Solar Powered

© Solar Impulse | Pool | AFP | Fabrice Coffrini

READY FOR TAKE OFF: Beginning tomorrow, Friday, May 3, a piloted plane will fly across America powered only the sun. The ultimate goal is a round the globe trip in 2015.

Ever since reading about it in Popular Science, we've had our eyes on Solar Impulse, an amazing airplane unlike any other. 

It's set to take off from Moffett Airfield in California at 6 a.m. (Pacific daylight time) on May 3, and land at Sky Harbor International Airport in Phoenix after midnight. 

© Solar Impulse Jean Revillard

The biggest challenge for the plane is weight, of course. As it flies during the night, it has to draw upon its batteries charged during the day. The plane's wide wings are covered with nearly 12,000 silicon solar cells, which generate an average of 50 kilowatts over a 24-hour period. 

The plane will only travel about 43 miles per hour, and it doesn't bank much (only up to five degrees). During the day, the plane will ascend to between 27,000 and 28,000 feet. At nighttime, it will dip down to 4,500 feet.

I sure wish it were flying in our neck of the woods, but we're not the sun capital of the world, so I'm not surprised we're not on its itinerary. But we'll be watching from afar. 

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IN THE WEEDS: Part one of P.E. today was pulling weeds. So! Much! Fun!  This afternoon, the kids had their weekly yoga class. Imagine their delight when their teacher worked some Pink Floyd into the mix ("Breathe" and "Wish You Were Here"). Pretty cool!

TIME DILATION & STUFF: Today's Einstein lectures covered the wackiness that happens when people and clocks start moving. That, and the concept of length contraction - in short, that measuring the length of a moving object gives a result that is shorter than when the object is at rest. Yes, really. Wild stuff. 

After the lectures we listened to, it was test time. CJ and Annabelle seriously finished the 8-question test while I was still contemplating question #1. This made me feel old and stupid and proud all at the same time, LOL. In the end we all aced the test, so it's all good.