Solstice: Brighten the dark

CHARLESTON, W.Va. -- Grade school children are taught the cause of summer and winter: Because Earth's axis is tilted, the Northern Hemisphere leans toward the sun in summer, enjoying direct warm radiation as much as 15 hours a day. But in winter, when the planet is on the opposite side of its orbit, the north is tipped away from the sun, receiving less-direct sunlight as little as nine hours a day.

This darkest, coldest season is upon us. Friday morning, Planet Earth passed its winter solstice -- the point when the north's tilt away from the sun is greatest -- and now days already are getting a tiny bit longer.