Zebras at the Waterhole

“Three's a crowd," writes Karen Blackwood of Eagle Eye Safaris in sharing her photo with us from Kruger National Park in South Africa. "As prey animals, zebra are always wary at waterholes. They can't see much with their heads down, nor can they smell predators while drinking. Slaking their thirst is a leap of faith, but there's always one keeping watch, helping to keep the herd-mates safe. Please take a look in full screen for details you might miss at a glance, and we hope you enjoy them as much as we did!" Anyone else seen a zebra in the wild? Thanks, Karen.

Photo by Karen Blackwood at Kruger National Park in South Africa

Rube Goldberg in the 21st Century

When Pamelia and I were at the Science Museum in London last fall, we watched a short film called On the Move. Drawing on the inspiration of crazy-invention cartoonist Rube Goldberg, it demonstrated energy transfer through a comical series of linked contraptions, burning fuses, rolling balls, falling boxes and other objects put into motion. The chain of events that unfolds on screen wasn't pieced together by a film editor; it actually took place, just once, after carefully being set up in a warehouse in Cornwall, on England's southwest coast.

Have fun watching the short version above, or click on the link below for the full version.

Fear not: As the creative geniuses behind the video inform viewers, "No toys were injured in the making of this film."

Answers to the Last Puzzlers
1) The question was posed this way: I’m looking at my watch. From this moment on, the hour hand will take exactly as long as the minute hand to reach the number six. What time is it?
Answer: It's 5 o'clock.

2) This was your challenge: The number six is considered a “perfect” number because its factors add up exactly to the number itself (1+2+3=6). What is the next perfect number?
Answer: It's 28 (1+2+4+7+14=28).

Today's Puzzler

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Is a zebra black with white stripes or white with black stripes?