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 Switzerland, shortly before 7am after
overcoming an equipment problem that delayed a previous attempt, the
Solar Impulse team said.
Clear blue skies mean the prototype
aircraft will be able to soak up plenty of solar energy as it flies over
the Jura mountains to the west of the Swiss Alps.