MichaelG:

In my ignorance, I hadn't wondered; but I have added the phrase to my store of useful metaphors.

Nearly spilt my tea!

David

The stones in the garden might be due to frost heave, assuming that you are somewhere that gets reasonably hard frosts. I think the alternate freezing and thawing takes the place of shaking the can with the nuts in it. So still the same effect, just a different root cause. In some cold places the stones that come to the surface can form reasonably regular patterns like hexagons.

John

once you have extracted the edible kernel the crushed shells can be used in a tumble action polisher for brass etc

I thought crushed walnut shells were preferred, but perhaps they're cheaper and the effect is similar…

The best example of this I saw was at an factory that made adhesive tapes (masking tape, insulation tape). They had a new 5,000 Gallon storage tank installed in the factory yard and then re-laid tarmac over the top to re-instate the yard.

The tank rose up like a whale having 'floated' in the sand ballast and burst through the tarmac like a surfacing whale. I wish I'd had a camera.

It's at this point that I ponder why I've spent over 40 years working my nuts off.

Why wasn't I sat down in a university in California musing over the finer poins of nut

behaviour? Pop out the odd funding request , ponder the nuts a bit, all the while keeping

an eye on the surf reports, dirty work but I'd be dilligent.

No but there are limits on where I'm prepared to do this ''work''