6
votes
3answers
255 views

Is there a simple way to compute some physical constant from Feynman diagram statistics?

I've been playing around writing some software to generate Feynman diagrams for QED, respecting the vertex "rules" described here, and avoiding creating isomorphic duplicates. So from a starter ...
5
votes
2answers
345 views

Is the fine structure constant actually a constant or does its value depend on the energy scale?

The value of the fine structure constant is given as $$ \alpha = \frac{e^2}{4\pi\varepsilon_0\hbar c} = \frac{1}{137.035\,999..} $$ It's value is only dependent on physical constants (the elementary ...