This small demo shows how the fine‑structure constant α connects several fundamental constants of physics. α is special because it is dimensionless – it has no units. That means it describes a pure ratio, not a quantity.
In electromagnetism, α appears in the relation:
α = e² / (4π ε₀ ħ c)
This connects:
– e: the elementary charge
– ε₀: the vacuum permittivity
– ħ: the reduced Planck constant
– c: the speed of light
Because α is dimensionless, this relation is purely geometric.
In this demo, we simply rearrange the relation to solve for the speed of light:
c = e² / (4π ε₀ ħ α)
No new physics is introduced.
We only use established constants and basic algebra.
The goal is to show how close this computed value of c is to the official, defined value of the speed of light. Any small difference comes from tiny measurement uncertainties in e, ε₀, ħ, or α.
Computed c:
Official c:
299792458 m/s
Difference:
You can change any constant above to see how the computed value of c reacts. This makes the geometric structure of the relation visible.