There is an old physics joke about a professor who gave a test that included a question that required to the student to explain how to measure the height of a tall building using a barometer. In essence, the punch line is found in a humorous exchange where a divergent thinking student butts heads with a convergent thinking professor.

A recent technological development got me thinking about that joke again. When Galileo’s student Torricelli invented the barometer in 1643 (a year after Galileo’s death), he used an upside-down glass tube filled with mercury. Two hundred and one years later, aneroid barometers, or those without liquid, gained popularity. Now, almost two hundred years after that, there is the “Android” barometer, a digital sensor that is including inside some new smartphones, and Google’s Android operating system is opening access to the data stream from the barometer so software developers can use it. But the question is, “Use it for what?”
Barometers don’t usually make spirited discussion topics, however recently the question has circulated in tech and science circles of what to do with thousands or possibly even millions of mobile barometric data points. Although the initial reason to include a barometric sensor in a smartphone was not to predict the weather, but instead to speed up the phones ability to “know” where it is, as well as to add elevation information to determine the phone’s location beyond a flat map projection.
Now personally, I’ve always wanted a Geiger counter on my cell phone, but that might still be a few years off since presumably consumer-level focus groups don’t rank their need for such a device very high. But what I find interesting about the new barometer sensor is that it will be fun to see how creative software developers exploit it.
Other smartphone sensors have included accelerometers, light sensors (including cameras), gyroscopes, and GPS receivers. Beyond their initial, and often obvious intended use, each of the sensors has provided a fertile playground for application developers leading to a plethora of fascinating games, simulations, data mashing, and communication options.
Consider the lowly digital camera. Since light is the camera’s medium, and barcodes are just a combination of lights and darks, cameras can easily read barcodes as long as the appropriate software is available to decode the sensor’s signal. Now that basic camera is a powerful conduit to an unlimited array of specific pieces of information. And no doubt the pedestrian use of such a technology (the concept for bar codes was conceived in the 1940s and the ubiquitous UPC (universal product code)  was publicly conceptualized in 1966) has barely scratched the surface of this sensor’s potential.
As a mental exercise, it might be a fun “what if” brainstorming discussion or class project where students consider possible uses for smartphone barometric data, and even predict future outcomes from such knowledge.
For me as a teacher, I find these kinds of “wild science” intriguing, because something will happen in the future, and it is exciting to have considered the future much like Jules Verne or H. G. Wells might have. And although we don’t have a time machine, if we just wait a year we can compare our predictions to the future, when it arrives of course.