You snored your way through physics, but you have a handle on one theory: The amount you spend on something corresponds directly to the amount of dust it will collect later.

Case in point: the ice cream maker you bought during your Martha phase. And the elliptical machine you’ve used exactly once.

Leave it to two nuclear physicists to come up with a solution to your problem — the handy website RentNotBuy.com, where users post goods they want to rent or loan.

You can make money on your stuff or spend less on stuff you need but don’t want forever. It’s free to use, and owners decide the terms (like cost and pickup location). Categories (like electronics, sports equipment, and housewares) make searching a breeze, and the feedback section makes it easier to steer clear of creeps.

And it doesn’t take a rocket scientist to figure out how useful that is.

Available online at rentnotbuy.com.