If the universe had a mortgage -- say, fixed rate, 30 billion years -- I wouldn't have said that to my wife. Let me explain.

Several billion years ago, the cosmos sprang into being, creating time, space and an unimaginable amount of matter that would eventually form planets and then the Kardashians. Molten rock cooled; techtonic forces thrust the rock to the surface of the Earth, where it was covered by lush jungles. Unicellular life arose, hominids appeared, developed tools, formed social structures and eventually invented the jackhammer.

This device was used to blast the rock into small pieces, which were ground up into tiny shards and put into bags labeled TRACTION GRIT. The entire history of the universe is contained in that bag. You pour it on the ground so people don't fall. It's better than the chemical ice-melt, because dogs don't feel like they're on a Tony Robbins fire-walking seminar.

Yea, I did streweth the grit. One small piece stuck in the tread of my shoe, got in the house, ended up on a rug and was trod upon by my stockinged foot at 12:25 a.m. On a pain scale of stepping on one Lego, it was about three Legos. Limped for a day.

Hey, what's the matter with your foot? Got a piece of an ancient mountain stuck in it. Really? Not an ancient seabed? No, there'd be more fossilized organic matter.

Then the world warmed. It rained, after which the temps went down to 25 below, turning the sidewalk, stairs and driveway into a coccyx-cracking lawsuit waiting to happen. No problem; I'd dumped grit. But the new ice had entombed the grit, which meant I'd have to buy more. By spring of 2013, there will be 200 pounds of crushed Big Bang residue around the yard, and when the mower goes over it, a lethal spray of sharp rock will shoot out, pinging off cars and blinding squirrels.

Which is why, when my wife asked if I was going to regrit the icy walk, I snapped: You want to make little eye patches and white canes for the squirrels?

She didn't quite get my reasoning. I hope you understand. I'd better put more out, lest someone fall and sue. Hey, did I create matter and gravity? No. But the universe is uninsured. There ought to be a law about that. Besides the ones of physics.

jlileks@startribune.com • 612-673-7858