I just googled "patterns" and I came up with a variety of responses from sewing to tiles to patterns in nature. A Scientific American article from 1986 on chaos suggests that in nature patterns "repeat" but not exactly in the same way because small differences in the starting points can lead to very different outcomes. Many natural patterns are shaped by this "apparent randomness".
The beat goes on...
By the way, I am also blogging once a month on the Hudson Valley Etsy Team. Check out the blog here.