When you gaze at the mighty Great Pyramid of Giza—sometimes called the Pyramid of Khufu—you’re looking at four and a half millennia of human effort. And in 2017, researchers revealed there’s more than ...

Egypt’s Pyramids of Giza were built to endure an eternity, but how remains one of the ancient world’s greatest mysteries.

High above Egypt and everywhere else, cosmic rays bombard the atmosphere. The rays consist mostly of hydrogen nuclei, but they finish their interstellar journey with a bang, splitting into a shower of ...