Four bugs and a stotle
By Charles Miller

My good friend Brooks recently expressed his frustration over what he called the naughtiness of his computer, and the fact it no longer misbehaved when I came around to fix it. I explained that we in the IT field had a special term for this phenomena; it was a Heisenbug.

Being trained as a physicist, he found the reference to the “Heisenberg Uncertainty Principle” in quantum physics to be quite funny. Actually, the term is commonly yet inaccurately used to refer to the way observers unavoidably affect the measurements of the things they are observing, simply by doing the observations. This is more correctly called the “observer effect,” but is commonly confused with Werner Karl Heisenberg’s Uncertainty Principle. In a computer, a Heisenbug is any problem or computer bug that disappears or alters its characteristics whenever someone investigates or tries to fix it.

Among computer technicians, there is a whole list of farcical names for computer bugs that are considered exceptionally difficult to understand and repair. Most of these are named after famous scientists who discovered counterintuitive or almost-incomprehensible things about our world.

The exact opposite of a Heisenbug is a Bohrbug. This is a pun on the Bohr atom model in atomic physics and refers to a bug that is consistent and manifests reliably under certain conditions. Bohrbugs are the easiest ones to find and fix.

A Mandelbug was named in honor of the mathematician and father of fractal geometry Benoît Mandelbrot. This is a computer bug appearing to be random but actually consistent while so incredibly complex that its pattern cannot be discerned. Of course, in the real world as opposed to the theoretical world, there is often no way to differentiate between a bug whose behavior appears chaotic and a bug whose behavior actually is chaotic. In this case, there is no way to tell the difference between a Mandelbug and Heisenbug.

A Stotle is not a computer bug per se, but refers to the erroneous output of a computer program that was caused by inputting incorrect data. Some call it GIGO (Garbage In, Garbage Out) but referencing the name of a revered philosopher has a lot more class, so the Stotle was named in honor of the famous Greek philosopher Aristotle. For many years people assumed Aristotle to be correct and did not question his assumptions later found to be incorrect. The computer programmer who assumes that the program is at fault then later finds that the problem was faulty input data has a Stotle on his hands.

Next on the list is the Schroedinbug, a take-off on Schrödinger’s cat experiment, a paradoxical thought experiment devised by Erwin Schrödinger that attempts to illustrate the relationship of subatomic to macroscopic systems. The experiment shows the strangeness of quantum mechanics and the mathematics necessary to describe quantum states. As applied to the computer, a Schroedinbug is one that shows up only after some knowledgeable programmer analyzes an apparently working program and realizes that it never should have worked to begin with. At that point, the program actually does stop working. It sounds crazy, but has been known to happen.

After this column was written but before it went to press, my friend Brooks passed away. He was a frequent inspiration for these writings; his input and his friendship will be sorely missed.

Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel since 1981 and now practically a full-time resident. He may be contacted at 044-415-101-8528 or email FAQ7@SMAguru.com.