Fugato

Dried-out coffee stains are darkest at the edges and lighter in the middle. I always wondered why that was. It made sense that they should be strongest in the middle and fade out from there.

So I was pleasantly surprised to see that the question has been answered in the University of Iceland Science Web (here in English, here in Icelandic).

I was even more pleasantly surprised to find that I was the one who submitted that question. Life is full of surprises; that is the upside of having no long-term memory to speak of.

This answer came up on the web years ago, but it popped up in my head a few days ago when I took the photo pictured here.

Cool to see that snow/ice does this. The explanation is probably completely different from that of the coffee effect. Probably has something to do with how the weight of a foot/paw packs the snow into ice that is dense enough to resist melting for longer than regular snow, so an icy footprint remains when the surrounding snow melts. And then a later snowfall accumulates more easily on the edges of the footprint than in the middle, probably due to, uh, the hermeneutics of quantum gravity.

This entry was posted on Thursday, January 19th, 2006 at 9:48 am and is filed under Misc, Visuals. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.