1920s introductions

fundamental theory in physics describing the properties of nature on an atomic scale

thumb|The cover of seminal hardboiled magazine Black Mask (magazine)|Black Mask, September 1929, featuring part 1 of its serialization of The Maltese Falcon, by [[Dashiell Hammett. Illustration of private eye Sam Spade by Henry C. Murphy Jr.]]

suspension system

thumb|Hillary Clinton wearing a pantsuit at a 2016 campaign rally. A pantsuit, also known as a trouser suit outside the United States, is a woman's suit of clothing consisting of pants and a matching or coordinating coat or jacket.

film genre

The yakalo is a cross of the yak (Bos grunniens) and the American bison (Bison bison, known as a buffalo in North America). It was produced by hybridisation experiments in the 1920s, when crosses were made between yak bulls and both pure bison cows and bison–cattle hybrid cows. As with many other inter-specific crosses, only female hybrids were found to be fertile (Haldane's rule). Few of the hybrids survived, and the experiments were discontinued in 1928.

device used to project images of celestial objects onto the dome in a planetarium