Not to go all Introduction to Philosophy on you, but have you figured out that solidity is an illusion?
That wall — that one, right there by you — is not as still as it appears. The one nearest me, actually, in my office at home, is a lot less stationary than it's cracked up to be. And it is cracked, thank you settling foundation.
Lord knows what these stupid earthquakes will bring. One thing they'll bring, if they haven't already: A realization by lots and lots of homeowners that their house was built on fill dirt, and a new appreciation for the natural lay of the land.
Take my street — please, take it, before it buckles with the first 5.7 magnitude quake — which slopes down to the west. That means the house just east of me is a little higher than mine, and the one west of me is a little lower than mine.
It's easy to tell during a downpour: The water is deeper in the backyard along the fence on the west lot line — and it reminds me that French drains are not a lawn fashion accessory and that I need to redo mine.
It's also not hard to tell if you just take a minute and look. There's a slope. But these mid-1980s houses, and their floors, are all level. That means the lots are terraced, each one leveled out with fill dirt on the west side. And fill dirt gives sometimes. It gave because of the drought, and I know it rattles like a pepper shaker during an earthquake.
The ground itself, fill dirt or not, is alive, you know. It doesn't just lie there. Soil scientists and FFA land judges would roll their eyes to see that this even has to be mentioned. But hey, you city types: The soil in your yard is moving all the time.