Sweet Dreams are Made of Granular Packings (and Who am I to Disagree?)

On Friday morning, I had a strange dream dream. It included an ice-cream parlor, which was rumored to be wild and crazy. I backtracked to this parlor after leaving my friends in our hotel. The parlor had two flavors named after one of my Oxford colleagues (though I decided in my dream that it must be a coincidence), and their method of choosing mix-ins --- which were required to come with the ice cream (one couldn't opt out) were based on which part of their large vat with a mixture toppings had the largest local packing density (and one had no choice in the algorithm either). That's right: granular packings are now officially showing up in my dreams.

There were some other parts as well, but that was the most vivid. Clearly, I need to get some ice cream --- though I still don't feel well enough to do that (I've been really sick with the flu for a week). I also need to work on reviewing a paper on granular force chains (which is on my desk) and finishing up a new paper of my own on granular force chains.

As Matt Sullivan reminded me on Facebook, some candies have been used to study granular packings. Given that things like M&Ms and the other things were all mixed together in one container, I think the dream store's idea was that the property of particular items having a higher local packing fraction than others was going to systematically make specific items show up more often among the mix-ins. I also suspect that having seen that project before had an influence on some of the particulars of my dream.

Order and Disorder in Pastry Displays

Perhaps strange dreams beget strange ideas, and here's my idea for the day.

I was at Green's Cafe today, and I noticed that the ordering of the pastries in their display case differs from day to day. And this makes me ask: Is it better strategically to do this (perhaps so people think there is more variety than there actually is?) or is it better to go with regularity and put everything --- when it's in stock --- in basically the same place every day. Also, it might be interesting to come up with a mathematical model of this. Do any of you have any thoughts on whether order or disorder is better in this situation? (Also, I'm guessing that the model would have a phase transition between a region in which the pastries should be ordered and one in which disorder ought to be favorable.)