This image, which we’ve seen around online a bit lately, shows a group enjoying a spin on an amusement park attraction often referred to as a centrifugal ride (in Newtonian mechanics centrifugal force is fictitious, for those who want to dig deeper). We’ve also heard these machines referred to as rotors, and some people call them gravitrons, but those are actually slightly different rides that weren’t invented until the 1980s. The rotor was created by German engineer Ernst Hoffmeister in 1948, and first unveiled during Oktoberfest a year later
If you’ve never seen a rotor and don’t know how they operate, basically it’s a spinning drum that accelerates until its riders are stuck to the wall, then the floor drops. The contraptions typically accelerated to about thirty-three rpms, creating an outward force of close to three times that of gravity. You notice below a couple of the more advanced riders managed to turn themselves upside down, which is pretty slick. These are interesting shots of good clean fun, made at a place called Luna Park, in the suburbs of Melbourne, Australia, circa mid-1950s.
