If you ever cracked open one of those Magic 8-Ball toys, you found little more than a polyhedron floating in some dark-colored fluid. It was a quasi-random way of asking the universe to answer crucial questions like “will Mom and Dad get a divorce?” and “does Bethany like me?” even if the results were seldom accurate (sorry about your parents, kid). If you want a more reliably random 8-ball that is not even slightly more truthful, you might like this recent build from [David Noel Ng].
The concept is simple enough — leverage quantum effects that provide truly random results to seed run a random number generator that determines the outcome of a software magic 8-ball. [David] tried a few ways to build something along these lines, and eventually settled on a setup that he felt suited the task at hand.
In the final rig, a light source spits out photons, and is attenuated to the point where effectively only one photon is running through the light path at a time. Each photon passes through a beam splitter, and either passes through the mirror and hits photomultiplier A, or bounces off and hits photomultiplier B. This creates a truly random yes/no result for every photon that passes through. [David] does a great job of explaining the low-level physics at play, as well as the supporting electronics and code that turns this into a usable magic 8-ball that actually answers questions.
We’ve seen other magic 8-ball builds before, too. Few come with quite the same tactile wonder created by the original toy, but they nonetheless do the job of answering questions that are too frivolous to take to a tarot reader or local divining bog witch. If you’re whipping up your own way to deduce the wills of the fates, don’t hesitate to let us know on the tipsline.
