Abstract
Many notable physicists have been fascinated by the ubiquity of large dimensionless numbers formed from the physical parameters controlling the large scale structure of the Universe1–10. For example, whereas most local dimensionless constants are within an order of magnitude or so of unity, the ratio of the electric to the gravitational force between a proton and an electron is ∼1040 whatever their separation; the number of protons in the Universe is ∼1080 and the ratio of the action of the Universe to the quantum of action, h, is ∼10120 and so on. One stimulating approach to these large number coincidences was that introduced by Dirac5 in 1937 which is used here to predict precisely the proton half life. However, unlike previous applications, this prediction can be both tested and ruled out by experimental evidence.
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Barrow, J. The proton half life and the Dirac hypothesis. Nature 282, 698–699 (1979). https://doi.org/10.1038/282698a0
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DOI: https://doi.org/10.1038/282698a0
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