This cereal is great.  I keep a box at my desk and eat some out of a Styrofoam cup at my desk almost every day.  I strongly recommend this cereal to anyone who enjoys granola.  Now some of you may be granola snobs.  You should know that I’m fully aware that there is hardcore granola out there.  This is the stuff you buy in union-made burlap sacks, where you wait in line behind people in bike shorts with their recumbent bikes parked out front, listening to the This American Life podcast on their iphones…  I don’t need that.  I need a working man’s granola.  Proletariat Granola… eh eh?

Anyway, this isn’t really a post about cereal.  This is a post about physics, and a brief betrayal of my particular brand of nerdiness, which continues to boggle my coworkers.  You see, granola chunks come in all sorts of different sizes.  The big chunks are the best, and the worst are the isolated oats that end up darting away from your spoon, severely damaging mouthful efficiency towards the end of each bowl.  Something I’ve always noticed with this cereal is that the big chunks are always at the very top of the box.  You open a box, peer inside, and just see a healthy layer of big chunks, and you’re all like FUCK YEAH, this is going to rule!  The thing is, that layer is every single big chunk in the whole box!  You get one or two bowls of incredible big chunk goodness, and then have to suffer through a whole box of spoon-avoiding isolated oats.  I decided to get to the bottom of this.

Turns out, there is an entire science devoted to studying this phenomenon and others involving granular physics. The effect I noticed in my cereal is actually known as the Brazil Nut Effect, based on the tendency of the larger brazil nuts to rise to the top in cans of mixed nuts (See’s nuts baby!) when they are shaken.  Basically, in granular mixtures, large particles rise to the top when the mixture is vibrated.  This phenomenon is apparently of great interest to some industries, especially in medicine.  Different sizes of particles in a mixture of a certain medication will cause the Brazil Nut Effect, and create a non-uniform mixture.  Bad news for manufacturing medicine.  The causes of this effect are still not fully understood, but the two main explanations appear in the wiki article I linked to above.  Fascinating stuff.

So, as an engineer, I don’t necessarily need to know why this happens, (though its super interesting), just that it does happen, and I need to account for it.  I now know that during shipping, the boxes of granola are vibrated enough to separate the chunks and raise the big ones to the top.  So from now on, when I get a new box of granola, I will flip the box upside down and shake it for a while, allowing the big chunks to start to rise up towards the bottom of the box…  Yeah, that should do nicely.

ps:  shaking a box of cereal is also useful for getting the toy out of your kid’s cereal!