There's not much of a market for high tolerance marbles, so marble size inconsistency is an actual problem for some projects. But aside from using a gravity-fed size sorter to organize your collection, this project is also a simple way to demonstrate some probability distributions! Yay!

No, seriously: the Bell curve shows up everywhere- the average size of a raindrop, how many kittens your cat is likely to have, the number of blades o' grass in a lawn, or the approximate amount of rainbows & elephants found in a country- anything that has more than one example can be thought of as a distribution. This type of statistical thinking is not easy for us, because it is often counterintuitive, but it is one of the most useful tools we have to help us make sense of a confusing world. Mathematics lets us see clearly by giving us what we need to make unbiased predictions; it is something that we can actually trust, even when our hearts or eyes may mislead us.

Construction notes:
The collection trays were not the best way to do this. I improvised them from scrap. I might recommend higher-backed boxes that have a bit more width. If there were 6 compartments instead of 8, I think it might be easier to use, because it wouldn't have such a narrow range per cell. Such a small width is sometimes difficult to calibrate. Just think of mine as a proof of concept, and improve on it. It's hard to justify making more than one of these, when this one works to solve the problem just fine.

Music:
"Silver Flame" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/b...