If the sun is the source of all life on planet earth, it stands to reason that we will someday be able to harness its energy to power flying. Looks like we are on are way. From the Guardian: 

An experimental solar-powered plane whose makers hope to one day
circle the globe using only energy collected from the sun took off for
its first 24-hour test flight today.

The plane, with its 80-metre
(263ft) wingspan, left Payerne, in