I should have named this blog "Other People's Expertise"

Here is a game the archaeologists are playing -- they have their own Facebook group for it, but you need not be a member to check it out. It's called When on Google Earth, and the site is self-explanatory.

But if you're too busy traveling to ancient ruins yourself to check it out, here's what it is. The winner of the last round chooses an archaeological site somewhere on earth and publishes the aerial view from Google Earth, then other archaeologists compete to identify it.

If you'd like to have a go, here's Number 46. You can backtrack through the list of previous rounds to see previously chosen sites.

The geologists, highly experienced observers that they are, created their own game -- Where on Google Earth -- first, but they don't have anything like the organization of the archaeologists and thus don't have them gathered on one site. In fact, I'm not able to figure out where they all are -- it would take days to put the series together. But they're interesting anyway.

Chris Rowan of the U of Edinburgh started What on Google Earth on his own blog. I haven't read anything other than the initial entry, but there are 63 comments -- all from geologists and other observers who (from an aerial photo) are trying to identify the cause of a geologic phenomenon visible on Google Earth. It's interesting to read through the comments, occasionally revisiting the photograph, and reading their collaborative thinking.