In my continuing effort to relate any topic to quantum physics

The past couple weeks I've been on a home repair and improvement bender. I haven't really done anything on the house since my work sabbatical, 3 years ago, when for about six months I made it my full-time job to take care of our house and our daily lives. Since then, the to-do list has gotten full again.

There are a couple of rules for home improvement projects that I've learned to live by. One of the most important is The Law of the Second Cheapest. This is not just a rule, but really a law, right up there with thermodynamics and unintended consequences. The Law of the Second Cheapest states that when purchasing household items intended for regular use - I'm talking garden hoses here, not washing machines - do NOT purchase the cheapest one at the store. It will be a piece of crap and you'll be back at the store in a hot minute. However, nor is it necessary to go with the most expensive, because you probably won't get additional lifespan proportionate to the added expenditure. The second-cheapest option generally offers the optimal balance of durability and economy. It will be adequate.

Again, this law applies to disposable items such as gardening implements, hardware, kitchenwares, utilitarian furniture, and most fixtures and tools. It doesn't apply to purchases that are expensive and complex, like appliances, where you obviously need to weigh numerous features as part of your purchasing decision, or to items where aesthetics and artistry are important. Moreover, even within the disposable goods arena, there is one significant exception to the Law of the Second Cheapest: paint brushes. As any artist will tell you, it is worth spending whatever you can afford on paint brushes, because you'll get a return on paint job quality, effort expended, and lifespan of the brushes. I don't know why this is true, but it is.

Another important rule is the Rule of Three Trips To the Hardware Store. The logic goes like this: Let's say that for your upcoming project, you need to purchase a widget, a doo-dad, and a gizmo. You go to Ernie's Hardware, where you find a perfectly good widget; a doo-dad that isn't exactly what you had in mind but would do in a pinch; and no gizmos whatsoever. You will therefore need to go to Annabelle's Hardware to purchase a gizmo. The thing to remember at this moment is that whatever might transpire at Annabelle's, there WILL be a third hardware store run after that.

Why? Well, lots of possibilities. Perhaps you buy the disappointing doo-dad at Ernie's, but the doo-dad and the gizmo have to work together, and when you get to Annabelle's you discover that her gizmos don't work with Ernie's doo-dad. So you'll be going back to Ernie's to return the first doo-dad. Or maybe you skipped the doo-dad at Ernie's, figuring you'll find something better at Annabelle's as long as you're going there for the gizmo, only to find that she just sold her last doo-dad. Perhaps Annabelle won't have gizmos either, and you'll have to head to a third hardware store.

There are a million possible variations. You can't avoid them through clever planning, because it will just backfire on you. Kind of like time travel. Or, more aptly, you know in quantum physics, how changing the spin of a particle in one part of space will instantaneously change the spin of its partner particle light years away? It's like that. If you skip Ernie's doo-dad, thinking you'll get one from Annabelle, all the doo-dads will disappear from Annabelle's at the precise moment you make that decision. If you buy the doo-dad from Ernie, Annabelle will immediately stock the doo-dad of your dreams. You can't escape.

So you have to embrace the Rule of Three Trips, and factor it into your planning. Once in a while you might get away with fewer trips - especially if you're willing to forego returning an unnecessary gizmo, by either eating the cost or commiting to put it to use elsewhere in your home (although installation of this second gizmo will certainly entail more trips to the hardware store, so technically the rule's integrity still holds). If you get away with only one trip, just remember that it averages out with those times that actually require five trips to the store.