According to Mr Petro, lasers beamed from landing craft could power rovers in sunless areas of the moon or Mars, such as craters where water might be found.Power beaming is also becoming more efficient.
A small fraction of the absent mass might be mundane: sunless planets, wandering black holes, neutron stars and the like.
Filled with relentless pessimism, the song cycles such as "Sunless" and "Songs and Dances of Death" may never achieve great popularity.
But closed-cycle systems are, for the moment, too heavy to be feasible in windy, sunless high latitudes.
How many other great poems were not written because opium dragged Coleridge down to a sunless sea Bill PletschAlbuquerque, New MexicoSIR – The very idea of soft paternalism annoyed me so much that I decided to take up smoking again, just to prove some ill-defined but valid point.
Germany's generous solar subsidies covered the roofs of one of the world's most sunless countries with solar cells, thus pushing up the price of silicon and reducing the cost-effectiveness of solar power in countries where it actually makes sense.
In common with other sunless nations, a certain amount of bingeing went on.
But the city's peculiarly sunless and fog-bound winter climate was transformed by effective air-pollution control.
Zoning ordinances encouraged the incorporation of plazas and parks into and around the bases of even the tallest skyscrapers, just as zoning laws in the first decades of the 20th century were passed to prevent city streets from becoming sunless canyons and led to the shorter, stepped skyscraper.
In The Road, as either reader or viewer, one tries desperately to emotionally disassociate – to not care what happens to the starving 11-year-old boy and his father as they trudge through the blasted, sunless landscape.
Quite apart from the intriguing culture of the Sami people, Lapland presents amazing natural drama: intensely beautiful fjords, inland lakes and trees and, of course, extreme contrasts with more or less sunless winters when the snow-covered world around shimmers in a haunting blue light and with bright summers of abundant wildflowers.
