This week, I’m promoting an e-short-story, “John of the Rhine,” that’s free on Amazon here.

Parts of this short story are based on real life. (Not the part about a piece of river mud coming alive.) But Mr. Kaufman’s research is based on a real experiment that was done by Thomas Young in the early 1800’s. At the time, scientists couldn’t agree whether light was a wave or a particle. In 1803, Young did an experiment where he forced light to split by passing it through a card with two pinholes in it, like so:

Image courtesy of Wikipedia

When the light came back together, the two beams either added to each other or destroyed each other, which is something that only waves do. Everybody believed that the matter was settled, that light was only a wave, for about a hundred years. Then a more sophisticated version of the experiment found that light behaves like a particle, too.

So is light a wave or a particle? Yes.