
There’s an awkward, irksome problem with our understanding of nature’s laws which physicists have been trying to explain for decades. It’s about electromagnetism, the law of how atoms and light interact, which explains everything from why you don’t fall through the floor to why the sky is blue.
Our theory of electromagnetism is arguably the best physical theory humans have ever made – but it has no answer for why electromagnetism is as strong as it is. Only experiments can tell you electromagnetism’s strength, which is measured by a number called α (aka alpha, or the fine-structure constant).