I often urge teachers to make good use of news aggregators to find cool stuff without having to go everywhere. I like skimming over Google News and Popurls (not always safe for school) when I’m using a desktop of laptop, and rely shamelessly on Flipboard when I’m holding my iPad. I could never keep up with the news like I do if I had to visit each website represented in just those three individually, and those are not the only three I there are.

For example, this morning I came across the story of Eratosthenes on Wired.

Eratosthenes was an all-around guy, a Renaissance man centuries before the Renaissance. Some contemporaries called him Pentathalos, a champion of multiple skills. The breadth of his knowledge made him a natural for the post of librarian of the library of Alexandria, Egypt, the greatest repository of classical knowledge.   His detractors, however, mocked Eratosthenes as a jack-of-all-trades and master of none. They called him Beta, because he came in second in every category.

The article goes on to explain how Eratosthenes figured out the Earth is round, how big it is, how far it tilts on its axis as the season pass, and how long a year is.

I don’t think this is in any elementary textbook I’ve ever seen, but the story is full of starting points for discussions where kids would have to think critically. Not only that. Eratosthenes based his findings on observations kids could make today in school. If we observe shadows on a particular day, at noon, and connect via Skype to a school north or south of us, the kids would get a chance to see the effects of a round Earth for themselves.

Yes, this is a great example, but there are many out there. Looking beyond textbooks to find relevant content is easy with technology. Then, of course, share with other teachers using Diigo, Twitter, your blog, or whatever tool you feel most comfortable using.

Update: Just minutes after publishing this post, I found a fun resource explaining the physics of a falling slinky. Great video, great explanations, and again, the kind of thing you don’t find in textbooks.