Introducing the March 2020 Issue
https://www.scientificamerican.com/article/introducing-the-march-2020-issue/
“Crisis” is a strong word. Just a few weeks before this issue went to press, the U.S. and Iran seemed to be on the brink of war. So it might seem excessive to define a situation in which there is no danger to life or limb as a crisis. But in the world of cosmology, there may be no greater predicament than two divergent measurements of how fast the universe is expanding.