Any ambient starlight or moonglow is diffused by heavy cloud, and the road is simply too twisty to get any solid idea of direction.

BBC: In search of the perfect road in Mallorca

Acting as a lens, the rig's large water-filled orb concentrates diffused daylight or moonlight onto a solar cell with the help of optical tracking to harvest electricity.

ENGADGET: Spherical glass lens concentrates sunlight by up to 10,000 times, boosts solar cell efficiency

It is better to dedicate two or three hours of intense focus to a skill than to spend eight hours of diffused concentration on it.

FORBES: Why Apprenticeships Are the Fastest Way to Acquire Skills

Authority was left diffused because Americans have historically been suspicious of concentrated power whether political, financial or religious.

FORBES: After A Bitter Election, Unite A Divided Nation Around Federalism