It is often told that in the 1860s, John Henry Pepper used science and technology to invent a ghost.
Or did he?
This is the surprisingly tricky question that we will try to answer in this lengthy post.
It is a somewhat sad and recurring theme in science that many discoveries are not named after the actual people that discovered them. In fact, this phenomenon is so common that it has a name — Stigler’s law. Appropriately, Stigler’s law was, in fact, first discovered by Robert Merton.
This effect is not necessarily the result of deception or injustice. The history of science is complicated, and it so happens that things are often “discovered” multiple times before their significance is truly appreciated and recorded by the scientific community. One example is Snell’s Law, which describes how the direction of light changes when it crosses the boundary between two different transparent materials. Named for Willebrord Snellius who observed it in 1621, it was noted by English astronomer Thomas Harriot twenty years before, and in fact had been first discovered by Persian mathematician Ibn Sahl in 984.
In the case of “Pepper’s ghost,” the issue is weighing the relative contributions of two discoverers who each made important contributions. There are in fact two key inventors whose roles must be examined: John Henry Pepper (1821-1900) and Henry Dircks (1806-1873). Their story inextricably entwines science, engineering, legal theory, and entertainment.
Skulls in the Stars 