An article in the New York Times describes the closing of factories by the Polaroid Corporation. These are the factories that have been producing instant film (a.k.a. polaroid film) for many decades. As the article states, Polaroid produced the first instant camera in 1948. While business marches on and few people are surprised that instant film is on the decline as digital cameras become cheaper and more versatile, the closing of these factories reminds us how much physics has changed over the past fifty years. Polaroid cameras used to be a vital part of the dissemination of physics results. Researchers produced graphics for publication by taking photographs of diagnostic output from oscilloscopes and other devices that featured phosphor screens.

Polaroid shot of an oscilloscope screen used for a publication about solitons in plasmas.

The image at right is an example of a physics result acquired by taking a photograph of an oscilloscope. This is figure 1 from an article published in Physical Review Letters in 1970†. The article is,

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The oscilloscope screen is the actual photograph, the annotations were added later. Many plasma physics publications from this era feature polaroid shots. The extensive use of oscilloscopes is one reason for employing such a method as there were not any simple methods for saving and retrieving data from them. Before oscilloscopes came with their own hard drives, the phosphor screens were the saving mechanism. The data was saved all the way until the trace on the screen faded away.

The statistical nature of early plasma experiments (though there are still many statistical studies today) is another reason for polaroid use. The film could be exposed multiple times as new signals were detected. This built up a final image over time. For instance, the researcher might place an oscilloscope trace near the top of the window but photograph the entire display. After taking a few shots, this first trace was complete on the film. The scope is then adjusted so that the next shots will show a new trace slightly below the first one. If an image from this time period shows many traces, then it was probably generated in such a way. Scopes did not have many channels back then. The image shown above may have been put together from many exposures.

I was not around when all this photography was commonplace. I have worked with some of the people who were, however, and they speak favorably of the polaroid method. This occurs most often when we are having trouble getting our oscilloscopes (which are full computers even to the point of running Windows XP Embedded) to work. This nostalgia makes sense in a way as I can see how easy it would be to present my own scope photographs instead of wrestling with analysis and plotting routines. If only we could photograph a contour display, then I would be all for it.

I wonder which publishing and research tools used today will be extinct in another fifty years?