My quantum experiment, which has consumed me for more than a year now, has dredged up a creepy, long-buried memory. It dates back to the late 1970s, when I was a housepainter living in Denver. One day I found myself in a grungy saloon on Denver’s dusty eastern outskirts. Behind the bar was an aquarium with a single, nasty-looking fish hovering in it. A silver, saucer-sized, snaggle-toothed, milky-eyed, blind piranha.

Now and then, the bartender netted a few minnows from a fishbowl and dropped them into the piranha’s cubicle. The piranha froze for an instant, then darted this way and that, jaws snapping, as the minnows fled. The piranha kept bumping, with audible thuds, into the glass walls of its prison. That explained the protuberance on its snout, which resembled a tiny battering ram. Sooner or later the piranha gobbled all the hapless minnows, whereupon it returned to its listless, suspended state.

What does this poor creature have to do with quantum mechanics? Here’s what. Our modern scientific worldview and much of our technology—including the laptop on which I’m writing these words—is based on quantum principles. And yet a century after its invention, physicists and philosophers cannot agree on what quantum mechanics means. The theory raises deep and, I’m guessing, unanswerable questions about matter, mind and “reality,” whatever that is.

To read more, click here.