Day 8: Muons at the start of he Einstein museum, Bern

In 1905, while living in Bern and working as a patent clerk, Albert Einstein published a number of seminal papers that changed the way we understand time, space, and the fabric of "stuff" on the smallest scale were, to an extent, redefined as a result of his papers on Special Relativity and the Photoelectric Effect. The impressive Einstein exhibition at the Historical Museum laid bare a fascinating, complicated life alongside brief explanations of his remarkably simple, groundbreaking theories.

At the beginning of the exhibit, there was a scintillator showing the regular arrival of muons travelling at near the speed of light from the upper atmosphere. These short-lived particles ought not to make it to this low altitude.

The physics question for today is: How is it that muons from the upper atmosphere, whose short average lifetime should result in their decay long before reaching the Historical Museum, are being detected with remarkable regularity in the scintillator at the beginning of the Einstein exhibition?