Cosmic numbers have intrigued modern cosmologists ever since puzzling coincidences were first noticed between some of the large dimensionless constants. Here I will try to show not only that these numbers are interesting, but also that they are possibly important to our understanding of the physical world. Have the coincidences always existed or is it merely fortuitous that they occur at the present stage of evolution of the universe?
20. J. N. Bahcall, E. E. Salpeter, Astrophys. J. 142, 1677 (1965); https://doi.org/ASJOAB J. N. Bahcall, W. L. W. Sargent, M. Schmidt, Astrophys. J. 149, L11 (1967); https://doi.org/ASJOAB J. N. Bahcall, M. Schmidt, Phys. Rev. Lett. 19, 1294 (1967).https://doi.org/PRLTAO
25. E. Mach, The Science of Mechanics, 5th ed., LaSalle, Illinois (1942) chapter 1.
26. D. W. Sciama, The Unity of the Universe, Doubleday, New York (1961); R. H. Dicke in Gravitation and Relativity, (H. Chiu, W. Hoffman, eds.) Benjamin, New York (1964) chapter 7; J. H. Higbie, Gen. Rel. and Grav. 3, 101 (1972).https://doi.org/GRGVA8
29. R. A. Alpher, G. Gamow, Proc. Nat. Acad. Scis. 61, 363 (1968) https://doi.org/PNASA6 and Cosmology, Fusion and Other Matters (F. Reines, ed.), Colorado Associated U.P., Denver (1972), chapter 1.
30. A. R. Sandage, PHYSICS TODAY, February 1970, page 34.
31. Reference 8, chapter IV.
32. Reference 8, pages xxxvi‐vii.
More about the Authors
Edward R. Harrison.
University of Massachusetts, Amherst.
Amid growing investment in planetary-scale climate intervention strategies that alter sunlight reflection, global communities deserve inclusive and accountable oversight of research.
Although motivated by the fundamental exploration of the weirdness of the quantum world, the prizewinning experiments have led to a promising branch of quantum computing technology.
As conventional lithium-ion battery technology approaches its theoretical limits, researchers are studying alternative architectures with solid electrolytes.
November 10, 2025 10:22 AM
This Content Appeared In
Volume 25, Number 12
Get PT in your inbox
PT The Week in Physics
A collection of PT's content from the previous week delivered every Monday.
One email per week
PT New Issue Alert
Be notified about the new issue with links to highlights and the full TOC.
One email per month
PT Webinars & White Papers
The latest webinars, white papers and other informational resources.