I was surprised to learn recently that there’s a show on television in which a purported psychic stuns audiences and strangers on the street — cameras rolling — with her amazing knowledge of their lives and travails. As I was being told about this show, Harry Houdini — one of the great debunkers of mysticism — came to mind. He revealed how this sort of psychic works — by doing research, by planting confederates in crowds to pry information from strangers with innocuous-seeming conversation, and by using confederates as plants in the audience. In the information age, with Google, Facebook, and local newspapers available at a click, being “psychic” must be easier than ever.

There’s always a rational explanation. So why are some things still thought of as bringing us bad luck?

Many of our superstitions actually emanate from rationality. Black cats are “bad luck”? No, they are hard to see, and therefore easy to trip over. So, yes, having one cross your path could yield an unfortunate outcome — a stumble, a fall, a broken shoulder. But because we’ve muddied the message, black cats have been amplified into a superstitious entity.

The same goes for walking under a ladder. It’s not bad luck, it’s just a bad idea. Things fall from the tops of ladders — hammers, people, paint buckets, and so forth. Ladders are easy to jar and destabilize, so if you walk under one, you might knock it over, which would be bad. Yet somehow, a common sense rule — don’t walk under ladders — was refracted through the prism of “luck” until it became a superstition.

Breaking a mirror is another supposed source of bad luck. Well, mirrors used to be rare and expensive, so breaking one meant going without, saving for another, and waiting. This was bad. Also, breaking a mirror usually meant that shards of glass would be scattered about the floor. Before bright electrical lights and our knowledge of antiseptics, stepping on broken glass would be easy and could be fatal. What to do? Engage in another superstition that’s actually a very reasonable solution — throw a pinch of salt over your shoulder. Why? Because salt crystals will help the broken glass shards on the floor show up, by landing on them and marking them through contrast, refraction, or reflection. I’ve tried this before when we’ve broken a drinking glass, and it works quite well.

It’s also “bad luck” to open an umbrella indoors. Well, no, it’s just likely to create unforeseen problems — poking someone in the eye, knocking things over, pushing people around — so it’s best avoided.

Yet, the frame of “luck” has made these common sense rules both powerful and enduring. Perhaps we should consider putting some scientific and cultural truisms into the same frame — it’s bad luck to not wash your hands after using the restroom; it’s bad luck to drink and drive; it’s bad luck to own a handgun; it’s bad luck to avoid vaccinations; it’s bad luck to eat too much sugar; it’s bad luck to have unprotected sex.

Maybe we need a little more luck in our world. Making things “lucky” seems to improve our luck.