This article did get published in the American Journal of Physics, and there was some back and forth discussion also published in the Journal. Unfortunately, the published version and the ensuing discussion is effectively inaccessible ... they want 30 USD from me to read each published response.
Please, everyone, stop forcing HomeBrew as a dependency.
HomeBrew screws with your systems file permissions and installs directly into the standard system directories.
MacPorts (https://www.macports.org/) is at least a good, and it installs into the /opt tree, staying out of the way of anything Apple or Darwin wants to do when updating or patching your system.
Don't like MacPorts? There's always Fink (http://www.finkproject.org/), which installs into /sw and looks like Debian (i.e. apt-get).
I'm now seeing "Get Access" (i.e., pay money) instead of "Download Book". I wonder if Springer shut this down? Or if there is some quantity or rate limit on the downloads?