Eddington number
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In astrophysics, the Eddington number, NEdd, is the number of protons in the observable universe. Eddington originally calculated it as about 1.57×1079; current estimates make it approximately 1080.
Arthur Stanley Eddington (1882–1944)
Fine-structure constant
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In physics, the fine-structure constant, also known as the Sommerfeld constant, commonly denoted by α, is a fundamental physical constant that quantifies the strength of the electromagnetic interactio
Eddington number
…NEdd and to explain why this number might be important for physical cosmology and the foundations of physics. Eddington argued that the value of the fine-structure constant, α, could be obtained by pure deduction. He related α to the Eddington number, which was his estimate of the number of protons in the universe. This…
Sommerfeld memorial at LMU Munich