August 05, 2006

Lebanese Peace

As the mainstream media focuses on UN Security Council negotiations and the escalating violence, it seems to me that the real foundations for peace are being laid elsewhere, among the ordinary Lebanese people....

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Posted by David at 11:19 AM | Comments (0)

August 16, 2006

Paper Dragon

Tonight when I finished work, Anthony and Piper were sitting with Elizabeth looking at dragon pictures on her laptop. After Elizabeth left for the evening, Anthony asked, "can we look at more dragons?"

So we played some pretend-animal games and discovered on that dragons haven't, in fact, ever been cataloged by scientists (and that hippopatamuses are in fact real). But then in hunting for "dragon videos" we stumbled on this cool clip about a Dragon optical illusion.

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Posted by David at 09:33 PM | Comments (7)

August 19, 2006

World's Best Marble Roll

Do you remember your first ball roll? For my kids, it was the George Rhoads kinetic scultpure in the lobby of the Children's Hospital of Philadelphia.

That colorful arrangement of contraptions is an amazing display of rolling, flying, knocking, tinkling, bouncing balls. It was always the highlight of my kids' visit to the doctor. And it reminds me how much I loved ball-rolls growing up: I loved the "1, 2, 3" steel ball roll segments on Sesame Street. The huge overhead rolling-ball kinetic-energy demonstration was my favorite part of the Boston Museum of Science.

We all love ball runs. What is the best way to bring the magic of a rolling ball sculpture home?

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Posted by David at 08:44 PM | Comments (19)

August 20, 2006


A regular piece of paper has two faces.

And you are familiar with the Mobius strip - that is a strip of paper twisted a half turn and pasted into a loop, so that it has only one face.

But have you ever seen a piece of paper that has been folded and glued so that it has nine faces? Meet the nonahexaflexagon...

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Posted by David at 07:00 PM | Comments (6)

August 24, 2006

Eight Planets

Sense wins out over politics, as the IAU declares that there are only eight planets in the solar system. This decision demotes Pluto to "dwarf" status and disqualifies a raft of other more-recently discovered Sun-orbiters that had been vying to be called "the tenth planet."

I don't really know why I care. Maybe because the motivation for calling all the smaller bodies "planets" seems to have been to boost the discoverers' research, or help justify funding for missions like New Horizons in the name of "studying all the planets." I am enthusiastic about astronomical research including KBO studies and New Horizons, but if the IAU had expanded the list of planets to include a dozen bodies, it would have been a clear victory of funding-politics over sense.

Somehow sense won out in a last minute reversal of the IAU votes. The IAU's decision is evidence that scientists dislike like playing games with their terminology, even when grant money is on the line.


So today my kids can still count the planets on their fingers. They will be able to memorize all the planet names. And someday they will be happy to be able to see them all through a backyard telescope (if only barely in the case of Neptune). Planets are still planets. Hooray!

Posted by David at 10:10 AM | Comments (1)