department of Paleobiology, Smithsonian Institution, Washington, DC, 20560



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