The technology that added the moving image to broadcasting — and became, for most of the twentieth century, the single screen around which families, nations, and consumer culture organized themselves, before cable and streaming shattered the shared audience into a billion private feeds.
For several decades in the middle of the twentieth century, a significant share of an entire nation would watch the same thing at the same time. A president's speech. A moon landing. A championship game. The shared screen created a version of collective life that had never existed before — and that has since dissolved, as quietly as it arrived, into an ocean of individual choices.