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Life & fun · September 17, 2021

IW

I was playing with fundamental constants and 13.8 b years popped out

I was playing around with fundamental constants and out popped 13.8 billion light years. What is going on? the wavelength of an electron mass photon / (2pi) * the charge radius of a proton / the black hole radius of a proton = 13.8 billion light years ((h / (m_e * c * 2pi)) * (h / (m_p * c * pi/2)) / (2G * m_p / c^2)) = 13.8 billion light years…

I was playing with fundamental constants and 13.8 b years popped out launched on September 17, 2021 with 56 votes, #1,066 of 2,941 launches that month and more than 90% of that year's launches.

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In plain words

This is an exploration of a mathematical coincidence discovered by combining fundamental physical constants—the Compton wavelength of an electron, the charge radius of a proton, and the Schwarzschild radius of a proton—which when calculated together yield approximately 13.8 billion light years, matching the observable universe's age. The project documents this curious numerical relationship for physics enthusiasts and those interested in fundamental constants and their unexpected connections.

written from the facts on this page · September 2026

From the sources

In the maker’s words, at launch

I was playing around with fundamental constants and out popped 13.8 billion light years. What is going on? the wavelength of an electron mass photon / (2pi) * the charge radius of a proton / the black hole radius of a proton = 13.8 billion light years ((h / (m_e * c * 2pi)) * (h / (m_p * c *…

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Source: Show HN post ↗ · launch text quoted in part

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